JP2017040834A - Optical sheet and method for producing optical sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sheet which can suppress occurrence of waviness and wrinkles or a scratch during manufacture, and has no unevenness and excellent brightness even when containing a quantum dot.SOLUTION: In an optical sheet 10, a gas barrier film 1 has a gas barrier layer 3 on a first surface on the side facing a quantum dot-containing layer 4 and a back coat layer 11 on a second surface on an opposite side to the first surface, at least a surface in a far side from the quantum dot-containing layer 4 of the back coat layer 11 is a surface 11a having an uneven structure, arithmetic average roughness Ra and maximum cross-sectional height Rt of the surface 11a having the uneven structure are in a specific range, and the quantum dot-containing layer 4 is a quantum dot-containing layer formed by polymerization or crosslinking reaction of a coated film containing the quantum dot and a curable resin precursor simultaneously with or after an operation of laminating the gas barrier-film 1 on the coating film.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical sheet and a method for manufacturing the optical sheet. More specifically, the present invention relates to an optical sheet or the like that can suppress the occurrence of undulations, wrinkles, or scratches during production, and has even brightness even with an optical sheet containing quantum dots.

  In recent years, optical members using quantum dots (hereinafter also referred to as “Quantum Dot”, “QD”, “semiconductor nanoparticles”, etc.) have attracted attention.

However, quantum dots have a problem that they are easily affected by moisture and oxygen.
Therefore, it is generally known that an optical sheet using quantum dots needs to be protected by a material and / or member having gas barrier properties.

In order to solve the problem of the optical sheet using such quantum dots, for example, in Patent Document 1, a layer containing quantum dots (hereinafter, also referred to as “quantum dot-containing layer”) is composed of two gas barrier films. It is disclosed that a quantum dot can be protected from environmental conditions such as high temperature, oxygen, and humidity by using an optical sheet having a quantum dot-containing layer (hereinafter also simply referred to as “optical sheet”) disposed between the layers. .
And this optical sheet can be obtained by dispersing quantum dots in a resin matrix and laminating between two opposing gas barrier films.
However, when a liquid crystal display is assembled using an optical sheet having a quantum dot-containing layer, there has been a problem that unevenness in light emission brightness and color unevenness occur.

As a result of intensive studies by the inventors, it has been found that the cause of the problem lies in the manufacturing process.
That is, as described above, the optical sheet is manufactured by laminating a resin matrix containing quantum dots (quantum dot-containing resin layer) with two gas barrier films. At that time, the gas barrier film is fixed by UV curing or heat curing. Therefore, it has been found that the optical sheet is affected by the energy for UV curing and thermal curing, and undulations, wrinkles or scratches are generated on the optical sheet on the conveying roll to be laminated.
The present inventors have found that light emission luminance and color unevenness are generated in the optical sheet due to the swells, wrinkles or scratches. In addition, in the optical sheet using quantum dots, due to its optical characteristics, even if fine waviness, wrinkles or scratches lead to a great amount of luminance and color unevenness, the occurrence of waviness, wrinkles or scratches becomes a big problem. .

  On the other hand, the technique which suppresses wrinkles at the time of conveyance by sticking a protective film on the back surface side of the film to laminate is disclosed (for example, refer patent document 2). These use polyester film as a protective film, and also refer to the light transmission at the time of ultraviolet irradiation. However, the loss of the light irradiated at the time of production results in poor curing and the production speed is limited. There is a problem of getting out.

Moreover, as a device on the laminating apparatus side, a technique for suppressing the generation of wrinkles and undulations by irradiating ultraviolet rays on a roll having a contour curve maximum height Rz ( ³ ) of 0.4 to 12S (μmRz) (for example, Patent Document 3), and a technique for preliminarily controlling distortion generation in the subsequent heat treatment by providing a pair of roller groups sandwiching the widthwise ends of the transport web from the front and back (see, for example, Patent Document 4). It has been published.
However, these techniques are insufficient to suppress the occurrence of waviness, wrinkles or scratches in an optical sheet having a quantum dot-containing layer that requires optically uniform light emission. It is not a solution.

Special table 2013-544018 gazette JP 2015-18834 A JP 2014-130234 A JP 2009-203055 A

  The present invention has been made in view of the above-described problems and situations, and the problem to be solved is that it is possible to suppress the occurrence of undulations, wrinkles or scratches during production, and even if an optical sheet containing quantum dots is uneven. And providing an optical sheet having excellent luminance.

In order to solve the above problems, the present inventor, in the process of examining the cause of the above problems, at least the surface far from the quantum dot-containing layer of the backcoat layer, the arithmetic average roughness Ra and the maximum cross-sectional height Rt If it is a surface having a concavo-convex structure within a specific range, it is possible to suppress the occurrence of tacking with a backlight unit or an optical sheet at the time of manufacture, and consequently, it is possible to suppress the occurrence of waviness, wrinkles or scratches, As a result, the present inventors have found that even an optical sheet containing quantum dots can provide an optical sheet having no unevenness and excellent brightness, and has reached the present invention.
That is, the said subject which concerns on this invention is solved by the following means.

1. An optical sheet having a quantum dot-containing layer laminated with a gas barrier film,
The gas barrier film has a gas barrier layer on a first surface facing the quantum dot-containing layer, and a back coat is applied to a second surface opposite to the first surface through a resin base material. Has a layer,
The surface on the side far from the quantum dot-containing layer of the backcoat layer is a surface having a concavo-convex structure,
The arithmetic average roughness Ra of the surface having the concavo-convex structure is in the range of 0.01 to 0.10 μm, the maximum cross-sectional height Rt is in the range of 0.2 to 2.0 μm, and
The quantum dot-containing resin layer formed by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or after the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor. An optical sheet characterized by the above.

  2. The surface of the back coat layer having the uneven structure is a surface derived from a structure formed by phase separation of a plurality of types of resin precursors or resins contained in the back coat layer. The optical sheet according to 1.

  3. The optical sheet according to item 2, wherein the hydroxy value of at least two of the plurality of resins is different by 20 mgKOH / g or more.

  4). The optical sheet according to any one of Items 1 to 3, wherein the back coat layer further contains a filler containing an acrylate resin or a polyamide resin.

  5). The optical sheet according to any one of Items 1 to 4, wherein the backcoat layer contains a compound having at least two isocyanate groups.

6). An optical sheet manufacturing method for manufacturing an optical sheet having a quantum dot-containing layer laminated with a gas barrier film according to any one of items 1 to 5,
In the step of producing the gas barrier film, a gas barrier layer is formed on the surface (first surface) of the resin substrate on the side facing the quantum dot-containing layer, and the side opposite to the first surface is formed. Forming a backcoat layer on the second surface;
The back coat layer is formed so that at least the surface on the side far from the quantum dot-containing layer is a surface having a concavo-convex structure,
The arithmetic mean roughness Ra of the surface having the concavo-convex structure is adjusted to be in the range of 0.01 to 0.10 μm, the maximum cross-sectional height Rt is adjusted to be in the range of 0.2 to 2.0 μm, and ,
In the step of forming the quantum dot-containing layer, the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor, and at the same time or after the polymerization or crosslinking reaction is performed by ultraviolet rays or heat. An optical sheet manufacturing method characterized by the above.

  7). 7. The optical sheet according to claim 6, wherein the surface of the back coat layer having the concavo-convex structure is formed by phase separation of a plurality of types of resin precursors or resins contained in the back coat layer. Method.

By the above means of the present invention, generation of undulations, wrinkles or scratches during production can be suppressed, and even an optical sheet containing quantum dots has no unevenness and excellent brightness, and a method for producing the optical sheet Can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

  In the present invention, a back coat layer having a concavo-convex structure with Ra of 0.01 to 0.10 μm and Rt of 0.1 to 1.0 μm is formed on the back side of the gas barrier film with respect to the above problem. Thus, since it is possible to suppress the occurrence of tacking with a backlight unit or the like or an optical sheet during production, it is possible to provide an optical sheet containing quantum dots that has no emission luminance or color unevenness even when used in a liquid crystal display.

The schematic diagram which shows an example of the layer structure of the optical sheet of this invention Schematic diagram showing an example of a vacuum plasma CVD apparatus used in the examples

  In the optical sheet of the present invention, the gas barrier film has a gas barrier layer on the first surface on the side facing the quantum dot-containing layer, and is backed on the second surface opposite to the first surface. A coating layer, at least a surface of the backcoat layer on the side far from the quantum dot-containing layer has an uneven structure having an arithmetic average roughness Ra and a maximum cross-sectional height Rt within a specific range; The inclusion layer is a quantum dot-containing resin layer formed by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or after the gas barrier film is laminated on a coating film containing quantum dots and a curable resin precursor. It is characterized by. This feature is a technical feature common to the inventions according to claims 1 to 7.

As an embodiment of the present invention, the surface having the concavo-convex structure of the backcoat layer is a surface derived from a structure formed by phase separation of a plurality of types of resin precursors or resins contained in the backcoat layer. This is preferable because there is no unevenness and good luminance can be realized.
In addition, it is preferable that the hydroxy value of at least two kinds of resins among the plurality of kinds of resins is different by 20 mgKOH / g or more because better luminance can be realized.

  As an embodiment of the present invention, it is preferable that the back coat layer further contains a filler containing an acrylate resin or a polyamide resin because the winding property and the transportability are improved.

  As an embodiment of the present invention, it is preferable that the back coat layer contains a compound having at least two or more isocyanate groups, because better luminance can be realized.

As a method for producing the optical sheet of the present invention, in the step of producing the gas barrier film, a gas barrier layer is formed on the first surface of the front resin base material, and the first side opposite to the first surface is formed. A back coat layer is formed on two surfaces, and at least the surface of the back coat layer on the side far from the quantum dot-containing layer has a concavo-convex structure in which the arithmetic average roughness Ra and the maximum cross-sectional height Rt are within a specific range. Furthermore, in the step of forming the quantum dot-containing layer, polymerization or cross-linking is performed simultaneously with or after the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor. It is preferable that the method is a method for producing an optical sheet, which is reacted to form a quantum dot-containing (resin) layer.
In particular, forming the surface of the back coat layer having the concavo-convex structure by phase separation of a plurality of types of resin precursors or resins contained in the back coat layer is more uniform and has good luminance. Since an optical sheet can be manufactured, it is preferable.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

  In the present invention, the arithmetic average roughness Ra and the maximum cross-sectional height Rt are the surface roughness specified by JIS B0601: 2001, for example, a non-contact three-dimensional micro surface shape measurement system (WYKO manufactured by Veeco) It is a value that can be measured using.

≪Summary of optical sheet≫
An example of the layer structure of the optical sheet of the present invention is shown in FIG.
In the optical sheet 10 shown in FIG. 1, 1 is a gas barrier film, 2 is a resin substrate, 3 is a gas barrier layer, 4 is a quantum dot-containing layer, 11 is a backcoat layer, and 11a is a surface having an uneven structure. is there.
Thus, the optical sheet 10 shown in FIG. 1 has the gas barrier layer 3 on the surface (first surface) facing the quantum dot-containing layer 4, and the first surface is interposed through the resin base material 2. The back coat layer 11 is provided on the opposite surface (second surface).
Hereinafter, each layer will be described in detail.

[Quantum dot-containing layer]
The quantum dot-containing layer according to the present invention is formed by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or after the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor.
That is, the quantum dot-containing layer is a layer (quantum dot-containing resin layer) containing a resin formed by polymerizing or crosslinking a curable resin precursor with ultraviolet rays or heat.

[Quantum Dodd (Semiconductor Nanoparticles)]
A quantum dot (hereinafter also referred to as “semiconductor nanoparticle”) is a particle of a predetermined size that is composed of a crystal of a semiconductor material and has a quantum confinement effect, and has a particle diameter of about several to several tens of nanometers. It is a fine particle and can obtain the quantum dot effect shown below.

  Specifically, the particle diameter of the semiconductor nanoparticles is preferably in the range of 1 to 20 nm, and more preferably in the range of 1 to 10 nm.

  The energy level E of such semiconductor nanoparticles is generally expressed by the following formula (1) when the Planck constant is “h”, the effective mass of electrons is “m”, and the radius of the semiconductor nanoparticles is “R”. ).

Formula (1)
E∝h ² / mR ²

As shown by the formula (1), the band gap of the semiconductor nanoparticles becomes larger in proportion to “R ⁻² ”, and so-called quantum dot effect is obtained. In this way, the band gap value of the semiconductor nanoparticles can be controlled by controlling and defining the particle diameter of the semiconductor nanoparticles. That is, by controlling and defining the particle diameter of the fine particles, it is possible to provide diversity that is not found in ordinary atoms. Therefore, it can be excited by light, or converted into light having a desired wavelength and emitted. Such a luminescent semiconductor nanoparticle material is defined as a semiconductor nanoparticle (quantum dot).

The average particle diameter of the semiconductor nanoparticles is about several nm to several tens of nm as described above, but is controlled to the average particle diameter corresponding to the target emission color. For example, when red light emission is desired, the average particle diameter of the semiconductor nanoparticles is preferably set within a range of 3.0 to 20 nm. When green light emission is desired, the average particle size of the semiconductor nanoparticles is determined. The diameter is preferably set in the range of 1.5 to 10 nm, and when it is desired to obtain blue light emission, the average particle diameter of the semiconductor nanoparticles is preferably set in the range of 1.0 to 3.0 nm. . Moreover, as a control method of an average particle diameter, a well-known method can be used, for example, the average particle diameter of the said semiconductor nanoparticle can be controlled to the desired range with the reaction time at the time of manufacturing a semiconductor nanoparticle.
In the present invention, it is preferable to use a plurality of quantum dots having different emission colors in order to further improve color reproducibility.

  A known method can be used as a method for measuring the average particle diameter of the semiconductor nanoparticles. For example, a method of observing semiconductor nanoparticles using a transmission electron microscope (TEM) and obtaining the number average particle size of the particle size distribution therefrom, or a method of obtaining an average particle size using an atomic force microscope (AFM) The particle size can be measured using a particle size measuring apparatus using a dynamic light scattering method, for example, “ZETASIZER Nano Series Nano-ZS” manufactured by Malvern. In addition, there is a method of deriving the particle size distribution from the spectrum obtained by the X-ray small angle scattering method using the particle size distribution simulation calculation of the semiconductor nanoparticles, but using an atomic force microscope (AFM). A method for obtaining an average particle size is preferred.

  In the semiconductor nanoparticles, the aspect ratio (major axis diameter / minor axis diameter) value is preferably in the range of 1.0 to 2.0, more preferably 1.1 to 1.7. It is a range. The aspect ratio (major axis diameter / minor axis diameter) related to the semiconductor nanoparticles can also be determined by measuring the major axis diameter and the minor axis diameter using, for example, an atomic force microscope (AFM). The number of individuals to be measured is preferably 300 or more.

  The addition amount of the semiconductor nanoparticles is preferably in the range of 0.01 to 50% by mass, and in the range of 0.5 to 30% by mass when the entire first coating solution is 100% by mass. More preferably, it is most preferable that it exists in the range of 2.0-25 mass%. If the addition amount is 0.01% by mass or more, sufficient luminance efficiency can be obtained, and if it is 50% by mass or less, an appropriate inter-particle distance of the semiconductor nanoparticles can be maintained, and the quantum size effect can be sufficiently obtained. It can be demonstrated.

(1) Constituent material of semiconductor nanoparticles As constituent materials of semiconductor nanoparticles, for example, simple substance of Group 14 element of periodic table, simple substance of Group 15 element of periodic table, simple substance of Group 16 element of periodic table, plural periods A compound comprising a group 14 element, a compound of a group 14 element of the periodic table and a group 16 element of the periodic table, a compound of a group 13 element of the periodic table and a group 15 element of the periodic table (or III-V group compound semiconductor) ), A compound of a periodic table group 13 element and a periodic table group 16 element, a compound of a periodic table group 13 element and a periodic table group 17 element, a periodic table group 12 element and a periodic table group 16 element Compound (or II-VI group compound semiconductor), compound of periodic table group 15 element and periodic table group 16 element, compound of periodic table group 11 element and periodic table group 16 element, periodic table 11th Compounds of Group elements and Group 17 elements of the Periodic Table, Group 10 elements of the Periodic Table and Compound with group 16 element of the periodic table, compound with group 9 element of the periodic table and group 16 element of the periodic table, compound of group 8 element of the periodic table and group 16 element of the periodic table, group 7 element of the periodic table And compounds of Group 16 elements of the periodic table, compounds of Group 6 elements of the periodic table and Group 16 elements of the periodic table, compounds of Group 5 elements of the periodic table and Group 16 elements of the periodic table, Group 4 of the periodic table Examples include compounds of elements and Group 16 elements of the periodic table, compounds of Group 2 elements of the periodic table and Group 16 elements of the periodic table, chalcogen spinels, barium titanate (BaTiO ₃ ), and the like. Among these, Si, Ge, GaN, GaP, InN, InP, Ga ₂ O ₃ , Ga ₂ S ₃ , In ₂ O ₃ , In ₂ S ₃ , ZnO, ZnS, CdO, and CdS are more preferable. Since these substances do not contain highly toxic negative elements, they are excellent in environmental pollution resistance and safety to living organisms, and because a pure spectrum can be stably obtained in the visible light region, light emitting devices Is advantageous for the formation of Moreover, said material may be used by 1 type and may be used in combination of 2 or more type.

  The semiconductor nanoparticles described above can be doped with a small amount of various elements as impurities as necessary. By adding such a doping substance, the emission characteristics can be greatly improved.

  The surface of the semiconductor nanoparticles is preferably coated with an inorganic coating layer or a film composed of an organic ligand. That is, the surface of the semiconductor nanoparticle has a core-shell structure having a core part composed of a semiconductor nanoparticle material and a shell part composed of an inorganic coating layer or an organic ligand (also referred to as a coating layer). It is preferable to have it.

  Such a core / shell structure is preferably formed of at least two kinds of compounds, and a gradient structure (gradient structure) may be formed of two or more kinds of compounds. Thereby, the aggregation of the semiconductor nanoparticles in the coating liquid can be effectively prevented, the dispersibility of the semiconductor nanoparticles can be improved, the luminance efficiency is improved, and the optical film containing the semiconductor nanoparticles When the light emitting device using the light source is continuously driven, the occurrence of color misregistration can be suppressed. Further, the light emission characteristics can be stably obtained by the presence of the coating layer.

  Further, when the surface of the semiconductor nanoparticles is covered with the shell portion, a surface modifier as described later can be reliably supported in the vicinity of the surface of the semiconductor nanoparticles.

  Although the thickness of a shell part is not specifically limited, It is preferable to exist in the range of 0.1-10 nm, and it is more preferable to exist in the range of 0.1-5 nm.

  Generally, the emission color can be controlled by the average particle diameter of the semiconductor nanoparticles, and if the thickness of the coating layer is within the above range, the thickness of the coating layer corresponds to the number of atoms. Thus, the thickness is less than one semiconductor nanoparticle, the semiconductor nanoparticle can be filled with high density, and a sufficient amount of light emission can be obtained. In addition, the presence of the coating layer can suppress the transfer of non-emissive electron energy due to defects present on the particle surfaces of the core particles and electron traps on the dangling bonds, thereby suppressing a decrease in quantum efficiency.

  As a method for producing semiconductor nanoparticles, any conventionally known method can be used. Moreover, it can also be purchased as a commercial product from Aldrich, CrystalPlex, NNLab, etc.

  For example, as a process under high vacuum, a molecular beam epitaxy method, a CVD method, etc .; As a liquid phase production method, a raw material aqueous solution is, for example, alkanes such as n-heptane, n-octane, isooctane, benzene, toluene, A reverse micelle method in which crystals exist in a reverse micelle in a nonpolar organic solvent such as an aromatic hydrocarbon such as xylene and crystal growth in this reverse micelle phase, a thermally decomposable raw material is injected into a high-temperature liquid phase organic medium Examples include a hot soap method for crystal growth, and a solution reaction method involving crystal growth at a relatively low temperature with an acid-base reaction as a driving force, as in the hot soap method. Any method can be used from these production methods, and among these, the liquid phase production method is preferred.

  As described above, the size (average particle diameter) of the semiconductor nanoparticles is preferably in the range of 1 to 20 nm. The size of the semiconductor nanoparticle is the total size composed of the core region composed of the semiconductor nanoparticle material, the shell layer composed of the inert inorganic coating layer or the organic ligand, and the surface modifier. Represent. If the surface modifier or shell is not included, the size does not include it.

[Curable resin precursor]
The curable resin precursor is not particularly limited as long as it is cured as a resin by polymerization or crosslinking reaction with ultraviolet rays or heat. Examples of such a curable resin precursor include a thermosetting or photocurable polymer and a monomer. Specifically, as the curable resin precursor, melamine resin, phenol resin, alkyl resin, epoxy resin, polyurethane resin, maleic acid resin, polyamide resin, polymethylmethacrylic acid, polyacrylic acid, polycarbonate, polyvinyl alcohol, Polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, and known curable resin precursors that form these resins can be suitably used. Moreover, as such a curable resin precursor, for example, a copolymer containing a monomer, a resin containing acrylic acid or methacrylic acid as a raw material and containing a reactive vinyl group, a photocrosslinkable resin usually containing a photosensitizer Etc. Furthermore, when a photosensitizer is not used, a thermosetting resin precursor may be used as the curable resin precursor. Among these, the curable resin precursor is preferably a resin precursor that is cured to become an epoxy resin. One type of curable resin precursor may be used alone, or two or more types may be used.

  The resin obtained by curing the curable resin precursor is preferably optically transparent to light having a wavelength in the visible range.

  The thickness of the quantum dot-containing layer used in the present invention is preferably in the range of 10 to 200 μm, more preferably in the range of 20 to 150 μm, and still more preferably in the range of 40 to 120 μm, from the viewpoint of light emission characteristics.

  The quantum dot-containing layer is formed by, for example, applying a coating liquid containing a curable resin precursor and semiconductor nanoparticles on a gas barrier film that serves as a support for the quantum dot-containing layer, and the quantum dot and the curable resin precursor. When a gas barrier film is laminated on the coating film, a quantum dot-containing layer (quantum dot-containing resin layer) is formed by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or later. A method is mentioned.

  The coating solution can be adjusted to an appropriate viscosity using a solvent as necessary. Such a solvent is not particularly limited as long as it does not react with semiconductor nanoparticles. For example, hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (Acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents can be appropriately selected or used by mixing them.

  Furthermore, you may add a required additive to a coating liquid. For example, when a curable resin precursor is cured, an appropriate additive may be added depending on the curing method. Here, as a method of curing by curing or curing the curable resin precursor with ultraviolet rays or heat, a known curing agent or a known method can be employed. Moreover, when hardening by ultraviolet irradiation, photoinitiators, such as Irgacure 819 (made by BASF Japan), can be used, for example.

  Although content of the semiconductor nanoparticle in a coating liquid is not specifically limited, For example, it is preferable that it is 0.1-10 mass%, and it is more preferable that it is 0.5-5 mass%.

  The coating method of the coating liquid is not particularly limited, and a conventionally known wet coating method can be appropriately selected and applied. Specifically, for example, spin coating method, die coating method, roller coating method, flow coating method, ink jet method, spray coating method, printing method, dip coating method, casting film forming method, bar coating method, gravure printing method, etc. Can be mentioned.

  It is preferable to dry the formed coating film after applying the coating solution. By drying, the organic solvent contained in the coating film can be removed. At this time, all of the organic solvent contained in the coating film may be dried or may be partially left. Even when a part of the organic solvent is left, a suitable quantum dot-containing layer can be obtained. The remaining organic solvent can be removed later.

  As a light source for the ultraviolet irradiation treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

[Gas barrier film]
The gas barrier film according to the present invention has a gas barrier layer on the first surface facing the quantum dot-containing layer, and on the second surface opposite to the first surface through the resin base material. It has a back coat layer. The gas barrier film according to the present invention is not particularly limited as long as it has such a gas barrier layer and a back coat layer, and a known configuration can be suitably employed.
The following is an example of a gas barrier film having a backcoat layer on a resin substrate and having an undercoat layer and a gas barrier layer on the opposite side of the processed surface of the resin substrate on which the backcoat layer is formed. Detailed explanation.

<Resin substrate>
As the resin base material according to the present invention, known materials can be used. Specifically, for example, the resins described in paragraphs 0027, 0028, 0029, 0034, 0035, etc. of JP-A-2015-024384 are used. it can. The resin substrate can be used alone or in combination of two or more.

In addition, the unstretched film may be sufficient as the resin base material quoted above, and a stretched film may be sufficient as it.
The resin base material can be manufactured by a conventionally known general method. About the manufacturing method of these resin base materials, the matter described in the paragraphs 0051-0055 of international publication 2013/002026 can be employ | adopted suitably.

  The surface of the resin base material may be subjected to various known treatments for improving adhesion, such as corona discharge treatment, flame treatment, oxidation treatment or plasma treatment, and the above treatments are performed in combination as necessary. It may be. The resin base material may be subjected to an easy adhesion treatment.

  The resin substrate may be a single layer or a laminated structure of two or more layers. When the resin base material has a laminated structure of two or more layers, the resin base materials may be the same type or different types.

  The thickness of the resin substrate according to the present invention (the total thickness in the case of a laminated structure of two or more layers) is preferably 10 to 200 μm, and more preferably 20 to 150 μm.

<Gas barrier layer>
The gas barrier layer according to the present invention is formed on a surface (first surface) on the side facing the quantum dot-containing layer in the gas barrier film.
As a method for forming the gas barrier layer, a known method can be used, for example, a plasma CVD (chemical vapor deposition) method described in Japanese Patent Application Laid-Open No. 2014-218202, a chemical vapor deposition method such as ALD (Atomic Layer Deposition), or the like. Can be used. In addition, as a physical vapor deposition method, a sputtering method, a vapor deposition method, an ion assist vapor deposition method, an ion plating method, or the like can be used as a forming method.

The gas barrier layer according to the present invention is a layer having gas barrier properties. Specifically, the gas barrier layer has a water vapor permeability (25 ± 0.5 ° C., relative humidity 90 ± 2%) measured by a method according to JIS-K-7129-1992 of 5.0 × 10 ⁻ The water vapor barrier property is preferably ² g / (m ² · 24 hours) or less, and more preferably 5.0 × 10 ⁻³ g / (m ² · 24 hours) or less. Moreover, the oxygen permeability measured by the method based on JIS-K-7126-1987 is 1 × 10 ⁻³ mL / (m ² · 24 hours · atm) or less, and the water vapor permeability is 1 × 10 ^{−. It} preferably has a gas barrier property of ⁵ g / (m ² · 24 hours) or less.

  As a constituent material of the gas barrier layer formed by the film forming method of the present invention, for example, inorganic silicon compounds such as silicon oxide, silicon oxynitride, silicon dioxide, silicon nitride, and organic silicon compounds can be used.

  In particular, the gas barrier layer is preferably formed by oxidizing or nitriding a gas obtained by vaporizing an organosilicon compound with a plasma CVD apparatus.

(Raw material gas)
In the formation of the gas barrier layer according to the present invention, it is preferable to use an organosilicon compound containing at least silicon as the source gas constituting the film forming gas.

  Examples of the organosilicon compound applicable to the present invention include hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, and trimethyl. Examples thereof include silane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, and octamethylcyclotetrasiloxane. Among these organosilicon compounds, hexamethyldisiloxane and 1,1,3,3-tetramethyldisiloxane are preferable from the viewpoints of handling in film formation and gas barrier properties of the obtained gas barrier layer. Moreover, these organosilicon compounds can be used individually or in combination of 2 or more types.

  The film forming gas preferably contains oxygen gas as a reaction gas in addition to the source gas. The oxygen gas is a gas used to react with the raw material gas to form an inorganic compound such as an oxide.

  As the film forming gas, a carrier gas may be used as necessary in order to supply the source gas into the vacuum chamber. Further, as a film forming gas, a discharge gas may be used as necessary in order to generate plasma discharge. As such carrier gas and discharge gas, known ones can be used as appropriate, and for example, a rare gas such as helium, argon, neon, xenon, or hydrogen gas can be used.

  When such a film forming gas contains a raw material gas containing an organosilicon compound containing silicon and an oxygen gas, the ratio of the raw material gas to the oxygen gas is such that the raw material gas and the oxygen gas are completely reacted. It is preferable that the oxygen gas ratio is not excessively higher than the theoretically required oxygen gas ratio. If the ratio of oxygen gas is excessive, it is difficult to obtain the target gas barrier layer in the present invention. Therefore, in order to obtain the desired performance as a barrier film, it is preferable that the total amount of the organosilicon compound in the film forming gas is less than the theoretical oxygen amount necessary for complete oxidation.

<Back coat layer>
In the gas barrier film, the back coat layer according to the present invention is formed on the second surface opposite to the first surface having the gas barrier layer through the resin base material.
The back coat layer is provided for the purpose of improving the curl balance of the gas barrier layer, device fabrication process resistance, handling suitability, and the like.

In the back coat layer according to the present invention, at least the surface far from the quantum dot-containing layer is a surface having a concavo-convex structure.
The arithmetic mean roughness Ra of the surface having the concavo-convex structure is in the range of 0.01 to 0.10 μm, and the maximum cross-sectional height Rt is in the range of 0.2 to 2.0 μm.
In addition, it is preferable that arithmetic mean roughness Ra of the surface which has the said uneven | corrugated structure exists in the range of 0.03-0.08 micrometer, and it is most preferable that it exists in the range of 0.05-0.08 micrometer.
Further, the maximum cross-sectional height Rt of the surface having the concavo-convex structure is preferably in the range of 0.5 to 1.5 μm, and most preferably in the range of 1.0 to 1.2 μm.

  The material of the backcoat layer according to the present invention is not particularly limited as long as it can realize the above Ra and Rt, and for example, known materials such as UV curable resin monomers and acrylic polymers can be used.

  Specifically, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, glycerol tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dicyclopentanyl di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate , Diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyunsaturated organic compounds such as polypropylene glycol di (meth) acrylate.

  Also, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl ( (Meth) acrylate, allyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol (meta ) Acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) Chlorate, butoxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, 2-methoxypropyl (meth) acrylate Unitary unsaturated organic compounds such as methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol (meth) acrylate can also be used. .

  In addition, for example, a composition containing an acrylate compound, a composition containing an acrylate compound and a mercapto compound containing a thiol group, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyethylene glycol acrylate, glycerol methacrylate A composition containing a polyfunctional acrylate monomer such as can also be used.

As a commercially available product, a hard coat material HR370-21-NLF manufactured by Yokohama Rubber Co., Ltd. can be suitably used.
The back coat layer may contain inorganic fine particles, a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin, a photopolymerization initiator, and the like as other components as necessary.

Moreover, it is preferable that the backcoat layer according to the present invention contains a filler selected from an acrylate resin and a polyamide resin because winding properties and transportability are improved. Specifically, for example, cross-linked acrylic monodisperse particles (MX-300, average particle size of 3 μm) manufactured by Soken Chemical Co., Ltd. can be used.
A preferred filler size is about 0.1 to 10 μm, preferably 0.5 to 5 μm, and more preferably 1 to 3 μm. If it is 0.1 micrometer or more, it is preferable for conveyance property, and if it is 10 micrometers or less, it is excellent optically and preferable. It is preferable that the filler size diameter is larger than the thickness of the backcoat layer. Preferably, 0.05 to 5 μm, more preferably 0.1 to 2 μm, can obtain the above effect.

Moreover, it is preferable that the back coat layer according to the present invention contains a compound having at least two or more isocyanate groups because better luminance can be realized.
As the compound having at least two isocyanate groups, known compounds can be used, for example, 2,4- (or 2,6-) tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, Aromatic polyisocyanates such as dianisidine diisocyanate; alicyclic polyisocyanates such as 2-methyl-cyclohexane-1,4-diisocyanate, isophorone diisocyanate, hydrogenated MDI (4,4'-disylhexylmethane diisocyanate) ; Aliphatic polyisocyanates such as hexamethylene diisocyanate, decamethylene diisocyanate, 1,6,11-undecane triisocyanate, and the like, and commercially available products include Coronate HX manufactured by Nippon Polyurethane Co., Ltd.

(Method for forming uneven structure)
Further, the method for forming the concavo-convex structure according to the present invention is not particularly limited, for example, a sand blast method, a method of forming with a resin containing a matting agent, a method of forming by phase separation of a plurality of types of resin precursors or resins, Examples include a physical etching method, a chemical etching method, and a mold transfer method. Among these, a surface derived from a structure formed by phase separation of a plurality of types of resin precursors or resins is preferable because optical design and adjustment are easy, and luminance and luminance unevenness are further improved.

(Multiple types of resin precursors or resins)
When forming the concavo-convex structure according to the present invention by phase separation, as the plurality of types of resin precursors or resins contained in the backcoat layer, a resin precursor that phase-separates when forming the backcoat layer or If it is resin, it will not specifically limit, A well-known thing can be used.
Examples of such resins include vinyl chloride-vinyl acetate copolymers, vinyl chloride resins, vinyl acetate resins, copolymers of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymers, and chlorides. Vinyl-based vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Copolymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose acetate butyrate resin Cellulose derivatives such as maleic acid and / or acrylic acid copolymers, acrylic Acid ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, polyester Examples include polyurethane resins, polyether polyurethane resins, polycarbonate polyurethane resins, polyester resins, polyether resins, polyamide resins, amino resins, styrene-butadiene resins, rubber resins such as butadiene-acrylonitrile resins, silicone resins, and fluorine resins. However, it is not limited to these. For example, as an acrylic resin, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR -80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105 , BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, EMB-456, EMB-448, EMB Various homopolymers and copolymers of acrylic and methacrylic monomer was prepared as a raw material of 457 etc. (Mitsubishi Rayon Co., Ltd.) are commercially available or can be selected as appropriate preferred from among these.

In addition, it is preferable that a plurality of types of resin precursors or resins are contained because uneven structures having a non-uniform shape can be formed, and the luminance is improved.
Furthermore, when forming a concavo-convex structure by phase separation of a plurality of types of resin precursors or resins, it is possible to form a concavo-convex structure having a non-uniform shape, so that at least two types have different hydroxy values of 20 mgKOH / g or more. This is preferable because the luminance is improved. Preferably it is 20-50 mgKOH / g, and 30-45 mgKOH / g is still more preferable.
In addition, the formation of the concavo-convex structure by phase separation can be confirmed by, for example, observation with a scanning electron microscope (SEM) or transmission electron microscope (TEM).

(Hydroxy value)
The hydroxyl value (also referred to as hydroxyl value) of the resin precursor or resin is necessary to neutralize acetic acid bonded to the hydroxy group when 1 g of the resin precursor or resin containing a hydroxy group is acetylated. Expressed in mg of potassium hydroxide. As a method for measuring the hydroxy group, titration, for example, a method defined in JIS K1557-1: 2007 can be used.

[Undercoat layer]
According to the present invention, an undercoat layer may be provided between the gas barrier film and the surface of the resin base material having the gas barrier layer, preferably between the resin base material and the gas barrier layer. The undercoat layer is used to flatten the rough surface of the substrate on which protrusions and the like exist, or to flatten the unevenness and pinholes generated in the gas barrier layer by the protrusions existing on the resin substrate. Provided. Further, it is provided for the purpose of improving the adhesiveness (adhesion) between the resin base material and the gas barrier layer.

  Such an undercoat layer may be formed of any material, but preferably includes a carbon-containing polymer, and more preferably includes a carbon-containing polymer. That is, the gas barrier film according to the present invention preferably further has an undercoat layer containing a carbon-containing polymer between the resin base material and the gas barrier layer.

  The undercoat layer also contains a carbon-containing polymer, preferably a curable resin. The curable resin is not particularly limited, and the active energy ray curable resin or the thermosetting material obtained by irradiating the active energy ray curable material or the like with an active energy ray such as an ultraviolet ray to be cured is heated. And thermosetting resins obtained by curing. These curable resins may be used alone or in combination of two or more.

  Examples of the active energy ray-curable material used for forming the undercoat layer include a composition containing an acrylate compound, a composition containing an acrylate compound and a mercapto compound containing a thiol group, and a polyfunctional acrylate monomer. And the like. Specifically, an organic / inorganic hybrid hard coat material OPSTAR (registered trademark) series (compound formed by bonding an organic compound having a polymerizable unsaturated group to silica fine particles), which is an ultraviolet curable material manufactured by JSR Corporation. Can be used. It is also possible to use any mixture of the above-mentioned compositions, and an active energy ray-curable material containing a reactive monomer having at least one photopolymerizable unsaturated bond in the molecule. If there is no restriction in particular.

  The undercoat layer formation method is not particularly limited, and after a known method, a coating solution containing a curable material is applied by a wet coating method such as a die coating method to form a coating film, an ultraviolet ray etc. A method in which the coating film is cured and formed by irradiation with active energy rays and / or heating is preferable.

[Method for producing optical sheet]
As a manufacturing method of the optical sheet concerning the present invention, it has a process of producing a gas barrier film, and a process of forming a quantum dot content layer, and it is preferred that these processes are the following modes.

<Process for producing gas barrier film>
In the step of producing the gas barrier film, a gas barrier layer is formed on the surface (first surface) of the resin substrate on the side facing the quantum dot-containing layer, and the first surface is a resin substrate. A back coat layer is formed on the second surface on the opposite side, and at least the surface of the back coat layer far from the quantum dot-containing layer is formed to have a concavo-convex structure, The arithmetic mean roughness Ra of the surface having the concavo-convex structure is adjusted to be in the range of 0.01 to 0.10 μm, and the maximum cross-sectional height Rt is adjusted to be in the range of 0.2 to 2.0 μm.

  In particular, in the method for producing an optical sheet according to the present invention, the surface having the concavo-convex structure of the backcoat layer is formed by phase separation of a plurality of types of resin precursors or resins contained in the backcoat layer. However, it is preferable because optical design and adjustment are easy, and as a result, luminance unevenness is improved.

  The phase separation method is not particularly limited and a known method can be used. For example, specifically, a curable resin monomer and a plurality of resins are mixed with PGME (propylene glycol monomethyl ether). A coating solution dissolved in an organic solvent such as the above may be applied using a die coater or the like, then dried, and further phase-separated by curing with a high-pressure mercury lamp or the like.

<Process for forming quantum dot-containing layer>
In the step of forming the quantum dot-containing layer, the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor, and at the same time or later, it is formed by polymerization or crosslinking reaction with ultraviolet rays or heat.

Specifically, a coating liquid is formed by applying a coating liquid containing quantum dots and a curable resin precursor on the surface of the gas barrier film on the gas barrier layer side, and a gas barrier film is further formed on the coating film. It is preferably a step of forming a quantum dot-containing layer (quantum dot-containing resin layer) by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or after the lamination and curing the coating film.
In addition, it is preferable to arrange | position a gas barrier film so that the surface by the side of a gas barrier layer may face a quantum dot content layer side. In addition, when the quantum dot-containing layer is a film having self-supporting property, the optical sheet containing semiconductor nanoparticles is obtained by laminating the gas barrier film according to the present invention on both surfaces of the quantum dot-containing layer with an adhesive or the like. It may be produced.

  Furthermore, about the manufacturing method of the optical sheet which has a quantum dot, a quantum dot content layer, and a quantum dot content layer etc., in addition, in the range which does not inhibit the effect of the present invention, JP, 2013-508895, A special table 2013- What is described in well-known literatures, such as 544018 gazette, can be used.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the examples, “%” is used, but “mass%” is indicated unless otherwise specified. Moreover, in the following operation, unless otherwise specified, the measurement of the operation and physical properties is performed under the conditions of room temperature (25 ° C.) / Relative humidity 40 to 50%.

<Production of gas barrier film>
<Example 1: Production of gas barrier film 101>
[Formation of back coat layer]
As a UV curable resin monomer, 20% by mass of a hard coat material HR370-21-NLF (solid content 52%) manufactured by Yokohama Rubber Co., Ltd., and BR-90 (hydroxy value: 0% KOH / g) 15% PGME solution 5% by mass, Mitsubishi Rayon EMB-456 (hydroxy value: 20 mg KOH / g) 15% PGME solution 5% by mass, and finally PGME 5% by mass A coating solution was prepared by addition.
After coating using a die coater on a Toray Industries polyethylene terephthalate film 125 μm thick substrate (type U403) so that the film thickness after drying is 2 μm, it passes through a drying line at 80 ° C. for 2 minutes, and further in an air atmosphere. Then, a high pressure mercury lamp was used under the condition of 1.0 J / cm ² to cure and form a backcoat layer.

(Measurement of hydroxy value)
The hydroxy value was measured as follows.

1. Preparation of reagent Acetylation reagent (25 g of acetic anhydride is taken into a 100-mL volumetric flask, pyridine is added to make a total volume of 100 mL, and shaken well.)
Phenolphthalein solution 0.5 kmol / m ³ potassium hydroxide ethanol solution

2. Measurement method (a) A resin precursor or resin to be measured is precisely weighed in a flat bottom flask within a range of 0.5 to 6.0 g, and 5 mL of an acetylating reagent is added thereto using a pipette.
(B) Place a small funnel in the mouth of the flask and immerse the bottom of about 1 cm in a glycerin bath within a temperature range of 95-100 ° C. and heat. In order to prevent the temperature of the neck of the flask from rising due to the heat of the glycerin bath, a cardboard disc with a round hole in it is put on the base of the neck of the flask.
(C) After 1 hour, the flask is removed from the glycerin bath, and after standing to cool, 1 mL of water is added from the funnel and shaken to decompose acetic anhydride.
(D) Further, in order to complete the decomposition, the flask is heated again in a glycerin bath for 10 minutes, and after cooling, the funnel and the wall of the flask are washed with 5 mL of ethanol (95).
(E) A few drops of phenolphthalein solution is added as an indicator, and titrated with 0.5 kmol / m ³ potassium hydroxide ethanol solution, and the end point is when the indicator is light red for about 30 seconds.
(F) The blank test is performed from (a) to (e) without adding the resin precursor or resin (a) to be measured.
(G) If the sample is difficult to dissolve, add a small amount of pyridine, or add xylene or toluene to dissolve.

The calculation formula is as follows.
A = [{(BC) × 28.05 × f} / S] + D
However,
A: Hydroxy value (mgKOH / g)
B: Amount (mL) of 0.5 kmol / m ³ potassium hydroxide ethanol solution used for the blank test
C: Amount of 0.5 kmol / m ³ potassium hydroxide ethanol solution used for titration (mL)
f: Factor S of 0.5 kmol / m ³ potassium hydroxide ethanol solution: Mass of resin precursor or resin to be measured (g)
D: Acid value 28.05: Formula weight of potassium hydroxide 56.11 × 1/2

[Formation of undercoat layer]
After applying the UV curable coating agent OPSTAR Z7527 manufactured by JSR Corporation on the surface opposite to the processed surface of the substrate on which the backcoat layer is formed, and using a die coater so that the film thickness after drying is 4 μm. Then, the film was passed through a drying line at 80 ° C. for 2 minutes, and further cured under an air atmosphere at a high pressure mercury lamp operating condition of 1.0 J / cm ² to form an undercoat layer.

[Formation of gas barrier layer]
The polyester film (thickness: 50 μm) on which the backcoat layer and the undercoat layer were formed was set in a production apparatus as shown in FIG. 2 and conveyed. Next, a magnetic field is applied between the film forming roller 39 and the film forming roller 40, and electric power is supplied to the film forming roller 39 and the film forming roller 40, respectively. Was discharged to generate plasma. Next, a film forming gas (a mixed gas of hexamethyldisiloxane (HMDSO) as a source gas and oxygen gas (also functioning as a discharge gas) as a source gas) is supplied to the formed discharge region, A gas barrier thin film (gas barrier layer) was formed on the undercoat layer by a plasma CVD method to obtain a gas barrier film, and the thickness of the gas barrier layer was 150 nm. Was as follows.

(Deposition conditions)
Supply amount of source gas: 50 sccm (Standard Cubic Centimeter per Minute, 0 ° C., 1 atm standard)
Oxygen gas supply amount: 500 sccm (0 ° C., 1 atm standard)
Degree of vacuum in the vacuum chamber: 2Pa
Applied power from the power source for plasma generation: 1.5 kW
Frequency of power source for plasma generation: 80 kHz
Film transport speed: 1.0 m / min

<< Evaluation of water vapor barrier property (water vapor permeability WVTR) >>
The gas barrier film produced above was evaluated for water vapor barrier properties.
Using AQUATRAN manufactured by MOCON, the water vapor transmission rate WVTR (g / m ² / day) was measured after the numerical value was stabilized under the condition of 38 ° C. and 90% RH. The gas barrier film produced in this example was 8 × 10 ⁻³ g / m ² / day.

<Example 2: Production of gas barrier film 102>
In the formation of the back coat layer of the gas barrier film 101, the same as the gas barrier film 101 except that EMB-448 (hydroxy value: 10 mgKOH / g) was used instead of BR-90 (hydroxy value: 0 mgKOH / g). A gas barrier film 102 was produced.

<Example 3: Production of gas barrier film 103>
In the formation of the back coat layer of the gas barrier film 101, the same as the gas barrier film 101 except that EMB-456 (hydroxy value: 43 mg KOH / g) was used instead of EMB-456 (hydroxy value: 20 mg KOH / g). A gas barrier film 103 was produced.

<Example 4: Production of gas barrier film 104>
In the formation of the back coat layer of the gas barrier film 101, 3% cross-linked acrylic monodisperse particles (MX-300, average particle size 3 μm) manufactured by Soken Chemical Co., Ltd. and 1% rheology control agent BYK-410 were added as fillers. A gas barrier film 104 was produced in the same manner as the production of the gas barrier film 101 except that the coating solution was prepared.

<Example 5: Production of gas barrier film 105>
In the production of the gas barrier film 104, nylon 12 particles (SP-500, average particle size 5 μm) manufactured by Toray Industries, Inc. were used as polyamide resin fine particles instead of the crosslinked acrylic monodispersed particles manufactured by Soken Chemical Co., Ltd. Thus, a gas barrier film 105 was produced.

<Example 6: Production of gas barrier film 106>
In the formation of the back coat layer of the gas barrier film 101, a gas barrier film 106 was produced in the same manner as the production of the gas barrier film 101 except that the coating solution was prepared as follows and the back coat layer was formed.

As a UV curable resin monomer, 20% by mass of hard coat material HR370-21-NLF (solid content 52%) manufactured by Yokohama Rubber Co., Ltd., and EMB-448 (hydroxy value: Mitsubishi Rayon Co., Ltd.) dialnal (acrylic polymer) are used. 10% KOH / g) of 15% PGME solution was added to 5% by mass, Mitsubishi Rayon EMB-457 (hydroxy value: 43 mgKOH / g) of 15% PGME solution was added to 5% by mass, and at least two more As a compound having an isocyanate group, 1.5% by mass of Coronate HX manufactured by Tosoh Corporation was added, and finally 3.5% by mass of PGME was added to prepare a coating solution.
After coating with a die coater on a polyethylene terephthalate film 125 μm thick substrate (type U403) manufactured by Toray Industries Inc. so that the film thickness after drying becomes 2 μm, a 100 ° C. drying line is passed through for 5 minutes to form a backcoat layer. Formed.

<Example 7: Production of gas barrier film 107>
In the formation of the back coat layer of the gas barrier film 106, 3% cross-linked acrylic monodisperse particles (MX-300, average particle size 3 μm) manufactured by Soken Chemical Co., Ltd. and 1% rheology control agent HYB-410 were applied as fillers. A gas barrier film 107 was produced in the same manner as the production of the gas barrier film 106 except that the liquid was prepared.

<Example 8: Production of gas barrier film 108>
As a UV curable resin monomer, a 20% by mass PGME solution of a hard coat material HR370-21-NLF (solid content 52%) manufactured by Yokohama Rubber Co., Ltd. was prepared as a coating solution.
After applying the coating solution on a polyethylene terephthalate film 125 μm thick substrate (type U403) manufactured by Toray Industries Inc. using a die coater so that the film thickness after drying becomes 2 μm, a 80 ° C. drying line is passed through for 2 minutes, Further, a back coat layer was formed by curing at 1.0 J / cm ² using a high-pressure mercury lamp in an air atmosphere.
Thereafter, a gas barrier film 108 was produced in the same manner as the production of the gas barrier film 101 except that a surface having a concavo-convex structure was formed on the backcoat layer by using a sand blast method.

<Comparative Example 1: Production of gas barrier film 109>
In the formation of the back coat layer of the gas barrier film 101, 20% by mass of a hard coat material HR370-21-NLF (solid content 52%) manufactured by Yokohama Rubber Co., Ltd. as a UV curable resin monomer, and a dialnal manufactured by Mitsubishi Rayon Co., Ltd. 15% PGME solution of BR-90 (hydroxy value: 0 mgKOH / g) of (acrylic polymer), 15% of BR-85 (hydroxy value: 0 mgKOH / g) of dialnal (acrylic polymer) manufactured by Mitsubishi Rayon Co., Ltd. A gas barrier film 109 was produced in the same manner as in the production of the gas barrier film 101 except that 10% by mass of a% PGME solution was added, and finally 5% by mass of PGME was added to obtain a coating solution.

<Comparative Example 2: Production of gas barrier film 110>
In the formation of the back coat layer of the gas barrier film 109, 3% cross-linked acrylic particles (filler, MX-3 μm) manufactured by Soken Chemical Co., Ltd. and 1% rheology control agent HYB-410 were added to prepare a coating solution. A gas barrier film 110 was produced in the same manner as the production of the gas barrier film 109.

<< Measurement of Arithmetic Average Roughness Ra and Maximum Section Height Rt >>
The arithmetic average roughness Ra and the maximum cross-sectional height Rt of the surface having the concavo-convex structure in the back coat layer are expressed by the surface roughness specified by JIS B0601: 2001, and are a non-contact three-dimensional micro surface shape measurement system (Veeco). Measurement was performed using WYKO).
The gas barrier films 101 to 110 produced above were measured for Ra and Rt and are shown in Table 1.

<< Evaluation of water vapor barrier property (water vapor permeability WVTR) >>
About the gas barrier film produced above, water vapor permeability WVTR (g / m ² / day) was measured in the same manner as the gas barrier film 101.
It was confirmed that each of the gas barrier films prepared above had a WVTR of 5 × 10 ⁻² g / m ² / day or less that can sufficiently obtain a water vapor barrier property.

[Manufacture of optical sheets]
(Synthesis of quantum dodd (semiconductor nanoparticles))
Indium myristate 0.1 mmol, stearic acid 0.1 mmol, trimethylsilylphosphine 0.1 mmol, dodecanethiol 0.1 mmol, and undecylenic acid zinc 0.1 mmol were placed in a three-necked flask together with octadecene 8 mL, and refluxed in a nitrogen atmosphere. InP / ZnS (quantum dots) was obtained by heating at 0 ° C. for 1 hour.

  By directly observing the synthesized quantum dots with a transmission electron microscope, it was confirmed that the core / shell structure was such that the surface of InP was covered with ZnS. In this specification, as a notation method of quantum dots having a core / shell structure, for example, when the core is InP and the shell is ZnS, it is expressed as InP / ZnS. Moreover, according to the observation, the InP / ZnS quantum dots synthesized above had a core part particle size of 2.1 to 3.8 nm and a core part particle size distribution of 6 to 40%. Here, a transmission electron microscope JEM-2100 manufactured by JEOL Ltd. was used for the observation.

  Moreover, the optical characteristic of the InP / ZnS quantum dot was acquired by measuring the octadecene solution containing a quantum dot. That is, it was confirmed that by changing the particle size of the quantum dots by controlling the synthesis time, quantum dots having an emission peak wavelength of 430 to 720 nm and an emission half width of 35 to 90 nm can be obtained arbitrarily. . Note that the luminous efficiency reached a maximum of 70.9%. Here, a fluorescence spectrophotometer FluoroMax-4 manufactured by JOBIN YVON was used to measure the emission characteristics of InP / ZnS quantum dots, and an absorption spectrum measurement of InP / ZnS quantum dots A was performed using Hitachi High-Technologies Corporation. A spectrophotometer U-4100 made by the company was used.

(Production of optical sheet)
The particle size is adjusted so that the quantum dots obtained above emit light in red and green, the red component and the green component are mixed in a ratio of 1: 6, and further UV curing type manufactured by DIC Corporation. To the resin Unidic V-5500, a photopolymerization initiator Irgacure 819 (manufactured by BASF Japan) was added, and a UV curable resin solution adjusted to a resin / initiator ratio of 95/5 at a solid content ratio (% by mass) was added. The coating liquid for quantum dot content layer formation in which the mass content rate of a quantum dot became 1 mass% was prepared.

For each of the produced gas barrier films 101 to 110, two rolls each slit so that the substrate width is 400 mm are prepared, and the gas barrier layer faces the upper and lower rollers of the roll laminator. The coating liquid for forming the quantum dot layer prepared above was spread and laminated before lamination on the lower roller side. Here, as the roll laminator, a metal roll having a mirror finish of 100 mmφ was used for both the upper roller and the lower roller, and laminating was performed so that the resin film thickness became 100 μm by adjusting the gap.
Subsequent to the above lamination, UV irradiation was performed using a low-pressure mercury lamp so that the irradiation amount was 300 mJ / cm ² , and curing was performed.

"Visual inspection"
After laminating and curing, trimming to a size of 350 mm × 450 mm was performed, the bonding state of the optical sheet was visually observed, and an appearance inspection was performed according to the following indices. The results are shown in Table 2.
◎: Good with no waviness, wrinkles, or scratches ○: Good with no wrinkles or scratches at the edges, but good with no wrinkles or scratches △: Good with no wrinkles or scratches at the edges, but good with no wrinkles or scratches ×: At the ends Swell, wrinkle or scratch of 10 mm or less XX: Swell, wrinkle or scratch of 10 mm or more at the end

In the above, swell, wrinkle and scratch are as follows.
Swell: Place flat on a flat table and measure the height generated by the swell of the edge.
Wrinkles: Folding creases that occur during transport and transfer due to deformation.
Scratches: Visible scratches caused by rubbing with a transport roller or the like due to poor transport.

<Brightness measurement>
The luminance was measured for each of the produced optical sheets. For the luminance measurement, a blue LED having an emission peak at an emission wavelength of λ450 nm ± 5 nm was used by using a surface light source diffused by a diffusion plate, and an optical sheet was placed on the surface light source to emit light. As a luminance meter, luminance was measured using a spectral radiance meter CS-2000 manufactured by Konica Minolta. Table 2 shows the relative values of the light emission luminances of the optical sheets using the gas barrier films 102 to 110 when the light emission luminance of the optical sheet produced using the gas barrier film 101 is taken as 100. The standards are as follows.
◎: Luminance 116 or higher ○: Luminance 106-115
Δ: Luminance 96-105

<Measurement of uneven brightness>
Similarly to the luminance measurement method described above, the luminance value of the produced optical sheet was obtained. Similarly, when the emission luminance of the optical sheet produced using the gas barrier film 101 was set to 100, the location of each sheet was changed to 20 points. Each measurement was performed to determine the standard deviation σ of the luminance value. Each sample was evaluated according to the following criteria.
A: σ ≦ 1.0
○: 1.0 <σ ≦ 3.0
Δ: 3.0 <σ ≦ 5.0
×: σ> 5.0

  The evaluation results of each example and each comparative example are shown in Table 2 below.

(Summary)
As described above, according to the configuration of the present invention, it is possible to suppress the occurrence of undulations, wrinkles or scratches at the time of manufacture, and even if the optical sheet contains quantum dots, there is no unevenness and an excellent luminance optical sheet is provided. It was shown that it can be done.
In addition, Examples 1 to 7 in which the surface having the concavo-convex structure is a surface derived from the structure formed by phase separation have an appearance, luminance, It was shown that the luminance unevenness was good.
Further, in the production of the optical sheets of Examples 1 to 8 and Comparative Examples 1 and 2, using a low-pressure mercury lamp simultaneously with the lamination, UV irradiation was performed so that the irradiation amount was 300 mJ / cm ² and curing was performed. In addition, the optical sheet produced in the same manner also had the same results as in Examples 1 to 8 and Comparative Example 1 and Comparative Example 2. If the structure of the present invention is used, undulations, wrinkles or scratches at the time of production will be obtained. It was shown that even an optical sheet that can suppress generation and contains quantum dots can provide an optical sheet with no unevenness and excellent luminance.

DESCRIPTION OF SYMBOLS 1 Gas barrier film 2 Resin base material 3 Gas barrier layer 4 Quantum dot content layer 10 Optical sheet 11 Backcoat layer 11a Surface which has an uneven structure 31 Manufacturing apparatus 32 Delivery roller 33, 34, 35, 36 Conveyance roller 39, 40 Film formation Roller 41 Gas supply pipe 42 Power source for generating plasma 43, 44 Magnetic field generator 45 Winding roller

Claims (7)

An optical sheet having a quantum dot-containing layer laminated with a gas barrier film,
The gas barrier film has a gas barrier layer on a first surface facing the quantum dot-containing layer, and a back coat is applied to a second surface opposite to the first surface through a resin base material. Has a layer,
The surface on the side far from the quantum dot-containing layer of the backcoat layer is a surface having a concavo-convex structure,
The arithmetic average roughness Ra of the surface having the concavo-convex structure is in the range of 0.01 to 0.10 μm, the maximum cross-sectional height Rt is in the range of 0.2 to 2.0 μm, and
The quantum dot-containing resin layer formed by polymerizing or crosslinking reaction with ultraviolet rays or heat at the same time or after the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor. An optical sheet characterized by the above.   2. The surface having the concavo-convex structure of the back coat layer is a surface derived from a structure formed by phase separation of a plurality of types of resin precursors or resins contained in the back coat layer. The optical sheet according to 1.   The optical sheet according to claim 2, wherein the hydroxy value of at least two of the plurality of resins is different by 20 mgKOH / g or more.   The optical sheet according to any one of claims 1 to 3, wherein the back coat layer further contains a filler containing an acrylate resin or a polyamide resin.   The optical sheet according to any one of claims 1 to 4, wherein the backcoat layer contains a compound having at least two isocyanate groups. It is a manufacturing method of an optical sheet which manufactures an optical sheet which has a quantum dot content layer which laminated a gas barrier film according to any one of claims 1 to 5,
In the step of producing the gas barrier film, a gas barrier layer is formed on the surface (first surface) of the resin substrate on the side facing the quantum dot-containing layer, and the side opposite to the first surface is formed. Forming a backcoat layer on the second surface;
The back coat layer is formed so that at least the surface on the side far from the quantum dot-containing layer is a surface having a concavo-convex structure,
The arithmetic mean roughness Ra of the surface having the concavo-convex structure is adjusted to be in the range of 0.01 to 0.10 μm, the maximum cross-sectional height Rt is adjusted to be in the range of 0.2 to 2.0 μm, and ,
In the step of forming the quantum dot-containing layer, the gas barrier film is laminated on the coating film containing the quantum dots and the curable resin precursor, and at the same time or after the polymerization or crosslinking reaction is performed by ultraviolet rays or heat. An optical sheet manufacturing method characterized by the above.   The surface of the back coat layer having the concavo-convex structure is formed by phase separation of a plurality of types of resin precursors or resins contained in the back coat layer. Method.

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