JP6948120B2 - Laminate manufacturing method, laminate, backlight device, and display device - Google Patents

Description

The present invention relates to a method for manufacturing a laminate, a laminate, a backlight device, and a display device.

A transmissive image display device such as a liquid crystal display device is generally arranged on the back side of a transmissive image display panel such as a liquid crystal display panel, and includes a backlight device that illuminates the transmissive image display panel. As a backlight device, a direct type or edge light type backlight device is known.

Currently, in order to improve color reproducibility, it is being studied to incorporate quantum dots into a backlight device (see Patent Document 1). Quantum dots can absorb primary light and emit secondary light with a wavelength different from that of the primary light. The wavelength of the secondary light emitted by the quantum dots mainly depends on the particle size of the quantum dots. Therefore, a backlight device incorporating quantum dots can reproduce various colors while using a light source that projects light in a single wavelength range. For example, when a light source that emits blue light is used, the laminate can also absorb the blue light and emit green light and red light. Since such a backlight device is excellent in color purity, a display device using this backlight device has excellent color reproducibility.

Japanese Unexamined Patent Publication No. 2013-218953

The methods for incorporating the quantum dots into the backlight device include the on-chip method in which the quantum dots are incorporated in the light source, the on-edge method in which the transparent tube containing the quantum dots is arranged between the light source and the light guide plate, and the light emitting side of the light guide plate. An on-surface method is known in which a sheet containing quantum dots (hereinafter, this sheet is referred to as a "light wavelength conversion sheet") is placed on a light source or a light source.

However, in the on-chip method, since the quantum dots are incorporated in the light source, the quantum dots are exposed to a high temperature, and the conversion efficiency of the quantum dots is inferior. Further, in the on-edge method, since the transparent tube containing the quantum dots is arranged between the light source and the light guide plate, the size becomes large. In particular, mobile devices are required to be miniaturized, so it is difficult to handle them with the on-edge method.

On the other hand, the on-surface method does not have the above-mentioned problems, and it is also possible to use a backlight device that has been conventionally used. For these reasons, it is currently under consideration to incorporate quantum dots into a backlight device by an on-surface method.

However, in the on-surface method, since the light wavelength conversion sheet containing the quantum dots is arranged, the thickness of the backlight device may be increased. On the other hand, in recent years, there has been a demand for thinner image display devices. Therefore, the backlight device incorporated in the image display device is also required to be thin. Further, in the on-surface type backlight device, it is required to reduce the number of manufacturing processes and further improve the light utilization efficiency.

Further, in an on-surface type backlight device (particularly an edge light type backlight device), when light is emitted, the color of the light emitted from the light source is at the center of the light emitting surface at the peripheral edge of the light emitting surface of the backlight device. There is a problem that it appears stronger than the club. This phenomenon becomes more remarkable when a luminescent substance having a small size (nm size) such as a quantum dot is used. For example, when a light source that emits blue light is used as the light source, the peripheral portion of the light emitting surface of the backlight device appears more bluish than the central portion of the light emitting surface (blueing).

INDUSTRIAL APPLICABILITY According to the present invention, the thickness of the backlight device can be reduced, the number of manufacturing steps of the backlight device can be reduced, the light utilization efficiency can be improved, and the color of the peripheral portion of the laminated body can be tinted at the time of light emission. It is an object of the present invention to provide a method for producing a laminated body, such a laminated body, a backlight device, and an image display device, which can suppress the color of the laminated body from being conspicuous as compared with the color of the central portion of the laminated body.

According to one aspect of the present invention, a lens layer having a plurality of unit lenses is formed on the first surface side of the first light transmitting base material, and the first light transmitting base material and the said The step of integrating the lens layer and the said of the first light transmitting base material before or after forming the lens layer on the first surface side of the first light transmitting base material. A step of arranging a coating film of a composition for an optical wavelength conversion layer containing a curable host matrix precursor and quantum dots on a second surface side opposite to the first surface, and the composition for the optical wavelength conversion layer. Provided is a method for producing a laminate, which comprises a step of curing a coating film of an object to form a light wavelength conversion layer and integrating the first light transmissive substrate and the light wavelength conversion layer. NS.

In the method for producing the laminate, the step of arranging the coating film of the composition for the light wavelength conversion layer is the step of arranging the second surface of the first light-transmitting base material and the second light-transmitting base material. It may be a step of arranging the coating film of the composition for the light wavelength conversion layer between the first surface and the surface of the above.

In the method for producing a laminate, a barrier layer is formed on the first surface of the first light-transmitting base material before the lens layer is formed, or the first light-transmitting base material is said to have a barrier layer. The second of the first light-transmitting substrate before arranging the composition for the light wavelength conversion layer between the second surface and the first surface of the second light-transmitting substrate. The light wavelength conversion between the step of forming a barrier layer on the surface of the light-transmitting base material and the second surface of the first light-transmitting base material and the first surface of the second light-transmitting base material. A barrier layer is formed on the first surface of the second light-transmitting substrate before the coating film of the layer composition is arranged, or the first surface of the second light-transmitting substrate is formed. A step of forming a barrier layer on the second surface opposite to the above may be further provided.

The method for producing a laminate further includes a step of forming a light diffusion layer having an uneven surface on a second surface side of the second light transmissive base material opposite to the first surface. You may.

According to another aspect of the present invention, a lens provided on the first surface side of the first light transmitting base material and the first light transmitting base material and having a lens layer having a plurality of unit lenses. The lens includes a sheet and an optical wavelength conversion layer provided on a second surface side of the first light transmissive substrate opposite to the first surface and containing a host matrix and quantum dots. Provided is a laminate in which the sheet and the light wavelength conversion layer are integrated.

The laminated body further includes a light transmissive sheet provided on the side of the light wavelength conversion layer opposite to the lens sheet side, and integrated with the lens sheet and the light wavelength conversion layer. The first surface or the barrier layer provided on the second surface of the first light-transmitting base material is further provided, and the light-transmitting sheet is the second light-transmitting base material and the said. A barrier layer provided on the first surface of the second light-transmitting substrate on the light wavelength conversion layer side or on the second surface of the second light-transmitting substrate opposite to the first surface. May be further provided.

In the laminated body, the surface of the laminated body may be the lens surface of the lens sheet, and the laminated body may have an uneven surface on the back surface which is a surface opposite to the front surface.

In the laminated body, the light wavelength conversion layer further contains light scattering particles, the difference in refractive index between the light scattering particles and the host matrix is 0.10 or more, and the average particle diameter of the light scattering particles. Is 8% or less when the film thickness of the light wavelength conversion layer is 100%, the quantum dots are made of one or more kinds of materials, and / or have at least one particle size distribution band. May be good.

According to another aspect of the present invention, the light transmissive base material containing quantum dots and a lens layer provided on one surface side of the light transmissive base material and having a plurality of unit lenses are provided. Provided is a laminate in which a light-transmitting base material and the lens layer are integrated.

In the laminate, 40 ° C., water vapor transmission rate of 0.1g ^/ (m 2 · 24h) at a relative humidity of 90% or more and 23 ° C., the oxygen permeability at a relative humidity of 90% 0.1 cm ³ / (m ^At least one of 2.24 h · atm) or more may be satisfied.

The laminate may further include an overcoat layer made of resin that covers at least one surface of the light wave conversion layer or at least one surface of the light transmissive substrate containing the quantum dots.

In the laminate, the light wavelength conversion layer or the light transmissive substrate containing the quantum dots further comprises light wavelength conversion particles, and the light wavelength conversion particles are selected from the group consisting of sulfur, phosphorus, and nitrogen. It may contain light-transmitting resin particles containing at least one of one or more elements and carboxylic acids, and the quantum dots encapsulated in the resin particles.

In the above-mentioned laminate, the light wavelength conversion layer or the light transmissive base material containing the quantum dots further contains light wavelength conversion particles, and the light wavelength conversion particles suppress the transmission of water vapor and oxygen. The quantum dots contained in the barrier material may be included.

According to another aspect of the present invention, there is provided a backlight device including a light source and the above-mentioned laminate that receives light from the light source.

The backlight device has an incoming surface that receives light from the light source and an outgoing surface that emits light from the light source, the light emitting surface is located on the laminate side, and the light from the light source is emitted from the light source. An optical plate that guides the laminate or diffuses the light from the light source may be further provided.

According to another aspect of the present invention, a light source, the above-mentioned laminated body, an incoming light receiving surface receiving light from the light source, and one of the uneven surfaces of the laminated body which emits light from the light source. It has a light emitting surface that is optically in close contact with the portion and forms an air layer between the concave and convex surfaces, and guides the light from the light source to the laminated body, or directs the light from the light source. A backlight device comprising an optical plate for diffusing is provided.

The backlight device further includes a frame that surrounds the periphery of the laminate and the periphery of the optical plate, and a fixing member that fixes the light source, the optical plate, and the laminate to the frame. The light source may be arranged between the optical plate and the frame, and the optical plate may be a light guide plate that guides the light from the light source to the laminated body.

In the backlight device, the first quantum dot in which the light source emits blue light and the quantum dot converts the blue light into green light, and the second quantum dot in which the blue light is converted into red light. May include.

According to another aspect of the present invention, there is provided a display device including the above-mentioned backlight device and a display panel arranged on the light emitting side of the backlight device.

According to the method for manufacturing a laminate according to one aspect of the present invention, the backlight device can be made thinner, the number of manufacturing steps of the backlight device can be reduced, and the light utilization efficiency can be improved. It is possible to provide a laminated body capable of suppressing the color of the peripheral portion of the laminated body from being conspicuous as compared with the color of the central portion of the laminated body at the time of light emission. Further, it is possible to provide such a laminated body, and a backlight device and an image display device including such a laminated body.

It is a perspective view of the laminated body which concerns on 1st Embodiment. FIG. 5 is a cross-sectional view taken along the line II of the laminated body of FIG. It is a schematic diagram which shows the optical action of the lens sheet shown in FIG. It is a schematic diagram which showed how the incident light is Mie scattered with respect to a light scattering particle. This is an example of a graph shown when the scattering efficiency of light incident on the light wavelength conversion layer is on the vertical axis and the particle size of the light scattering particles is on the horizontal axis. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic block diagram of another laminated body which concerns on 1st Embodiment. It is a schematic manufacturing process drawing of the laminated body which concerns on 1st Embodiment. It is a schematic manufacturing process drawing of the laminated body which concerns on 1st Embodiment. It is a schematic block diagram of the display device including the backlight device which concerns on 1st Embodiment. It is a perspective view of the upper lens sheet shown in FIG. It is a schematic plan view of the fixed structure of the laminated body which concerns on 1st Embodiment. FIG. 17 is a cross-sectional view of the vicinity of a fixing member having a fixed structure shown in FIG. It is a schematic block diagram of another backlight apparatus which concerns on 1st Embodiment. It is a perspective view of the laminated body which concerns on 2nd Embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of the laminated body of FIG.

[First Embodiment]
Hereinafter, the laminate, the manufacturing method thereof, the backlight device, and the display device according to the first embodiment of the present invention will be described with reference to the drawings. In the present specification, terms such as "sheet" and "film" are not distinguished from each other based only on the difference in designation. Therefore, for example, "film" is used to include a member that can also be called a sheet, and "sheet" is used to include a member that can also be called a film. FIG. 1 is a perspective view of the laminated body according to the present embodiment, FIG. 2 is a cross-sectional view of the laminated body of FIG. 1 along the line I-I, and FIG. 3 is an optical view of the lens sheet shown in FIG. FIG. 4 is a schematic diagram showing how incident light scatters with respect to light-scattering particles, and FIG. 5 shows the scattering efficiency of light incident on the light wavelength conversion layer on the vertical axis. This is an example of a graph shown when the particle size of the light-scattering particles is taken as the horizontal axis. 6 to 12 are schematic configuration diagrams of other laminated bodies according to the present embodiment, and FIGS. 13 and 14 are schematic manufacturing process diagrams of the laminated bodies according to the present embodiment.

<<< Laminated body >>
As shown in FIGS. 1 and 2, the laminate 10 includes a lens sheet 20, a light wavelength conversion layer 30, and a light transmissive sheet 40 in this order. The lens sheet 20 includes a first light-transmitting base material 21, a lens layer 22 provided on the first surface 21A side of the first light-transmitting base material 21, and a first light-transmitting base material 21. It is provided with a barrier layer 23 provided on the second surface 21B opposite to the first surface 21A of the above. The light wavelength conversion layer 30 is provided on the second surface 21B side of the first light transmissive base material 21. The light transmissive sheet 40 includes a second light transmissive base material 41 having a first surface 41A on the light wavelength conversion layer 30 side and a second surface 41B on the side opposite to the first surface 41A, and a second surface. The barrier layer 42 provided on the first surface 41A of the light transmissive base material 41 and the light diffusion layer 43 provided on the second surface 41B of the second light transmissive base material 41 are provided. .. The laminate 10 may include the lens sheet 20 and the light wavelength conversion layer 30, and may not include the light transmissive sheet 40. The lens sheet 20 and the light transmissive sheet 40 do not have to include the barrier layers 23 and 42 and the light diffusing layer 43. In the lens sheet 20, the barrier layer 23 is provided on the second surface 21B of the first light-transmitting base material 21, but is provided on the first surface 21A of the first light-transmitting base material 21. You may be. In this case, the barrier layer 23 is arranged between the first light-transmitting base material 21 and the lens layer 22. Similarly, in the light transmissive sheet 40, the barrier layer 42 is provided on the first surface 41A of the second light transmissive base material 41, but the second light transmissive base material 41 has a second surface. It may be provided on the surface 41B. Further, instead of the light diffusion layer 43, a sticking prevention layer may be provided. Hereinafter, for the sake of simplification of the description, the first light transmitting base material 21 will be referred to as a light transmitting base material 21, and the second light transmitting base material 41 will be referred to as a light transmitting base material 41. There is also.

In the laminated body 10, the lens sheet 20 and the light wavelength conversion layer 30 are integrated. In the present specification, "the lens sheet and the light wavelength conversion layer are integrated" means that the lens sheet and the light wavelength conversion layer are directly connected so that there is no air interface between the lens sheet and the light wavelength conversion layer. Not only when they are integrated in contact with each other, but also through an arbitrary layer and / or an arbitrary light-transmitting substrate so that there is no air interface between the lens sheet and the optical wavelength conversion layer. This includes the case where the light wavelength conversion layer and the light wavelength conversion layer are integrated in a state where they are not in direct contact with each other. Further, in the present embodiment, the lens sheet 20, the light wavelength conversion layer 30, and the light transmissive sheet 40 are integrated.

The surface 10A of the laminate 10 shown in FIGS. 1 and 2 is the lens surface 20A of the lens sheet 20. As used herein, the term "lens surface" refers to a surface that exerts a lens action (refraction action) in the lens layer. Further, the back surface of the laminated body 10 shown in FIGS. 1 and 2 is an uneven surface 10B. In the present embodiment, since the light diffusing layer 43 is the outermost layer on the back surface side of the laminated body 10, the uneven surface 10B is located on the side opposite to the surface of the light diffusing layer 43 on the light transmitting base material 41 side. Although the uneven surface 43A is formed, the uneven surface may be composed of another layer.

The arithmetic mean roughness (Ra) of the uneven surface 10B of the laminated body 10 is preferably 0.01 μm or more from the viewpoint of preventing the laminated body 10 from sticking to the optical plate 82 described later. The definition of "Ra" shall be in accordance with JIS B0601-1994.

<< Lens sheet >>
The lens sheet 20 has a function of changing the traveling direction of the incident light and emitting the incident light from the light emitting side. In the present embodiment, as shown in FIG. 3, together with a function (condensing function) of changing the traveling direction of the incident light L3 and emitting it from the light emitting side to intensively improve the brightness in the front direction. It has a function (retroreflection function) of reflecting the incident light L4 and returning it to the light wavelength conversion layer 30 side. As described above, the lens sheet 20 has a light transmissive base material 21, a lens layer 22 provided on the first surface 21A of the light transmissive base material 21, and having a plurality of unit lenses 24, and light transmissive. It is provided with a barrier layer 23 provided on the second surface 21B of the base material 21.

<First light-transmitting substrate>
The light-transmitting base material 21 is not particularly limited as long as it has light-transmitting property, but the light-transmitting base material 21 may be deteriorated by moisture, oxygen, or the like and the luminous efficiency may be lowered. It is preferable that the quantum dots 32 have a function of protecting the quantum dots 32 from water and oxygen by suppressing the permeation of water and oxygen.

The thickness of the light-transmitting base material 21 is not particularly limited, but is preferably 10 μm or more and 150 μm or less. If the thickness of the light-transmitting substrate is less than 10 μm, the laminated body may be assembled, wrinkles or breaks may occur during handling, and if it exceeds 150 μm, it may not be suitable for weight reduction and thinning of the display. There is. The more preferable lower limit of the thickness of the light transmissive substrate is 50 μm or more, and the more preferable upper limit is 125 μm or less.

The average thickness of the light transmissive substrate 21 can be calculated using, for example, an image of a cross section taken with a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM).

Examples of the constituent raw materials of the light-transmitting base material 21 include polyester (for example, polyethylene terephthalate and polyethylene naphthalate), cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether sulphon, polysulphon, and polypropylene. , Polymethylpentene, Polyvinyl Chloride, Polyvinyl Acetal, Polyether Ketone, Polymethyl methacrylate, Polycarbonate, Polyurethane and other thermoplastics. Preferred examples of the constituent material of the base film include polyester (for example, polyethylene terephthalate and polyethylene naphthalate) and cellulose triacetate.

The light-transmitting base material 21 may be composed of a single base material, or may be a laminated base material composed of a plurality of base materials. Such a laminated base material may be composed of a plurality of layers composed of layers of the same type of constituent raw materials, or may be composed of a plurality of layers composed of layers of different types of constituent raw materials, depending on the intended use. good.

<Lens layer>
The lens layer 22 includes a plurality of unit lenses 24, but also includes a sheet-shaped main body 25. The plurality of unit lenses 24 are arranged side by side on the light emitting side of the main body 25.

The main body 25 functions as a sheet-like member that supports the unit lens 24. As shown in FIG. 3, unit lenses 24 are arranged on the light emitting side surface 25A of the main body 25 without leaving a gap. Therefore, the light emitting surface of the lens sheet 20 is formed by the lens surface 20A. On the other hand, as shown in FIG. 3, in the present embodiment, the main body portion 25 has a smooth surface forming the light entering side surface of the lens layer 22 as the light entering side surface 25B facing the light emitting side surface 25A. There is.

The unit lenses 24 are arranged side by side on the light emitting side surface 25A of the main body 25. As shown in FIG. 1, the unit lens 24 extends linearly in a direction intersecting the arrangement direction AD of the unit lens 24, particularly linearly in the present embodiment. Further, in the present embodiment, a large number of unit lenses 24 included in one lens sheet 20 extend in parallel with each other. Further, the longitudinal direction LD of the unit lens 24 of the lens sheet 20 is orthogonal to the arrangement direction AD of the unit lens 24 in the lens sheet 20.

The unit lens may have a triangular columnar shape, or may have a wavy shape or a bowl shape such as a hemispherical shape. In the present embodiment, as a unit lens, a triangular columnar lens whose width becomes narrower toward the light emitting side will be described. The shape of the cross section (also called the main cut surface of the lens sheet) parallel to both the normal direction ND of the sheet surface of the main body 25 and the arrangement direction AD of the unit lens 24 is a triangular shape protruding toward the light emitting side. .. In particular, from the viewpoint of intensively improving the frontal brightness, the cross-sectional shape of the unit lens 24 on the main cutting surface is an isosceles triangle shape, and the apex angle located between the equilateral sides is the light emitting side surface 25A of the main body 25. Each unit lens 24 is configured so as to project from the light emitting side.

From the viewpoint of improving the efficiency of light utilization, the unit lens 24 preferably has an apex angle θ of 80 ° or more and 100 ° or less, and more preferably an apex angle θ of about 90 °. However, the tip of the unit lens 24 may be a curved surface in consideration of damage to the tip of the unit lens when winding the laminated body.

The dimensions of the lens sheet 20 can be set as follows, as an example. First, as a specific example of the unit lens 24, the arrangement pitch of the unit lens 24 (corresponding to the width of the unit lens 24 in the illustrated example) can be set to 10 μm or more and 200 μm or less. However, in recent years, the arrangement of the unit lens 24 has been rapidly improved in definition, and it is preferable that the arrangement pitch of the unit lens 24 is 10 μm or more and 50 μm or less. Further, the protruding height of the unit lens 24 from the main body 25 along the normal direction ND of the lens sheet 20 to the sheet surface can be set to 5 μm or more and 100 μm or less. Further, the apex angle θ of the unit lens 24 can be set to 60 ° or more and 120 ° or less.

<Barrier layer>
The barrier layer 23 is a layer for suppressing the permeation of water and oxygen to protect the quantum dots 32 from water and oxygen. Further, the barrier layer 23 preferably has a function of improving the adhesion with the light wavelength conversion layer 30.

The material for forming the barrier layer 23 is not particularly limited as long as it can obtain a barrier property, and examples thereof include inorganic oxides, metals, and sol-gel materials. Specifically, examples of the inorganic oxide include silicon oxide (SiO _x ), aluminum oxide (Al _{n Om} ), titanium oxide (TIO ₂ ), yttrium oxide, boron oxide (B ₂ O ₃ ), and oxidation. Calcium (CaO), silicon oxide nitride (SiO _x N _{yC z} ) and the like can be mentioned, examples of the metal include Ti, Al, Mg, Zr and the like, and examples of the sol-gel material include siloxane. Examples include sol-gel materials. These materials may be used alone or in combination of two or more.

The thickness of the barrier layer 23 is not particularly limited, but is preferably 0.01 μm or more and 1 μm or less. If it is less than 0.01 μm, the barrier performance of the barrier layer may be insufficient, and if it exceeds 1 μm, the barrier performance may be easily deteriorated due to cracks in the barrier layer or the like. The more preferable lower limit of the thickness of the barrier layer is 0.03 μm, and the more preferable upper limit is 0.5 μm.

The thickness of the barrier layer is determined by photographing the cross section of the barrier layer using a scanning electron microscope (SEM), measuring the thickness of the barrier layer at 20 points in the image of the cross section, and using the average value of the thicknesses of the 20 points. .. Further, the barrier layer 23 may be a single layer or a stack of a plurality of layers. When a plurality of barrier layers are laminated, each layer constituting the barrier layer may be directly laminated or laminated.

Examples of the method for forming the barrier layer 23 include a physical vapor deposition (PVD) method such as a sputtering method and an ion plating method, a vapor deposition method such as a chemical vapor deposition (CVD) method, a roll coating method, and a spin coating method. Law etc. can be mentioned. Moreover, you may combine these methods.

The barrier layer 23 is not particularly limited as long as it has the above-mentioned barrier property, but from the viewpoint of high barrier property and the like, it is preferable to use a thin-film deposition layer formed by a thin-film deposition method.

The type of the vapor deposition method is not particularly limited as long as it is a layer formed by the vapor deposition method, and the vapor deposition layer may be a layer formed by the CVD method or by the PVD method. It may be a formed layer.

When the vapor deposition layer is formed by a CVD method such as a plasma CVD method, it is possible to form a dense layer having a high barrier property, but from the viewpoint of manufacturing efficiency and cost, the vapor deposition layer is formed by the PVD method. It is preferable to form.

Examples of the PVD method include a vacuum vapor deposition method, a sputtering method, an ion plating method, and the like. Among them, the vacuum vapor deposition method is preferably used from the viewpoint of its barrier property and the like. Examples of the vacuum vapor deposition method include a vacuum vapor deposition method using an electron beam (EB) heating method, a vacuum vapor deposition method using a high-frequency dielectric heating method, and the like.

As the material of the vapor deposition layer, a metal or an inorganic oxide is preferable, and specifically, a metal such as Ti, Al, Mg, Zr, silicon oxide, aluminum oxide, silicon oxide nitride, aluminum oxide, magnesium oxide, and oxidation. zinc, indium oxide, tin oxide, yttrium _oxide, B ₂ O 3, CaO inorganic oxides such like. Among them, silicon oxide is preferable from the viewpoint of having high barrier property and transparency.

The thickness of the thin-film deposition layer varies depending on the type and composition of the material used and is appropriately selected, but is preferably 0.01 μm or more and 1 μm or less, and a more preferable upper limit is 500 nm. If the thickness of the vapor-deposited layer is thinner than the above range, it may be difficult to form a uniform layer, and the barrier property may not be obtained. Further, when the thickness of the vapor-deposited layer is thicker than the above-mentioned range, the barrier property may be significantly impaired due to cracks in the vapor-deposited layer due to external factors such as tension after the film is formed. In addition, it takes time to form and the productivity may decrease.

An anchor layer may be formed as a base layer of the barrier layer 23. Thereby, the barrier property and the weather resistance can be enhanced. Examples of the material for forming the anchor layer include adhesive resins, inorganic oxides, organic oxides, and metals.

Examples of the method for forming the anchor layer include a PVD method such as a sputtering method and an ion plating method, a CVD method, a roll coating method, and a spin coating method. Moreover, you may combine these methods. Among them, in-line coating at the time of film formation is preferable because it is excellent in mass productivity and can improve the adhesion of the anchor layer.

The oxygen transmission rate (OTR: Oxygen Transmission Rate) when the barrier layer 23 is formed on the light-transmitting base material 21 is 1.0 × 10 ^{− under the conditions of 23 ° C. and 90% Rh (relative humidity). 1} cm ³ / is preferably ^(m 2 · 24h · atm) is less than, and more preferably ^{1.0 × 10 -2 cm 3 / (} m 2 · 24h · atm) or less. The oxygen permeability can be measured using an oxygen gas permeability measuring device (product name "OX-TRAN 2/21", manufactured by MOCON).

The water vapor transmittance (WVTR: Water Vaper Transmission Rate) in the state where the barrier layer 23 is formed on the light transmissive base material 21 is 1.0 × 10 ^-1 g under the conditions of 40 ° C. and 90% Rh. / is preferably ^(m 2 · 24h) is less than, and more preferably ^{1.0 × 10 -2 g / (m} 2 · 24h) or less. The water vapor transmittance can be measured using a water vapor transmittance measuring device (product name "PERMATRAN-W3 / 31", manufactured by MOCON).

<< Optical wavelength conversion layer >>
The optical wavelength conversion layer 30 includes a host matrix 31 and quantum dots 32 for performing wavelength conversion of incident light. The quantum dots 32 shown in FIG. 2 are dispersed in the host matrix 31. Further, the light wavelength conversion layer 30 may further include light scattering particles 33. In the laminate, the term "light scattering" means light scattering due to particles inside the laminate, and the term "light diffusion" mainly means light diffusion due to the surface of the laminate. ..

As shown in FIG. 2, when light is incident from the first surface 30A through the light transmissive sheet 40, the light (primary light) L1 incident on the quantum dots 32 has a wavelength different from that of the light L1. Light (secondary light) L2 is converted and emitted from the second surface 30B. On the other hand, even when light is incident from the first surface 30A through the light transmissive sheet 40, the light L1 passing between the quantum dots 32 is emitted from the second surface 30B without being wavelength-converted. do.

The film thickness of the optical wavelength conversion layer 30 is substantially uniform. The average film thickness of the optical wavelength conversion layer 30 is preferably 10 μm or more and 150 μm or less. When the film thickness of the optical wavelength conversion layer 30 is within this range, it is suitable for reducing the weight and thinning of the backlight device.

The average thickness of the light wavelength conversion layer 30 is determined by using, for example, images of cross sections taken at 20 locations at random with a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM). Can be calculated. Among these, considering that the film thickness of the light wavelength conversion layer 30 is on the order of μm, it is preferable to use SEM. In the case of SEM, the acceleration voltage is preferably 30 kV and the magnification is preferably 1000 to 7000 times, and in the case of TEM or STEM, the acceleration voltage is preferably 30 kV and the magnification is preferably 50,000 to 300,000 times.

<Host Matrix>
The host matrix 31 is not particularly limited, and examples thereof include a binder resin and the like. The host matrix is composed of a cured product (polymer, crosslinked product) of a curable host matrix precursor. Examples of the curable host matrix precursor include polymerizable compounds including ionizing radiation polymerizable compounds and / or thermopolymerizable compounds. The ionizing radiation polymerizable compound has at least one ionizing radiation polymerizable functional group. As used herein, the "ionizing radiation-polymerizable functional group" is a functional group capable of undergoing a polymerization reaction by irradiation with ionizing radiation. Examples of the ionizing radiation polymerizable functional group include ethylenically unsaturated groups such as (meth) acryloyl group, vinyl group and allyl group. The "(meth) acryloyl group" means that both the "acryloyl group" and the "methacryloyl group" are included. Further, examples of the ionizing radiation irradiated when polymerizing the ionizing radiation polymerizable compound include visible light, ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays.

Examples of the ionizing radiation-polymerizable compound include an ionizing radiation-polymerizable monomer, an ionizing radiation-polymerizable oligomer, and an ionizing radiation-polymerizable prepolymer, which can be appropriately adjusted and used. As the ionizing radiation-polymerizable compound, a combination of an ionizing radiation-polymerizable monomer and an ionizing radiation-polymerizable oligomer or an ionizing radiation-polymerizable prepolymer is preferable.

Examples of the ionizing radiation polymerizable monomer include a monomer containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, and ethylene glycol di (meth) acrylate. , Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethyl propantri (meth) acrylate, trimethylol ethanetri (meth) ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate (Meta) acrylic acid esters such as, etc. can be mentioned.

As the ionizing radiation polymerizable oligomer, a polyfunctional oligomer having two or more functional groups is preferable, and a polyfunctional oligomer having three or more (trifunctional) ionizing radiation polymerizable functional groups is preferable. Examples of the polyfunctional oligomer include polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and isocyanurate. Examples thereof include (meth) acrylate and epoxy (meth) acrylate.

The ionizing radiation polymerizable prepolymer has a weight average molecular weight of more than 10,000, and the weight average molecular weight is preferably 10,000 or more and 80,000 or less, and more preferably 10,000 or more and 40,000 or less. When the weight average molecular weight exceeds 80,000, the viscosity is high, so that the coating suitability is lowered, and the appearance of the obtained light wavelength conversion layer may be deteriorated. Examples of the polyfunctional prepolymer include urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, and epoxy (meth) acrylate.

The thermopolymerizable compound is not particularly limited, and for example, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, and melamine-urea cocondensation. Examples thereof include resins, silicon resins, and polysiloxane resins. The heat-polymerizable compound may be used alone or in combination of two or more. Among these, epoxy resin and urethane resin are preferable from the viewpoint of curability and heat resistance.

Examples of the epoxy resin include a combination of an epoxy resin (main agent), an acid anhydride, an amine compound, or an amino resin (curing agent), and a photocationic polymerization initiator. The epoxy resin as the main agent is not particularly limited as long as it has an epoxy group in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type. Epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, 3 Functional epoxy resin, tetraphenylol ethane type epoxy resin, dicyclopentadienephenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, A glycidylamine type epoxy resin, a glioxal type epoxy resin, an alicyclic epoxy resin, a heterocyclic epoxy resin and the like can be used.

Examples of the urethane resin include a combination of a polyol compound (main agent) and an isocyanate compound (curing agent). The polyol compound used as the main agent in the urethane resin is not particularly limited, and examples thereof include polyester polyols, polyester polyurethane polyols, polyether polyols, and polyether polyurethane polyols. These polyol compounds may be used alone or in combination of two or more.

The isocyanate-based compound used as a curing agent in the urethane resin is not particularly limited, and for example, polyisocyanate, its adduct, its isocyanurate modified, its carbodiimide modified, its alohanate modified, and its burette. Denatured substances and the like can be mentioned. Specific examples of the polyisocyanate include diphenylmethane diisocyanate (MDI), polyphenylmethane diisocyanate (polymeric MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), and bis (4-isophorone diisocyanate) methane (H12MDI). , Isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (1,5-NDI), 3,3'-dimethyl-4,4'-diphenylenediocyanide (TODI), xylene diisocyanate (XDI) and other aromatic diisocyanes. An aliphatic diisocyanate such as tramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate and isophorone diisocyanate; an alicyclic diisocyanate such as 4,4'-methylenebis (cyclohexylisocyanide) and isophorone diisocyanate can be mentioned. Specific examples of the adduct body include those obtained by adding trimethylolpropane, glycol, or the like to the polyisocyanate. These isocyanate compounds may be used alone or in combination of two or more.

<Quantum dot>
The quantum dot 32 is a nano-sized semiconductor particle having a quantum confinement effect. The particle size of the quantum dots 32 is, for example, 1 nm or more and 20 nm or less. When the quantum dot 32 absorbs light from the excitation source and reaches an energy excited state, the quantum dot 32 emits energy corresponding to the energy band gap of the quantum dot 32. Therefore, by adjusting the particle size or the composition of the substance of the quantum dots 32, the energy band gap can be adjusted, and energy in various levels of wavelength bands can be obtained. In particular, the quantum dots 32 can generate strong fluorescence in a narrow wavelength band.

Specifically, the energy band gap of the quantum dots 32 increases as the particle size decreases. That is, as the crystal size becomes smaller, the emission of the quantum dots shifts to the blue side, that is, to the high energy side. Therefore, by changing the particle size of the quantum dots, the emission wavelength can be adjusted over the entire wavelength of the spectrum in the ultraviolet region, the visible region, and the infrared region. For example, when the quantum dot 32 is composed of CdSe / ZnS described later, when the particle size of the quantum dot is 2.0 nm or more and 4.0 nm or less, blue light is emitted and the particle size of the quantum dot is 3. When it is 0 nm or more and 6.0 nm or less, it emits green light, and when the particle size of the quantum dots is 4.5 nm or more and 10.0 nm or less, it emits red light. In the above, the range of the particle size of the quantum dot that emits blue light and the particle size of the quantum dot that emits green light partially overlaps, and the particle size of the quantum dot that emits green light and the red light are overlapped. The range of the particle size of the emitted quantum dots overlaps in part, but even if the quantum dots have the same particle size, the emission color may differ depending on the thickness of the shell of the quantum dots, so there is no contradiction. It's not a thing.

In the present specification, "blue light" is light having a wavelength range of 380 nm or more and less than 480 nm, "green light" is light having a wavelength range of 480 nm or more and less than 590 nm, and "red light" is Light having a wavelength range of 590 nm or more and 750 nm or less.

As the quantum dots 32 included in the optical wavelength conversion layer 30, one type of quantum dots may be used, but at least two or more types of quantum dots having different particle sizes or materials may also be used. As shown in FIG. 2, the optical wavelength conversion layer 30 includes a first quantum dot 32A and a second quantum dot 32B having a particle size larger than that of the first quantum dot 32 as the quantum dot 32.

As described above, some light emitted from the laminated body 10 is transmitted without being absorbed by the quantum dots 32. Therefore, a light source that emits blue light is used as the light source, and blue light is used as the first quantum dots 32A. When a quantum dot that converts green light is used and a quantum dot that converts blue light to red light is used as the second quantum dot 32B, blue light, green light, and red light are mixed from the laminate 10. Light can be emitted.

The quantum dots 32 can generate strong fluorescence in a desired narrow wavelength range. Therefore, the backlight device using the laminated body 10 can illuminate the display panel with light of the three primary colors having excellent color purity. In this case, the display panel will have excellent color reproducibility.

The quantum dot 32 may have a core-shell type structure mainly having a core made of a semiconductor compound of about 2 nm or more and 10 nm or less and a shell made of a semiconductor compound different from this core. The shell functions as a protective layer that protects the core.

Examples of core materials include MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe and HgTe. II-VI semiconductor compounds such as AlN, AlP, AlAs, AlSb, GaAs, GaP, GaN, GaSb, InN, InAs, InP, InSb, TiN, TiP, TiAs and III-V semiconductor compounds such as TiSb. , A semiconductor compound such as a group IV semiconductor such as Si, Ge and Pb, or a semiconductor crystal containing a semiconductor. Further, a semiconductor crystal containing a semiconductor compound containing three or more elements such as InGaP can also be used. Among these, semiconductor crystals such as CdS, CdSe, CdTe, InP, and InGaP are preferable from the viewpoints of ease of fabrication, controllability of particle size capable of obtaining light emission in the visible range, and the like.

The shell can improve the luminous efficiency of quantum dots by using a semiconductor compound having a bandgap higher than that of the semiconductor compound forming the core so that excitons are confined in the core. Examples of the core-shell structure (core / shell) having such a bandgap magnitude relationship include CdSe / ZnS, CdSe / ZnSe, CdSe / CdS, CdTe / CdS, InP / ZnS, Gap / ZnS, Si / ZnS, and the like. InN / GaN, InP / CdSSe, InP / ZnSeTe, InGaP / ZnSe, InGaP / ZnS, Si / AlP, InP / ZnSTe, InGaP / ZnSTe, InGaP / ZnSse and the like can be mentioned.

The quantum dots 32 may have an organic polymer called a ligand on the outside of the shell. The organic polymer has a function of enhancing the compatibility between the quantum dots and the host matrix, and is appropriately selected depending on the type of the host matrix.

The shape of the quantum dot 32 is not particularly limited, and may be, for example, spherical, rod-shaped, disk-shaped, or other shape. When the quantum dots 32 are not spherical, the particle size of the quantum dots 16 can be a true spherical value having the same volume.

Information such as the particle size, shape, and dispersion state of the quantum dots 32 can be obtained by a transmission electron microscope (TEM). Further, the crystal structure and particle size of the quantum dots can be known by X-ray crystal diffraction (XRD). Furthermore, information on the particle size of quantum dots and the like can be obtained from the ultraviolet-visible (UV-Vis) absorption spectrum.

<Light scattering particles>
The light scattering particles 33 are particles having an action of changing the traveling direction of light by scattering the light that has entered the light wavelength conversion layer 30. In the laminated body 10, the average particle size of the light scattering particles 33 is preferably 8% or less when the film thickness of the light wavelength conversion layer 30 is 100%. This is because if the average particle size of the light-scattering particles exceeds 8%, it may not be possible to sufficiently improve the light conversion efficiency of the incident light by the laminated body. Further, the average particle size of the light scattering particles 33 is preferably 3% or less when the film thickness of the light wavelength conversion layer 30 is 100%.

If the average particle size of the light-scattering particles is too small with respect to the thickness of the light wavelength conversion layer, it becomes difficult to obtain the effect of scattering the incident light by the light-scattering particles. Therefore, the average particle size of the light-scattering particles is preferably set to the lower limit of the range in which the incident light on the light wavelength conversion layer can be scattered. The average particle size of the light-scattering particles can be obtained by measuring the particle size of 20 light-scattering particles observed in the cross-sectional microscope observation of the laminated body and calculating the average value thereof.

In the laminated body, it is important to highly control the particle size of the light-scattering particles in order to improve the light conversion efficiency of the incident light. However, the refractive index of the light-scattering particles and the host matrix Controlling the difference in refractive index is also important for improving the light conversion efficiency of the incident light. Specifically, the refractive index of the light-scattering particles has a refractive index difference of 0.10 or more with respect to the refractive index of the host matrix. If the difference in refractive index is less than 0.10, excellent light conversion efficiency may not be obtained. Since the light scattering efficiency tends to increase as the refractive index of the light scattering particles increases, light scattering particles having a smaller average particle diameter than the film thickness of the light wavelength conversion layer can be used. ..

As a method for measuring the refractive index of the light scattering particles before being contained in the optical wavelength conversion layer, for example, the Becke method, the minimum ellipsometry, the ellipsometry, the mode line method, the ellipsometry method and the like can be used. can. As a method for measuring the refractive index of the host matrix (cured product) and the light scattering particles in the light wavelength conversion layer, for example, a fragment of the light scattering particles or a fragment of the host matrix in the cured and produced light wavelength conversion layer can be used. The Becke method can be used for some form of extraction. In addition, the difference in refractive index between the host matrix and the light-scattering particles is measured using a phase-shift laser interference microscope (such as a phase-shift laser interference microscope manufactured by FK Optical Laboratory or a two-beam interference microscope manufactured by Mizojiri Optical Co., Ltd.). can do. When the host matrix contains the above-mentioned (meth) acrylate and other resins, the refractive index of the host matrix is a cured product of all the resin components contained except for quantum dots and light-scattering particles. Means the average refractive index of.

The light scattering particles 33 preferably have an average particle diameter that mainly causes Mie scattering with respect to the light incident on the light wavelength conversion layer 30. FIG. 4 is a diagram schematically showing how the light-scattering particles scatter me with respect to the incident light. As shown in FIG. 4, the incident light is me-scattered by the light-scattering particles 33. Therefore, the incident light is strongly scattered in the traveling direction. When the light scattering particles 33 have such an average particle size that mainly causes Mie scattering, the improvement of the light wavelength conversion efficiency by the laminated body 10 becomes extremely excellent. The reason for this is that the light incident on the light wavelength conversion layer is scattered by the light scattering particles in the layer (mainly me scattering), so that the optical path length in the light wavelength conversion layer is extended, and the wavelength conversion process by quantum dots is carried out. It is presumed that this is because the chances of it happening increase.

In the laminated body 10, the scattering efficiency of the light incident on the light wavelength conversion layer 30 is on the vertical axis, and the particle diameter of the light scattering particles is on the horizontal axis. , 20% or more of the particle size distribution of the light scattering particles 33 is preferably contained. FIG. 5 is an example of a graph shown when the scattering efficiency of light incident on the light wavelength conversion layer is on the vertical axis and the particle size of the light scattering particles is on the horizontal axis. As shown in FIG. 5, the above-mentioned "maximum peak" means that a plurality of peaks appear as the particle size increases in the above graph, and therefore the largest peak among them (usually, the particle size as shown in FIG. 5). Is the first peak that appears on the smaller side). Then, since 20% or more of the particle size distribution of the light scattering particles 33 is included in the range of the half width of the maximum peak, the laminated body 10 is extremely suitable for improving the light wavelength conversion efficiency with respect to the incident light. It becomes possible to plan for. The reason for this is that light-scattering particles whose particle size is within the range of the half-value width of the maximum peak have high light scattering efficiency. Therefore, the light wavelength is increased by containing a large amount of such light-scattering particles. This is because the light incident on the conversion layer is more strongly scattered by the light scattering particles in the layer, the optical path length in the light wavelength conversion layer is further extended, and the chance of the wavelength conversion process by the quantum dots is increased. Guessed. The "particle size distribution of light-scattering particles" is a particle size distribution with the abundance ratio on the vertical axis and the particle size on the horizontal axis, and the particle size is the cross-sectional TEM, STEM of the light wavelength conversion layer. Or it is measured by SEM observation. When the light wavelength conversion layer has light-scattering particles having different particle size distribution bands, it is preferable that the particle size distribution of each light-scattering particle is within the half-value width of the maximum peak, but at least the most. It suffices if the particle size distribution of the light-scattering particles having a large content is within the range of the half-price width of the maximum peak.

The light-scattering particles 33 may be inorganic particles and / or organic particles, and specifically, antimony-doped tin oxide (ATO) particles, indium tin oxide (ITO) particles, MgO particles, Al ₂ O ₃ particles, and the like. At _{least one selected from the group consisting of TiO 2} particles, BaTiO ₃ particles, Sb ₂ O ₅ particles, SiO ₂ particles, ZrO ₂ particles, ZnO particles, acrylic resin particles, styrene resin particles, melamine resin particles, and urethane resin particles. It is preferably a seed.

When the light scattering particles 33 are inorganic particles, it is possible to suitably scatter the incident light on the light wavelength conversion layer 30, and it is possible to preferably improve the light wavelength conversion efficiency with respect to the incident light. It becomes. In particular, the light scattering particle 33 is preferably at least one selected from the group consisting _{of Al 2} O ₃ particles, TiO ₂ particles, Ba _{TiO 3} particles, Sb ₂ O ₅ particles and ZrO _{2 particles.} The light scattering particles 33 may be made of two or more kinds of materials because the light wavelength conversion efficiency with respect to the incident light by the laminated body 10 can be more preferably improved. In this case, it is preferable that the average particle size of each of the two or more types of light-scattering particles satisfies the above-mentioned requirements for the film thickness of the light wavelength conversion layer.

When the light wavelength conversion layer contains light scattering particles, the light wavelength conversion layer preferably contains 0.01 to 10 parts by mass of quantum dots with respect to 100 parts by mass of the light scattering particles. If it is less than 0.01 parts by mass, it is difficult to improve the light wavelength conversion efficiency with respect to the incident light, and if it exceeds 10 parts by mass, the brightness may be lowered. The more preferable lower limit of the quantum dot content is 0.1 parts by mass, and the more preferable upper limit is 3 parts by mass.

When the light scattering particles are contained in the light wavelength conversion layer, the light scattering particles have a preferable lower limit of 5 parts by mass and a preferable upper limit of 50 parts by mass with respect to 100 parts by mass of the host matrix in the light wavelength conversion layer. If it is less than 5 parts by mass, a sufficient improvement in light wavelength conversion efficiency may not be obtained, and if it exceeds 50 parts by mass, a good light scattering state is obtained due to deterioration of the dispersion state of the light scattering particles. It may not be possible.

<< Light Transparency Sheet >>
As described above, the light transmissive sheet 40 includes a light transmissive base material 41, a barrier layer 42 provided on the first surface 41A of the light transmissive base material 41, and a second light transmissive base material 41. It is provided with a light diffusion layer 43 provided on the surface 41B of the above.

<Second light-transmitting base material>
Since the light-transmitting base material 41 is the same as the light-transmitting base material 21, the description thereof will be omitted here.

<Barrier layer>
Since the barrier layer 42 is the same as the barrier layer 23, the description thereof will be omitted here.

<Light diffusion layer>
The light diffusion layer 43 has a function of diffusing the light incident on the laminated body 10. By providing the light diffusion layer 43, the light conversion efficiency in the laminated body 10 can be improved. Further, the laminated body comes into contact with the optical plate described later in the backlight device, but when the laminated body and the optical plate stick to each other, the interface between the laminated body and the optical plate is wetted with water called wet out. As shown in FIGS. 1 and 2, the light diffusing layer 43 is a layer for preventing the laminate 10 and the optical plate 82 from sticking to each other. It is preferable that the surface of 43 opposite to the surface of the light-transmitting base material 41 is an uneven surface 43A. By forming the uneven surface 43A, the contact area between the light diffusion layer 43 and the optical plate 82 shown in FIG. 15 can be reduced, and the air layer 90 can be formed between the optical plate 82. , It is possible to prevent the laminated body 10 and the optical plate 82 from sticking to each other. The light diffusion layer 43 contains surface unevenness-forming particles 44 and a binder resin 45.

The difference in refractive index between the surface unevenness-forming particles 44 of the light diffusion layer 43 and the binder resin 45 is preferably 0.02 or more and 0.15 or less. If it is less than 0.02, the light diffusivity due to the refractive index of the surface unevenness-forming particles cannot be obtained optically, and the improvement of the light wavelength conversion efficiency of the laminated body may be insufficient. If it exceeds, the transmittance of the light diffusing layer may decrease. The more preferable lower limit of the difference in refractive index between the surface unevenness-forming particles 44 of the light diffusion layer 43 and the binder resin 45 is 0.03 or more, and the more preferable upper limit is 0.12 or more. The refractive index of the surface unevenness-forming particles 44 and the refractive index of the binder resin 45 may be larger. Here, the refractive indexes of the surface unevenness-forming particles 44 and the binder resin 45 can be measured by the same method as the refractive indexes of the light-scattering particles 33 and the host matrix 31.

(Surface unevenness forming particles)
The average particle size of the surface unevenness-forming particles 44 is, for example, preferably 1 μm or more and 30 μm or less, and more preferably 1 μm or more and 20 μm or less. If the average particle size of the surface unevenness-forming particles is less than 1 μm, the light wavelength conversion efficiency of the laminated body may be insufficient, and the amount of the surface unevenness-forming particles added is large in order to obtain sufficient light diffusivity. There is a need to. On the other hand, when the average particle size of the surface unevenness-forming particles exceeds 30 μm, the light diffusion performance becomes excellent, but the light transmittance of the light diffusion layer tends to be significantly reduced. The average particle size of the surface unevenness-forming particles can be measured by the same method as the quantum dots described above.

The surface unevenness-forming particles 44 are preferably 10 times or more and 20,000 times or less, more preferably 10 to 5000 times the average particle size of the quantum dots described above. If it is less than 10 times, sufficient light diffusivity may not be obtained in the light diffusing layer, and if it exceeds 20,000 times, the light diffusing performance of the light diffusing layer becomes excellent, but that of the light diffusing layer The light transmittance is likely to decrease significantly.

The surface unevenness-forming particles 44 may be particles made of an organic material or particles made of an inorganic material. The organic material constituting the surface unevenness-forming particles 44 is not particularly limited, and for example, polyester, polystyrene, melamine resin, (meth) acrylic resin, acrylic-styrene copolymer resin, silicone resin, benzoguanamine resin, benzoguanamine / formaldehyde condensation. Examples thereof include resins, polycarbonates, polyethylenes and polyolefins. Of these, crosslinked acrylic resin is preferably used. The inorganic material constituting the surface unevenness-forming particles is not particularly limited, and examples thereof include inorganic oxides such as silica, alumina, titania, tin oxide, antimony-doped tin oxide (ATO), and zinc oxide fine particles. .. Of these, silica and / or alumina are preferably used.

(Binder resin)
The binder resin 45 is not particularly limited, but the same binder resin as the binder resin described in the section of the optical wavelength conversion layer 30 can be used, and thus the description thereof will be omitted here.

<<< Other laminates >>>
In FIGS. 1 and 2, a laminate 10 in which a lens sheet 30, a light wavelength conversion layer 30, and a light transmissive sheet 40 are laminated in this order is shown, but the laminate is a wavelength conversion layer 30. The structure may be the structure shown in FIG. 6 in order to further improve the adhesion between the barrier layers 23 and 42, or may be the structure shown in FIG. 7 in order to further improve the adhesion.

The laminated body 50 shown in FIG. 6 is a laminated body 50 in which a lens sheet 20, a primer layer 51, a light wavelength conversion layer 30, a primer layer 52, and a light transmissive sheet 40 are laminated in this order. In FIG. 6, the members having the same reference numerals as those in FIG. 2 are the same as the members shown in FIG. 2, and therefore the description thereof will be omitted.

<< Primer layer >>
The primer layers 51 and 52 are layers that enhance the adhesion between the barrier layers 23 and 42 and the light wavelength conversion layer 30, are arranged between the barrier layers 23 and 42 and the light wavelength conversion layer 30, and are barrier layers. 41, 42 and the light wavelength conversion layer 30 are in close contact with each other. As the constituent materials of the primer layers 51 and 52, known materials may be appropriately selected and used. For example, a polymer of a photopolymerizable compound similar to the photopolymerizable compound described in the column of the host matrix or thermosetting Alternatively, thermoplastic polyester resin and polyurethane resin can be mentioned. In addition, different constituent materials may be used for the primer layers 51 and 52, respectively. The thickness of the primer layers 51 and 52 is not particularly limited, but can be, for example, 10 nm or more and 5 μm or less.

In the laminate 60 shown in FIG. 7, the lens sheet 20, the adhesive layer 61, the light transmissive base material 62, the light wavelength conversion layer 30, the light transmissive base material 63, the adhesive layer 64, and the light transmissive sheet 40 are in this order. It is laminated with. The light-transmitting base materials 62 and 63 and the adhesive layers 61 and 64 are for further improving the adhesion between the barrier layers 23 and 42 and the light wavelength conversion layer 30. In FIG. 7, the members having the same reference numerals as those in FIG. 2 are the same as the members shown in FIG. 2, and therefore the description thereof will be omitted.

<< Adhesive layer >>
The adhesive layers 61 and 64 are arranged between the barrier layers 23 and 42 and the light transmitting base materials 62 and 63, and are in close contact with the barrier layers 23 and 42 and the light transmitting base materials 62 and 63. The constituent materials of the adhesive layers 61 and 64 are not particularly limited, but for example, polyurethane resin, polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, polyvinyl alcohol. Based resins, polyvinyl acetal resins, copolymers of ethylene and vinyl acetate or acrylic acid, copolymers of ethylene and styrene and / or butadiene, thermoplastic resins such as olefin resins and / or modified resins thereof, light At least one of a polymer of a polymerizable compound and a thermosetting resin such as an epoxy resin can be used. It is preferable to use an acrylic resin, an epoxy resin or a polyester resin as a constituent material of the adhesive layers 61 and 64 from the viewpoint of heat resistance and adhesiveness. In addition, different constituent materials may be used for the adhesive layers 61 and 64, respectively. The thickness of the adhesive layers 61 and 64 is not particularly limited, but can be, for example, 100 nm or more and 30 μm or less.

<< Light-transmitting substrate >>
The light-transmitting base materials 62 and 63 are arranged between the adhesive layers 61 and 64 and the light wavelength conversion layer 30, and are in close contact with the adhesive layers 61 and 64 and the light wavelength conversion layer 30. Since the light-transmitting base materials 62 and 63 are the same as those of the light-transmitting base material 21, the description thereof will be omitted here.

<<< Other laminates >>>
As shown in FIG. 8, the laminated body includes the lens sheet 80, the light wavelength conversion layer 90, and the light transmissive sheet 100 in this order, and the layer 70 and the lens sheet 80, and the light wavelength conversion layer. The laminated body 110 may include the 90 and the light diffusing layer 43 in this order. The lens sheet 80 includes a light-transmitting base material 21 and a lens layer 22 provided on the first surface 21A side of the light-transmitting base material 21. Further, the light transmitting sheet 100 includes a light transmitting base material 41 and a light diffusion layer 43 provided on the second surface 41B of the light transmitting base material 41. The lens sheet 80 and the light transmissive sheet 100 of the present embodiment do not have a barrier layer. In the laminated body 70, the lens sheet 80, the light wavelength conversion layer 90, and the light transmissive sheet 100 are integrated, and in the laminated body 110, the lens sheet 80, the light wavelength conversion layer 90, and the light diffusion layer 43 are integrated. Is integrated. In the laminated body 70, since the lens sheet 80 and the light transmissive sheet 100 do not have a barrier layer, the light wavelength conversion layer 90 is bonded to the light transmissive base materials 21 and 41. Further, in the laminated body 110, since the lens sheet 80 does not have a barrier layer, the light wavelength conversion layer 90 is bonded to the light transmitting base material 21 and the light diffusing layer 43. In FIGS. 8 and 9, the members having the same reference numerals as those in FIG. 2 are the same as the members shown in FIG. 2, and therefore the description thereof will be omitted except for the contents described later.

<< Optical wavelength conversion layer >>
The optical wavelength conversion layer 90 includes a host matrix 91 and quantum dots 32. The quantum dots 32 shown in FIG. 9 are dispersed in the host matrix 91. Since the lens sheet 80 and the light transmissive sheet 100 do not have a barrier layer, the host matrix 91 is a group consisting of sulfur, phosphorus, and nitrogen in addition to the components of the host matrix 31 from the viewpoint of suppressing the deterioration of quantum dots. It is preferable to contain at least one of one or more elements selected from the above (hereinafter, this element is referred to as "specific element") and carboxylic acid. It is considered that the reason why the quantum dots are easily deteriorated is as follows. First, as described above, a ligand composed of a sulfur-based compound, a phosphorus-based compound, or the like is coordinated on the surface of the quantum dot, and this ligand is easily desorbed by light or heat. When the ligand is desorbed from the quantum dots, water and oxygen are likely to adhere to the quantum dots, so that the quantum dots are oxidized and deteriorated. It is considered that this causes the quantum dots to deteriorate. On the other hand, when the host matrix 91 contains at least one of the above-mentioned specific element and carboxylic acid, at least one of a sulfur component, a phosphorus component, a nitrogen component and a carboxylic acid is present in the vicinity of the quantum dots. This makes it possible to suppress the deterioration of quantum dots without providing a barrier layer. This is such that at least one of the sulfur component, phosphorus component, nitrogen component and carboxylic acid present in the host matrix 91 assists the role of the ligand even when the ligand is desorbed from the quantum dots ( For example, it binds to quantum dots instead of ligands and exerts at least one of the functions of substituting the ligand and capturing oxygen), which is considered to be because the deterioration of the quantum dots is suppressed. .. The specific element or carboxylic acid does not have to be fixed in the host matrix 91, but it is preferably fixed in the host matrix 91 in order to suppress the elution of the specific element or carboxylic acid.

The curable host matrix precursor for forming the host matrix 91 is one or more compounds selected from the group consisting of a sulfur-containing compound, a phosphorus-containing compound, a nitrogen-containing compound, and a carboxylic acid, in addition to a polymerizable compound. Hereinafter, this compound is referred to as a "specific compound"). By including a specific compound in the curable host matrix precursor, at least one of a specific element and a carboxylic acid can be contained in the host matrix 91. Since the polymerizable compound is the same as the polymerizable compound described in the column of the host matrix, the description thereof will be omitted here.

<Sulfur-containing compound>
The sulfur-containing compound is a compound containing sulfur. The sulfur-containing compound is not particularly limited, and examples thereof include a thiol compound, a thioether compound, a disulfide compound, and a thiophene compound. When a thiol compound is used as the sulfur compound, it is preferable that the thiol compound and the polymerizable compound form a copolymer by a thiol-ene reaction in the light wavelength conversion layer. By copolymerizing the thiol compound and the polymerizable compound, the thiol compound can be immobilized in the light wavelength conversion layer. When a thiol compound is used, it is preferable to use a primary thiol compound from the viewpoint of excellent curability by ionizing radiation or heat, but from the viewpoint of pot life at the time of coating and suppression of odor, secondary thiol is used. It is preferable to use a compound or a tertiary thiol compound.

The primary thiol compound refers to a compound in which one hydrocarbon group is bonded to carbon to which a thiol group is bonded. The secondary thiol compound is a compound in which two hydrocarbon groups are bonded to carbon to which a thiol group is bonded. The tertiary thiol compound refers to a compound in which three hydrocarbon groups are bonded to carbon to which a thiol group is bonded. The thiol compound may have one or more thiol groups in one molecule, but is preferably two or more from the viewpoint of suppressing deterioration of quantum dots.

式中、Ｒ^１は水素原子、置換されていてもよい炭素原子数１〜１０のアルキル基であり、Ｒ^２は置換されていてもよい炭素原子数１〜１０のアルキレン基であり、Ｒ^３は炭素原子以外の原子を含んでいてもよい炭素原子数１〜１５のｎ価の脂肪族基であり、ｍは１〜２０の整数であり、ｎは１〜３０の整数である。 The thiol compound is not particularly limited, but a compound represented by the following general formula (1) is preferable from the viewpoint of curability during formation of the optical wavelength conversion layer and suppression of deterioration of quantum dots.

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be ^{substituted, and R 2} is an alkylene group having 1 to 10 carbon atoms which may be substituted, and R ³ Is an n-valent aliphatic group having 1 to 15 carbon atoms which may contain atoms other than carbon atoms, m is an integer of 1 to 20, and n is an integer of 1 to 30.

The alkyl group of R ¹ may be linear or branched. Examples of the alkyl group of R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, n-pentyl group and neopentyl group. tert-Pentyl group, isopentyl group, 2-methylbutyl group, 1-ethylpropyl group, hexyl group, isohexyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3 , 3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl Examples thereof include a group, a 2-ethylbutyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.

The alkylene group of R ² may be either linear or branched. Examples ^{of the alkylene group of R 2} include a methylene group, an ethylene group, a trimethylene group, a propylene group, an isopropylene group and the like.

When the alkyl group of ^{R 1 or the alkylene group of R 2} is substituted, the substituent includes a halogen atom, a hydroxyl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, a carboxyl group, a phenyl group and the like. The groups to be selected are listed. Halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms.

One methylene group in the alkyl group of R ^{1 or the alkylene group of R 2} or two or more non-adjacent methylene groups are -O-, -S-, -SO _2- , -CO-, -COO-,-. ^{OCO -, - NR 4 -,} - CONR 4 -, - NR 4 CO -, - N = CH- and -CH = CH- may be substituted with at least one group selected from the group consisting of (formula Among them, R ⁴ independently represents hydrogen or an alkyl group having 1 to 5 carbon atoms.)

Examples of atoms other than carbon atoms that may be contained in the aliphatic group of R ^{3 include nitrogen atoms, oxygen atoms, sulfur atoms and the like.}

Of these, from the viewpoint of curability during formation of the optical wavelength conversion layer and suppression of deterioration of quantum dots, R ¹ is an alkyl group having 1 to 5 carbon atoms which may be ^{substituted, and R 2} is substituted. It is an alkylene group having 1 to 5 carbon atoms which may be used, R ³ is an aliphatic group having 1 to 10 carbon atoms, m is 1 to 10, and n is 1 to 15. A thiol compound or a secondary thiol compound is preferable. One methylene group in the alkylene group of R ² or two or more non-adjacent methylene groups may be substituted with the same group as described above.

Specific examples of the primary thiol compound include hexanedithiol, decandithiol, ethylene glycol bisthioglycolate, 1,4-butanediol bisthioglycolate, trimethylolpropanetristhioglycolate, pentaerythritol tetrakisthioglycolate, and ethylene. Glycerolbis (3-mercaptopropionate), 1,2-propylene glycolbis (3-mercaptopropionate), 1,3-propylene glycolbis (3-mercaptopropionate), 1,4-butanediolbis (3-Mercaptopropionate), Glycerintris (3-Mercaptopropionate), Trimethylolpropanthris (3-Mercaptopropionate), Trimethylolethanetris (3-Mercaptopropionate), Pentaerythritol tetrakis (3-mercaptopropionate) 3-Mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate) and the like.

Specific examples of the secondary thiol compound include 1,4-bis (3-mercaptobutylyloxy) butane and 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2. , 4,6 (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane ethanetris (3-mercaptobutyrate), etc. Can be mentioned. Specific examples of the tertiary thiol compound include tert-butyl mercaptan and the like.

式中、ｑは０または１の整数であり、Ｒ^５〜Ｒ^７は、それぞれ独立して、水素、水酸基、置換されていてもよい炭素原子数１〜３０の直鎖または分岐のアルキル基、置換されていてもよい炭素数１〜３０の直鎖または分岐のアルコキシ基、置換されていてもよい炭素数１〜３０の直鎖または分岐のアルケニル基、置換されていてもよい炭素数１〜３０の直鎖または分岐のアルキニル基、置換されていてもよい炭素数３〜６のシクロアルキル基、置換されていてもよいフェニル基、置換されていてもよいビフェニル基、置換されていてもよいナフチル基、置換されていてもよいフェノキシ基、または置換されていてもよい複素環基、または水酸基を表す。 <Phosphorus-containing compound>
The phosphorus-containing compound is a compound containing phosphorus. The phosphorus-containing compound is not particularly limited, and examples thereof include a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound, a phosphonic acid compound, a phosphinic acid compound, and a phosphine compound. Among these, the compound represented by the following general formula (2) is preferable from the viewpoint of curability during formation of the light wavelength conversion layer and suppression of deterioration of quantum dots.

In the formula, q is an integer of 0 or 1, and R ^{5 to} R ⁷ are independently hydrogen, hydroxyl group, or a linear or branched alkyl group having 1 to 30 carbon atoms which may be substituted. A linear or branched alkoxy group having 1 to 30 carbon atoms which may be substituted, a linear or branched alkenyl group having 1 to 30 carbon atoms which may be substituted, and a linear or branched alkenyl group having 1 to 30 carbon atoms which may be substituted. 30 linear or branched alkynyl groups, optionally substituted cycloalkyl groups having 3 to 6 carbon atoms, optionally substituted phenyl groups, optionally substituted biphenyl groups, optionally substituted Represents a naphthyl group, an optionally substituted phenoxy group, or an optionally substituted heterocyclic group, or a hydroxyl group.

When ^{any of R 5 to} R ⁷ has a substituent, the substituent includes a halogen atom (F, Cl, Br), an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An alkenyl group having 1 to 6 carbon atoms, an alkynyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a (meth) acryloyl group, a (meth) acryloyloxy group, an amino group, a hydroxyl group, a carboxyl group, Examples thereof include an alkylamino group having 1 to 6 carbon atoms, a nitro group, a phenyl group, a biphenyl group, a naphthyl group, a phenoxy group, a heterocyclic group and the like.

Heterocyclic groups include pyridyl group, pyrimidinyl group, pyridadyl group, pyrazole group, frill group, thienyl group, oxazolyl group, isoxazolyl group, oxadiazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, triazolyl group, pyrrole group and pyrazolyl group. , Or a tetrazolyl group.

Specific examples of the phosphorus compound include tris (2-ethylhexyl) phosphine, trilaurylphosphine, tris (tridecylic) phosphine, bis (decyl) pentaerythritol diphosphite, and bis (tridecylic) pentaerythritol diphosphite. , Triphenylphosphine, Trisnonylphenylphosphine, Butyl acid phosphate, Oleyl acid phosphate, Tetracosyl acid phosphate, 2-Hydroxyethyl methacrylate acid phosphate, Dibutyl phosphate, dimethyl vinyl phosphate, Di-2-ethylhexyl hydrozen phosphate , Georail Hydrozenphosphite and the like.

<Nitrogen-containing compound>
The nitrogen-containing compound is a compound containing nitrogen. The nitrogen-containing compound is not particularly limited, but an amine compound is preferable from the viewpoint of curability during formation of the optical wavelength conversion layer and suppression of deterioration of quantum dots. The amine compound may be any of a primary amine compound, a secondary amine compound, a tertiary amine compound, and a diamine compound.

Specific examples of the amine compound include laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, behenylamine, distearylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylstearylamine, dilaurylmonomethylamine, and trioctylamine. , Oleyl propylene diamine and the like.

<Carboxylic acid>
Carboxylic acid is a compound containing at least one carboxyl group. The carboxylic acid may contain two or more carboxyl groups, or may contain a polymerizable functional group.

The weight average molecular weight of the carboxylic acid is preferably 150 or more and 50,000 or less from the viewpoint of being difficult to volatility, having excellent dispersibility, and being easy to work with. In the present specification, the "weight average molecular weight" is a value obtained by dissolving in a solvent such as tetrahydrofuran (THF) and converting into polystyrene by a conventionally known gel permeation chromatography (GPC) method. The lower limit of the weight average molecular weight of the carboxylic acid is more preferably 300 or more, and the upper limit is more preferably 10,000 or less.

The carboxyl group equivalent (weight average molecular weight / number of carboxyl groups) of the carboxylic acid is preferably 150 or more and 50,000 or less from the viewpoint of facilitating the presence of the carboxylic acid around the quantum dots. The lower limit of the carboxyl group equivalent of the carboxylic acid is more preferably 300 or more, and the upper limit is more preferably 10,000 or less.

Specific examples of the above carboxylic acid include ω-carboxy-polycaprolactone mono (meth) acrylate, monohydroxyethyl phthalate (meth) acrylate, 2-acryloyloxyethyl succinic acid, a reaction product of pentaerythritol and acrylic acid, and succinate anhydride. Acid reactants include 3-butenoic acid, 10-undecenoic acid, n-octanoic acid, stearic acid, adipic acid, dodecanoic acid, 4,4'-dicarboxydiphenyl ether, octadecanoic acid and the like. Among these, ω-carboxy-polycaprolactone mono (meth) acrylate and 2-acryloyl from the viewpoint of fixing the carboxylic acid in the resin constituting the optical wavelength conversion layer and facilitating the presence of the carboxylic acid around the quantum dots. Oxyethyl succinic acid is preferred.

<<< Other laminates >>>
As shown in FIG. 10, the laminate may be a laminate 120 including a lens sheet 80, a light wavelength conversion layer 90, an overcoat layer 121, and a light diffusion layer 43 in this order. .. In the laminated body 120, the lens sheet 80, the light wavelength conversion layer 90, the overcoat layer 121, and the light diffusion layer 43 are integrated, and the light wavelength conversion layer 90 is the light transmissive base material 21 and the overcoat layer 121. Is in contact with. In the present embodiment, the overcoat layer 121 is formed on one side of the light wavelength conversion layer 90, but the overcoat layer may be formed on both sides of the light wavelength conversion layer.

<< Overcoat layer >>
The overcoat layer 121 is a layer made of a resin that covers the surface of the light wavelength conversion layer 90 and is formed by coating. Another layer such as a light diffusion layer may be formed on the overcoat layer 121.

The overcoat layer 121 is provided to prevent the light wavelength conversion layer 90 from being directly exposed to the atmosphere. By providing such an overcoat layer 121 on at least one surface of the light wavelength conversion layer 90, the quantum dots 32 can be further protected from moisture and oxygen, and the light transmissive base material can be provided on the light wavelength conversion layer 90. The thickness of the laminate can be made thinner than that provided on at least one surface of the laminate.

The overcoat layer 121 may have some function other than the function of preventing the light wavelength conversion layer 90 from being directly exposed to the atmosphere. Specifically, the overcoat layer 121 may be, for example, a layer having at least one of functions such as antiblocking property, light diffusing property, antistatic property, and antireflection property. When the overcoat layer 121 is a layer having a function of preventing the light wavelength conversion layer 90 from being directly exposed to the atmosphere and some other function, a material for having some function is added to the overcoat layer 121. You may be.

The film thickness of the overcoat layer 121 is preferably 0.1 μm or more and 100 μm or less from the viewpoint of preventing the light wavelength conversion layer 90 from being directly exposed to the atmosphere and thinning the laminate. The film thickness of the overcoat layer 121 can be measured by the same method as the film thickness of the light wavelength conversion layer 30. The lower limit of the film thickness of the overcoat layer 121 is more preferably 1 μm or more, and the upper limit is more preferably 50 μm or less.

The overcoat layer 121 preferably has a hardness of at least one of a vertical force of 10 μN or more and a horizontal force of −5 μN or less in the scratch test. When the overcoat layers 51 and 52 have such hardness, the overcoat layer 121 becomes a dense film, and therefore has a high ability to prevent the light wavelength conversion layer 90 from exposure to the atmosphere. The vertical force and horizontal force in the scratch test are indented (Cube) from the cross section of the overcoat layer to the inside of the overcoat layer using a nanoindentation device (product name "TI950 TriboIndenter", manufactured by HYSITRON). Corner: Ti037_110410 (12)) is pushed in by 50 nm, the depth is kept constant, and the average vertical force (load) and horizontal force measured when this indenter is moved horizontally at a moving speed of 4 μm / min for 30 seconds. The values were obtained respectively, and the average value of the five average values of the vertical force (5 times average value) and the average value of the five average values of the horizontal force (5 times average value) obtained by repeating this scratch test 5 times. And. The larger the value of the normal force and the smaller the value of the horizontal force, the higher the hardness of the overcoat layer 121. From the viewpoint of enhancing the ability to prevent the light wavelength conversion layer 90 from exposure to the atmosphere, the normal force of the overcoat layer 121 in the scratch test is more preferably 15 μN or more, and the horizontal force is more preferably −8 μN or less.

The overcoat layer 121 is not particularly limited as long as it has the above hardness, and is, for example, a (meth) acrylate compound, an epoxy compound, a combination of isocyanate and a polyol, a metal alkoxide, a silicon-containing resin, a water-soluble polymer, or these. It is possible to form using a composition for an overcoat layer containing a mixture of. Among these, the overcoat layer 121 contains zinc acrylate, a hydrolysis product of alkoxysilane, polyvinyl alcohol, polysilazane, or a mixture thereof from the viewpoint of preventing the light wavelength conversion layer 90 from being directly exposed to the atmosphere. It is preferably formed using a composition for an overcoat layer containing the mixture.

<<< Other laminates >>>
As shown in FIG. 11, the laminate may be a laminate 130 including the lens sheet 80, the light wavelength conversion layer 140, and the light transmissive sheet 100 in this order. In the laminated body 130, the lens sheet 80, the light wavelength conversion layer 140, and the light transmissive sheet 100 are integrated. The lens sheet 80 and the light transmissive sheet 100 are joined to the light wavelength conversion layer 140. Further, an overcoat layer may be formed instead of the light transmissive sheet 100.

The light wavelength conversion layer 140 includes a host matrix 31 and light wavelength conversion particles 141. The light wavelength conversion particles 141 are dispersed in the host matrix 31. The light wavelength conversion particles 141 include the resin particles 142 and the quantum dots 32 included in the resin particles 142. The light wavelength conversion particles 141 may further include a coat layer that covers the surface of the resin particles 142.

In the laminate 130, since the lens sheet 80 and the light transmissive sheet 100 do not have a barrier layer, the resin particles 142 are at least one of the above-mentioned specific element and carboxylic acid from the viewpoint of suppressing deterioration of the quantum dots 32. Is preferably included. Since the specific elements and carboxylic acids contained in the resin particles 142 are the same as described above, the description thereof will be omitted here.

Whether or not the resin particles 142 contain at least one of a specific element and a carboxylic acid can be confirmed as follows. First, since a ligand composed of a sulfur-based compound, a phosphorus-based compound, a nitrogen-based compound, a carboxyl group-containing compound, or the like is bound to the surface of the shell of the quantum dot, a specific element or carboxylic acid from the light wavelength conversion particles is bonded. Even when is detected, the detected specific element or carboxylic acid is not necessarily the specific element or carboxylic acid contained in the resin particles. On the other hand, the ligand of the quantum dot is bound to the surface of the shell, and the size of the coordination site of the ligand is usually within about 1 nm, so that the ligand does not exist at a position separated from the surface of the shell by 3 nm or more. Therefore, a specific element is detected by X-ray photoelectron spectroscopy (XPS) or energy dispersive X-ray analysis (EDS) at an arbitrary position on the surface or inside of the resin particle at a distance of 3 nm or more from the surface of the shell of the quantum dot. If carboxylic acid is detected by microinfrared spectroscopic analysis (IR), it can be determined that the resin particles contain a specific element or carboxylic acid.

When the light wavelength conversion particles include a coat layer, the function of the coat layer is not particularly limited. For example, the coat layer has a function of maintaining the shape of the resin particles, a function of preventing the components in the resin particles from being eluted to the outside of the particles, and a resin. A function to prevent permeation of components in the dispersion liquid or composition into the particles, a function to impart a barrier property to oxygen and water vapor, a function to prevent reflection of excitation light incident on the resin particles, and a resin particle when used as a dispersion liquid or composition. It has at least one of the dispersibility-imparting functions.

The film thickness of the coat layer depends on the function exhibited by the coat layer, but is preferably 10 nm or more and 5000 nm or less, and 20 nm or more and 1000 nm from the viewpoint of ease of production and an appropriate size of the resin particles. The following is more preferable. In particular, when the coat layer exerts a barrier property-imparting function, the film thickness of the coat layer is more preferably 50 nm or more and 1000 nm or less from the viewpoint of preventing cracks in the coat layer while maintaining the barrier property. Further, the relationship between the binder resin of the light wavelength conversion layer in which the coat layer exerts an antireflection function and the refractive index is described later <coat layer <relationship of resin particles or binder resin of light wavelength conversion layer> coat layer> resin particles. When satisfied, the thickness of the coat layer is more preferably 50 nm or more and 300 nm or less from the viewpoint of suppressing reflection on the surface of the light wavelength conversion particles and efficiently incorporating the excitation light into the resin particles. The thickness of the coat layer is determined by photographing the cross section of the light wavelength conversion particle using a scanning electron microscope (SEM), measuring the film thickness of the light wavelength conversion particle 1 at 20 points in the image of the cross section, and measuring the film thickness at 20 points. The average value of the film thickness of.

Although it depends on the function of the coat layer, when the coat layer has a function of retaining the shape of the resin particles, the coat layer can be formed by using, for example, a composition for a coat layer containing a polymerizable compound. .. Since the polymerizable compound is the same as the polymerizable compound described in the column of the host matrix, the description thereof will be omitted here.

In the light wavelength conversion particles 141, the content of a specific element in the light wavelength conversion particles 141 measured by fluorescent X-ray analysis (XRF) is preferably 0.5% by mass or more. When the content of the specific element is 0.5% by mass or more, the deterioration of the quantum dots can be further suppressed. The content of a specific element can be measured by using a fluorescent X-ray analyzer (product name "EDX-800HS", manufactured by Shimadzu Corporation). The lower limit of the content of the specific element in the light wavelength conversion particle 1 measured by fluorescent X-ray analysis (XRF) is more preferably 1% by mass or more, and the upper limit of the content of the specific element is 20% by mass. It is more preferably% or less, and further preferably 10% by mass or less. If the content of a specific element exceeds 20% by mass, sufficient curing may not be performed when the light wavelength conversion particles are formed.

The average particle size of the light wavelength conversion particles 141 is preferably twice or more the average particle size of the quantum dots 32 and 50 μm or less. When the average particle size of the light wavelength conversion particles 141 is twice or more the average particle size of the quantum dots 4, the distance from the quantum dots 32 to the surface of the light wavelength conversion particles 141 can be sufficiently secured, so that moisture and moisture and water can be secured. Deterioration of the quantum dots 32 from oxygen can be further suppressed. Further, when the average particle size of the light wavelength conversion particles 141 is 50 μm or less, the dispersibility is good and it is unlikely to be a defect when processing the light wavelength conversion member. The average particle size of the light wavelength conversion particles 141 is obtained by measuring the particle size of 20 light wavelength conversion particles in the observation of the light wavelength conversion particles with a scanning electron microscope (SEM) and calculating the average value thereof. do. The lower limit of the average particle size of the light wavelength conversion particles 141 is more preferably 10 nm or more, further preferably 20 nm or more, and the average of the light wavelength conversion particles 1 from the viewpoint of further suppressing the deterioration of the quantum dots. The upper limit of the particle size is more preferably 30 μm or less, and further preferably 10 μm or less.

The shape of the light wavelength conversion particles 141 is not particularly limited, and for example, spherical (true spherical, substantially true spherical, elliptical spherical, etc.), polyhedral, rod-shaped (cylindrical, prismatic, etc.), flat plate, flaky, indefinite. The shape and the like can be mentioned. When the shape of the light wavelength conversion particle 141 is not spherical, the particle size of the light wavelength conversion particle 1 can be a true spherical value having the same volume.

It is preferable that each of the light wavelength conversion particles 141 contains one or more quantum dots 4. If the number of quantum dots contained in one optical wavelength conversion particle is less than one, the brightness may decrease. The number of quantum dots contained in one light wavelength conversion particle is 100,000 to 500,000 times the cross section of 20 light wavelength conversion particles at random using a transmission electron microscope or a scanning transmission electron microscope. The number of quantum dots contained in one light wavelength conversion particle is calculated from the obtained cross-sectional image, and the average value of the calculated number of quantum dots is calculated.

Each light wavelength conversion particle 141 contains two or more quantum dots 32, and the average distance between the quantum dots 32 in the quantum dots 32 contained in one light wavelength conversion particle 141 is 1 nm or more. Is preferable. If the average distance between the quantum dots is less than 1 nm, the luminous efficiency may decrease due to the concentration quenching that causes quenching due to the energy transfer between the quantum dots. The average distance between the quantum dots was obtained by randomly photographing the cross sections of 20 light wavelength conversion particles with a transmission electron microscope or a scanning transmission electron microscope at a magnification of 100,000 to 500,000 times. The distance between the quantum dots is calculated from the image of, and the average value of the calculated distances between the quantum dots is calculated. It is more preferable that the upper limit of the average distance between the quantum dots 32 in the quantum dots 32 is 100 nm or less.

The light wavelength conversion particle 141 can be produced, for example, by the following method. First, a light wavelength conversion composition containing quantum dots 32, a polymerizable compound, and the above-mentioned specific compound is dispersed in a poor solvent such as water in a granular manner. Then, in a state where the light wavelength conversion composition is dispersed in a granular state, the light wavelength conversion composition is polymerized by, for example, suspension polymerization or emulsion polymerization. Thereby, the light wavelength conversion particle 141 can be obtained. The "poor solvent" means a solvent in which the light wavelength conversion composition is hardly dissolved, and examples thereof include polar solvents such as water. The light wavelength conversion composition preferably contains a polymerization initiator.

The light wavelength conversion particle 141 can also be produced by the following method. First, the optical wavelength conversion composition containing the quantum dots 32, the polymerizable compound, and the above-mentioned specific compound is irradiated with electron radiation or heated to cure the optical wavelength conversion composition, thereby curing the optical wavelength conversion composition. Get things. Then, this cured product is pulverized by, for example, a bead mill. Thereby, the light wavelength conversion particle 141 can be obtained. The light wavelength conversion composition preferably contains a polymerization initiator.

<<< Other laminates >>>
As shown in FIG. 12, the laminate may be a laminate 150 including a lens sheet 80, an optical wavelength conversion layer 160, and a light transmissive sheet 100 in this order. In the laminated body 150, the lens sheet 80, the light wavelength conversion layer 160, and the light transmissive sheet 100 are integrated. The lens sheet 80 and the light transmissive sheet 100 are joined to the light wavelength conversion layer 160. Further, an overcoat layer may be formed instead of the light transmissive sheet 100.

The light wavelength conversion layer 160 includes a host matrix 31 and light wavelength conversion particles 161. The light wavelength conversion particles 161 are dispersed in 31 in the host matrix. The light wavelength conversion particle 161 is composed of a quantum dot 32 and a light-transmitting barrier material 162 that encloses the quantum dot 32 and protects the quantum dot 32 from moisture and oxygen.

The barrier material 162 wraps the quantum dots 32, has a light transmissive property, and has a barrier property that suppresses the permeation of water and oxygen. By wrapping the quantum dots 32 with the barrier material 162, it is possible to prevent the quantum dots 32 from coming into contact with water or oxygen, so that it is possible to prevent the quantum dots 32 from being deteriorated by water or oxygen. As a result, it is possible to suppress a decrease in the luminous efficiency of the quantum dots 32 without providing a barrier layer. In the present specification, "light transmission" means having a property of transmitting light, and "light transmission" also includes transparency. When the quantum dots are wrapped with a barrier material, it can be said that the barrier material has light transmission if the light emission from the quantum dots emitted from the laminate can be confirmed. The emission of quantum dots can be confirmed using a fluorometer. For "barrier property", a durability test is performed in which the laminated body is left in an environment of 40 ° C. and 90% relative humidity for 300 hours, and the rate of decrease in the emission peak intensity of the laminated body before and after the durability test is within 10%. For example, it can be determined that the barrier material has a barrier property. However, since the light from the light source transmitted through the laminate is not the light generated by the light emission of the laminate, the peak intensity of the light from the light source transmitted through the laminate is not included in the emission peak intensity of the laminate. do. Further, when there are a plurality of emission peaks of light emitted from the laminated body, "the reduction rate of the emission peak intensity is within 10%" means that the reduction rate of the intensity at each emission peak is within 10%. Means that. Assuming that the rate of decrease in the emission peak of the laminate before and after the durability test is A, the emission peak intensity of the laminate before the durability test is B, and the emission peak intensity of the laminate after the durability test is C, before and after the durability test. The reduction rate (A) of the emission peak of the laminated body in the above is calculated by the following formula.
A = (BC) / B × 100

The material for forming the barrier material 162 is not particularly limited as long as it has light transmittance and barrier properties, and examples thereof include inorganic oxides. Specifically, examples of the inorganic oxide include silicon oxide (SiO _x ) such as silica, aluminum oxide (Al _{n Om} ) such as alumina, titanium oxide (TiO ₂ ), yttrium oxide, and boron oxide (B). ₂ O ₃ ), calcium oxide (CaO), silicon oxide nitride (SiO _x N _{yC z} ), etc. Among these, silica or alumina such as glass is selected from the viewpoint of low permeability of oxygen and water vapor. preferable. These materials may be used alone or in combination of two or more. It is also possible to use inorganic oxides other than oxide semiconductors.

The light wavelength conversion particle 161 preferably contains 1 or more and 50 or less quantum dots 32, and each contains 1 or more and 40 or less quantum dots or 1 or more and 35 or less quantum dots 32. It is more preferable to be. If the number of quantum dots contained in one light wavelength conversion particle is less than one, the brightness may be lowered, and if the number of quantum dots contained in one light wavelength conversion particle exceeds 50, the quantum is quantum. Luminous efficiency may decrease due to density extinction that causes quenching due to energy transfer between dots. The number of quantum dots contained in one light wavelength conversion particle is obtained by randomly photographing the cross section of 20 light wavelength conversion particles using a scanning transmission electron microscope (STEM) at a magnification of 100,000 to 500,000 times. Then, it can be obtained by calculating the number of quantum dots contained in one light wavelength conversion particle from the obtained image of the cross section and calculating the average value of the calculated number of quantum dots.

Each light wavelength conversion particle 161 contains two or more quantum dots 32, and the average distance between the quantum dots 32 in the quantum dots 32 included in one light wavelength conversion particle 162 is 1 nm or more. Is preferable. If the average distance between the quantum dots is less than 1 nm, energy transfer between the quantum dots is likely to occur, and the luminous efficiency may decrease. For the average distance between quantum dots, a scanning transmission electron microscope (STEM) was used to randomly photograph the cross sections of 20 optical wavelength-converted particles at a magnification of 100,000 to 500,000 times, and an image of the cross section obtained. It can be obtained by calculating the distance between the quantum dots from the above and calculating the average value of the calculated distances between the quantum dots. It is more preferable that the upper limit of the average distance between the quantum dots 32 in the optical wavelength conversion particles 125 is 100 nm or less.

The average particle size of the light wavelength conversion particles 161 is preferably 10 nm or more and 500 nm or less. If the average particle size of the optical wavelength conversion particles is less than 10 nm, it is not possible to sufficiently impart barrier properties to the quantum dots, and the quantum dots may undergo oxidative deterioration or the like. Although the reason is not clear, the barrier property of the barrier material may become unstable. The average particle size of the light wavelength conversion particles shall be obtained by measuring the particle size of 20 light wavelength conversion particles in the observation of the light wavelength conversion particles with a scanning electron microscope (SEM) and calculating the average value. .. The lower limit of the average particle size of the light wavelength conversion particles 161 is preferably 20 nm or more, and the upper limit of the average particle size of the light wavelength conversion particles 161 is preferably 200 nm or less, more preferably 100 nm or less.

When the quantum dot 32 contains Cd, the thickness of the barrier material 162 (distance from the surface of the quantum dot to the outer surface of the barrier material) must be 2 nm or more in order to prevent the elution of Cd contained in the quantum dot 32. Is preferable, and 4 nm or more is more preferable. When the average particle size of the barrier material 162 is about 50 nm, the thickness of the barrier material 162 can be 10 nm or more. Further, when the average particle size of the light wavelength conversion particles 161 is about 100 nm, the thickness of the barrier material 161 can be 20 nm or more. The thickness of the barrier material can be easily measured as an outer portion that does not contain quantum dots in transmission electron microscope observation. If the thickness varies depending on the position of the peripheral edge of the barrier material, the average thickness of the entire peripheral edge of the barrier material is used as the thickness of the barrier material.

The light wavelength conversion particles 161 can be produced, for example, by using the sol-gel method (see Patent No. 5682069). Specifically, first, quantum dots are prepared, and an appropriate amount of a metal alkoxide (1) such as tetraethoxysilane is added to the quantum dots and hydrolyzed appropriately to make the surface of the quantum dots metal alkoxide. Replace with the hydrolyzate of (1). Such a liquid is referred to as an organic solvent A. On the other hand, an aqueous solution B is obtained by dispersing a metal alkoxide (2) such as 3-mercaptopropyltrimethoxysilane in the aqueous solution and partially hydrolyzing it. Here, the metal alkoxide (2) is selected to have a slower hydrolysis rate than the metal alkoxide (1). Then, by mixing the organic solution A and the aqueous solution B, a layer of the metal alkoxide (2) is further formed on the surface of the quantum dots covered with the metal alkoxide (1). Quantum dots that come into contact with water become hydrophilic because the metal alkoxide on the surface is hydrolyzed, and move to the aqueous phase. At this time, the quantum dots form an aggregate. Since the metal alkoxide (2) near the surface is hydrolyzed slower than the metal alkoxide (1), the alkoxide on the surface of the quantum dots is dehydrated and condensed at once when it moves to the aqueous phase, forming a large mass. prevent. An inorganic oxide layer such as a silica glass layer is further deposited on the aggregate in the aqueous phase. This can be done by hydrolyzing a small amount of metal alkoxide (3) in the alkaline region with a large amount of water and alcohol and depositing it on an aggregate of core quantum dots by the usual Stöber process. Thereby, the light wavelength conversion particle 161 including the quantum dot 32 and the barrier material 162 can be obtained.

In the laminates 70, 110, 120, 130, and 150, deterioration of the quantum dots 32 can be suppressed by at least one of the above-mentioned specific element and carboxylic acid, so that the entire laminate is at 40 ° C. and 90% relative humidity. water vapor transmission rate (WVTR: Water vapor transmission rate) may be a 0.1g ^/ (m 2 · 24h) or more. The water vapor permeability is a numerical value obtained by a method based on JIS K7129: 2008. The water vapor transmission rate can be measured using a water vapor transmission rate measuring device (product name "PERMATRAN-W3 / 31", manufactured by MOCON). Since the laminates 10, 50, and 60 include the barrier layers 23 and 42, the laminates 70, 110, 120, 130, and 150 have higher water vapor permeability than the laminates 10, 50, and 60. That is, the laminated bodies 70, 110, 120, 130, 150 are more easily permeable to water than the laminated bodies 10, 50, 60.

In the laminates 70, 110, 120, 130, and 150, deterioration of the quantum dots 32 can be suppressed by at least one of the above-mentioned specific element and carboxylic acid, so that the entire laminate is at 23 ° C. and 90% relative humidity. oxygen permeability (OTR: oxygen transmission rate) may be a ^{0.1cm 3 / (m 2 · 24h} · atm) or more. The laminate 70, 110, 120, 130, 150 may satisfy the water vapor permeability and the oxygen permeability at the same time. The oxygen permeability is a numerical value obtained by a method based on JIS K7126: 2006. The oxygen permeability can be measured using an oxygen gas permeability measuring device (product name "OX-TRAN 2/21", manufactured by MOCON). Since the laminates 10, 50, and 60 include the barrier layers 23 and 42, the laminates 70, 110, 120, 130, and 150 have higher oxygen permeability than the laminates 10, 50, and 60. That is, the laminated bodies 70, 110, 120, 130, 150 are more easily permeated with oxygen as well as water as compared with the laminated bodies 10, 50, 60.

40 ° C. in the laminate 70,110,120,130,150, water vapor transmission rate of 90% relative humidity may be made with 1g ^/ (m 2 · 24h) or more, the laminate 70,110,120, 23 ° C. in 130, 150, an oxygen permeability at 90% relative humidity may be a ^{1cm 3 / (m 2 · 24h} · atm) or more.

<<< Manufacturing method of laminated body >>>
The laminate 10 can be produced, for example, as follows. 13 and 14 are schematic manufacturing process diagrams of the laminate according to the present embodiment. First, as shown in FIG. 13A, the barrier layer 23 is formed on the second surface 21B of the light transmissive base material 21 by a vapor deposition method or the like to form the light transmissive base material 21 with the barrier layer 23. .. Similarly, the barrier layer 42 is formed on the first surface 41A of the light transmissive base material 41 by a vapor deposition method or the like to form the light transmissive base material 41 with the barrier layer 42. The barrier layer 23 may be formed on the first surface 21A of the light-transmitting base material 21, and similarly, the barrier layer 42 may be formed on the second surface 41B of the light-transmitting base material 41. ..

Next, as shown in FIG. 13B, a lens sheet in which the lens layer 22 is formed on the first surface 21A of the light transmissive base material 21 and the light transmissive base material 21 and the lens layer 22 are integrated. 20 is formed. The lens sheet 20 can be manufactured, for example, as follows. That is, first, the composition for a lens layer containing a photopolymerizable compound is uniformly applied onto the light-transmitting base material 21 to form a coating film of the composition for the lens layer, and a laminate for a lens sheet is formed. .. Then, the lens sheet laminate is fed into the rotating molding mold having a recess having an inverse shape with respect to the shape of the unit lens 24 so that the coating film of the lens layer composition is on the molding mold side, and molding is performed. The shape of the unit lens 24 is formed on the coating film of the lens layer composition depending on the mold, and the coating film of the lens layer composition is irradiated with light such as ultraviolet rays via the light transmissive base material 21 with the barrier layer 23. Then, the coating film of the lens layer composition is cured. Then, when the cured coating film of the lens layer composition is peeled off from the molding mold that rotates together with the light transmissive base material 21 with the barrier layer 23, the lens layer is formed on the first surface 21A of the light transmissive base material 21. A lens sheet 20 on which 22 is formed can be obtained. The photopolymerizable compound contained in the lens layer composition is not particularly limited, but is widely used as a material for an optical sheet incorporated in a display device, and has excellent mechanical properties, optical properties, stability, processability, and the like. Examples of photopolymerizable compounds which have the above and are available at low cost include epoxy acrylates and urethane acrylates. When the barrier layer 23 is formed on the first surface 21A of the light transmissive base material 21, the barrier layer 23 is formed before the lens layer 22 is formed on the first surface 21A of the light transmissive base material 21. Is formed on the first surface 21A of the light transmissive base material 21, and the lens layer 22 is formed on the barrier layer 23.

On the other hand, a composition for a light diffusing layer containing surface unevenness forming particles 44 and a curable binder resin precursor is applied to the second surface 41B of the light transmissive base material 41, respectively, and dried to be used for the light diffusing layer. Form a coating of the composition. Then, the coating film is cured by light irradiation or the like. As a result, as shown in FIG. 13C, a light diffusion layer 43 is formed on the second surface 41B of the light transmissive base material 41, and a barrier layer is formed on the first surface 41A of the light transmissive base material 41. A light transmissive sheet 40 having 42 and having a light diffusing layer 43 on the second surface 41B is formed.

Next, as shown in FIG. 14 (A), a light wavelength including quantum dots 32 and a curable host matrix precursor 34 such as a curable binder resin precursor on the surface of the barrier layer 42 in the light transmissive sheet 40. The conversion layer composition is applied and dried to form a coating film 35 of the light wavelength conversion layer composition.

Then, as shown in FIG. 14B, the coating film 35 of the composition for the light wavelength conversion layer is brought into contact with the coating film 35 of the composition for the light wavelength conversion layer so that the surface of the barrier layer 23 of the lens sheet 20 is in contact with the coating film 35 of the composition for the light wavelength conversion layer. The lens sheet 20 is arranged on the lens sheet 20. As a result, the coating film 35 of the composition for the light wavelength conversion layer is arranged on the second surface 21B side of the light transmissive base material 21. Specifically, the coating film 35 of the composition for the light wavelength conversion layer is arranged between the second surface 21B of the light transmissive base material 21 and the first surface 41A of the light transmissive base material 41. ..

Then, as shown in FIG. 14C, the coating film 35 of the composition for the light wavelength conversion layer is irradiated with light or heated through the light transmissive sheet 40 to obtain a curable host matrix precursor. The body 34 is cured to form the light wavelength conversion layer 30, and the lens sheet 20, the light wavelength conversion layer 30, and the light transmissive sheet 40 are integrated. As a result, the laminated body 10 shown in FIGS. 1 and 2 is obtained.

One of the light-transmitting base materials is obtained by sandwiching the composition for the light wavelength conversion layer between the light-transmitting base materials and curing the composition for the light wavelength conversion layer, that is, after forming the light wavelength conversion layer. It is also possible to form a lens layer on the surface of the light. However, in this case, when the composition for the lens layer is cured, the composition for the lens layer is irradiated with light such as ultraviolet rays not only through the light-transmitting base material but also through the light wavelength conversion layer. , Blue light is absorbed by the quantum dots contained in the light wavelength conversion layer, and the light conversion efficiency is inferior.

In the laminated bodies 50 and 60, similarly to the laminated body 10, the light wavelength conversion layer is used between the second surface 21B of the light transmissive base material 21 and the first surface 41A of the light transmissive base material 41. By arranging the coating film 35 of the composition, the laminates 50 and 60 in which the lens sheet 20, the light wavelength conversion layer 30, and the light transmissive sheet 40 are integrated can be produced. Further, in the laminated bodies 70, 130 and 140, similarly to the laminated body 10, the above is described between the second surface 21B of the light transmitting base material 21 and the first surface 41A of the light transmitting base material 41. By arranging a coating film of a composition for a light wavelength conversion layer containing a specific compound or light wavelength conversion particles 141, 161, the lens sheet 80, the light wavelength conversion layers 90, 140, 160, and the light transmissive sheet 100 are arranged. The laminated bodies 70, 130, and 140 in which the above are integrated can be produced. Further, in the laminates 110 and 120, by arranging the coating film of the composition for the light wavelength conversion layer containing the specific compound on the second surface 21B side of the light transmissive base material 21 in the lens sheet 80, the coating film is arranged. Laminates 110 and 120 in which the lens sheet 80 and the light wavelength conversion layer 90 are integrated can be manufactured.

According to the present embodiment, the lens layer 22 is formed on the first surface 21A of the light transmissive base material 21, and the light wavelength conversion layers 30, 90, 140, 160 are formed on the second surface 21B side. There is. That is, the light-transmitting base material of the lens sheet and the light-transmitting base material of the light wavelength conversion sheet are shared. Therefore, one light-transmitting substrate can be reduced as compared with the case where the lens sheet and the light wavelength change sheet are separately produced. Further, although an air layer exists between the conventional lens sheet and the wavelength conversion sheet, in the present embodiment, since the lens sheet and the light wavelength conversion layer are integrated, the lens sheet and the light wavelength conversion are performed. There is no air layer between the layers. Therefore, it is possible to reduce the thickness.

In addition, when the lens sheet and the light wavelength conversion sheet are usually manufactured separately, a sticking prevention layer for preventing the lens sheet and the light diffusing plate from sticking to the front surface and the back surface of the light wavelength conversion layer is usually obtained. Need to be formed. In the present embodiment, the lens layer 22 is formed on the first surface 21A of the light transmissive base material 21, and the light wavelength conversion layers 30, 90, 140, 160 are formed on the second surface 21B side. Therefore, it is not necessary to provide a sticking prevention layer between the lens layer 22 and the light wavelength conversion layers 30, 90, 140, 160. As a result, the number of steps can be reduced.

According to the present embodiment, since the lens sheet 20 and the light wavelength conversion layers 30, 90, 140, and 160 are integrated, light is compared with the case where the lens sheet and the light wavelength conversion sheet are arranged separately and independently. Utilization efficiency can be improved. That is, when the lens sheet and the light wavelength conversion sheet are arranged separately and independently, since there is an air interface between the lens sheet and the light wavelength conversion sheet, light may be reflected by this air interface. .. On the other hand, in the present embodiment, since the lens sheet 20 and the light wavelength conversion layers 30, 90, 140, 160 are integrated, the lens sheet 20 and the light wavelength conversion layers 30, 90, 140, 160 are combined. There is no air interface between them. As a result, it is possible to suppress the reflection of light, so that the light utilization efficiency can be improved and the brightness can be improved.

When emitting light, the phenomenon that the tint of the light from the light source (primary light) appears stronger in the peripheral part of the light emitting surface than in the central part of the light emitting surface of the backlight device is the light from the light source transmitted through the light wavelength conversion sheet. It is considered that one of the causes is that the light leaks from the peripheral edge of the light wavelength conversion sheet. That is, in a backlight device, since the lens sheet and the light wavelength conversion sheet are usually arranged separately and independently, an air layer exists between the lens sheet and the light wavelength conversion sheet. Therefore, the light transmitted from the light wavelength conversion sheet and emitted from the peripheral edge of the light wavelength conversion sheet leaks through the air layer between the lens sheet and the light wavelength conversion sheet, and the above phenomenon occurs. Is considered to occur. In particular, in an edge light type backlight device, the light emitted from the light source travels in the horizontal direction along the light guide plate, so that the light from the light source transmitted through the light wavelength conversion sheet is the peripheral portion of the light wavelength conversion sheet. The above phenomenon is likely to occur. On the other hand, in the present embodiment, since the lens sheet 20 and the light wavelength conversion layers 30, 90, 140, 160 are integrated, the light wavelength conversion layer 30, 90, 140, 160 is emitted from the peripheral edge portion. The light from the light source is incident on the lens sheet 20 without passing through the air layer. Therefore, it is possible to reduce the leakage of light from the light source emitted from the peripheral portions of the optical wavelength conversion layers 30, 90, 140, 160, and thus the laminated body 10, 50, 60, 70, 110, 120, 130, The color of the light emitted from the peripheral portions 10C, 50A, 60A, 70A, 110A, 120A, 130A, 150A of the 150 is the central portion 10D, 50B of the laminated body 10, 50, 60, 70, 110, 120, 130, 150. , 60B, 70B, 110B, 120B, 130B, 150B can be suppressed from being conspicuous as compared with the tint of light emitted.

In a laminate having a light wavelength conversion layer containing quantum dots and light scattering particles, the present inventors have determined that the average particle size and refractive index of the light scattering particles contained in the light wavelength conversion layer are light. By highly controlling the film thickness of the wavelength conversion layer and the refractive index of the host matrix of the light wavelength conversion layer so as to satisfy a specific relationship, the light of the incident light to the optical wavelength conversion layer by the quantum dots It has been found that the wavelength conversion efficiency can be suitably improved. In the present embodiment, the light wavelength conversion layer contains light scattering particles, the difference in refractive index between the light scattering particles and the host matrix is 0.10 or more, and the average particle diameter of the light scattering particles is light wavelength conversion. When the film thickness of the layer is 100%, it is 8% or less, so that the light wavelength conversion efficiency by the quantum dots can be suitably improved. Note that Patent No. 5138145 discloses a phosphor laminated structure having a phosphor layer made of a phosphor, a diffusing material, and a binder resin, but in this document, color unevenness in the case of laminating is eliminated. Therefore, the brightness and efficiency are improved, and control of the refractive index of the diffusing material or the like has been studied, but the average particle size of the diffusing material has not been studied at all. That is, in a laminated body having a conventional structure in which quantum dots and light-scattering particles are contained in the same layer, only the refractive index of the light-scattering particles can be controlled independently, or the method of dispersing the light-scattering particles can be used. Most of them are of interest, and it is considered to control the particle size of light-scattering particles to a high degree in relation to the thickness of the light wavelength conversion layer and to control the refractive index of light-scattering particles. It never happened. Here, by increasing the concentration of quantum dots in the optical wavelength conversion layer, the light conversion efficiency of the incident light to the optical wavelength conversion layer can be increased, but the increase in the amount of expensive quantum dots used increases the manufacturing cost. Invite. On the other hand, in the laminated body 10, 50, 60, 70, 110, 120, 130, 150 in the present embodiment, the light wavelength conversion layer 30 is obtained only by adjusting the average particle diameter and the refractive index of the light scattering particles 33. Since the light conversion efficiency of the incident light to 90, 140, and 160 can be increased, the amount (concentration) of the quantum dots 32 used can be reduced, and the cost can be reduced.

According to the present embodiment, since the light wavelength conversion layers 30, 90, 140, and 160 contain the light scattering particles 33, the green emission can be enhanced preferentially over the red emission. The reason for this is not clear, but light-scattering particles may impede energy transfer from the first quantum dot that converts blue light to green light to the second quantum dot that converts blue light to red light. It is considered that this is because the green light emission, which was originally deactivated by the above energy transfer, reaches the light emission process without being deactivated, and as a result, the green light emission increases.

The laminates 10, 50, 60, 70, 110, 120, 130, 150 can be used, for example, by incorporating them into a backlight device and a display device. 15 is a schematic configuration diagram of a display device including a backlight device according to the present embodiment, FIG. 16 is a perspective view of an upper lens sheet shown in FIG. 15, and FIG. 17 is a laminated body according to the present embodiment. 18 is a schematic plan view of the fixed structure of the above, FIG. 18 is a cross-sectional view of the vicinity of the fixed member of the fixed structure shown in FIG. 17, and FIG. 19 is a schematic configuration diagram of another backlight device according to the present embodiment. be.

<<< Display device >>
The display device 170 shown in FIG. 15 includes a backlight device 180 and a display panel 200 arranged on the light emitting side of the backlight device 180. The display device 170 has a display surface 170A for displaying an image. In the display device 170 shown in FIG. 15, the surface of the display panel 200 is the display surface 170A.

The backlight device 180 illuminates the display panel 200 from the back side in a plane shape. The display panel 200 functions as a shutter that controls the transmission or blocking of light from the backlight device 180 for each pixel, and is configured to display an image on the display surface 170A.

<< Display panel >>
The display panel 200 shown in FIG. 15 is a liquid crystal display panel, and is between the polarizing plate 201 arranged on the incoming light side, the polarizing plate 202 arranged on the light emitting side, and the polarizing plate 201 and the polarizing plate 202. It includes an arranged liquid crystal cell 203. The polarizing plates 201 and 202 decompose the incident light into two orthogonal linearly polarized light components (S-polarized light and P-polarized light) and vibrate in one direction (direction parallel to the transmission axis) (for example, P). It has a function of transmitting polarized light) and absorbing a linearly polarized light component (for example, S-polarized light) that vibrates in the other direction (direction parallel to the absorption axis) orthogonal to the one direction.

The liquid crystal cell 203 is configured so that a voltage can be applied to each region forming one pixel. Then, the orientation direction of the liquid crystal molecules in the liquid crystal cell 203 changes depending on the presence or absence of voltage application. As an example, the linearly polarized light component in a specific direction transmitted through the polarizing plate 201 arranged on the incoming light side rotates its polarization direction by 90 ° when passing through the liquid crystal cell 203 to which a voltage is applied, while rotating the polarization direction by 90 °. When passing through the liquid crystal cell 203 to which no voltage is applied, the polarization direction is maintained. In this case, depending on whether or not a voltage is applied to the liquid crystal cell 203, the linearly polarized light component that vibrates in a specific direction transmitted through the polarizing plate 201 can be transmitted through the polarizing plate 202, or absorbed by the polarizing plate 202 and blocked. can. In this way, the display panel 200 is configured so that the transmission or blocking of light from the backlight device 180 can be controlled for each pixel. The details of the liquid crystal display panel are described in various publicly known documents (for example, "Flat Panel Display Dictionary (supervised by Tatsuo Uchida and Hiraki Uchiike)" published by Kogyo Chosakai in 2001). The detailed description of is omitted.

<< Backlight device >>
The backlight device 180 shown in FIG. 15 is configured as an edge light type backlight device, and emits light from the light source 181 and the optical plate 182 that functions as a light guide plate arranged on the side of the light source 181 and the optical plate 182. The laminated body 10 arranged on the side, the lens sheet 183 arranged on the light emitting side of the laminated body 10, the reflective polarizing separation sheet 84 arranged on the light emitting side of the lens sheet 183, and the light emitting side of the optical plate 182 are It is provided with a reflective sheet 185 arranged on the opposite side. The backlight device 180 includes an optical plate 182, a lens sheet 183, a reflective polarizing separation sheet 184, and a reflective sheet 185, but these sheets and the like may not be provided. In the present specification, the “light emitting side” means the side of each member where light emitted in the direction of emission from the backlight device is emitted.

The backlight setting 180 has a light emitting surface 180A that emits light in a planar manner. In the backlight device 180 shown in FIG. 15, the light emitting surface of the reflective polarizing separation sheet 184 is the light emitting surface 180A of the backlight device 180.

In the backlight device 180, the laminated body 10 is arranged so that, for example, the light diffusion layer 43 is on the optical plate 182 side and the lens sheet 20 is on the lens sheet 183 side. In this case, the uneven surface 43A of the light diffusion layer 43 is the light incoming surface, and the lens surface 20A of the lens sheet 20 is the light emitting surface.

The laminate 10 is preferably fixed to the optical plate 182. For example, as shown in FIGS. 17 and 18, the frame body 191 that surrounds the periphery of the laminate 10 and the periphery of the optical plate 182, and the light source 181, the optical plate 182, and the laminate 10 are fixed to the frame body 191. The laminated body 10 may be fixed to the optical plate 182 by using the fixing member 192. In this case, the laminated body 10 is laminated on the optical plate 182, and the light source 181 is arranged between the optical plate 182 and the frame body 191.

The fixing member 192 is formed in a linear shape as shown in FIG. 17, and is arranged along one side of the frame body 191. As shown in FIG. 18, the fixing member 192 is composed of, for example, a linear double-sided tape 193 and a linear black tape 194. The double-sided tape 193 is mainly for fixing the optical plate 182 to the black tape 194, and is arranged between the black tape 194 and the edge portion 182D on one side of the optical plate 182, and is arranged between the black tape 194 and the optical plate 194. It is attached to the edge of 182. The size of the laminated body 10 is smaller than the size of the optical plate 182 so that the edge portion 182D of the optical plate 182 is not covered by the laminated body 10. Further, the black tape 194 is for fixing the light source 181, the optical plate 182, and the laminated body 10 to the frame body 191. One side of the frame body 191 and the upper surface of the light source 181, the double-sided tape 193, and the laminated body 194. It is attached to the edge 10E on one side of the body 10.

<Light source>
The light source 181 can be configured in various forms such as a fluorescent lamp such as a linear cold cathode fluorescent lamp, a point-shaped light emitting diode (LED), and an incandescent lamp. In the present embodiment, the light source 181 is provided by a large number of point-shaped light emitters, specifically, a large number of light emitting diodes (LEDs) arranged side by side on the light receiving surface 182B side of the optical plate 182, which will be described later. ,It is configured.

Since the laminated body 10 is arranged in the backlight device 180, the light source 181 can use only a light emitting body that emits light in a single wavelength range. For example, as the light source, only a blue light emitting diode that emits blue light having high color purity can be used.

<Optical plate>
The optical plate 182 as the light guide plate has a quadrangular shape in a plan view. The optical plate 182 extends between the light emitting surface 182A formed by one main surface on the display panel 200 side, the back surface 182B composed of the other main surface facing the light emitting surface 182A, and the light emitting surface 182A and the back surface 182B. It has sides and. The side surface of the side surface on the light source 181 side is an incoming light receiving surface 182C that receives light from the light source. The light incident on the optical plate 182 from the light entry surface 182C is guided in the optical plate in the direction connecting the light entry surface 182C and the opposite surface facing the light entry surface 182C (light guide direction), and the light exit surface. Emitted from 182A.

As a material constituting the optical plate 182, a material that is widely used as a material for an optical sheet incorporated in a display device, has excellent mechanical properties, optical properties, stability, workability, etc., and is inexpensively available. For example, a transparent resin containing one or more of acrylic resin, polystyrene, polycarbonate, polyethylene terephthalate, polyacrylonitrile, etc. as a main component, and epoxy acrylate or urethane acrylate-based reactive resin (ionizing radiation curable resin, etc.) are preferably used. obtain. If necessary, a light diffusing material having a function of diffusing light can be added to the optical plate 182. As the light diffusing material, for example, particles made of a transparent substance such as silica (silicon dioxide), alumina (aluminum oxide), acrylic resin, polycarbonate resin, and silicone resin having an average particle size of 0.5 μm or more and 100 μm or less can be used. can.

<Lens sheet>
As shown in FIG. 16, the lens sheet 183 has substantially the same structure as the lens sheet 20, but does not have a barrier layer. That is, the lens sheet 183 includes a light-transmitting base material 186 and a lens layer 187 provided on one surface of the light-transmitting base material 186 and having a plurality of unit lenses 188, and the lens layer 187 is provided. In addition to the unit lens 188, a sheet-shaped main body 189 is provided. The light transmissive base material 186, the lens layer 187, the unit lens 188, and the main body portion 189 are the same as the light transmissive base material 21, the lens layer 22, the unit lens 24, and the main body portion 25 in the lens sheet 20, so here. The description shall be omitted.

As can be understood from FIG. 15, the arrangement direction of the unit lens 24 of the lens sheet 20 and the arrangement direction of the unit lens 188 of the lens sheet 183 intersect, and more specifically, are orthogonal to each other.

<Reflective polarization separation sheet>
The reflective polarization separation sheet 184 transmits only the first linearly polarized light component (for example, P-polarized light) among the light emitted from the lens sheet 183, and is a second straight line orthogonal to the first linearly polarized light component. It has a function of reflecting polarized light components (for example, S-polarized light) without absorbing them. The second linearly polarized light component reflected by the reflective polarization separation sheet 84 is reflected again, and the polarized light is eliminated (a state in which both the first linearly polarized light component and the second linearly polarized light component are included). It is incident on the reflective polarizing separation sheet 84 again. Therefore, the reflective polarization separation sheet 184 transmits the first linearly polarized light component of the light incident again, and the second linearly polarized light component orthogonal to the first linearly polarized light component is reflected again. Hereinafter, by repeating the same process, about 70 to 80% of the light initially emitted from the lens sheet 183 is emitted as the light source light as the first linearly polarized light component. Therefore, by matching the polarization direction of the first linearly polarized light component (transmission axis component) of the reflective polarization separation sheet 184 with the transmission axis direction of the polarizing plate 201 of the display panel 200, the light emitted from the backlight device 180 Can all be used for image formation on the display panel 200. Therefore, even if the light energy input from the light source 81 is the same, it is possible to form an image with higher brightness than when the reflective polarizing separation sheet 184 is not arranged, and the energy utilization efficiency of the light source 181 is also high. improves. In particular, the light reflected by the reflective polarizing separation sheet 184 can be wavelength-converted by the optical wavelength conversion layer of the laminated body 10. Therefore, by arranging the reflective polarizing separation sheet 184, the light wavelength conversion efficiency of the laminated body 10 can be further increased. Therefore, further improvement in light utilization efficiency can be expected.

As the reflective polarizing separation sheet 184, "DBEF" (registered trademark) available from 3M can be used. In addition to "DBEF", a high-intensity polarizing sheet "WRPS" available from Shinwha Intertek, a wire grid polarizer, or the like can be used as the reflective polarizing separation sheet 84.

<Reflective sheet>
The reflective sheet 185 has a function of reflecting the light leaked from the back surface 182B of the optical plate 182 and causing it to enter the optical plate 182 again. The reflective sheet 182 can be composed of a white scattered reflective sheet, a sheet made of a material having a high reflectance such as metal, a sheet containing a thin film made of a material having a high reflectance (for example, a metal thin film) as a surface layer, and the like. .. The reflection on the reflection sheet 182 may be regular reflection (specular reflection) or diffuse reflection. When the reflection on the reflection sheet 182 is diffuse reflection, the diffuse reflection may be isotropic diffuse reflection or anisotropic diffuse reflection.

<< Other backlight devices >>
The backlight device incorporating the laminate may be a direct type backlight device as shown in FIG. The backlight device 210 shown in FIG. 19 includes a light source 181 and an optical plate 211 that receives the light of the light source 181 and functions as a light diffusing plate, and a laminate 10 arranged on the light emitting side of the optical plate 211. A lens sheet 183 arranged on the light source side of 10 and a reflection type polarization separation sheet 184 arranged on the light source side of the lens sheet 184 are provided. In the present embodiment, the light source 181 is arranged not on the side of the optical plate 211 but directly below the optical plate 211. In FIG. 19, the members having the same reference numerals as those in FIG. 15 are the same as the members shown in FIG. 15, and thus the description thereof will be omitted. The backlight device 210 is not provided with an optical plate 182.

<Optical plate>
The optical plate 211 as a light diffusing plate has a quadrangular shape in a plan view. The optical plate 211 includes an light emitting surface 211A formed by one main surface on the display panel 200 side and an incoming light surface 211B formed by the other main surface facing the light emitting surface 211A and receiving light from the light source 181. Have. The light incident on the optical plate 211 from the light incoming surface 211B is diffused in the optical plate 211 and emitted from the light emitting surface 211A.

The optical plate 211 is not particularly limited as long as the light from the light source 181 can be diffused, and examples thereof include a plate in which surface unevenness-forming particles are dispersed in a transparent material. The transparent material is not particularly limited, and examples thereof include transparent resin and inorganic glass. As the transparent resin, a transparent thermoplastic resin is preferably used because it is easy to mold. The transparent thermoplastic resin is not particularly limited, but for example, a polystyrene resin, a styrene-methyl methacrylate copolymer resin, a styrene-methacrylate copolymer resin, and a styrene-maleic anhydride copolymer resin. , Methacrylic resin, acrylic resin, polycarbonate resin, ABS resin (acrylonitrile-butadiene-styrene copolymer resin), AS resin (acrylonitrile-styrene copolymer resin), polyolefin resin (polyethylene resin, polypropylene resin, etc.) and the like. .. One of these may be used, or two or more of these may be mixed and used.

Since the surface unevenness-forming particles included in the optical plate 211 are the same as the surface unevenness-forming particles 44 in the light diffusion layer 43, the description thereof will be omitted here.

[Second Embodiment]
Hereinafter, the laminate, the backlight device, and the display device according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 20 is a perspective view of the laminated body according to the present embodiment, and FIG. 21 is a cross-sectional view of the laminated body of FIG. 20 along the line II-II. In the present embodiment, the same members as those described in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

<<< Laminated body >>
The laminate 220 shown in FIGS. 20 and 21 has a light transmitting base material 221 containing light wavelength conversion particles 225, a lens layer 222 in close contact with the first surface 221A of the light transmitting base material 221 and light transmitting. It is provided with a light diffusion layer 223 provided on the second surface 221B side opposite to the first surface 221A of the sex substrate 221. The laminate 220 may include a light transmitting base material 221 including quantum dots 32 and a lens layer 222, and may not include a light diffusing layer 223. On the contrary, a barrier layer may be provided on the first surface 221A of the light transmissive base material 221. In the laminated body 220, the lens layer 222, the light transmitting base material 221 and the light diffusing layer 223 are integrated.

<< Light-transmitting substrate >>
Since the light transmissive base material 221 is the same as the light transmissive base material 21 except that the light wavelength conversion particles 161 are contained therein, the description of the material and the like will be omitted. Further, since the light wavelength conversion particles 161 contained in the light transmissive base material 221 are the same as the light wavelength conversion particles 161 contained in the light wavelength conversion layer 160, the description thereof will be omitted.

<< Lens layer >>
As shown in FIGS. 20 and 21, the lens layer 222 has the same configuration as the lens layer 22. That is, the lens layer 222 includes a plurality of unit lenses 226 and a sheet-shaped main body portion 227. Since the unit lens 226 and the main body 227 are the same as the unit lens 24 and the main body 25, the description thereof will be omitted here.

<< Light diffusion layer >>
Like the light diffusion layer 43, the light diffusion layer 223 contains surface unevenness-forming particles 44 and a binder resin 45, and other configurations are the same as those of the light diffusion layer 43. Therefore, description thereof will be omitted here. And.

In the laminated body 220, the light wavelength conversion particles 151 may be used instead of the light wavelength conversion particles 161 or an overcoat layer may be formed on the second surface side of the light transmissive base material 221. ..

The laminate 220 can be incorporated into the same backlighting and display devices as the backlighting devices 180, 210 and display 170 shown in FIGS. 15 and 19.

According to the present embodiment, the light transmissive base material 221 contains the quantum dots 32, and the lens layer 222 integrated with the light transmissive base material 221 is formed on the first surface 221A of the light transmissive base material 221. Therefore, one light-transmitting base material can be reduced as compared with the case where the lens sheet and the light wavelength change sheet are separately produced. Further, in the present embodiment, since the light transmitting base material 221 and the lens layer 222 are integrated, no air layer is interposed between the light transmitting base material 221 and the lens layer 223. Therefore, it is possible to reduce the thickness.

In the present embodiment, since the lens layer 222 integrated with the light transmissive base material 221 is formed on the first surface 221A of the light transmissive base material 221 including the quantum dots 32, the lens in the light wavelength conversion sheet The sticking prevention layer provided on the sheet side can be omitted. As a result, the number of steps can be reduced.

According to the present embodiment, since the lens layer 222 integrated with the light transmissive base material 221 is formed on the first surface 221A of the light transmissive base material 221 including the quantum dots 32, the light transmissive base material is formed. There is no air interface between the 221 and the lens layer 222. As a result, light is not reflected by the air interface, so that the efficiency of light utilization can be improved.

According to the present embodiment, since the lens layer 222 integrated with the light transmissive base material 221 is formed on the first surface 221A of the light transmissive base material 221 including the quantum dots 32, the first embodiment. For the same reason as described in the above, when light is incident on the laminated body 220, the color of the light emitted from the peripheral portion 220A of the laminated body 220 is the color of the light emitted from the central portion 220B of the laminated body 220. It can be suppressed to stand out compared to.

According to the present embodiment, since the quantum dots 32 are wrapped with the barrier material 162, the quantum dots 32 can be protected from moisture and oxygen. Therefore, it is not necessary to separately provide a barrier layer, and deterioration of the quantum dots 32 existing in the peripheral edge portion 220A of the laminated body 220 can be further suppressed.

When the barrier layer is formed by a vapor deposition method, when the optical wavelength conversion sheet is bent, the barrier layer may be cracked, and moisture or oxygen may infiltrate into the optical wavelength conversion sheet to deteriorate the quantum dots. .. On the other hand, in the present embodiment, since the barrier layer is not provided, it is possible to cope with foldable.

According to this embodiment, since it is not necessary to provide a separate barrier layer, it is possible to support mobile products (portable computer terminal devices including devices called so-called smartphones) that have strict requirements for thickness.

In order to explain the present invention in detail, examples will be given below, but the present invention is not limited to these descriptions.

<Manufacturing of light wavelength conversion particles>
Light wavelength conversion particles were obtained according to the following procedure.
(Light wavelength conversion particle 1)
In a polymerization vessel having a stirrer, first, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), tetraethylene glycol bis (3-mercaptopropionate) (Product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.) 50 parts by mass, green emission quantum dots (Product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 part by mass, red light emitting quantum dot (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) 1.0 part by mass , And a thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.). As a solvent, 10 parts by mass of polyvinyl alcohol as a dispersant was dissolved in 900 parts by mass of ion-exchanged water. Then, the composition 1 for light wavelength conversion particles was finely dispersed as droplets in a poor solvent by stirring with a stirring device at a stirring speed of 400 rpm for 10 minutes. Subsequently, stirring by the stirrer is continued at a stirring speed of 400 rpm, the temperature of the reaction solution containing the composition 1 for light wavelength conversion particles and the poor solvent is raised to 50 ° C., and the temperature of the reaction solution is 50 ° C. Suspension polymerization is carried out in this state for 3 hours, and then the temperature of the reaction solution is raised to 80 ° C. in order to completely inactivate the thermal radical initiator, and the temperature of the reaction solution is 80 ° C. Stirring for 3 hours gave a particulate polymer. Then, the reaction solution containing the polymer in the polymerization vessel was cooled to room temperature while stirring with a stirrer. Next, the reaction solution was suction-filtered, the residue of the filtration was washed with ion-exchanged water, and then the solution was removed to obtain light wavelength conversion particles 1. In the light wavelength conversion particle 1, green emission quantum dots and red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles 1 was 3 μm. The average particle size of the light wavelength conversion particles 1 was determined by measuring the particle size of 20 light wavelength conversion particles 1 with a scanning electron microscope and calculating the average value thereof. The average particle size of the following light wavelength conversion particles 2 to 5 was also determined to be the same method as that of the light wavelength conversion particles 1.

(Light wavelength conversion particle 2)
Instead of composition 1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 2-metacloyloxyethyl acid phosphate (product name) "Light ester P-2M", manufactured by Kyoeisha Chemical Co., Ltd.) 50 parts by mass, green emitting quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3. 3 nm) 1.0 part by mass, red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) 1.0 part by mass, and Light wavelength except that the composition 2 for light wavelength conversion particles consisting of 1 part by mass of a thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used. Light wavelength conversion particles 2 were obtained by the same procedure as for conversion particles 1. In the light wavelength conversion particles 2, green light emitting quantum dots and red light emitting quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles 5 was 3 μm.

(Light wavelength conversion particle 3)
Instead of composition 1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), stearylamine (product name "Farmin 80", Kao) 50 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 parts by mass, red emission Quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) 1.0 part by mass, and thermal radical polymerization initiator (2,2' -Azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) Light by the same procedure as for the light wavelength conversion particles 1 except that the composition 3 for light wavelength conversion particles consisting of 1 part by mass was used. The wavelength conversion particles 3 were obtained. In the light wavelength conversion particles 3, green emission quantum dots and red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles 3 was 3 μm.

(Light wavelength conversion particle 4)
Instead of composition 1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), ω-carboxy-polycaprolactone mono (meth) acrylate (Product name "M-5300", manufactured by Toa Synthetic Co., Ltd.) 50 parts by mass, green emission quantum dots (Product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3 .3 nm) 1.0 part by mass, red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) 1.0 part by mass, Light radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) except that the composition 4 for light wavelength conversion particles consisting of 1 part by mass was used. Light wavelength conversion particles 4 were obtained by the same procedure as for wavelength conversion particles 1. In the light wavelength conversion particles 4, green emission quantum dots and red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles 4 was 3 μm.

(Light wavelength conversion particle 5)
First, 1.0 parts by mass of green emitting quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle diameter 3.3 nm) and 1.0 parts by mass. Red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) were prepared. After preparing the green emission quantum dots and the red emission quantum dots, the surfaces of the green emission quantum dots and the red emission quantum dots are covered with dodecylamine, and these quantum dots are put into a toluene solution (0.4 mL, 1.5 μM / L). Distributed. Next, tetraethoxysilane (TEOS, 10 μL) was added to this solution, and the mixture was stirred for 3 hours to prepare an organic solution 1.

On the other hand, 3-mercaptopropyltrimethoxysilane (MPS, 1 μL) was mixed with ethanol (25 mL) and aqueous ammonia (4 mL, ammonia concentration 10 wt%) to prepare an aqueous solution 2.

Then, when the organic solution 1 and the aqueous solution 2 were mixed and stirred for 3 hours, the green emission quantum dots and the red emission quantum dots moved to the aqueous phase, and further, an aggregate of the green emission quantum dots and the red emission quantum dots in the aqueous phase. Was formed. The aggregate was removed by centrifugation.

Finally, 0.5 mL of the aqueous solution in which the above aggregates were dispersed was taken out, ethanol (8 mL) and aqueous ammonia (0.1 mL, 25 wt%) were added, and TEOS (14 μL) was further added. As a result, an aggregate composed of green emission quantum dots and red emission quantum dots was wrapped in silica glass as a barrier material to obtain light wavelength conversion particles 5 having an average particle diameter of 50 nm.

<Preparation of composition for optical wavelength conversion layer>
First, each component was blended so as to have the composition shown below to obtain a composition for an optical wavelength conversion layer.
(Composition for Light Wavelength Conversion Layer 1)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 99 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass, photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass

(Composition for Light Wavelength Conversion Layer 2)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red light emitting quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, alumina particles (product name "DAM-03") , Manufactured by Electrochemical Industry Co., Ltd., Average particle size 4 μm): 10 parts by mass

(Composition for Light Wavelength Conversion Layer 3)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red light emitting quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, alumina particles (product name "MM-P") , Made by Nippon Light Metal Co., Ltd., average particle size 1.5 μm): 10 parts by mass

(Composition for Light Wavelength Conversion Layer 4)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass, photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, zirconia particles (product name "TZ-3YS-" E ”, manufactured by Toso Co., Ltd., average particle diameter 0.1 μm): 10 parts by mass

(Composition for Light Wavelength Conversion Layer 5)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red light emitting quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, titania particles (product name "R-38L") , Sakai Chemical Industry Co., Ltd., average particle size 0.4 μm): 10 parts by mass

(Composition for Light Wavelength Conversion Layer 6)
-Light wavelength conversion particles 1:20 parts by mass-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 80 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacare" Registered trademark) 184 ", manufactured by BASF Japan Ltd.): 1 part by mass

(Composition for Light Wavelength Conversion Layer 7)
-Light wavelength conversion particles 2: 20 parts by mass-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 80 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacare" Registered trademark) 184 ", manufactured by BASF Japan Ltd.): 1 part by mass

(Composition for Light Wavelength Conversion Layer 8)
-Light wavelength conversion particles 3: 20 parts by mass-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 80 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacare" Registered trademark) 184 ", manufactured by BASF Japan Ltd.): 1 part by mass

(Composition for Light Wavelength Conversion Layer 9)
-Light wavelength conversion particles 4: 20 parts by mass-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 80 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacare" Registered trademark) 184 ", manufactured by BASF Japan Ltd.): 1 part by mass

(Composition for Light Wavelength Conversion Layer 10)
-Light wavelength conversion particles 5:20 parts by mass-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 80 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacare" Registered trademark) 184 ", manufactured by BASF Japan Ltd.): 1 part by mass

(Composition for Light Wavelength Conversion Layer 11)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 50 parts by mass-Tetraethylene glycol bis (3-mercaptopropionate) (product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.) : 50 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm): 0.20 parts by mass, red emission quantum Dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm): 0.20 parts by mass-photopolymerization initiator (1-hydroxycyclohexylphenyl ketone) , Product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass

(Composition for Light Wavelength Conversion Layer 12)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass, photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, alumina particles (product name "DAM-07") , Made by Electrochemical Industry Co., Ltd., Average particle size 10 μm): 10 parts by mass

(Composition for Light Wavelength Conversion Layer 13)
-Epoxy acrylate (product name "Unidic V-5500", manufactured by DIC): 89 parts by mass-Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS , Average particle size 3.3 nm): 0.20 parts by mass, red light emitting quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm) : 0.20 parts by mass photopolymerization initiator (1-hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184", manufactured by BASF Japan): 1 part by mass, silica particles (product name "KE-P250") , Nippon Catalyst Co., Ltd., average particle size 2.5 μm): 10 parts by mass

<Preparation of composition for light diffusion layer>
Each component was blended so as to have the composition shown below to obtain a composition for a light diffusion layer.
(Composition for light diffusion layer)
-Pentaerythritol triacrylate: 99 parts by mass-Surface unevenness forming particles (crosslinked polystyrene resin beads, product name "SBX-4", manufactured by Sekisui Kasei Kogyo Co., Ltd., average particle diameter 4 μm): 158 parts by mass-Photopolymerization initiator (1-Hydroxycyclohexylphenyl ketone, product name "Irgacure (registered trademark) 184, manufactured by BASF Japan, Inc.): 1 part by mass / solvent (methylisobutylketone: cyclohexanone = 1: 1 (mass ratio)): 170 parts by mass

<Preparation of composition for overcoat layer>
Each component was blended so as to have the composition shown below to obtain a composition for an overcoat layer.
(Composition 1 for overcoat layer)
-Zinc acrylate (product name "ZN-DA" manufactured by Nippon Shokubai Co., Ltd.): 30 parts by mass-Methanol: 70 parts by mass-Photopolymerization initiator (1-hydroxycyclohexylphenylketone, product name "Irgacure (registered trademark) 184," BASF Japan): 1 part by mass

<Adjustment of composition for polyethylene terephthalate film>
Each component was blended so as to have the composition shown below to obtain a composition 1 for a polyethylene terephthalate film.
(Composition 1 for polyethylene terephthalate film)
-Polyethylene terephthalate: 100 parts by mass-Light wavelength conversion particles 5: 8 parts by mass

<Example 1>
First, two polyethylene terephthalate films with a silica-deposited layer were produced by the following method. In a high-frequency sputtering apparatus, by applying a high-frequency power of 13.56 MHz and a power of 5 kW to the electrodes, a discharge is generated in the chamber, and polyethylene terephthalate as a light-transmitting substrate having a size of 7 inches and a thickness of 50 μm is generated. A silica-deposited layer made of a target substance (silica), having a thickness of 50 nm and a refractive index of 1.46, was formed on one side of a film (product name "Lumirror T60", manufactured by Toray Co., Ltd.). As a result, two polyethylene terephthalate films with a silica vapor deposition document having a silica vapor deposition layer formed on one surface of the polyethylene terephthalate film were formed.

Next, a prism layer was formed on a surface of the polyethylene terephthalate film with a silica-deposited layer opposite to the surface on the silica-deposited layer side to form a prism sheet. Specifically, first, the composition for a prism layer containing urethane acrylate is uniformly applied on the surface of the polyethylene terephthalate film opposite to the surface on the side opposite to the silica-deposited layer side, and the coating film of the composition for the prism layer is applied. It was formed to form a laminated body for a prism sheet. Then, the traveling speed of the prism sheet laminate is such that the coating film of the lens layer composition is on the molding mold side in the rotating molding mold having recesses having a shape opposite to the desired unit prism shape. The shape of the unit prism is formed on the coating film of the composition for the prism layer by supplying at 20 m / min using a molding mold, and ultraviolet rays are applied to the coating film of the composition for the prism layer via a polyethylene terephthalate film with a silica vapor deposition layer. The coating film of the composition for the prism layer was cured by irradiating with light such as. Finally, the cured coating film of the composition for the prism layer is peeled off from the molding mold together with the polyethylene terephthalate film with the silica-deposited layer, and the prism layer is formed on the surface of the polyethylene terephthalate film opposite to the surface on the silica-deposited layer side. A prism sheet in which silica was formed was obtained. The prism layers are arranged side by side on the sheet-shaped main body and each of them extends in a direction intersecting the arrangement direction, the apex angle is 90 °, the width is 47 μm, and the height is high. It had a plurality of triangular columnar unit prisms having a height of 30 μm.

On the other hand, the composition for a light diffusion layer was applied to a surface of the other polyethylene terephthalate film with a silica-deposited layer opposite to the surface on the silica-deposited layer side to form a coating film. Next, the solvent in the coating film was evaporated by passing dry air at 80 ° C. for 30 seconds to dry the formed coating film. Then, by irradiating ultraviolet rays so that the integrated light amount becomes 150 mJ / cm ² and curing the coating film, a light diffusion layer having a film thickness of 10 μm is formed, which is opposite to the surface of the polyethylene terephthalate film on the silica vapor deposition layer side. A light-transmitting sheet having a light-diffusing layer on the side surface was formed.

Next, the composition 1 for the light wavelength conversion layer was applied to the surface of the silica-deposited layer of the light-transmitting sheet to form a coating film. Then, the prism sheet was laminated on the surface of the coating film opposite to the surface on the light-transmitting sheet side so that the silica-deposited layer was in contact with the surface. In this state, the coating film was cured by irradiating the coating film with ultraviolet rays so that the integrated light amount was 500 mJ / cm ² , to form a 100 μm light wavelength conversion layer in close contact with the prism sheet and the light transmissive sheet. As a result, the laminated body according to the example was obtained. The thickness of the light wavelength conversion layer was obtained by randomly photographing the cross section of the laminated body at 20 points using a scanning electron microscope (SEM) and obtaining an image of the cross section.

<Example 2>
In Example 2, a laminate was produced in the same manner as in Example 1 except that the composition 2 for the light wavelength conversion layer was used instead of the composition 1 for the light wavelength conversion layer. The refractive index of alumina in the optical wavelength conversion layer was 1.77, and the refractive index of the binder resin was 1.51. Further, the quantum dots in the optical wavelength conversion layer are optically isotropic particles, and are shown when the scattering efficiency of light incident on the optical wavelength conversion layer is on the vertical axis and the particle diameter of the light scattering particles is on the horizontal axis. 20% of the particle size distribution of the light-scattering particles was included in the range of 0.6 μm to 2.0 μm, which is the half-value width of the maximum peak appearing in the graph.

<Example 3>
In Example 3, a laminated body was produced in the same manner as in Example 2 except that the film thickness of the light wavelength conversion layer was 60 μm.

<Example 4>
In Example 4, a laminate was produced in the same manner as in Example 1 except that the composition 3 for the light wavelength conversion layer was used instead of the composition 1 for the light wavelength conversion layer. It should be noted that the vertical axis is the scattering efficiency of the light incident on the optical wavelength conversion layer, and the horizontal axis is the particle size of the light-scattering particles. Within the range of 0 μm, 40% of the particle size distribution of the light-scattering particles was included.

<Example 5>
In Example 5, a laminate was produced in the same manner as in Example 1 except that the composition 4 for the light wavelength conversion layer was used instead of the composition 1 for the light wavelength conversion layer. The refractive index of zirconia was 2.17.

<Example 6>
In Example 6, a laminate was produced in the same manner as in Example 1 except that the composition 5 for the light wavelength conversion layer was used instead of the composition 1 for the light wavelength conversion layer. The refractive index of titania was 2.7.

<Example 7>
In Example 7, the composition 6 for the optical wavelength conversion layer is used instead of the composition 1 for the optical wavelength conversion layer, and two silica-deposited layers are used instead of the polyethylene terephthalate film with two silica-deposited layers. A laminate was produced in the same manner as in Example 1 except that a polyethylene terephthalate film (product name “Lumilar T60”, manufactured by Toray Co., Ltd.) having a size of 7 inches and a thickness of 50 μm was used. The laminate according to Example 7 was an integrated prism sheet without a silica-deposited layer, an optical wavelength conversion layer, a polyethylene terephthalate film without a silica-deposited layer, and a light diffusion layer. ..

<Example 8>
In Example 8, a laminate was produced in the same manner as in Example 7, except that the composition 7 for the light wavelength conversion layer was used instead of the composition 6 for the light wavelength conversion layer.

<Example 9>
In Example 9, a laminate was produced in the same manner as in Example 7, except that the composition 8 for the light wavelength conversion layer was used instead of the composition 6 for the light wavelength conversion layer.

<Example 10>
In Example 10, a laminate was produced in the same manner as in Example 7, except that the composition 9 for the light wavelength conversion layer was used instead of the composition 6 for the light wavelength conversion layer.

<Example 11>
In Example 11, a laminate was produced in the same manner as in Example 7 except that the composition 10 for the light wavelength conversion layer was used instead of the composition 6 for the light wavelength conversion layer.

<Example 12>
In Example 12, a laminate was produced in the same manner as in Example 7, except that the composition 11 for the optical wavelength conversion layer was used instead of the composition 6 for the optical wavelength conversion layer.

<Example 13>
First, the same method as in Example 1 was applied to one surface of a polyethylene terephthalate film (product name "Lumilar T60", manufactured by Toray Industries, Inc.) having a size of 7 inches and a thickness of 50 μm in which a silica-deposited layer was not formed. A prism layer having the same shape as that of the above was formed, and a prism sheet without a silica-deposited layer was formed. Next, the composition 6 for an optical wavelength conversion layer was applied to the other surface of the polyethylene terephthalate film of this prism sheet to form a coating film. In this state, a 100 μm light wavelength conversion layer was formed by irradiating the coating film with ultraviolet rays so that the integrated light amount was 500 mJ / cm ^2. Then, the composition 1 for the overcoat layer was applied to the surface of the light wavelength conversion layer opposite to the surface on the prism sheet side to form a coating film. Then, ultraviolet rays were irradiated so that the integrated light intensity was 500 mJ / cm ² , and the coating film was cured to obtain an overcoat layer having a film thickness of 5 μm. Further, the composition 1 for the light diffusion layer was applied to the surface of the overcoat layer opposite to the surface on the light wavelength conversion layer side to form a coating film. Next, the solvent in the coating film was evaporated by passing dry air at 80 ° C. for 30 seconds to dry the formed coating film. Then, an ultraviolet ray was irradiated so that the integrated light amount was 150 mJ / cm ² , and the coating film was cured to form a light diffusion layer having a film thickness of 10 μm. As a result, a laminated body in which the prism sheet, the light wavelength conversion layer, the overcoat layer, and the light diffusion layer were integrated was produced.

<Example 14>
In Example 14, a laminate was produced in the same manner as in Example 13 except that the composition 11 for the light wavelength conversion layer was used instead of the composition 6 for the light wavelength conversion layer.

<Example 15>
The raw material composition 1 for polyethylene terephthalate film was melted at 290 ° C., extruded into a sheet through a film forming die, and cooled by being brought into close contact with a water-cooled rotary quenching drum to prepare an unstretched film. This unstretched film is preheated at 120 ° C. for 1 minute in a biaxial stretching test device (manufactured by Toyo Seiki Co., Ltd.), and then stretched at 120 ° C. in the longitudinal direction of the unstretched film at a draw ratio of 3.5 times. , The film was stretched in the width direction at a stretching ratio of 4.2 times to obtain a polyethylene terephthalate film having a thickness of 50 μm containing the light wavelength conversion particles 5.

Next, a prism layer was formed on one surface of the polyethylene terephthalate film in the same manner as in Example 1 to prepare a laminated body. The shape of the unit prism of the prism layer was the same as the shape of the unit prism of the prism layer of Example 1.

<Comparative example 1>
First, two polyethylene terephthalate films with a silica-deposited layer were produced by the following method. In a high-frequency sputtering apparatus, by applying a high-frequency power of 13.56 MHz and a power of 5 kW to the electrodes, a discharge is generated in the chamber, and polyethylene terephthalate as a light-transmitting substrate having a size of 7 inches and a thickness of 50 μm is generated. A silica-deposited layer made of a target substance (silica), having a thickness of 50 nm and a refractive index of 1.46, was formed on one side of a film (product name "Lumirror T60", manufactured by Toray Co., Ltd.). As a result, two polyethylene terephthalate films with a silica vapor deposition document having a silica vapor deposition layer formed on one surface of the polyethylene terephthalate film were formed.

Then, the composition for the light diffusion layer was applied to a surface of the polyethylene terephthalate film with a silica-deposited layer opposite to the surface on the silica-deposited layer side to form a coating film. Next, the solvent in the coating film was evaporated by passing dry air at 80 ° C. for 30 seconds to dry the formed coating film. Then, by irradiating ultraviolet rays so that the integrated light amount becomes 150 mJ / cm ² and curing the coating film, a light diffusion layer having a film thickness of 10 μm is formed, which is opposite to the surface of the polyethylene terephthalate film on the silica vapor deposition layer side. A light-transmitting sheet having a light-diffusing layer on the side surface was formed.

Next, the composition 1 for the light wavelength conversion layer was applied to the surface of the silica-deposited layer of the light-transmitting sheet to form a coating film. Then, the other polyethylene terephthalate film with a silica-deposited layer was laminated on the surface of the coating film opposite to the surface on the light-transmitting sheet side so that the silica-deposited layer was in contact with the surface. In this state, the coating film is cured by irradiating ultraviolet rays so that the integrated light amount is 500 mJ / cm ² , so that a 100 μm light wavelength conversion layer adhered to the light transmissive sheet and the polyethylene terephthalate film with a silica-deposited layer is formed. Formed. As a result, an optical wavelength conversion sheet according to a comparative example was obtained. The thickness of the light wavelength conversion layer was obtained by randomly photographing the cross section of the light wavelength conversion sheet at 20 points using a scanning electron microscope (SEM) and obtaining an image of the cross section.

On the other hand, a prism layer is formed on one side of a polyethylene terephthalate film (product name "Lumirror T60", manufactured by Toray Industries, Inc.) as a light-transmitting base material with a size of 7 inches and a thickness of 50 μm by a drum printing system method (DPS method). Then, a prism sheet was formed. Specifically, first, a composition for a prism layer containing urethane acrylate is uniformly applied on one surface of a polyethylene terephthalate film to form a coating film of the composition for a prism layer, and a laminate for a prism sheet is formed. Formed. Then, the traveling speed of the prism sheet laminate is such that the coating film of the lens layer composition is on the molding mold side in the rotating molding mold having recesses having a shape opposite to the desired unit prism shape. The shape of the unit prism is formed on the coating film of the prism layer composition by supplying at 20 m / min using a molding mold, and light such as ultraviolet rays is applied to the coating film of the prism layer composition via a polyethylene terephthalate film. Irradiation was performed to cure the coating film of the composition for the prism layer. Finally, the cured coating film of the prism layer composition was peeled off from the molding mold together with the polyethylene terephthalate film to obtain a prism sheet in which the prism layer was formed on one surface of the polyethylene terephthalate film. The prism sheet is arranged side by side on the sheet-shaped main body, and each extends in a direction intersecting the arrangement direction, has an apex angle of 90 °, a width of 47 μm, and a height. It had a plurality of triangular columnar unit prisms having a height of 30 μm.

<Comparative example 2>
In Comparative Example 2, an optical wavelength conversion sheet and a prism sheet were produced in the same manner as in Comparative Example 1 except that the composition 2 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer. ..

<Comparative example 3>
In Comparative Example 3, an optical wavelength conversion sheet and a prism sheet were produced in the same manner as in Comparative Example 1 except that the composition 3 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer. ..

<Comparative example 4>
In Comparative Example 4, an optical wavelength conversion sheet and a prism sheet were produced in the same manner as in Comparative Example 1 except that the composition 4 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer. ..

<Comparative example 5>
In Comparative Example 5, an optical wavelength conversion sheet and a prism sheet were produced in the same manner as in Comparative Example 1 except that the composition 5 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer. ..

<Reference example 1>
In Reference Example 1, a laminated body was produced in the same manner as in Example 1 except that the film thickness of the light wavelength conversion layer was 40 μm.

<Reference example 2>
In Reference Example 2, a laminate was produced in the same manner as in Example 1 except that the composition 6 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer.

<Reference example 3>
In Reference Example 3, a laminate was produced in the same manner as in Example 1 except that the composition 7 for the optical wavelength conversion layer was used instead of the composition 1 for the optical wavelength conversion layer. The refractive index of silica was 1.47.

<Measurement of chromaticity on the light emitting surface>
The laminate according to Examples 1 to 15 and the light wavelength conversion sheet and the prism sheet according to Comparative Examples 1 to 5 were incorporated into the backlight device, respectively, and the laminates according to Examples 1 to 7 and Comparative Examples 1 to 5 were incorporated. In the backlight device, the chromaticity of the peripheral portion and the central portion of the light emitting surface of the backlight device at the time of light emission was measured using a spectral emission luminance meter (product name “CS2000”, manufactured by Konica Minolta Co., Ltd.), respectively.

When incorporating the laminate according to Examples 1 to 15 and the light wavelength conversion sheet and prism sheet according to Comparative Examples 1 to 5 into the backlight device, first, the backlight device (light emission peak wavelength) of Kindle Fire (registered trademark) HDX7 is used. A blue light emitting diode having a wavelength of 450 nm, a light guide plate, and two prism sheets) were prepared. The two prism sheets include a sheet-shaped main body portion and a plurality of triangular columnar unit prisms arranged side by side on the main body portion and each extending in a direction intersecting the arrangement direction, and the top of the unit prism. Although the angle is 90 °, one prism out of two prism sheets was used.

In Examples 1 to 15, the light guide plate is arranged so that the blue light emitting diode side is the light entrance surface, and the laminate and the prism sheet according to the Examples according to Examples 1 to 15 are placed on the light emission surface of the light guide plate. Arranged in this order, a backlight device was obtained. The prism sheets on the observer side were arranged so that the arrangement direction of the unit prisms was orthogonal to the arrangement direction of the unit prisms of the prism sheet of the laminated body according to the embodiment.

In Comparative Examples 1 to 5, the light guide plate is arranged so that the blue light emitting diode side is the light incoming surface, and the light wavelength conversion sheet according to Comparative Examples 1 to 5 and Comparative Examples 1 to 5 are placed on the light emitting surface of the light guide plate. The prism sheet and the prism sheet according to the above were arranged in this order to obtain a backlight device. The prism sheet on the observer side was arranged so that the arrangement direction of the unit prisms was orthogonal to the arrangement direction of the unit prisms of the prism sheet according to the comparative example. In this way, a backlight device incorporating the light wavelength conversion sheet and the prism sheet according to the comparative example was obtained.

<Visual evaluation of light emitting surface>
In a dark room, the peripheral edge of the light emitting surface at the time of light emission in the backlight device is used by using the backlight device incorporating the laminate according to Examples 1 to 15 and the light wavelength conversion sheet and the prism sheet according to Comparative Examples 1 to 5. The portion (the portion between the edges and the position near 5 mm from the edge) and the central portion were visually observed, and it was observed whether the tint of the peripheral portion of the light emitting surface was conspicuous as compared with the tint of the central portion. The evaluation criteria are as follows.
◯: The color of the peripheral part was the same as the color of the central part, or the color of the peripheral part was slightly different from the color of the central part, but there was no problem in practical use.
X: The color of the peripheral portion was more prominent than the color of the central portion.

<Measurement of light utilization efficiency>
In the backlight device incorporating the laminate according to Examples 1 to 15 and the light wavelength conversion sheet and the prism sheet according to Comparative Examples 1 to 5, the front direction of the backlight device is set to 0 degrees, and the brightness in the horizontal direction is increased. The angular characteristics were measured from -50 degrees to 50 degrees in 5 degree increments using a spectral radiance meter (product name "CS2000", manufactured by Konica Minolta). Then, the integrated value of the brightness at each angle in each backlight device is calculated, and the relative value of the integrated value of the brightness of the examples and the comparative example when the integrated value of the brightness of Comparative Example 1 is set to 100% is used by light. It was made efficient.

<Measurement of water vapor permeability and oxygen permeability>
The water vapor permeability and the oxygen permeability were measured in the laminates according to Examples 1 to 15, respectively. The water vapor transmission rate of the laminate is based on JIS K7129: 2008, using a water vapor transmission rate measuring device (product name "PERMATRAN-W3 / 31", manufactured by MOCON) under the conditions of 40 ° C. and 90% relative humidity. Measured below. The oxygen permeability of the laminate is 23 ° C. and relative humidity 90 using an oxygen gas permeability measuring device (product name "OX-TRAN 2/21", manufactured by MOCON) in accordance with JIS K7126: 2006. Measured under the condition of%.

<Measurement of optical wavelength conversion efficiency>
First, in the backlight device incorporating the laminates according to Examples 1 to 6 and Reference Examples 1 to 3, and the backlight apparatus not incorporating the laminate according to Examples, a spectroradiometer (product name "SR-UL2") , (Manufactured by Topcon) was used to obtain spectral spectra. From the spectral spectra obtained in each, the integrated value of the blue light spectrum, the integrated value of the green light spectrum (480 nm-590 nm), and the integrated value of the red light spectrum (590 nm-750 nm) were calculated. Incorporate the laminate according to the example for each of the integrated value of the green light spectrum and the integrated value of the red light spectrum measured by using the backlight device incorporating the laminate according to Examples 1 to 6 and Reference Examples 1 to 3. The light wavelength conversion efficiency was measured by dividing by the integrated value of the blue light spectrum measured using a non-backlit device.

The results are shown in Tables 1 and 2 below.

The results will be described below. In Comparative Examples 1 to 5, the bluish color of the peripheral portion of the light emitting surface was stronger and more prominent than that of the central portion. On the other hand, in Examples 1 to 15, the bluish tint of the peripheral portion of the light emitting surface was reduced as compared with Comparative Examples 1 to 5. Therefore, in Examples 1 to 15, the laminate in which the prism sheet and the light wavelength conversion sheet are integrated is from the peripheral edge of the laminate as compared with the case where the prism sheet and the light wavelength conversion sheet are laminated via the air layer. It was confirmed that the tint of the emitted light can be suppressed from being conspicuous as compared with the tint of the light emitted from the central portion of the laminate.

Examples 1 and 7 to 14 have higher light utilization efficiency than Comparative Example 1, Example 2 has higher light utilization efficiency than Comparative Example 2, and Example 4 has higher light utilization efficiency than Comparative Example 3. Example 5 had higher light utilization efficiency than Comparative Example 4, and Example 6 had higher light utilization efficiency than Comparative Example 5. Therefore, it was confirmed that the laminated body in which the prism sheet and the light wavelength conversion sheet are integrated has improved light utilization efficiency as compared with the case where the prism sheet and the light wavelength conversion sheet are laminated via the air layer.

In the light wavelength conversion sheet according to Reference Example 2, the average particle diameter of the light-scattering particles with respect to the thickness of the light wavelength conversion layer exceeded 8%, and therefore, the light wavelength conversion sheet according to Reference Example 3 was light-scattering. Since the difference between the refractive index of the silica particles as the sex particles and the refractive index of the binder resin of the optical wavelength conversion layer was less than 0.10, all of them were higher than the optical wavelength conversion efficiency of the laminate according to Examples 2 to 6. It was inferior. Since the laminated body according to Example 1 did not contain light scattering particles in the light wavelength conversion layer, it was inferior to the light wavelength conversion efficiency of the laminated body according to Examples 2 to 5. Further, from the result of Reference Example 1, it can be seen that the light wavelength conversion efficiency is inferior unless the light wavelength conversion layer contains light scattering particles. On the other hand, from the results of Examples 2 to 6, it can be seen that the light wavelength conversion efficiency is increased by including the predetermined light scattering particles in the light wavelength conversion layer.

10, 50, 60, 70, 110, 120, 130, 150 ... Laminates 20, 80 ... Lens sheets 21, 41, 62, 63, 221 ... Light-transmitting base materials 22, 122 ... Lens layers 23, 42 ... Barriers Layers 24, 226 ... Unit lenses 30, 90, 140, 160 ... Optical wavelength conversion layers 30C, 50A, 60A, 70A, 110A, 120A, 130A, 150A ... Peripheral portions 30D, 50B, 60B, 70B, 110B, 120B, 130B , 150B ... Central portion 31, 91 ... Host matrix 32 ... Quantum dots 34 ... Curable host matrix precursor 35 ... Coating 43 ... Light diffusion layer 170 ... Display 180, 210 ... Backlight device 200 ... Display panel

Claims (11)

A lens sheet provided with a first light-transmitting base material and a lens layer provided on the first surface side of the first light-transmitting base material and having a plurality of unit lenses, and a lens sheet.
A light wavelength conversion layer provided on the second surface side of the first light transmissive substrate opposite to the first surface and containing a host matrix and quantum dots.
The light wavelength conversion layer includes a light diffusion layer formed on a side opposite to the lens sheet side and having an uneven surface.
The lens sheet, the light wavelength conversion layer, and the light diffusion layer are integrated .
The quantum dots include a core made of a first semiconductor compound, a shell made of a second semiconductor compound different from the first semiconductor compound, and a ligand located outside the shell.
The light wavelength conversion layer further contains light wavelength conversion particles.
The light wavelength conversion particles are a light-transmitting resin particle containing at least one of one or more elements selected from the group consisting of sulfur, phosphorus, and nitrogen and a carboxylic acid, and the said particles encapsulated in the resin particles. Including quantum dots
40 ° C., water vapor transmission rate at a relative humidity of 90% 0.1g ^/ (m 2 · 24h) or higher and 23 ° C., the oxygen permeability at a relative humidity of 90% ^{0.1cm 3 / (m 2 · 24h} · atm ) A laminate that satisfies at least one of the above. The laminate according to claim 1 , wherein the surface of the laminate is the lens surface of the lens sheet, and the back surface of the laminate, which is the surface opposite to the surface, is the uneven surface of the light diffusion layer. body. The light wavelength conversion layer further contains light scattering particles, the difference in refractive index between the light scattering particles and the host matrix is 0.10 or more, and the average particle diameter of the light scattering particles is the light wavelength conversion. and 8% or less when the thickness of the layer is 100%, the quantum dots are made up of one or more materials, and / or at least one particle size distribution range, lamination of claim 1 body. With a light-transmitting substrate containing quantum dots,
A lens layer provided on one surface side of the light transmissive substrate and having a plurality of unit lenses, and a lens layer.
A light diffusing layer formed on the side of the light transmissive substrate opposite to the lens layer side and having an uneven surface is provided.
The light transmitting base material, the lens layer, and the light diffusing layer are integrated .
The quantum dots include a core made of a first semiconductor compound, a shell made of a second semiconductor compound different from the first semiconductor compound, and a ligand located outside the shell.
The light transmissive substrate contains light wavelength conversion particles and contains.
The light wavelength conversion particles are a light-transmitting resin particle containing at least one of one or more elements selected from the group consisting of sulfur, phosphorus, and nitrogen and a carboxylic acid, and the said particles encapsulated in the resin particles. Including quantum dots
40 ° C., water vapor transmission rate at a relative humidity of 90% 0.1g ^/ (m 2 · 24h) or higher and 23 ° C., the oxygen permeability at a relative humidity of 90% ^{0.1cm 3 / (m 2 · 24h} · atm ) A laminate that satisfies at least one of the above. The laminate according to claim 1 or 4 , further comprising an overcoat layer made of resin that covers at least one surface of the light wavelength conversion layer or at least one surface of a light transmissive substrate containing the quantum dots. Light source and
The laminate according to claim 1 or 4 , which receives light from the light source, and
A backlight device equipped with. It has an incoming surface that receives light from the light source and an outgoing surface that emits light from the light source, the light emitting surface is located on the laminate side, and the light from the light source is guided to the laminated body, or The backlight device according to claim 6 , further comprising an optical plate that diffuses light from the light source. Light source and
The laminate according to claim 2 and
An incoming surface that receives light from the light source and a light from the light source are emitted, and are optically in close contact with a part of the uneven surface of the laminated body, and between the other part of the uneven surface. An optical plate having a light emitting surface forming an air layer and guiding light from the light source to the laminate or diffusing light from the light source.
A backlight device equipped with. A frame body that surrounds the periphery of the laminated body and the periphery of the optical plate, the light source, the optical plate, and a fixing member that fixes the laminated body to the frame body are further provided, and the light source is the optical plate. The backlight device according to claim 7 or 8 , wherein the backlight device is arranged between the frame and the optical plate, and the optical plate is a light guide plate that guides light from the light source to the laminated body. Wherein the light source emits blue light, and includes first and quantum dots the quantum dots to convert the blue light into green light, and a second quantum dot that converts the blue light into red light, according to claim 6 The backlight device described in. The backlight device according to claim 6 and
A display device including a display panel arranged on the light emitting side of the backlight device.

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