JP7139742B2 - Phosphor laminated sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a phosphor laminate sheet containing phosphors such as quantum dots (also referred to as “QD”), and a backlight unit, which can be suitably used as a constituent member of a display device or the like.

2. Description of the Related Art In recent years, there has been a tendency to sharpen the emission spectrum of backlights in order to improve the definition and color reproducibility of liquid crystal display devices. For example, in Patent Document 1, quantum dots that emit red light and green light are used as phosphors between a blue LED light source and a light guide plate to reproduce white light, thereby increasing brightness and improving color reproducibility. techniques have been proposed.
As an example of a liquid crystal display device using such quantum dot technology, a reflector plate equipped with a blue LED and a resin sheet containing quantum dots (also referred to as “QD”) as a phosphor (from the light source side) ( protective films are attached to the front and back), and a liquid crystal display device having a structure in which a prism sheet, a diffusion sheet and a polarizing plate are laminated. Two or three types of quantum dots with different emission properties can be excited by the light incident from the LED to embody white light.

When a laminate obtained by laminating a protective film on the surface of a resin sheet containing phosphors such as quantum dots is incorporated into a display unit, a striped pattern due to light interference, the so-called Newton ring phenomenon, is likely to occur, especially in liquid crystal display devices. This was a serious technical issue in applications requiring high visibility.

As a countermeasure for preventing the Newton ring phenomenon, for example, Patent Document 2 proposes a method of preventing the Newton ring phenomenon by roughening the outer surface of a protective film that is attached to the surface of a resin sheet containing a phosphor. .

In Patent Document 3, the problem of Newton's rings is improved by making the film surface uneven by giving it a matte finish. In order to solve such a problem, a hard coating is provided on a transparent support as a matte optical film that can prevent the deterioration of the display quality (occurrence of display unevenness, luminance unevenness, etc.) without causing a decrease in display luminance. matte layer, wherein the hard coat layer contains a crosslinked binder polymer and transparent fine particles, and has a surface roughness Ra of 0.1 to 0.3 μm and an Rz of 1 to 3 μm. Optical films have been proposed.

Further, Patent Document 4 discloses a planar light source that emits primary light, and the wavelength A backlight comprising a conversion member, a retroreflective member arranged to face the planar light source with the wavelength conversion member interposed therebetween, and a reflector plate arranged to face the wavelength conversion member with the planar light source interposed therebetween. unit, wherein the wavelength conversion member emits the fluorescence using at least part of the primary light emitted from the planar light source as the excitation light, and emits at least light including secondary light composed of the fluorescence. It proposes a backlight unit that emits light.

JP 2012-169271 A JP 2017-217919 A JP-A-2001-33625 JP 2016-071341 A

As described above, when the surface of the protective film is roughened to give a matte finish, the occurrence of the Newton's ring phenomenon can be suppressed, but on the other hand, there is a problem that the brightness of the display device is lowered.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new phosphor laminated sheet that can suppress the occurrence of the Newton ring phenomenon and can improve the luminance.

The present invention is a phosphor comprising a protective film (10), a phosphor layer containing a resin and a phosphor, and a protective film (20) in this order such that the protective film (20) is on the viewing side. A body laminated sheet,
The protective film (10) is an optical protective film having a particle-containing layer on the front and back sides of the base film, that is, on the side opposite to the viewing side,
The difference between the reflectance R2(1) of the film surface of the protective film (10) not provided with the particle-containing layer and the reflectance R2(2) of the film surface of the protective film (20) on the phosphor layer side is A phosphor laminate sheet is proposed, characterized in that it is greater than 3%.

The phosphor laminated sheet proposed by the present invention has protective films (10) and (20) having different optical properties laminated on both front and back sides of a phosphor layer, and a particle-containing layer of the protective film (10) is provided. The difference between the reflectance R2(1) of the film surface without the protective film (20) and the reflectance R2(2) of the film surface on the phosphor layer side of the protective film (20) is greater than 3%. As a result, not only can the occurrence of the Newton ring phenomenon be suppressed, but among the light emitted by the phosphor, the light incident on the particle-containing layer can be reflected toward the phosphor laminated sheet side, and the phosphor emits light. Since efficiency can be increased, luminance can be improved.

1 is a cross-sectional view showing an example of a protective film that constitutes the phosphor laminated sheet of the present invention; FIG. FIG. 3 is a cross-sectional view showing another example of a protective film that constitutes the phosphor laminated sheet of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of a phosphor laminated sheet and a backlight according to an example of the present invention in an exploded state; 1 is a cross-sectional view showing an example of a phosphor laminated sheet and a backlight according to an example of the present invention; FIG. FIG. 4 is a cross-sectional view showing another example of the phosphor laminated sheet and the backlight according to the embodiment of the present invention;

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiments described below.

<<<This phosphor laminated sheet>>>
A phosphor laminate sheet (referred to as "this phosphor laminate sheet") according to an example of an embodiment of the present invention comprises a protective film (10), a phosphor layer containing a resin and a phosphor, and a protective film (20). and are provided in this order so that the protective film (20) is on the viewing side.

Since the present phosphor laminated sheet only needs to include the protective film (10), the phosphor layer, and the protective film (20) in this order, Other layers may be interposed between the protective film (10) and the phosphor layer or between the phosphor layer and the protective film (20).

<<Optical properties of this phosphor laminated sheet>>
One feature of the present phosphor laminated sheet is that the optical properties of the protective films (10) and (20) are different from each other.
That is, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, as shown in FIG. It is preferably larger than the reflectance R2(2) of the film surface on the phosphor layer side of 20).
Among them, the difference between the reflectance R2(1) of the protective film (10) and the reflectance R2(2) of the protective film (20) is preferably more than 3%, especially 4% or more, especially 6% or more, more preferably 10% or more.

In addition, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, the protective film In (20), it is preferable that the light transmittance T2(2) measured when light is irradiated from the side opposite to the phosphor is larger.
Among them, the difference between the light transmittance T2(1) of the protective film (10) and the light transmittance T2(2) of the protective film (20) is preferably greater than 4%, especially 5% or more, Among them, it is more preferably 6% or more, more preferably 10% or more.

Moreover, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, it is preferable that the film haze of the protective film (10) is larger than that of the protective film (20).
Among them, the difference between the film haze of the protective film (10) and the film haze of the protective film (20) is preferably more than 10%, especially 20% or more, especially 30% or more, especially 50% or more. More preferred.
is good.

<Optical properties of protective film (10)>
The protective film (10) has a reflectance R2(1) on the film surface opposite to the particle-containing layer and a reflectance R1(1) on the surface on the particle-containing layer side, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness. is preferably more than 4%, more preferably more than 5%, more preferably more than 6%, more preferably more than 10%. Although the upper limit is not particularly limited, considering the light control effect, it can be considered to be about 20%.

The protective film (10) is an optical protective film having the particle-containing layer on one side of the base film (1) as described above, and the reflectance R2 ( 1) and the reflectance R1(1) of the particle-containing layer side surface is greater than 4%, for example, as shown in FIGS. A protective film (10) is placed so that the particle-containing layer is positioned on the light source side, and a phosphor sheet containing a phosphor is placed on the display screen side of the protective film (10), in other words, on the side opposite to the light source. Then, the protective film (10) can suppress the occurrence of the Newton ring phenomenon by means of the particle-containing layer, and can suitably transmit the light from the light source and supply it to the phosphor sheet. Of the light emitted in the 360° direction by excitation, the light incident on the protective film (10) side can be reflected to the phosphor sheet side, so the luminous efficiency of the phosphor is increased and the brightness of the display screen can increase

From the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, the reflectance R1(1) is preferably less than 14%, more preferably less than 10%, more preferably less than 6%. The lower limit is not particularly limited, but considering the light control effect, it can be considered to be about 5%.
On the other hand, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, the reflectance R2(1) is preferably larger than 14%, more preferably larger than 16%, more preferably larger than 18%. Although the upper limit is not particularly limited, it can be considered to be about 26% in consideration of the light control effect.

From the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, the protective film (10) is such that the light transmittance T1(1) measured when light is irradiated from the particle-containing layer side is It preferably has an optical characteristic that is greater than the light transmittance T2(1) measured when light is irradiated from a light source.
At this time, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon and improving brightness, the difference between the light transmittance T1(1) and the light transmittance T2(1) is preferably greater than 4%, more preferably greater than 5%. Among them, more than 6%, more preferably more than 10%. Although the upper limit is not particularly limited, considering the light control effect, it can be considered to be about 20%.

Above all, the light transmittance T1(1) is preferably greater than 87%, more preferably greater than 88%, more preferably greater than 89%. Although the upper limit is not particularly limited, considering the light control effect, it can be considered to be about 90%.
On the other hand, the light transmittance T2(1) is preferably less than 85%, more preferably less than 80%, more preferably less than 76%. Although the lower limit is not particularly limited, it can be considered to be about 74% in consideration of the light control effect.

Further, the total value of the light transmittance T1(1) and the reflectance R1(1) is greater than 97%, especially more than 98%, and the total value of the light transmittance T2 and the reflectance R2 is 97%. %, preferably greater than 98%. If the total value is greater than 97%, the light from the light source can be efficiently supplied to the display screen, which is preferable.

In addition, the film haze value of the protective film (10) is preferably larger than 40%, especially larger than 50%, especially larger than 60%, especially larger than 70%, from the viewpoint of suppressing the occurrence of the Newton ring phenomenon. is more preferred.
Although it may be inconceivable from a technical point of view that the haze value of a film used for optical purposes is greater than 40%, the protective film (10) has special optical properties as described above. Even if the haze value is greater than 40%, it can be suitably used for optical applications.

<Optical properties of protective film (20)>
Regarding the optical properties of the protective film (20), the reflectance R2(2) of the film surface opposite to the phosphor layer side, i.e., the viewing side, is preferably less than 14%, especially 13%, from the viewpoint of improving brightness. % or less, preferably 11% or less.
On the other hand, the reflectance R1(2) of the viewer-side film surface of the protective film (20) is preferably 14% or less, more preferably 13% or less, and more preferably 11% or less, from the viewpoint of improving brightness. preferable.

In addition, the light transmittance T2(2) measured when the protective film (20) is irradiated with light from the side opposite to the phosphor, i.e., from the viewing side, is preferably 86% or more from the viewpoint of improving brightness. It is preferably 88% or more, and more preferably 90% or more.
On the other hand, the light transmittance T1(2) of the protective film (20) measured when light is irradiated from the viewing side is preferably 86% or more, especially 88% or more, from the viewpoint of improving luminance. preferably 90% or more.

From the viewpoint of improving brightness, the film haze of the protective film (20) is preferably less than 35%, more preferably 30% or less, and more preferably 25% or less.

<<Phosphor layer>>
In the present phosphor laminated sheet, the phosphor layer (corresponding to the phosphor sheet (30) in the drawing) may be a quantum dot layer. However, it is not limited to this.
At this time, the "quantum dot layer" may be a layer containing quantum dots, that is, a nanoscale colloidal semiconductor, and the quantum dot film is a monolayer film containing quantum dots, or the quantum dot layer. as a surface layer.
A preferred example of the quantum dot layer is a layer in which two or more types of quantum dots with different fluorescence properties are dispersed in a resin matrix. At this time, the two or more types of quantum dots having different fluorescence properties are quantum dots that emit fluorescence (red light) LR when excited by blue light LB and fluorescence (green light) LG when excited by blue light LB. One example is the combination with luminous quantum dots. However, it is not limited to this combination.

Quantum dots deteriorate when they come into contact with oxygen or moisture. Therefore, when using quantum dots, it is particularly preferable to laminate a gas barrier layer or a water vapor barrier layer on one or both sides of the phosphor sheet.

The thickness of the phosphor layer or the phosphor sheet composed of the phosphor layer is preferably 10 to 250 μm, more preferably 25 μm or more or 125 μm or less, and more preferably 38 μm or more or 100 μm or less.

<<protective film (10)>>
The protective film (10) is preferably a film having a particle-containing layer (referred to as "this particle-containing layer") on one side of the base film (referred to as "this base film").

The protective film (10) may have a structure in which a particle-containing layer is provided on one surface of the base film (10). For example, as shown in FIG. The present particle-containing layer (3) may be provided in an asymmetric configuration, or the present particle-containing layer (3) may be provided on the front and back sides of the base film (1), and the front and back sides of the base film (1) may be provided. An asymmetric configuration with a base film (2) on the other side is also possible. Further, as shown in FIG. 2, the present particle-containing layer (3) is provided on one surface of the substrate film (1), and the adhesive layer (4) is provided on the other surface of the substrate film (1). It may also be an asymmetric configuration with the substrate film (2) in between.

In addition, the other side of the base film (2), the other side of the front and back of the particle-containing layer (3), or between the base film (1) and the base film (2), or the base A layer having various functions (also referred to as a "functional layer") may be provided between the material film (1) and the present particle-containing layer (3), or at two or more of these. .
Examples of the functional layer include layers such as an anchor coat layer, an inorganic substance-containing layer, an easy adhesion layer, and an intermediate buffer layer. Each functional layer will be described later.

<This particle-containing layer>
The particle-containing layer preferably contains a binder resin and particles having an average particle size of 3 μm to 10 μm in order to impart the above optical properties to the protective film (10).
If the average particle diameter of the particles contained in the present particle-containing layer is 3 μm or more, it is effective in imparting the above optical properties. In the post-process, it is possible to suppress the occurrence of problems such as falling off of particles.
From this point of view, the average particle diameter of the particles contained in the present particle-containing layer is preferably 3 μm to 10 μm, especially 3 μm or more or 8 μm or less, especially 3 μm or more or 6 μm or less, especially 3 μm or more or 5 μm or less. is more preferred.
The average particle diameter of the particles in the present particle-containing layer can be determined by arbitrarily selecting 10 or more particles present in the present particle-containing layer and measuring the diameter of each particle using a scanning electron microscope (SEM). It can be obtained as an average value. At that time, in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter ((minor diameter+major diameter)/2) can be measured as the diameter of each particle.

In order to impart the above optical properties to the protective film (10), the particle-containing layer contains large particles with a particle size of 3 μm to 10 μm and small particles with a particle size of 1 μm to 5 μm in combination. is more preferred.
At this time, the particle size of each particle can be determined by a scanning electron microscope (SEM), and in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter can be measured as the diameter of each particle.
The particle diameter of the large particles is more preferably 5 μm or more or 10 μm or less, and more preferably 5 μm or more or 8 μm or less.
On the other hand, the particle size of the small particles is more preferably 2 μm or more or 5 μm or less, and more preferably 2 μm or more or 4 μm or less.
In addition to the large particle size particles and the small particle size particles, particles of different sizes may be present in the present particle-containing layer.

When the present particle-containing layer contains large particles with a particle size of 3 μm to 10 μm, small particles with a particle size of 1 μm to 5 μm, and, if necessary, particles with other sizes. , Large particles with a particle size of 3 μm to 10 μm preferably account for 40 to 80% by weight of the particles contained in the particle-containing layer, especially 50% by weight or more or 80% by weight or less, and among them 50% by weight or more. Alternatively, it is more preferably 70% by mass or less.

The type of particles contained in the present particle-containing layer is not particularly limited. For example, it may be inorganic particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, titanium oxide, synthetic zeolite, alumina, smectite, styrene resin, urethane resin, benzoguanamine resin, Organic fine particles such as silicone resins and acrylic resins may be used, or two or more of these may be used in combination.
Among them, acrylic beads composed of an acrylic crosslinked resin are preferably used from the viewpoint of particle transparency and scratch resistance.

The shape of the particles is not particularly limited. For example, spherical, lumpy, rod-shaped, flattened and the like can be mentioned. Two or more kinds of these particles may be used in combination, if necessary.

On the other hand, as the binder constituting the present particle-containing layer, for example, polymers made of polyester-based resins, acrylic-based resins, acrylic-urethane-based resins, polyester-acrylate-based resins, polyurethane-acrylate-based resins, epoxy-acrylate-based resins, and urethane-based resins Resin can be used.

The content of particles in the present particle-containing layer is preferably 40 to 300 parts by mass with respect to 100 parts by mass of the binder resin. By satisfying this range, it is possible to control the transmittance and reflectance by the light scattering property of the film, that is, to achieve both so-called light control and transparency, which is preferable.
From this point of view, the particle content in the particle-containing layer is preferably 40 to 300 parts by mass with respect to 100 parts by mass of the binder resin, especially 50 parts by mass or more or 200 parts by mass or less, especially 60 parts by mass or more. Alternatively, it is more preferably 100 parts by mass or less.

The ratio of the average particle size of the particles in the particle-containing layer to the maximum thickness of the particle-containing layer is preferably 1/6 to 1/2, more preferably 1/5 or more or 1/2 or less. Among them, it is more preferably 1/4 or more or 1/2 or less.

<This base film>
The present base film (the above base film (1) and base film (2) also belong to the "present base film") has transparency and has necessary and sufficient rigidity as a protective film. The material and configuration are not limited as long as the film is a thin film.

The base film may have a single-layer structure or a multilayer structure.
When the present substrate film has a multi-layer structure, it may have a multi-layer structure of four or more layers in addition to the two-layer or three-layer structure as long as it does not exceed the gist of the present invention.

Regardless of whether the base film has a single-layer structure or a multi-layer structure, the main component resin of each layer is preferably polyester.
In this case, the "main component resin" means a resin having the highest content ratio among the resins constituting the base film, for example, 50% by mass or more, particularly 70% by mass, of the resins constituting the base film. % or more, especially 80 mass % or more (including 100 mass %).
Each layer of the base film may contain a resin other than polyester or a component other than resin as long as it contains polyester as the main component resin.

The above polyester may be a homopolyester or a copolyester.
When it is made of homopolyester, it is preferably obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol.
Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid.
Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and the like.
Typical polyesters include polyethylene terephthalate and the like.

On the other hand, the dicarboxylic acid component of the copolymer polyester may include one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, sebacic acid, and the like. One or more of glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like can be mentioned.

Specific examples of polyester include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polyarylates, polyethersulfone, polycarbonate, polyetherketone, Polysulfone, polyphenylene sulfide, polyester-based liquid crystal polymer, triacetyl cellulose, cellulose derivatives, polypropylene, polyamides, polyimide, polycycloolefins and the like can be exemplified. Among these, PET and PEN are preferable in terms of handleability.

The present base film may contain particles for the main purposes of roughening the film surface to impart lubricity and preventing the occurrence of scratches in each step.
The type of the particles is not particularly limited as long as they are particles capable of imparting lubricity. For example, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, inorganic particles such as titanium oxide, acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, benzoguanamine Organic particles, such as resin, etc. can be mentioned. These may be used individually by 1 type, or may be used in combination of 2 or more types among these.
Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.
The shape of the particles is not particularly limited. For example, it may be spherical, blocky, rod-shaped, or flat.
Further, the hardness, specific gravity, color, etc. of the particles are not particularly limited. Two or more types of these series of particles may be used in combination, if necessary.

The average particle size of the particles is preferably 5 μm or less, more preferably 0.01 μm or more or 3 μm or less, and more preferably 0.5 μm or more or 2.5 μm or less. If it exceeds 5 μm, the surface roughness of the present base film becomes too rough, and problems may occur when various surface functional layers are formed in subsequent steps.

The particle content is preferably 5% by mass or less of the base film, especially 0.0003% by mass or more or 3% by mass or less, and among these, 0.01% by mass or more or 2% by mass or less More preferred. By setting the particle content in such a range, it is possible to achieve both lubricity and transparency of the film, which is preferable.

The method for adding particles to the base film is not particularly limited, and conventionally known methods can be employed. For example, it can be added at any stage of polyester production. It is preferably added after completion of the esterification or transesterification reaction.

Conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, ultraviolet absorbers, and the like can be added to the base film, if necessary.

The thickness of the base film is not particularly limited as long as it can be formed as a film. It is more preferable to have

The present base film can be formed, for example, by forming a resin composition into a film shape by a melt film-forming method or a solution film-forming method. Multilayer structures may be co-extruded.
In addition, a uniaxially or biaxially stretched film may be used, and a biaxially stretched film is preferable from the viewpoint of rigidity.

<<adhesive layer>>
As described above, as shown in FIG. 2, the base film includes the particle-containing layer (3) on one side of the base film (1), and the other side of the base film (1). Alternatively, it may be an asymmetric configuration with the substrate film (2) interposed through the adhesive layer (4).
For the adhesive layer (4) at this time, a known adhesive may be appropriately selected and used. Among them, a known adhesive capable of bonding polyester films to each other and ensuring transparency may be appropriately selected and used. Examples thereof include adhesives composed of one or a combination of two or more of polyester, polyvinyl alcohol, acrylic resin, urethane resin, polyalkylene glycol, polyalkyleneimine, methylcellulose and hydroxycellulose.

<<Function layer>>
As described above, the other side of the base film (2), or the one side of the particle-containing layer (3), or between the base film (1) and the base film (2), Alternatively, between the substrate film (1) and the present particle-containing layer (3), or at two or more of these, layers having various functions, i.e., functional layers, may be provided as necessary. can be done.
Examples of the functional layer include layers such as an anchor coat layer, an inorganic substance-containing layer, an easy-adhesion layer, and an intermediate buffer layer, which will be described below. However, it is not limited to these.

<Anchor coat layer>
The anchor coat layer includes the base film (1) and the base film (2), the base film (1) and the present particle-containing layer (3), the base film (1) and each functional layer, or the base film This is a layer for enhancing adhesion between (2) and each functional layer, and can be provided as necessary.

The anchor coat layer can be formed from an anchor coat agent.
Examples of the anchor coating agent include solvent-based or water-based polyesters, urethane resins, acrylic resins, vinyl alcohol resins, ethylene vinyl alcohol resins, vinyl modified resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, and isocyanate group-containing resins. Containing resins, alkoxy group-containing resins, modified styrene resins, modified silicone resins, and the like can be mentioned, and these can be used alone or in combination of two or more. Among them, from the viewpoint of adhesion and hot water resistance, at least one selected from polyesters, urethane resins, acrylic resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, isocyanate-containing resins, and copolymers thereof. It is preferable to use them alone or in combination of two or more. Among them, one or more of polyester, urethane resin, acrylic resin, oxazoline group-containing resin, carbodiimide group-containing resin, epoxy group-containing resin, and isocyanate group-containing resin. It is preferable to use at least one selected alone or in combination with two or more.

When the thickness of the anchor coat layer is 5 μm or less, the slip property is good, and the anchor coat layer itself hardly separates from the base film due to internal stress. is preferable because a uniform thickness can be maintained.
From this point of view, the thickness of the anchor coat layer is preferably 0.005 to 5 μm, more preferably 0.01 μm or more or 1 μm or less, and more preferably 0.02 μm or more or 0.5 μm or less.

<Inorganic substance-containing layer>
The inorganic substance-containing layer is a layer that mainly serves to suppress gas permeation, and can be provided as necessary.

The inorganic substance-containing layer is a layer containing an inorganic substance, especially an inorganic oxide, as a main component, and not only has excellent gas barrier properties, especially water vapor barrier properties, but also is easy to form a film and has good adhesion to other layers. is also excellent.
The main component means that the inorganic substance accounts for 50% by mass or more, especially 70% by mass or more, especially 80% by mass or more, especially 90% by mass or more of the inorganic substance-containing layer.

The inorganic substance-containing layer is one or more selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon oxycarbonitride, aluminum oxide, aluminum nitride, aluminum oxynitride and aluminum oxycarbide. containing an inorganic compound is preferable.

The inorganic-containing layer can be formed by, for example, a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, or a method in which inorganic particles are dispersed in an organic polymer and applied, as described below. can be formed by

(PVD inorganic substance-containing layer)
The inorganic substance-containing layer preferably comprises at least one PVD inorganic substance-containing layer formed by a PVD method. Thereby, a high gas barrier property can be exhibited.

The PVD inorganic substance-containing layer is preferably a layer composed of silicon oxide represented by, for example, SiOx (1.0<X≤2.0).
The PVD inorganic substance-containing layer is composed of a silicon oxide represented by SiOx (1.0<X≦2.0). In some cases, the silicon oxide film itself becomes yellowish and has low transparency. The above composition can be confirmed by XPS (X-ray photoelectron spectroscopy) analysis or the like.

A preferable pressure during the formation of the PVD inorganic substance-containing layer is preferably 1×10 ⁻⁷ to 1 Pa, especially 1×10 ⁻⁶ or more, from the viewpoint of gas barrier properties, evacuation ability, and degree of oxidation of the SiOx layer to be formed. Alternatively, it is 1×10 ⁻¹ Pa or less, more preferably 1×10 ⁻⁴ or more or 1×10 ⁻² Pa or less. The partial pressure at which oxygen is introduced is in the range of 10 to 90% of the total pressure, preferably 20 to 80%.

The inorganic substance-containing layer may have a single layer structure consisting of the PVD inorganic substance-containing layer, and in order to ensure higher gas barrier properties, a chemical vapor phase (for example, JP-A-2013-226829 Japanese Laid-Open Patent Publication Nos. 2003-200030, etc.) may be a multilayer (two or more layers) structure in which a CVD inorganic substance-containing layer is formed by a vapor deposition method, or a PVD inorganic substance-containing layer having the same or different composition is formed.

A structure in which a PVD inorganic substance-containing layer and a CVD inorganic substance-containing layer are alternately formed (for example, a three-layer structure of a PVD inorganic substance-containing layer, a CVD inorganic substance-containing layer, and a PVD inorganic substance-containing layer) may be used. In particular, by forming a CVD inorganic substance-containing layer on a PVD inorganic substance-containing layer, defects such as defects in the PVD inorganic substance-containing layer are filled, and gas barrier properties and interlayer adhesion tend to be improved.

(CVD inorganic substance-containing layer)
The CVD inorganic material-containing layer contains carbon, and the carbon content is 20 at. %, preferably less than 10 at. % or less, and among them, 5 at. % or less is most preferred. When the carbon content satisfies the above range, the surface energy of the inorganic substance-containing layer is increased, and the adhesion between the inorganic substance-containing layers is improved, so that the barrier film has improved bending resistance and peeling resistance. do.
Also, the carbon content of the CVD inorganic-containing layer is 0.5 at. % or more, preferably 1 at. % or more, more preferably 2 at. % or more is good. By containing a small amount of carbon in the intermediate layer of the CVD inorganic substance-containing layer, stress is efficiently relieved, which leads to an effect of reducing curling of the barrier film itself.
In addition, "at. %" indicates an atomic composition percentage (atomic%). Also, the composition can be confirmed by XPS analysis or the like.

The formation of the CVD inorganic substance-containing layer is preferably carried out under a reduced pressure environment of 10 Pa or less and at a transport speed of 100 m/min or more for the base film, particularly the base film provided with the anchor coat layer. The pressure when forming a thin film by chemical vapor deposition (CVD) is preferably under reduced pressure in order to form a dense thin film, and is preferably 10 Pa or less from the viewpoint of film formation speed and barrier properties. It is preferably 1×10 ⁻² or more or 10 Pa or less, and more preferably 1×10 ⁻¹ or more or 1 Pa or less.

In order to improve water resistance and durability, the CVD inorganic substance-containing layer may be cross-linked by electron beam irradiation, if necessary.

The CVD inorganic-containing layer is preferably composed of a thin film containing at least one selected from metals, metal oxides and metal nitrides. Metals such as silicon and aluminum are more preferable from the viewpoint of gas barrier properties and adhesion. As the metal oxide or metal nitride, it is preferable to use oxides, nitrides and mixtures thereof from the viewpoint of gas barrier properties and adhesion.
The CVD inorganic substance-containing layer is more preferably made of at least one selected from silicon oxide, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, silicon nitride and aluminum oxide. Moreover, as the metal oxide or metal nitride, those obtained by plasma decomposition of an organic compound are preferable.

As a raw material for forming a CVD inorganic substance-containing layer such as a silicon oxide film, a compound such as a silicon compound can be used regardless of whether it is in a gaseous, liquid or solid state under normal temperature and normal pressure. In the case of gas, it can be directly introduced into the discharge space. In the case of a liquid or solid, it is used after being vaporized by means such as heating, bubbling, pressure reduction, and ultrasonic irradiation. Moreover, it may be used after diluting with a solvent, and as the solvent, organic solvents such as methanol, ethanol, n-hexane, and mixed solvents thereof can be used.

Examples of the silicon compound include silane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-t-butoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane. Silane, diphenyldimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, phenyltriethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, hexamethyldisiloxane, bis(dimethylamino)dimethylsilane, bis (dimethylamino)methylvinylsilane, bis(ethylamino)dimethylsilane, N,O-bis(trimethylsilyl)acetamide, bis(trimethylsilyl)carbodiimide, diethylaminotrimethylsilane, dimethylaminodimethylsilane, hexamethyldisilazane, hexamethylcyclotrisilazane , heptamethyldisilazane, nonamethyltrisilazane, octamethylcyclotetrasilazane, tetrakisdimethylaminosilane, tetraisocyanatosilane, tetramethyldisilazane, tris(dimethylamino)silane, triethoxyfluorosilane, allyldimethylsilane, allyltrimethylsilane , benzyltrimethylsilane, bis(trimethylsilyl)acetylene, 1,4-bistrimethylsilyl-1,3-butadiyne, di-t-butylsilane, 1,3-disilabutane, bis(trimethylsilyl)methane, cyclopentadienyltrimethylsilane, phenyl Dimethylsilane, phenyltrimethylsilane, propargyltrimethylsilane, tetramethylsilane, trimethylsilylacetylene, 1-(trimethylsilyl)-1-propyne, tris(trimethylsilyl)methane, tris(trimethylsilyl)silane, vinyltrimethylsilane, hexamethyldisilane, octamethyl Cyclotetrasiloxane, tetramethylcyclotetrasiloxane, hexamethyldisiloxane, hexamethylcyclotetrasiloxane, M silicate 51 and the like can be mentioned.

The thickness of the inorganic substance-containing layer (when the inorganic substance-containing layer has a multilayer structure, the total thickness thereof) is preferably 0.1 nm to 500 nm, especially 1 nm or more or 300 nm or less, especially 5 nm or more or 100 nm or less. is more preferable.
If the thickness of the inorganic substance-containing layer is within such a range, it is possible to ensure the desired gas barrier properties.

(Layer structure of inorganic substance-containing layer)
The inorganic substance-containing layer preferably has a structure of two or more layers by laminating a flexible layer on the inorganic substance-containing layer. That is, the coarse protrusions of the base film are generated as starting points, and when the inorganic substance-containing layer is formed by thermal vapor deposition, the raw materials fly in lumps and adhere to the inorganic substance-containing layer. In some cases, minute defects called pinholes may occur, and the gas barrier properties may be lowered by passing gas through the voids caused by these defects. It is preferable to laminate to form a structure of two or more layers to further enhance gas barrier properties.

In this case, the flexible layer is composed of a flexible composition that easily fills the voids of the inorganic substance-containing layer, such as organic substances such as polyester resin, acrylic resin, urethane resin, and polyvinyl alcohol (PVA), as well as inorganic or organic compounds. A layer containing a filler as a main component is preferred.
The main component means that the main component accounts for 50 mass % or more, especially 70 mass % or more, especially 80 mass % or more, especially 90 mass % or more of the flexible layer.

<Easy adhesion layer>
The easy-adhesion layer includes the base film (1) and the base film (2), the base film (1) and the present particle-containing layer (3), the base film (1) and each functional layer, or the base film It is a layer for enhancing the adhesiveness between (2) and each functional layer, or between the base film (2) and various optical members such as a phosphor-containing sheet, and can be provided as necessary.

From the viewpoint of improving the adhesiveness between the substrate film (2) and the phosphor-containing sheet, particularly the quantum dot layer or the quantum dot film, the easy-adhesion layer contains at least a compound having a carbon-carbon double bond and urethane A layer containing any one of the resins is preferable.

(a compound having a carbon-carbon double bond)
Examples of the compound having a carbon-carbon double bond include compounds having a monofunctional (meth)acrylate group, a bifunctional (meth)acrylate group, a polyfunctional (meth)acrylate group, a vinyl group, an allyl group, and the like. can.
In addition, the notation of "(meth)acrylate compound" represents "acrylate compound and methacrylate compound".

The monofunctional (meth)acrylate is not particularly limited. For example, alkyl (meth)acrylate such as methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, etc. hydroxyalkyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate ) acrylate, alkoxyalkyl (meth)acrylate such as ethoxypropyl (meth)acrylate, aromatic (meth)acrylate such as benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, diaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate ) Amino group-containing (meth)acrylates such as acrylate, methoxyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, ethylene oxide-modified (meth)acrylates such as phenylphenol ethylene oxide-modified (meth)acrylate, glycidyl ( Meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid and the like can be mentioned.

The bifunctional (meth)acrylate is not particularly limited. For example, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecanedi alkanediol di(meth)acrylates such as methylol di(meth)acrylate; bisphenol-modified di(meth)acrylates such as bisphenol A ethylene oxide-modified di(meth)acrylate; bisphenol F ethylene oxide-modified di(meth)acrylate; (Meth)acrylate, polypropylene glycol di(meth)acrylate, urethane di(meth)acrylate, epoxy di(meth)acrylate and the like.

The polyfunctional (meth)acrylate is not particularly limited. For example, dipentaerythritol hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane ethylene oxide modified Tetra (meth) acrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate, isocyanuric acid modified tri (meth) acrylate such as ε-caprolactone modified tris (acryloxyethyl) isocyanurate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer , pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, and the like.

These monofunctional (meth)acrylate group-containing compounds, difunctional (meth)acrylate group-containing compounds, polyfunctional (meth)acrylate group-containing compounds, vinyl group-containing compounds and allyl group-containing compounds are They may be used alone, or two or more of them may be used in combination.
From the viewpoint of improving adhesion, among these (meth)acrylate compounds, bifunctional (meth)acrylates and polyfunctional (meth)acrylates are preferred, and among these, polyfunctional (meth)acrylates are particularly preferred.

When using a (meth) acrylate compound, the ratio of the carbon-carbon double bond portion to the (meth) acrylate compound is preferably 3% by weight or more, more preferably, considering the adhesion to the quantum dot layer. 5% by weight or more. The upper limit is usually 40% by weight.

(urethane resin)
The urethane resin may be a polymer compound having urethane bonds in the molecule, and may be a polymer compound obtained by reaction of polyol and isocyanate.
Examples of the polyol include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, acrylic polyols, etc. These compounds may be used singly or in combination. From the viewpoint of improving adhesion, polycarbonate polyols or polyester polyols are preferable, and polycarbonate polyols are more preferable.

Polycarbonate polyols constituting the urethane resin include those obtained by dealcoholization reaction from polyhydric alcohols and carbonate compounds.
At this time, polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, trimethylolpropane, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonane diol, 1,10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane and the like.
Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, etc. Polycarbonate-based polyols obtained from these reactions include, for example, poly(1,6-hexylene) carbonate, poly( 3-methyl-1,5-pentylene)carbonate and the like can be mentioned.

Polyester polyols constituting the urethane resin include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.). ) or their acid anhydrides and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2 ,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl- 2,4-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1, 3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol , 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, lactonediol, etc.), poly Examples include those having a derivative unit of a lactone compound such as caprolactone.

Polyether polyols constituting the urethane resin include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol and the like.

Examples of polyisocyanates constituting the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, α, α, α', α'-tetra Aliphatic diisocyanates having aromatic rings such as methylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate and hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4 -cyclohexyl isocyanate), dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl diisocyanate and other alicyclic diisocyanates. These polyisocyanate compounds may be used singly or in combination, and these polyisocyanate compounds may be dimers, trimers typified by isocyanuric rings, or higher polymers. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferable than aromatic isocyanates from the viewpoints of improving adhesion to active energy ray-curable paints and preventing yellowing due to ultraviolet rays.

A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with isocyanate groups. Alternatively, a chain extender having two amino groups can be mainly used.
Examples of chain extenders having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol, butanediol and pentanediol, aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene, neopentyl glycol, and neopentyl glycol. Glycols such as ester glycols such as hydroxypivalate can be mentioned. Examples of chain extenders having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3- Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- aliphatic diamines such as decanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylitincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1 , 3-bisaminomethylcyclohexane, and alicyclic diamines such as isophoronediamine.

The urethane resin may use a solvent as a medium, or may use water as a medium.
In the case of water-based urethane resins, methods for dispersing or dissolving the urethane resin in water include a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, a water-based type, and the like. In particular, a self-emulsifying type in which an ionic group is introduced into the skeleton of a urethane resin to form an ionomer is preferable because it is excellent in the storage stability of the liquid and the water resistance, transparency and adhesiveness of the resulting coating layer. As the ionic group to be introduced, various groups such as carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid and quaternary ammonium salts can be mentioned, among which carboxyl group is preferred.
As a method for introducing a carboxyl group into the urethane resin, various methods can be adopted in each stage of the polymerization reaction. For example, when synthesizing the prepolymer, a method of using a resin having a carboxyl group as a copolymer component, or a method of using a component having a carboxyl group as one component such as a polyol, polyisocyanate, or chain extender can be employed. In particular, a method of using a carboxyl group-containing diol and introducing a desired amount of carboxyl groups depending on the charged amount of this component is preferred. For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, etc. can be copolymerized with the diol used in the polymerization of the urethane resin. can be done. The carboxyl group is preferably neutralized with ammonia, amines, alkali metals, inorganic alkalis or the like to form a salt. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a urethane resin, the carboxyl groups removed from the neutralizing agent during the drying process of the coating liquid can be used as cross-linking reaction points by other cross-linking agents. This makes it possible to further improve the durability, water resistance, blocking resistance, etc. of the easy-adhesion layer to be obtained, which is excellent in stability in the state of the coating liquid.

(binder polymer)
In addition to the urethane resin or the compound having a carbon-carbon double bond, the easy-adhesion layer preferably contains a binder polymer from the viewpoint of improving coating appearance, transparency and adhesion.

Binder polymer refers to a polymer with a high number average molecular weight (Mn) of 1000 or more by gel permeation chromatography (GPC) measurement according to the polymer compound safety evaluation flow scheme (organized by the Chemical Substances Council in November 1985). It is a molecular compound and a polymer having film-forming properties. As a necessary condition, it may be a polymer compound having a number average molecular weight (Mn) of 1000 or more and a polymer having film-forming properties.

Specific examples of binder polymers include polyester resins, polyvinyl (polyvinyl alcohol, polyvinyl chloride, vinyl acetate/vinyl chloride copolymer, etc.), polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches, and the like. These may be used alone, or two or more of them may be used in combination.

The above polyester resin as a binder polymer may be a resin composed mainly of a polyvalent carboxylic acid and a polyvalent hydroxy compound as described below.

Polyvalent carboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalene. Dicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric Acids, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salts and ester-forming derivatives thereof can be used. .

Examples of polyhydroxy compounds include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2- Methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, ethylene glycol-modified bisphenol A, diethylene glycol-modified bisphenol A, diethylene glycol, triethylene glycol, polyethylene Glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate etc. can be used. One or more of these polyvalent carboxylic acids and polyvalent hydroxy compounds may be appropriately selected, and a polyester resin may be synthesized by a conventional polycondensation reaction.

The polyvinyl alcohol as the binder polymer may be a compound having a polyvinyl alcohol moiety. For example, conventionally known polyvinyl alcohol can be used including partially acetalized or butyralized modified compounds for polyvinyl alcohol.

The degree of polymerization of polyvinyl alcohol is not particularly limited, but is preferably 100 or more, more preferably 300 or more or 40,000 or less, and more preferably 500 or more or 10,000 or less. By satisfying this range, the water resistance of the coating layer can be ensured.
The degree of saponification of polyvinyl alcohol is not particularly limited, and is preferably 70 mol% or more, among which 80 mol% or more or 99.9 mol% or less, among which 86 mol% or more or 97 mol% or less, among which More preferably, it is 95 mol % or less.

The content of the binder polymer in the easy-adhesion layer is preferably 30% by weight or more, more preferably 40% by weight or more, and more than 50% by weight, from the viewpoint of obtaining good adhesion with the quantum dot layer. is more preferred.
On the other hand, from the viewpoint of obtaining good coating film strength, the content of the binder polymer in the easy-adhesion layer is preferably 90% by weight or less, more preferably 80% by weight or less, and more preferably 75% by weight or less. is more preferred.

(crosslinking agent)
By further containing a cross-linking agent, the easy-adhesion layer can increase the degree of cross-linking of the easy-adhesion layer and improve its adhesiveness and durability.

As the cross-linking agent, it is preferable to use an oxazoline compound, an isocyanate compound, an epoxy compound, a melamine compound and a carbodiimide compound. Among them, from the viewpoint of improving adhesion, it is more preferable to use at least one of oxazoline compounds and isocyanate compounds.

The above-mentioned oxazoline compound used as a cross-linking agent is a compound having an oxazoline group in the molecule, and a polymer containing an oxazoline group is particularly preferable. . Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among them, 2-isopropenyl-2-oxazoline is suitable because it is easily available industrially. Other monomers are not limited as long as they are monomers copolymerizable with addition polymerizable oxazoline group-containing monomers. n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene Unsaturated carboxylic acids such as sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; meth)acrylamide, N,N-dialkyl(meth)acrylamide, (as alkyl groups, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; vinyl chloride and vinylidene chloride Halogen-containing α,β-unsaturated monomers such as; α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene; be able to.
From the viewpoint of improving adhesion, the amount of oxazoline groups in the oxazoline compound is preferably 0.5 to 10 mmol/g, especially 1 mmol/g or more or 9 mmol/g or less, especially 3 mmol/g or more or 8 mmol/g or less. , more preferably 4 mmol/g or more or 6 mmol/g or less.

The isocyanate compound used as a cross-linking agent is a compound having an isocyanate derivative structure represented by isocyanate or blocked isocyanate. Examples of isocyanates include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate and naphthalene diisocyanate, and aromatic rings such as α,α,α',α'-tetramethylxylylene diisocyanate. Aliphatic isocyanates such as aliphatic isocyanate, methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis(4-cyclohexyl isocyanate), isopropylidene dicyclohexyl diisocyanate, etc. can be exemplified by alicyclic isocyanates of Polymers and derivatives of these isocyanates, such as buret products, isocyanurate products, uretdione products, and carbodiimide modified products, are also included. These may be used alone or in combination of multiple types. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are suitable as measures against yellowing caused by ultraviolet irradiation.

When used in the form of blocked isocyanate, examples of blocking agents include bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. active methylene compounds such as methyl isobutanoylacetate, dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; ε-caprolactam, δ-valerolactam, etc. lactam compounds, diphenylaniline, aniline, amine compounds such as ethyleneimine, acetanilide, acetic acid amide acid amide compounds, formaldehyde, acetaldoxime, acetone oxime, methyl ethyl ketone oxime, cyclohexanone oxime and other oxime compounds, These may be used alone or in combination of two or more.

The isocyanate compound may be used alone, or may be used as a mixture or combination with various polymers. From the standpoint of improving the dispersibility and crosslinkability of the isocyanate compound, it is preferable to use a mixture or combination with a polyester resin or a urethane resin.

The above-mentioned epoxy compound used as a cross-linking agent is a compound having an epoxy group in the molecule. Examples include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris(2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Examples of polyglycidyl ethers and diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. , polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, monoepoxy compounds such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, glycidylamine compounds such as N, N, N', N '-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylamino)cyclohexane and the like can be mentioned. From the viewpoint of improving adhesion, a polyether-based epoxy compound is preferred. As for the amount of epoxy groups, a polyepoxy compound having a polyfunctionality of 3 or more is preferable to a bifunctional one.

The above-mentioned melamine compound used as a cross-linking agent is a compound having a melamine skeleton in the compound. compounds, and mixtures thereof can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, the melamine compound may be either a monomer or a polymer of dimers or higher, or a mixture thereof. Further, a type in which urea or the like is co-condensed with a part of melamine, and a catalyst may be used in combination to improve the reactivity of the melamine compound.

The carbodiimide compound used as a cross-linking agent is a compound having a carbodiimide structure, and is a compound having one or more carbodiimide structures in the molecule. A polycarbodiimide compound having the above is more preferable.
This carbodiimide compound can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and both aromatic and aliphatic compounds can be used. Examples include methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, dicyclohexylmethane diisocyanate and the like.

The content of the carbodiimide groups contained in the carbodiimide compound is preferably 100 to 1000, in terms of carbodiimide equivalent (the weight [g] of the carbodiimide compound for giving 1 mol of carbodiimide groups), especially 250 or more or 800 or less. Among them, 300 or more or 700 or less is more preferable. By using it in the above range, the durability of the coating film is improved.

Further, in order to improve the water-solubility and water-dispersibility of the polycarbodiimide compound, addition of a surfactant, polyalkylene oxide, quaternary ammonium salt of dialkylaminoalcohol, Hydrophilic monomers such as hydroxyalkylsulfonates may be added and used.

When such a cross-linking component is contained, a component for promoting cross-linking, such as a cross-linking catalyst, can be used in combination.

In addition, if an easy-adhesion layer is formed in this way, it can be assumed that unreacted products of these cross-linking agents, compounds after reaction, or mixtures thereof are present in the easy-adhesion layer.

The content of the cross-linking agent in the easy-adhesion layer is preferably 10% by weight or more, more preferably 20% by weight or more, and more preferably 25% by weight or more, from the viewpoint of obtaining good coating film strength. preferable.
On the other hand, from the viewpoint of obtaining good adhesion to the phosphor sheet, particularly the quantum dot layer, the content of the cross-linking agent in the easy-adhesion layer is preferably 70% by weight or less, especially 60% by weight or less, Among them, the range of 50% by weight or less is more preferable.

(Ingredients)
The easy-adhesion layer may contain particles for improving slipperiness and blocking.
When the easy-adhesion layer contains particles, the average particle diameter thereof is preferably in the range of 1.0 μm or less, especially 0.5 μm or less, especially 0.2 μm or less, from the viewpoint of film transparency. is more preferred.
Examples of particles contained in the easy-adhesion layer include particles such as silica, alumina, kaolin, calcium carbonate, and organic particles.

The easy-adhesion layer may contain antifoaming agents, coatability improvers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, etc., if necessary.
These additives may be used alone, or two or more of them may be used in combination as necessary.

(Method for forming easy-adhesion layer)
Conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating can be used as the method for providing the easy-adhesion layer.

The easy-adhesion layer can be provided, for example, by in-line coating. However, it is not limited to this formation method.
When provided by in-line coating, it is preferable to apply the above series of compounds as an aqueous solution or water dispersion on the polyester film with a coating solution adjusted to a solid content concentration of about 0.1 to 50% by weight. preferable.
In addition, the coating liquid may contain a small amount of an organic solvent for the purpose of improving the dispersibility in water, improving the film-forming properties, etc., within the scope not impairing the gist of the present invention. Only one type of organic solvent may be used, or two or more types may be used as appropriate.

The drying and curing conditions for forming the easy-adhesion layer are not particularly limited. Heat treatment is preferably performed at 180° C. for 3 to 40 seconds as a guideline.
On the other hand, when the easy-adhesion layer is provided by in-line coating, heat treatment is usually performed at 70 to 280° C. for 3 to 200 seconds as a guide.

Further, regardless of off-line coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used together as needed.
In addition, the target surface on which the easy-adhesion layer is to be formed may be previously subjected to surface treatment such as corona treatment or plasma treatment.

(Layer structure of easy-adhesion layer)
The easy-adhesion layer may be a single layer or may be composed of two or more layers.
The term “two layers” as used herein means that the easy-adhesion layer itself may be composed of two or more layers, or the structure of the film having the easy-adhesion layer may be two or more layers, and in either case. It is interpreted as

For example, an example of a configuration of two or more layers including an adhesive substrate layer and an adhesive layer can be given.
In this case, the adhesive layer may be as described above for the easy-adhesive layer, and the thickness and formation method thereof may also be as described above.
On the other hand, the adhesive substrate layer may be any layer that functions as a substrate for the adhesive layer. Polyethylene, polypropylene, polyethylene naphthalate, polyamide, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, polyacrytonitrile, polyimide, polycarbonate, polyacrylate, polymethacrylate, polystyrene, ABS, cyclic olefin copolymers (COC), cycloolefin polymers , a resin layer or a resin film containing, as a main component resin, triacetyl cellulose or the like. In order to increase the strength, these stretched films may be used.
The thickness of the adhesive substrate layer is preferably 3 μm to 50 μm, more preferably 4 μm or more or 30 μm or less, and more preferably 5 μm or more or 25 μm or less, from the viewpoint of ensuring support properties.

(thickness)
The film thickness (after drying) of the easy-adhesion layer is preferably 0.002 μm to 10.0 μm, especially 0.005 μm or more or 5 μm or less, especially 0.01 μm or more or 2 μm or less, especially 0.01 μm or more. Alternatively, it is more preferably in the range of 0.5 μm or less.
If the film thickness of the easy-adhesion layer is within the above range, adhesion can be ensured, and deterioration of blocking, increase in haze, and the like can be suppressed.

<Intermediate buffer layer>
When the inorganic-containing layer and the easy-adhesion layer are provided, an intermediate buffer layer that absorbs surface unevenness of the inorganic-containing layer may be provided between the inorganic-containing layer and the easy-adhesion layer, if necessary.
This intermediate buffer layer is also called a top coat layer, and is a layer provided for the purpose of absorbing the surface irregularities of the inorganic substance-containing layer and suppressing yellowing or yellowing caused by the inorganic substance-containing layer.

The intermediate buffer layer is a layer containing (a) polyvinyl alcohol and (b) a silicon compound, and optionally (c) an ethylene-unsaturated carboxylic acid copolymer or (d) a cross-linking agent. preferable.
By providing the intermediate buffer layer, the haze value can be lowered and the color tone and transparency can be improved.

(Composition of intermediate buffer layer)
From the viewpoint of gas barrier properties and transparency, the content ratio of (a) polyvinyl alcohol and (b) silicon compound in the intermediate buffer layer is preferably 1/6 to 1/2, preferably 1/5 to 1/2 in mass ratio. /3 is more preferable.

From the viewpoint of gas barrier properties and printing resistance, the intermediate buffer layer preferably contains (a) polyvinyl alcohol in an amount of 5 to 70 mass %, more preferably 10 to 30 mass %.
In terms of high-speed gravure coating properties, printing resistance, and hot water adhesion, it is preferable to contain (b) silicon compound particles in an amount of 20 to 70% by mass, and among these, the ratio is 30% by mass or more or 60% by mass or less. Containing is more preferable.
Also, from the viewpoint of gas barrier properties, high-speed gravure coating properties, and hot water adhesion, it is preferable to contain (c) an ethylene-unsaturated carboxylic acid copolymer in an amount of 10 to 70% by mass, especially 20% by mass or more or 60% by mass. % or less is more preferable.
Furthermore, from the viewpoint of hot water resistance, it is preferable to contain (d) a cross-linking agent in an amount of 2 to 30% by mass, more preferably 3% by mass or more or 10% by mass or less.

((a) polyvinyl alcohol)
Polyvinyl alcohol as a component of the intermediate buffer layer can be produced by a known method, and is usually obtained by saponifying a vinyl acetate polymer. The saponification degree is preferably 80% or more, 90% or more, more preferably 95% or more, and particularly preferably 98% or more.

The average degree of polymerization of polyvinyl alcohol is usually 200 to 3500, preferably 300 to 2000, more preferably 500 or more or 1500 or less, from the viewpoint of improving gas barrier properties, strength and coatability.
As polyvinyl alcohol, a type obtained by copolymerizing ethylene at a ratio of 40% or less can also be used, and a carboxyl-modified type can also be used.
The degree of saponification and the average degree of polymerization can be measured according to JIS K6726 (polyvinyl alcohol test method).
The polyvinyl alcohol aqueous solution can be prepared, for example, by supplying polyvinyl alcohol resin in water at normal temperature while stirring, raising the temperature, and stirring at 80 to 95° C. for 30 to 60 minutes.

((b) silicon compound)
As the silicon compound, oxides of silicon are preferable, and examples thereof include silicon dioxide particles, silicon oxide particles represented by SiOx, silica sol, etc. These may be used singly or in combination of two or more. may be used.
X of SiOx is preferably greater than 1.0 and less than or equal to 2.0.
From the viewpoint of hot water resistance and cohesive failure resistance, the average particle size is preferably 0.5 nm to 2 μm, more preferably 1 nm or more or 200 nm or less, and particularly preferably 100 nm or less.
The average particle size of the silicon compound particles can be measured by, for example, a nitrogen gas adsorption (BET) method, electron microscope observation, small-angle X-ray scattering analysis, dynamic light scattering, or the like. However, in the present invention, values measured by the dynamic light scattering method are used.

A method for preparing the silicon compound particles is not particularly limited. For example, the method described in International Publication WO95/17349, page 2, line 16 to page 10, line 26, or paragraphs [0012] to [0031] of JP-A-6-16414, specifically, alkoxy It can be prepared by a method of hydrolyzing and aging silane, or a method of dissolving, ion-exchanging and concentrating water glass.
Calculation of the functional group ratio in the case of the former preparation method can be performed, for example, by the method described on page 15, line 19 to page 16, line 8 of the above-mentioned international pamphlet. 100 mol % can be estimated.

In general, regarding the use of alkoxysilane, it is known to apply a coating solution obtained by mixing alkoxysilane or its hydrolyzate to a resin on a film having an inorganic substance-containing layer. Since the cohesive stress is very strong, it rather damages the inorganic substance-containing layer and lowers the gas barrier properties. Especially under hot water, this tendency is remarkable.
By hydrolyzing and condensing the alkoxysilane and aging it to sufficiently advance the partial cross-linking reaction, the silica is made into particles and preferably contains silanol groups, so that interaction and aggregation with the resin component of the coating layer are prevented. power can be adjusted.

((c) ethylene-unsaturated carboxylic acid copolymer)
The ethylene-unsaturated carboxylic acid copolymer used as a component of the intermediate buffer layer includes ethylene, acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monoethyl maleate, anhydrous It is a copolymer with an unsaturated carboxylic acid such as maleic acid or itaconic anhydride. Among them, a copolymer of ethylene and acrylic acid or methacrylic acid is preferable from the viewpoint of versatility. The ethylene-unsaturated carboxylic acid copolymer may contain any other monomers.

The proportion of the ethylene component in the ethylene-unsaturated carboxylic acid copolymer is preferably 65 to 90% by mass, especially 70% by mass or more or 85% by mass or less, from the viewpoint of versatility and flexibility. More preferred.
The proportion of the unsaturated carboxylic acid component is preferably 10 to 35% by mass, more preferably 15% by mass or more or 30% by mass or less.

Other monomer components that may be contained in the ethylene-unsaturated carboxylic acid copolymer include, for example, vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, Examples include unsaturated carboxylic acid esters such as n-butyl acrylate, isobutyl acrylate, isooctyl acrylate, methyl methacrylate, isobutyl methacrylate, dimethyl maleate, and diethyl maleate. It can be contained at a rate of up to 50% by mass. Such an ethylene-unsaturated carboxylic acid copolymer can be obtained by a known method such as radical polymerization at high temperature and high pressure.

From the viewpoint of gas barrier property, adhesion, etc., the ethylene-unsaturated carboxylic acid copolymer preferably contains a neutralized product thereof, and the neutralization degree of the neutralized product is 10 to 100 from the viewpoint of gas barrier property %, preferably 20% or more or 100% or less, more preferably 40% or more or 100% or less.
The degree of neutralization can be determined by the following formula.

Neutralization degree = (A / B) × 100 (%)
(A: the number of moles of neutralized carboxyl groups in 1 g of the neutralized ethylene-unsaturated carboxylic acid copolymer, B: the carboxyl groups in 1 g of the ethylene-unsaturated carboxylic acid copolymer before neutralization number of moles of
In the case of an aqueous dispersion, simply, the above A is (the number of metal ions in the solvent) × (the valence of the metal ion), and B is the ethylene-unsaturated carboxylic acid copolymer before neutralization. It can be calculated as the number of carboxyl groups.

From the viewpoint of gas barrier properties, the ethylene-unsaturated carboxylic acid copolymer is combined with a dispersion medium containing at least one selected from the above copolymer and ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. It is preferable to use an aqueous dispersion consisting of, and the dispersion medium is used so that the degree of neutralization is the above value with respect to the total number of moles of carboxyl groups possessed by the ethylene-unsaturated carboxylic acid copolymer. preferable.
In order to produce an aqueous dispersion from the ethylene-unsaturated carboxylic acid copolymer and the dispersion medium, for example, a predetermined amount of water and the two raw materials are supplied to a stirrable vessel, and the temperature is set to 90 to 150 ° C. can be obtained by stirring for about 10 minutes to 2 hours at . The aqueous dispersion obtained in this manner has excellent stability, and the particle size and viscosity do not change significantly even after long-term storage.

The ethylene-unsaturated carboxylic acid copolymer may further contain a divalent or trivalent metal. Such a divalent or trivalent metal can be introduced into the copolymer by adding it as an oxide together with a dispersion medium when producing an aqueous dispersion. In addition to oxides, they can also be introduced into the copolymer by adding them in the form of metal carbonates or metal sulfates. The blending amount thereof can be introduced at a rate of 0 to 60 mol % relative to the number of moles of carboxyl groups in the ethylene-unsaturated carboxylic acid copolymer.
The above ethylene-unsaturated carboxylic acid copolymers may be used alone, or two or more of them may be used in combination.

((d) cross-linking agent)
By adding a cross-linking agent to the intermediate buffer layer, it is possible to improve the coating strength of the intermediate buffer layer and the adhesion to the base film.

The cross-linking agent may be a compound capable of reacting with the reactive functional groups of the polyvinyl alcohol of the component (a) and the ethylene-unsaturated carboxylic acid copolymer of the component (b) to cross-link them, and is particularly limited. compounds having various groups corresponding to the above reactive functional groups.
The reactive functional groups of the polyvinyl alcohol and ethylene-unsaturated carboxylic acid copolymer include carboxyl groups, salt-type carboxylic acid groups, and other active hydrogens depending on other components to be further copolymerized as desired. Various functional groups can be mentioned.
Examples of crosslinkable functional groups in the crosslinker include groups capable of reacting with the reactive functional groups of the polyvinyl alcohol and ethylene-unsaturated carboxylic acid copolymers described above, such as carbodiimide groups, oxazoline groups, isocyanate groups, epoxy groups, and methylol groups. , an aldehyde group, an acid anhydride group, an aziridinyl group, etc., but from the viewpoint of the stability of the mixed aqueous dispersion, a carbodiimide group, an oxazoline group, an isocyanate group or an epoxy group is preferred. One type of these crosslinkable functional groups may be introduced in one molecule, or two or more types may be introduced in one molecule. It is preferable that one or more of them are introduced.

As the aqueous polymer having two or more oxazoline groups in the molecule, one obtained by polymerizing an oxazoline group-containing monomer and optionally an ethylenically unsaturated monomer can be used.
Examples of oxazoline group-containing monomers include 2-vinyl-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like can be mentioned. These may be used singly or in combination of two or more. Among them, 2-isopropenyl-2-oxazoline is easily available industrially and is suitable.

As the cross-linking agent, an aqueous polymer having a cross-linkable functional group is preferable, and is particularly excellent in reactivity with the carboxyl group or salt-type carboxylic acid group of polyvinyl alcohol or ethylene-unsaturated carboxylic acid copolymer, and the desired An aqueous polymer having two or more oxazoline groups, carbodiimide groups, epoxy groups, isocyanate groups or the like in the molecule, which gives a crosslinked resin film having performance, is more preferable.

(Method for forming intermediate buffer layer)
The intermediate buffer layer can be formed, for example, by the method described below.
First, an aqueous dispersion containing (a) polyvinyl alcohol and (b) a silicon compound is prepared.
From the viewpoints of water vapor barrier properties, high-speed gravure coating properties, and hot water adhesion, it is desirable to further contain (c) an ethylene-unsaturated carboxylic acid copolymer and (d) a cross-linking agent.
After that, the resin layer can be formed as an intermediate buffer layer by applying it to the surface of the inorganic substance-containing layer and drying it.

In the aqueous dispersion used for forming the intermediate buffer layer, (a) polyvinyl alcohol and (b) silicon compound particles, and optionally (c) ethylene It is preferable to contain each component of -unsaturated carboxylic acid copolymer and (d) a cross-linking agent.

Various known additives can be added to the aqueous dispersion, if necessary. Examples of such additives include polyhydric alcohols such as glycerin, ethylene glycol, polyethylene glycol and polypropylene glycol, silane coupling agents, lower alcohols such as methanol, ethanol, normal propanol and isopropanol, ethylene glycol monomethyl ether and propylene glycol monomethyl ether. Ethers, ethers such as propylene glycol diethyl ether, diethylene glycol monoethyl ether, and propylene glycol monoethyl ether, esters such as propylene glycol monoacetate and ethylene glycol monoacetate, antioxidants, weather stabilizers, UV absorbers, antistatic agents agents, pigments, dyes, antibacterial agents, lubricants, inorganic fillers, antiblocking agents, adhesives and the like.

Furthermore, the aqueous dispersion can be used by mixing with aqueous dispersions of other resins. Such aqueous resin dispersions include polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, acrylic resin, acrylamide resin, methacrylamide resin, acrylonitrile resin, styrene-acrylic acid copolymer. , polyurethane, styrene-maleic acid copolymer, styrene-butadiene copolymer, high-impact polystyrene resin, butadiene resin, polyester, acrylonitrile-butadiene copolymer, polyethylene, polyethylene oxide, propylene-ethylene copolymer, maleic anhydride Aqueous dispersions such as graft-propylene-ethylene copolymers, chlorinated polyethylene, chlorinated polypropylene, EPDM, phenolic resins, and silicone resins can be used singly or in combination of two or more.

A method for preparing the aqueous dispersion is not particularly limited. For example, each resin is dissolved in water, and silicon compound particles or an aqueous solution thereof, a cross-linking agent comprising an aqueous polymer having a crosslinkable functional group or an aqueous solution thereof are added to the solution. a method of mixing compound particles or an aqueous solution thereof, a cross-linking agent comprising an aqueous polymer having a crosslinkable functional group or an aqueous solution thereof, polymerizing each monomer in an aqueous solution of polyvinyl alcohol, followed by silicon compound particles or an aqueous solution thereof, A method of adding a cross-linking agent comprising an aqueous polymer having a cross-linkable functional group or an aqueous solution thereof, a method in which each monomer is polymerized in an aqueous solution of polyvinyl alcohol, neutralized with an alkali, and then silicon compound particles or an aqueous solution thereof are added. , a method of adding a cross-linking agent comprising an aqueous polymer having a cross-linkable functional group or an aqueous solution thereof, or the like. In the above case, the mixture may be prepared using solvents other than water, such as alcohols.

Regarding the coating liquid, it is preferable to use a water-based coating liquid from the viewpoint of environmental load due to VOC (volatile organic compound) generation and health effects on workers. , reverse roll coater, gravure coater, rod coater, air doctor coater or spray can be applied. Moreover, after forming the inorganic substance-containing layer on the base film, the base film may be immersed in the aqueous dispersion.

(Thickness of intermediate buffer layer)
The thickness of the intermediate buffer layer is not particularly limited. It is preferably 0.05 μm to 20 μm, more preferably 0.1 μm or more or 10 μm or less, more preferably 1 μm or more or 5 μm or less.

In order to improve water resistance and durability, the intermediate buffer layer may be subjected to cross-linking treatment by active energy ray irradiation such as electron beam irradiation, if necessary.

<Thickness of protective film (10)>
By adjusting the overall thickness of the protective film (10), it is possible to suppress the occurrence of wrinkles while ensuring light transmittance and light reflectivity.
From this point of view, the overall thickness of the protective film (10) is preferably 20 μm or more, more preferably 23 μm or more or 500 μm or less, and particularly preferably 23 μm or more or 250 μm or less.

<<protective film (20)>>
The protective film (20) preferably has a structure in which a layer having various functions (also referred to as a "functional layer") is provided on the front and back sides of the base film.
At this time, as the base film, the same one as the protective film (10) can be used. However, it may be the same as or different from the protective film (10).
As the functional layer, the functional layer of the protective film (10), such as an anchor coat layer, an inorganic substance-containing layer, an easy-adhesion layer, and an intermediate buffer layer can be used. This may be the same as or different from the protective film (10).

<<Use of this phosphor laminated sheet>>
The present phosphor laminated sheet can be arranged on the viewing side of the light source to constitute a backlight unit or a display device.

<This backlight unit>
The present phosphor laminated sheet constitutes a backlight unit (referred to as "the present backlight unit") (100) arranged on the visible side of the planar light source (50), as shown in FIGS. 3 and 4, for example. can do.
At this time, the protective film (10) is positioned on the light source side of the phosphor sheet (30), and in the protective film (10), the particle-containing layer (3) is opposite to the phosphor sheet (30). It is necessary to arrange it so that it is positioned on the side, that is, on the light source side.

With the backlight unit (100) having such a configuration, as shown in FIG. 4, the _primary light beam L1 emitted from the planar light source (50) is transmitted through the protective film (10) to the phosphor sheet. (30), a portion of the _primary light beam L1 excites the phosphor 30A to emit _secondary light beam L2 in 360-degree directions. Part of the _secondary light beam L2 enters the protective film (10) side, the particle-containing layer (3) reflects the _secondary light beam L2 to the phosphor sheet (30) side, and part of it The phosphor 30A is excited to emit a _tertiary ray L3 in 360-degree directions. Since this process is repeated, the luminous efficiency of the phosphor (30) can be increased, and the brightness of the display device can be improved.

The planar light source may be of a direct type in which light sources are arranged in a parallel plane on the side opposite to the visible side of the wavelength conversion film laminate. At this time, if necessary, a diffusion plate or the like may be provided between the wavelength conversion film laminate and the light source.
Further, the planar light source may be of an edge light type, which includes a light source arranged on the peripheral side and a light guide plate that guides and emits the primary light emitted from the light source to the viewing side. .
In either case, a light emitting diode, a laser light source, or the like can be used as the light source.

The backlight unit may optionally include known optical members.
For example, a retroreflective member may be provided so as to face the planar light source with the wavelength conversion film laminate sandwiched therebetween. As the retroreflective member, a known diffusion plate, diffusion sheet, prism sheet, light guide plate, or the like can be used.
Moreover, you may provide a reflecting plate so that it may be arrange|positioned facing this wavelength conversion film laminated body on both sides of a planar light source. A known reflector can be used as the reflector.
More specifically, a prism sheet, a diffusion sheet, or both can be provided on the viewing side of the protective film (10) or the protective film (20). For example, if a prism sheet and a diffusion sheet are sequentially laminated on the visible side of the protective film (20), the light emitted from the light source passes through the protective film (10), the phosphor sheet (30) and the protective film (20). Light can be collected by a prism sheet and then diffused by a diffusion sheet.

As shown in FIG. 5, if the present wavelength conversion film laminate (40) is placed on the visible side of the planar light source (50) and the prism sheet (60) is placed on the visible side, the above-described present bag can be obtained. In addition to multiple reflection by the light unit (100), the light beam L4 incident _on the prism sheet (60) from the light source side and reflected to the light source side enters the phosphor sheet (30) to excite the phosphor 30A. Therefore, light rays _L5 are emitted in 360-degree directions. Part of this light beam L5 is incident _on the protective film (10) side, the particle-containing layer ( ₃ ) reflects the light beam L5 to the phosphor sheet (30) side, and part of the light beam L5 passes through the phosphor 30A. It is excited to emit light rays L6 in 360 _- degree directions, causing further multiple reflections, which can further improve the luminous efficiency of the phosphor sheet and further improve the brightness of the display device.

(this display device)
A display device (referred to as "this display device"), for example, a liquid crystal display device, can be configured by combining the present backlight unit and a display unit, for example, a liquid crystal unit.

In this case, the liquid crystal cell unit usually has a structure in which two liquid crystal cells are sandwiched between polarizing plates.

This display device further comprises an optical compensation member for optical compensation, a color filter substrate, a thin layer transistor substrate, a lens film, a diffusion sheet, a hard coat layer, an antireflection layer, a low reflection layer, an antiglare layer, and a front side. A scattering layer, a primer layer, an antistatic layer, an undercoat layer, an adhesive layer, and the like can be optionally provided.

<<<explanation of words>>>
In the present invention, the term "film" includes the "sheet", and the term "sheet" includes the "film".
In addition, the expression "panel" such as an image display panel, a protective panel, etc. includes a plate, a sheet and a film.

In the present invention, when described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably Y It also includes the meaning of "less than".
In addition, when described as "X or more" (X is an arbitrary number), it includes the meaning of "preferably greater than X" unless otherwise specified, and is described as "Y or less" (Y is an arbitrary number). If not otherwise specified, it also includes the meaning of "preferably smaller than Y".

EXAMPLES The present invention will be specifically described below with reference to Examples. However, the present invention is by no means limited to the following examples.
The measurement methods and evaluation methods used in the present invention are as follows.

(1) Intrinsic viscosity of polyester (dl/g)
1 g of polyester was precisely weighed, dissolved in 100 ml of a mixed solvent of phenol/tetrachloroethane=50/50 (weight ratio), and measured at 30.degree.

(2) Average particle size of particles in polyester raw material (D50: μm)
The value of 50% of the integrated (weight basis) in the equivalent spherical distribution measured using a centrifugal sedimentation particle size distribution analyzer (manufactured by Shimadzu Corporation, SA-CP3) was taken as the average particle size.

(3) Method for measuring film thickness of coating layer (ILC) The surface of the coating layer was dyed with RuO ₄ and embedded in epoxy resin. After that, the section prepared by the ultrathin section method was stained with RuO ₄ again, and the cross section of the coating layer was measured using a transmission electron microscope (H-7650 manufactured by Hitachi, accelerating voltage 100 kV).

(4) Film Haze and Total Light Transmittance According to JIS K 7136, haze and total light transmittance were measured using a haze meter HM-150 manufactured by Murakami Color Research Laboratory.

(5) Gas barrier property (WvTR)
The water vapor barrier properties of the gas barrier films of Examples and Comparative Examples conformed to the conditions of JIS Z0222 "Testing method for moisture permeability of moisture-proof packaging container" and JIS Z0208 "Testing method for moisture permeability of moisture-proof packaging material (cup method)". It was evaluated by the following method.
On the surface of a 60 μm thick non-oriented polypropylene (CPP) film (“P1146” manufactured by Toyobo Co., Ltd.), a urethane adhesive [AD900 and CAT-RT85 manufactured by Toyo Morton Co., Ltd. AD900: CAT-RT85 = 10:1.5 (weight ratio)] was applied and then dried to form an adhesive layer having a thickness of about 3 µm.
On this adhesive layer, the gas barrier films of Examples and Comparative Examples were laminated so that the inorganic thin film layer side was adjacent to the adhesive layer to obtain a sample film for water vapor barrier evaluation.
Using two pieces of each sample film with a moisture permeable area of 10.0 cm × 10.0 cm square, about 20 g of anhydrous calcium chloride was put as a moisture absorbent to make a bag with four sides sealed, and the bag was placed at a temperature of 40 ° C. and a relative humidity of 90%. Put it in a constant temperature and humidity device, measure the mass (in units of 0.1 mg) for up to 14 days as a guideline for the weight increase to be almost constant at intervals of 48 hours or more, and calculate the water vapor transmission rate from the following formula. shown in the item.
Water vapor transmission rate [g/m ² /day] = (m/s)/t
m: Increased mass (g) at the last two weighing intervals during the test period
s; Moisture permeable area (m ² )
t; Time of the last two weighing intervals during the test period (h)/24 (h)

(6) Film thickness of inorganic substance-containing layer formed by vacuum deposition method (PVD) The film thickness of the inorganic substance-containing layer was measured using fluorescent X-rays. This method utilizes the phenomenon that when an atom is irradiated with X-rays, it emits fluorescent X-rays peculiar to that atom. can be done. The fluorescent X-ray intensity was similarly measured for the measurement sample, and the film thickness was measured from the calibration curve.

(7) Thickness of inorganic substance-containing layer formed by chemical vapor deposition (CVD) A sample was prepared by an epoxy resin-embedded ultra-thin section method, and the cross section of the film was measured by a cross-sectional TEM device (JEM- 1200EXII) at an acceleration voltage of 120 KV.
Regarding the thickness of the CVD inorganic layer of 10 nm or less, it is difficult to obtain an accurate value even by measurement by the cross-sectional TEM method. , the film formation rate per unit running speed was calculated by measuring by the cross-sectional TEM method, and the thickness when the film was formed at the running speed described in the examples was calculated.

(8) Carbon content of CVD inorganic substance-containing layer Using an XPS analyzer K-Alpha manufactured by Thermo Fisher Scientific Co., Ltd., binding energy was measured by XPS (X-ray photoelectron spectroscopy), Si2 _P , C1 The elemental composition (at. %) was calculated by converting from the areas of the peaks corresponding to _S 2 , N1 _S , O1 _S and the like. The carbon content of the CVD inorganic layer was evaluated by reading the value of the CVD inorganic layer portion of the XPS chart.

(9) Presence or absence of anti-Newton ring effect The presence or absence of the anti-Newton ring effect of the gas barrier film was confirmed by the following evaluation method.
(Evaluation method)
A 30 cm x 30 cm piece of gas barrier film was cut out, placed on a light guide plate (BR-U10 manufactured by Bright Co., Ltd.), light from an LED light source was incident on the light guide plate, and the state of the film was visually observed after 10 minutes. The presence or absence of Newton rings was confirmed by checking.
(criterion)
○ (good): There is an anti-Newton ring effect.
× (poor): No anti-Newton ring effect.

(10) Luminance evaluation A commercially available tablet terminal (Kindle Fire HDX7″ manufactured by Amazon) was disassembled, QDEF (quantum dot film manufactured by 3M) was taken out from the backlight unit, and instead of the QDEF, the present invention was cut into a rectangle. A laminate structure member in which a protective film is attached to the quantum dot-containing resin sheet of the example and comparative example is incorporated to produce a liquid crystal display device for evaluation.After that, the surface of the light guide plate is 760 mm in the vertical direction. The luminance was measured with a luminance meter (manufactured by Konica Minolta: CA-2000) placed at the position of , and the luminance of the comparative example was taken as a relative value of 100. Judgment was made according to the following judgment criteria.
(criterion)
○ (good): relative value exceeds 100;
x (poor): Relative value is 100 or less.

(11) Comprehensive Evaluation Each protective film obtained in Examples and Comparative Examples was evaluated according to the following criteria.
(criterion)
○ (good): ○ for each item of gas barrier property, anti-Newton ring effect, and luminance.
△ (little good): At least one of gas barrier property, anti-Newton ring effect, and luminance was △ and the rest were ◯.
× (poor): At least one of the items of gas barrier property, anti-Newton ring effect, and luminance is ×.

Various materials used in Examples and Comparative Examples were prepared as follows.

<Method for producing polyester A>
100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol were used as starting materials, and 0.09 parts by weight of magnesium acetate tetrahydrate as a catalyst was placed in a reactor. The reaction temperature was raised to 230° C. after 3 hours. After 4 hours, the transesterification reaction was virtually complete. After adding 0.04 part of ethyl acid phosphate to this reaction mixture, 0.04 part of antimony trioxide was added, and polycondensation reaction was carried out for 4 hours. That is, the temperature was gradually raised from 230°C to 280°C. On the other hand, the pressure was gradually reduced from normal pressure to 0.3 mmHg finally. After the reaction was started, the reaction was stopped at a point corresponding to the intrinsic viscosity of 0.63 dl/g due to changes in the stirring power of the reactor, and the polymer was discharged under nitrogen pressure. The resulting polyester A had an intrinsic viscosity of 0.63 dl/g.

<Method for producing polyester B>
In the method for producing polyester A, after adding 0.04 parts of ethyl acid phosphate, 0.3 parts of silica particles having an average particle size of 1.6 μm dispersed in ethylene glycol and 0.04 parts of antimony trioxide were added. Polyester B was obtained in the same manner as the method for producing polyester A, except that the polycondensation reaction was stopped at the time point corresponding to the intrinsic viscosity of 0.65 dl/g. The resulting polyester B had an intrinsic viscosity of 0.65 dl/g.

<Method for producing polyester C>
Polyester A was preliminarily crystallized at 160° C. and then solid-phase polymerized in a nitrogen atmosphere at 220° C. to obtain polyester C having an intrinsic viscosity of 0.85 dl/g.

<Method for producing polyester film F1>
A layer with a blending ratio of polyester A / B = 90/10 (% by mass) and a raw material for B layer with a blending ratio of polyester A = 100 (% by mass) are supplied to two twin-screw extruders, each After melting at 285° C., layer A is the outermost layer (outer layer) and layer B is the intermediate layer, which are co-extruded onto a casting drum cooled to 20° C. in a two-kind, three-layer structure, and solidified by cooling to form a non-oriented sheet. Obtained. Next, after stretching 3.4 times in the longitudinal direction at 90 ° C., after preheating in a tenter, stretching 4.2 times in the transverse direction at 125 ° C., heat treatment at 235 ° C. for 5 seconds, and then A 2.0% relaxation was applied in the width direction at 160° C. to obtain a polyester film F1 having a layer structure of A layer/B layer/A layer/=2 μm/19 μm/2 μm and a thickness of 23 μm.

<Method for producing polyester film F2>
Manufactured in the same manner as polyester film F1 except that the blending ratio of polyester C / B = 90/10 (% by mass) is used as the raw material for layer A and the blending ratio of polyester A = 100 (% by mass) is used as the raw material for layer B, and the layer structure A polyester film F2 having a layer A/layer B/layer A=2 μm/19 μm/2 μm and a thickness of 23 μm was obtained.

<Method for producing polyester film F3>
In the polyester film F1, after longitudinal stretching, before guiding the film to the tenter, the following anchor coat composition was applied under the conditions of a compounding ratio of oxazoline compound: resin A: resin B = 60% by mass: 20% by mass: 20% by mass. Polyester film F3 produced in the same manner as polyester film F1 except that the coating amount (after drying) is applied so as to be 0.1 g / m ² , and has a layer structure of A layer / B layer / A layer / anchor coat layer got

・Oxazoline compound:
Acrylic polymer Epocross having an oxazoline group and a polyalkylene oxide chain (oxazoline group weight = 4.5 mmol/g, manufactured by Nippon Shokubai Co., Ltd.)
Resin A (aqueous acrylic resin): A mixture of 40 parts by weight of ethyl acrylate, 30 parts by weight of methyl methacrylate, 20 parts by weight of methacrylic acid, and 10 parts by weight of glycidyl methacrylate is solution-polymerized in ethyl alcohol, and water is added after polymerization. Ethyl alcohol was removed by heating while stirring. The pH was adjusted to 7.5 with aqueous ammonia to obtain a water-based acrylic resin water-based paint.
Resin B (aqueous urethane resin): First, a polyester polyol was obtained consisting of 664 parts by weight of terephthalic acid, 631 parts by weight of isophthalic acid, 472 parts by weight of 1,4-butanediol, and 447 parts by weight of neopentyl glycol. Next, 321 parts by mass of adipic acid and 268 parts by mass of dimethylolpropionic acid were added to the obtained polyester polyol to obtain pendant carboxyl group-containing polyester polyol A. Further, 160 parts by mass of hexamethylene diisocyanate was added to 1880 parts by mass of the polyester polyol A to obtain a water-based polyurethane resin water-based paint.

<Method for producing polyester film F4>
In the polyester film F1, after longitudinal stretching, before guiding the film to the tenter, the following particle-containing layer composition is applied so that the coating amount (after drying) is 0.1 g / m ^2. Polyester film F1 and A polyester film F4 having a layer structure of particle-containing layer/A layer/B layer/A layer was obtained in the same manner.

(Particle-containing layer composition)
・Resin B (aqueous urethane resin): 60% by mass
Same as used in the anchor coat layer of polyester film F3.
・Oxazoline compound: 10% by mass
Acrylic polymer having oxazoline group and polyalkylene oxide chain
Epocross (oxazoline group weight = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)
・Melamine compound: Hexamethoxymethylol melamine 10% by mass
・ Particles: 20% by mass of silica particles with an average particle size of 0.20 μm

[Example 1]
An anchor coat layer composition prepared as described below was coated on polyester film F1 so that the coating amount (after drying) was 0.025 g/m ² and dried to form an anchor coat layer.

(Preparation of Anchor Coating Agent Composition)
An isocyanate compound ("Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) and a saturated polyester ("Vylon 300" manufactured by Toyobo Co., Ltd., number average molecular weight 23,000) are blended at a 1:1 mass ratio to form an anchor coating agent. was prepared.

(PVD inorganic substance-containing layer formation)
Next, using a vacuum deposition apparatus, SiO (purity of 99.9% or more) is evaporated by a heating method, oxygen is introduced, and the oxygen partial pressure is 3.5 × 10 ^-3 Pa, and the oxygen partial pressure is 5 × 10 ^-3 . A PVD inorganic-containing layer of SiOx having a thickness of 40 nm was formed on the anchor coat layer under a vacuum of Pa.

(Formation of intermediate buffer layer)
Furthermore, on the surface of the inorganic substance-containing layer, an intermediate buffer layer composition prepared as follows was applied by gravure coating in an amount (2.9 g/m ² in a wet state) and dried with hot air at 90°C for 5 seconds to obtain a thickness of A gas barrier film with an intermediate buffer layer of 0.4 g/m ² (after drying) was obtained.

(Preparation of intermediate buffer layer composition)
(a), (b), (c) and (d) prepared as follows are mixed in a mixing ratio of 10:30:30:30 (mass ratio) to form an aqueous dispersion An intermediate buffer layer composition was prepared.
(a) Polyvinyl alcohol (PVA, "Gosenol NM-14" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., degree of saponification 99% mol or more, degree of polymerization 1400) is added to ion-exchanged water while stirring, and heated at 95°C for 60 minutes. was dissolved to prepare an aqueous PVA liquid (a) having a solid concentration of 10%.
(b) Ethylene methacrylic acid copolymer (EMAA) (20% by weight of methacrylic acid, MFR: 300 g/10 min), ammonia and ion-exchanged water were stirred and mixed at 95° C. for 2 hours to obtain a neutralization degree of 60% and a solid content of 60%. A 20% aqueous solution (b) was prepared.
(c) According to the description of JP-A-6-16414, sodium water glass JIS3 was dissolved in an aqueous sodium nitrate solution to prepare an aqueous sodium silicate solution. Then, after passing through a hydrogen type cation exchange resin column, a hydroxyl group type anion exchange resin column, and a hydrogen type cation exchange resin column again in this order, an aqueous sodium hydroxide solution was added to obtain an aqueous silicic acid solution. Then, 20% of the silicic acid aqueous solution was distilled under reduced pressure to remove the evaporated water, and the remaining silicic acid aqueous solution was continuously and gradually supplied to continuously perform the reduced pressure distillation to prepare a colloidal silica sol. The colloidal silica sol is passed through a hydrogen-type cation exchange resin column, a hydroxyl-type anion exchange resin column, and again through a hydrogen-type cation exchange resin column in this order, and immediately after that, special grade ammonia water is added to obtain pH 9, average particle size 4 nm, and various metal oxidations. An aqueous silica sol (c) having a substance concentration of 500 ppm was prepared.
(d) 179 parts by mass of deionized water and 2,2'-azobis(2-amidinopropane) dihydrochloride as a polymerization initiator were placed in a flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer and a dropping funnel. 1 part by mass of salt was charged and heated to 60° C. while gently flowing nitrogen gas, and 2 parts by mass of previously prepared ethyl acrylate, 2 parts by mass of methyl methacrylate and 16 parts by mass of 2-isopropenyl-2-oxazoline were added thereto. was dropped from the dropping funnel over 1 hour. Thereafter, the mixture was reacted at 60° C. for 10 hours under a nitrogen stream, and cooled after the reaction to prepare a 2-oxazoline group-containing resin aqueous solution (d) having a solid content concentration of 10% by weight.

(Formation of easy-adhesion layer)
The easy adhesion layer composition prepared as follows was blended so that A1/U1/C1=30/50/20 (% by mass), and adjusted to 10% by mass with a toluene solvent. After that, it was coated on the intermediate buffer layer so that the coating amount (after drying) was 30 nm, and dried to form an easy-adhesion layer.

(Preparation of easy-adhesion layer composition)
The following was used as an easy-adhesion layer composition.
(A1) Tetramethylolmethane ethylene oxide-modified tetraacrylate (total ethylene glycol chain = 35). A tetrafunctional acrylate having a carbon-carbon double bond ratio of 5% by weight with respect to the whole.
(U1): A polyester urethane resin formed from isophorone diisocyanate: terephthalic acid: isophthalic acid: ethylene glycol: diethylene glycol: dimethylolpropanoic acid = 12:19:18:21:25:5 (mol%).
(C1): Acrylic polymer Epocross having an oxazoline group and a polyalkylene oxide chain (oxazoline group weight = 4.5 mmol/g, manufactured by Nippon Shokubai Co., Ltd.)

As described above, a gas barrier film comprising polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer was produced.

Next, a particle-containing layer composition composed of the following particle-containing layer (A) composition was applied on the polyester film F1 of the gas barrier film by a bar coating method so as to have a thickness (after drying) of 3 μm, A particle-containing layer was provided by drying to prepare a protective film composed of particle-containing layer (A)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer.

(Particle-containing layer (A) composition)
Particles: Crosslinked acrylic beads (average particle size: 5 µm) 30 parts by mass Particles: Crosslinked acrylic beads (average particle size: 3 µm) 10 parts by mass Binder resin: Acrylic polyol 42 parts by mass Curing agent: Isocyanate 18 parts by mass Solvent: Ethyl acetate 10 part by mass

On the other hand, as a urethane-based adhesive, AD900 and CAT-RT85 manufactured by Toyo-Morton Co., Ltd. were mixed at a ratio of AD900:CAT-RT85 = 10:1.5 (weight ratio), and was applied to one surface of the polyester film F1. It is applied and then dried to form an adhesive layer (having a thickness of 3 μm after drying), and an easy-adhesive layer is applied to the other surface of the polyester film F1 so that the coating amount (after drying) is 30 nm and dried. A laminated film consisting of an adhesive layer/polyester film F1/easy-adhesive layer was produced.

Then, the laminated film having the polyester film F1/easy-adhesion layer structure is laminated so that the film F1 side is in contact with the adhesive base layer, and the particle-containing layer (A)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/ A protective film (10) having a structure of intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer was obtained.

(Formation of quantum dot layer composition film)
The quantum dot layer composition is applied on the easy-adhesion layer of the protective film so that the thickness after drying is 10 μm, and this is separately prepared (quantum dot layer side) polyester film F1 / anchor coat layer / After lamination with a protective film (20) composed of a PVD inorganic-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer, an integrated amount of light is 1000 mJ with a high-pressure mercury lamp of 160 W from an ultraviolet irradiation device. / cm ² to cure the acrylic resin constituting the quantum dot layer composition by irradiating ultraviolet rays so that the protective film (20) / quantum dot layer (phosphor layer) / protective film (10) composition, Specifically, particle-containing layer (A)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer/quantum dot layer/polyester film F1 /anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer was obtained.

- Quantum dot-containing layer composition:
Quantum dot 1: CdSe/ZnS (emission peak 530 nm) 2 parts by weight Quantum dot 2: CdSe/ZnS (emission peak 620 nm) 2 parts by weight Dipentaerythritol pentaacrylate 63 parts by weight Nippon Kayaku KARAYAD R-128H 10 parts by weight ethylene Glycol-modified bisphenol A acrylate (ethylene glycol chain = 8) 20 parts by weight Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide 3 parts by weight

For the protective film (10), the reflectance R2 (1) of the film surface opposite to the quantum dot layer and the reflectance R1 (1) of the quantum dot layer side surface are measured, and light is irradiated from the quantum dot layer side. A light transmittance T1(1) measured when light was applied, a light transmittance T2(1) measured when light was irradiated from the side opposite to the quantum dot layer, and a film haze value were measured.
On the other hand, for the protective film (20), the reflectance R2 (2) of the film surface opposite to the quantum dot layer side and the reflectance R1 (2) of the film surface on the quantum dot layer side are measured, and the quantum dot layer The light transmittance T2 (2) measured when light is irradiated from the opposite side, the light transmittance T1 (2) measured when light is irradiated from the quantum dot layer side, and the film haze value It was measured.

[Example 2]
In Example 1, the particle-containing layer (B)/polyester film F1 was produced in the same manner as in Example 1 except that the following particle-containing layer (B) composition was used instead of the particle-containing layer (A) composition. /anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer was obtained.

(Particle-containing layer (B) composition)
Particles: Acrylic beads (average particle size: 6 μm) 20 parts by mass Particles: Acrylic beads (average particle size: 3 μm) 10 parts by mass Binder resin: Acrylic polyol 50 parts by mass Curing agent: Isocyanate 20 parts by mass Solvent: Ethyl acetate 30 parts by mass

Next, in the same manner as in Example 1, particle-containing layer (B)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easily adhesive layer/adhesive layer/polyester film F1/easily adhesive layer/ A protective film laminate having a structure of quantum dot layer/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer was obtained in the same manner as in Example 1. The optical characteristic values were measured.

[Example 3]
In Example 1, the particle-containing layer (C)/polyester film F1 was produced in the same manner as in Example 1 except that the following particle-containing layer (C) composition was used instead of the particle-containing layer (A) composition. /anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer was obtained.

(Particle-containing layer (C) composition)
Particles: Acrylic beads (average particle size: 6 µm) 20 parts by mass Particles: Acrylic beads (average particle size: 3 µm) 10 parts by mass Binder resin: Acrylic polyol 50 parts by mass Curing agent: Isocyanate 20 parts by mass Solvent: Ethyl acetate 10 parts by mass

Next, in the same manner as in Example 1, particle-containing layer (C)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easily adhesive layer/adhesive layer/polyester film F1/easily adhesive layer/ A protective film laminate having a structure of quantum dot layer/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer was obtained in the same manner as in Example 1. The optical characteristic values were measured.

[Example 4]
In Example 1, it was produced in the same manner as in Example 1 except that the polyester film F2 was changed, and the particle-containing layer (A) / polyester film F2 / anchor coat layer / PVD inorganic substance-containing layer / intermediate buffer layer / easy adhesion layer A protective film having a structure of /adhesive layer/polyester film F2/adhesive layer was obtained.
Next, in the same manner as in Example 1, particle-containing layer (C)/polyester film F2/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easily adhesive layer/adhesive layer/polyester film F1/easily adhesive layer/ A protective film laminate having a structure of quantum dot layer/polyester film F2/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer was obtained in the same manner as in Example 1. The optical characteristic values were measured.

[Example 5]
In Example 1, the polyester film F3 was changed to the polyester film F3, and the particle-containing layer ( A)/polyester film F3/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F3/adhesive layer was obtained.
Next, in the same manner as in Example 1, particle-containing layer (C)/polyester film F3/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easily adhesive layer/adhesive layer/polyester film F3/easily adhesive layer/ A protective film laminate having a structure of quantum dot layer/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer was obtained in the same manner as in Example 1. The optical characteristic values were measured.

[Comparative Example 1]
In Example 1, the particle-containing layer (D)/polyester film F1 was produced in the same manner as in Example 1 except that the following particle-containing layer (D) composition was used instead of the particle-containing layer (A) composition. /anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/adhesive layer/adhesive layer/polyester film F1/adhesive layer.

(Particle-containing layer (D) composition)
Particles: Average particle size 2 μm Silica particles 5 parts by mass Binder: Acrylic polyol 50 parts by mass Curing agent: Isocyanate 10 parts by mass Solvent: Ethyl acetate 30 parts by mass

Next, in the same manner as in Example 1, particle-containing layer (D)/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easily adhesive layer/adhesive layer/polyester film F1/easily adhesive layer/ A protective film laminate having a structure of quantum dot layer/polyester film F1/anchor coat layer/PVD inorganic substance-containing layer/intermediate buffer layer/easy-adhesion layer/adhesive layer/polyester film F1/easy-adhesion layer was obtained in the same manner as in Example 1. The optical characteristic values were measured.

<Evaluation results>
The properties of each gas barrier film obtained in the above examples and comparative examples are shown in Table 1 below.
In the table below, ILC is an abbreviation for in-line coating (coating and stretching method), and OLC is an abbreviation for offline coating.

<Discussion>
From the above examples and the results of tests conducted by the inventors so far, protective films (10) and (20) having different optical properties are laminated on both the front and back sides of the phosphor layer, and the particles of the protective film (10) A special optical system in which the difference between the reflectance R2(1) of the film surface not provided with the containing layer and the reflectance R2(2) of the protective film (20) on the phosphor layer side is greater than 3%. By imparting the properties, not only can the occurrence of the Newton ring phenomenon be suppressed, but among the light emitted by the phosphor, the light incident on the particle-containing layer can be reflected to the phosphor laminated sheet side, It was found that the luminous efficiency of the phosphor can be increased.
In particular, for example, by arranging an optical protective film on one side of the phosphor sheet so that the side opposite to the particle-containing layer is located on the side of the phosphor sheet, out of the light emitted by the phosphor , the light incident on the particle-containing layer can be reflected to the phosphor sheet side, the luminous efficiency of the phosphor can be increased, and the luminance can be improved.

In addition, regarding the protective film (10) having a particle-containing layer on one side of the base film (a polyester film is used in this example), the light-scattering property of the particle-containing layer is increased to a greater extent than in the past. It has been found that light transmittance and reflectance can be selectively controlled. At this time, in the protective film (10), the incident light from the film surface on which the particle-containing layer is not provided is more strongly reflected in the vicinity of the interface between the particle-containing layer and the base film layer that is in direct contact with the particle-containing layer. It is speculated that the optical characteristics can be controlled to be good.

From the above examples and the results of the tests conducted by the inventors so far, the present particle-containing layer has particles stacked like a stone wall, the particle density in a certain spatial volume is high, and the gaps between the particles are minimized. It can be considered preferable to form abutting structures.
When light is incident on a general particle-containing layer, it should normally travel straight, but in the case of the present particle-containing layer, part of the light propagates between the particle interfaces that are in contact with each other. In the end, it is speculated that some of the light scatters (reflects) at an angle close to the direction it originally came from.
Furthermore, by mixing particles with a smaller average particle size, it is assumed that the particles are arranged so as to fill the gaps between the large particles, causing even finer light scattering. Therefore, it can be inferred that the reflectance unexpectedly increased due to the synergistic effect of light scattering by large and small particles having different particle diameters.

The particle-containing layer has special optical properties as described above. Part of the light that passes through the protective film and enters the phosphor sheet and is emitted omnidirectionally by the phosphor itself is emitted toward the light source. Fine scattering occurs at the interface. By repeating this multiple reflection, the light emitted by various phosphors (red, green) in the phosphor sheet can be efficiently emitted (because the total of transmittance and reflectance is 98% or more, light absorption etc. It is suggested that the optical loss is also small due to the fact that it can be used, so it is speculated that the brightness will improve.

On the other hand, Comparative Example 1 suggests that small optical loss alone does not always contribute to improvement in luminance.
In addition, in the present invention, a double-sided asymmetric structure (the side closer to the light source), which is different from the conventional structure (conventional products have a symmetrical structure on both sides; a film having a particle-containing layer on both sides) is used through the phosphor sheet. It is also noteworthy that the use of a film having a particle-containing layer provided only on the surface of the film produced a remarkable effect of improving brightness.

In the above examples, the particle-containing layer is provided on one side of the base film (1), and the adhesive layer, the base film (2) and other layers are provided on the other side of the base film (1). However, from the above mechanism of action, if the particle-containing layer is provided on the front and back sides of the base film (1), that is, on the light source side, the viewer side of the base film (1) It can be considered that the same effect can be obtained with any configuration as long as it is a configuration known as a configuration for optical use.

INDUSTRIAL APPLICABILITY The phosphor laminated sheet and the backlight unit of the present invention can suppress the occurrence of the Newton's ring phenomenon and can improve the luminance. Therefore, it can be suitably used as a constituent member of various display devices such as a liquid crystal display (LCD).

Claims (14)

A phosphor laminated sheet comprising a protective film (10), a phosphor layer containing a resin and a phosphor, and a protective film (20) in this order such that the protective film (20) is on the viewing side There is
The protective film (10) is an optical protective film having a particle-containing layer on the front and back sides of the base film, that is, on the side opposite to the viewing side,
The reflectance R2(1) of the film surface on which the particle-containing layer of the protective film (10) is not provided is larger than the reflectance R2(2) of the film surface of the protective film (20) on the phosphor layer side, and The difference between the reflectance R2(1) and the reflectance R2(2) is greater than 3% , and
A phosphor laminated sheet , wherein the film haze of the protective film (10) is larger than the film haze of the protective film (20) . A phosphor laminated sheet comprising a protective film (10), a phosphor layer containing a resin and a phosphor, and a protective film (20) in this order such that the protective film (20) is on the viewing side There is
The protective film (10) is an optical protective film having a particle-containing layer on the front and back sides of the base film, that is, on the side opposite to the viewing side,
The reflectance R2(1) of the film surface on which the particle-containing layer of the protective film (10) is not provided is larger than the reflectance R2(2) of the film surface of the protective film (20) on the phosphor layer side, and The difference between the reflectance R2(1) and the reflectance R2(2) is greater than 3% , and
From the side opposite to the phosphor of the protective film (20) than the light transmittance T2 (1) measured when light is irradiated from the side opposite to the particle-containing layer of the protective film (10) A phosphor laminated sheet characterized in that the light transmittance T2(2) measured when irradiated with light is larger . A phosphor laminated sheet comprising a protective film (10), a phosphor layer containing a resin and a phosphor, and a protective film (20) in this order such that the protective film (20) is on the viewing side There is
The protective film (10) is an optical protective film having a particle-containing layer on the front and back sides of the base film, that is, on the side opposite to the viewing side,
The reflectance R2(1) of the film surface on which the particle-containing layer of the protective film (10) is not provided is larger than the reflectance R2(2) of the film surface of the protective film (20) on the phosphor layer side, and The difference between the reflectance R2(1) and the reflectance R2(2) is greater than 3% , and
A phosphor laminated sheet, wherein the water vapor transmission rate (WvTR) of the protective film (10) or the protective film (20) or both of them is less than 1 g/m ² /day. Any one of claims 1 to 3 , characterized in that the reflectance R2(1) of the protective film (10) is greater than 14% and the reflectance R2(2) of the protective film (20) is less than 14%. The phosphor laminated sheet according to . 5. The phosphor-laminated sheet according to any one of claims 1 to 4, wherein the difference between the film haze of the protective film (10) and the film haze of the protective film (20) exceeds 10%. The phosphor laminate according to any one of claims 1 to 5 , characterized in that the film haze of the protective film (10) is greater than 40% and the film haze of the protective film (20) is less than 35%. sheet. The light transmittance T2(1) measured when the protective film (10) is irradiated with light from the side opposite to the particle-containing layer is less than 85%, and the protective film (20) is opposite to the phosphor. The phosphor laminated sheet according to any one of claims 1 to 6 , characterized in that the light transmittance T2(2) measured when light is irradiated from the side is greater than 87%. 8. The protective film (10) according to any one of claims 1 to 7 , characterized in that the light transmittance T1(1) measured when light is irradiated from the particle-containing layer surface side is greater than 87%. phosphor lamination sheet. The light transmittance (T1(1)) measured when the protective film (10) is irradiated with light from the particle-containing layer side, and the reflectance R1(1) of the surface of the protective film (10) on the particle-containing layer side. and is greater than 97%, and the total value of the light transmittance (T2 (1)) and the reflectance (R2 (1)) is greater than 97%. 9. The phosphor laminated sheet according to any one of 8 . 10. The phosphor laminated sheet according to any one of claims 1 to 9 , wherein the protective film (10) or the protective film (20) or both of them are provided with a gas barrier layer. A backlight unit comprising the phosphor laminated sheet according to any one of claims 1 to 10 and a light source arranged on the opposite side of the protective film (10) from the viewing side. The phosphor laminated sheet according to any one of claims 1 to 10 , a light source arranged on the side opposite to the visible side of the protective film (10), and a prism sheet arranged on the visible side of the protective film (20). and a backlight unit. The phosphor laminated sheet according to any one of claims 1 to 10 , a light source arranged on the side opposite to the visible side of the protective film (10), and a diffusion sheet arranged on the visible side of the protective film (20). and a backlight unit. A display device comprising the backlight unit according to any one of claims 11 to 13 and a display unit.

Images