JP2020144159A - Phosphor protective film with release film and wavelength conversion sheet - Google Patents

Abstract

To provide a wavelength conversion sheet, as a phosphor protective film for sandwiching the surface and reverse side of a quantum dot layer, with which wrinkles and unevenness do not occur even when such a thin phosphor protective film is used that causes wrinkles by heat.SOLUTION: Provided is a phosphor protective film 10-1 comprising a phosphor protective film 1 having barrier capability and a release film 2 provided on one side of the phosphor protective film and releasable from the phosphor protective film. The release film includes an adhesive layer 3 on a contact surface with the phosphor protective film, and is characterized in that peel strength between the phosphor protective film and the release film based on JIS K6854-3 is 0.05 to 1.0 N/25 mm.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wavelength conversion sheet used for a backlight of a liquid crystal display. More specifically, the present invention relates to a protective film (fluorescent protective film) of a quantum dot (QD) layer that has a wavelength conversion function of a wavelength conversion sheet.

As a technique for expanding the color reproduction range of a liquid crystal display, quantum dots (fluorescent materials in the visible light region in which CdS, CdSe, CdTe and the like are made into nanoparticles of about several nm to 20 nm) are attracting attention. Quantum dots are fluorescent materials that can obtain white light by converting blue light emitted from a blue light emitting diode into green light and red light and combining it with blue light, and have better color reproducibility than current white LEDs. Are better.

However, since the quantum dots are deteriorated by moisture, it is necessary to prevent the infiltration of moisture into the quantum dot layer by using a gas barrier film (hereinafter, also referred to as a barrier film).

Wavelength conversion films using quantum dots have been mounted on large TVs of 65 inches or more, but because of their good color reproducibility, they are being considered for use in small displays such as smartphones. In order to apply it to a small display, it is necessary to reduce the thickness of the wavelength conversion film.

FIG. 6A exemplifies the layer structure of the phosphor protective film used in the current wavelength conversion sheet for large TVs. This layer structure is an example of a layer structure in which a bulky PET film (thickness 75 μm) provided with a matte layer (thickness 3 μm) and a barrier film (thickness 23 μm) are bonded via an optical adhesive layer (thickness 5 μm). Is shown. A primer layer (thickness 80 μm) is provided on the surface of the barrier film opposite to the optical adhesive layer.

In order to reduce the thickness of such a phosphor protective film, first, as shown in FIG. 6B, a layer structure in which the bulky PET film (thickness 75 μm) and the optical adhesive layer (thickness 5 μm) are removed is formed. investigated. Although thinning can be achieved with this layer structure, since the bulky PET film that reinforces the rigidity of the wavelength conversion sheet is removed, when the wavelength conversion sheet is produced by holding the quantum dot layer, the phosphor protective film is used. The thermal wrinkles cause unevenness in the quantum dot layer. Thermal wrinkles are shrinkage wrinkles that occur when the coating film shrinks in the process of heating and drying after applying the coating film to the film.

This shrinkage wrinkle can be reduced to the same level as the fluorescent film protective film for large TVs shown in FIG. 6 (a) in the thinned fluorescent film protective film shown in FIG. 6 (b). However, even if a wavelength conversion film was produced using a thin phosphor protective film having no such unevenness, the unevenness of the quantum dot layer could not be improved. This is because the rigidity of the thinned phosphor protective film is reduced, and slight thermal wrinkles are generated when the quantum dot layer is thermally laminated using the thinned phosphor protective film. It is presumed that unevenness occurred.

Japanese Unexamined Patent Publication No. 2001-39068

In view of the above circumstances, the present invention does not cause wrinkles or unevenness even if a fluorescent protective film thin enough to generate thermal wrinkles is used as the fluorescent protective film that sandwiches the front and back surfaces of the quantum dot layer. An object of the present invention is to provide a wavelength conversion sheet.

As a means for solving the above-mentioned problems, the invention according to claim 1 of the present invention comprises a fluorophore protective film having a barrier property and a fluorophore protective film provided on one surface of the fluorophore protective film. Equipped with a release film that can be peeled off from
The release film has an adhesive layer on the contact surface with the phosphor protective film.
It is a fluorescent film protective film with a release film, characterized in that the release strength between the phosphor protective film and the release film based on JIS K 6854-3 is 0.05 to 1.0 N / 25 mm.

The peeling according to claim 1, wherein the phosphor protective film includes a barrier film including a barrier film base material and an inorganic thin film layer. It is a phosphor protective film with a film.

Further, in the invention according to claim 3, the fluorophore protective film has a functional layer on the surface on the release film side.
The functional layer is characterized in that it exhibits at least one function selected from the group consisting of an interference fringe prevention function, an antireflection function, a light diffusion function, an antistatic function, and a scratch prevention function. The phosphor protective film with a release film according to claim 1 or 2.

Further, the invention according to claim 4 is configured by having two fluorescent substance protective films according to claim 3 and sandwiching a fluorescent substance layer containing a phosphor between the two fluorescent substance protective films. Each of the two fluorescent material protective films is a wavelength conversion sheet characterized in that the functional layer is arranged so as to be the outermost layer.

According to the fluorophore protective film of the fluorophore protective film with a release film of the present invention, the thickness of only the barrier film and the functional layer is thin enough to cause heat wrinkles, but it is adhered to and supported by the release film and the adhesive layer. Therefore, heat wrinkles and the like do not occur. Further, after the QD layer is sandwiched between two phosphor protective films with a release film and laminated, the release film and the adhesive layer are separated from the functional layer, so that only a thin barrier film and the functional layer are left on the QD layer side. Since it remains, it can be made into a thin wavelength conversion sheet.

Further, according to the wavelength conversion sheet of the present invention, since the phosphor protective film of the present invention is used, it is possible to reduce the thickness.

The cross-sectional explanatory view which illustrated the layer structure of the fluorescent substance protective film with a release film for the quantum dot layer of this invention. The cross-sectional explanatory view which illustrated the layer structure of the fluorescent substance protective film with a release film for the quantum dot layer of this invention. The cross-sectional explanatory view which illustrated the layer structure of the fluorescent substance protective film with a release film for the quantum dot layer of this invention. It is sectional drawing which shows an example of the manufacturing method of the wavelength conversion sheet using the fluorescent film protective film with a release film of this invention, (a) is laminated with the fluorescent substance protective film with a release film on the front and back sides of the QD layer. (B) shows a state in which the release film is peeled from the adhesive layer, and (c) shows a completed wavelength conversion sheet. The cross-sectional explanatory view which shows the layer structure of the fluorescent substance protective film with a release film in Example 1. FIG. It is sectional drawing which illustrated the layer structure of the conventional fluorescent body protective film, (a) is an example of a fluorescent body protective film used for the wavelength conversion sheet for large-sized TV, (b) was initially examined. Examples of thinned phosphor protective films are shown.

<Fluorescent protective film>
The fluorescent protective film with a release film of the present invention includes a fluorescent protective film having a barrier property and a release film provided on one surface of the fluorescent protective film that can be peeled from the fluorescent protective film. ing. Here, the barrier property refers to a gas barrier property against water vapor, oxygen gas, and the like. More specifically, it refers to having the gas barrier properties required by quantum dots.

The release film of the fluorophore protective film with a release film of the present invention is provided with an adhesive layer on the contact surface with the phosphor protective film, and JIS between the phosphor protective film and the release film.
The peel strength based on K 6854-3 is 0.05 to 1.0 N / 25 mm.

Further, the phosphor protective film may include a barrier film including a barrier film base material and an inorganic thin film layer.

Further, the phosphor protective film may have a functional layer on the surface on the release film side. The functional layer may be a layer exhibiting at least one function selected from the group consisting of an interference fringe prevention function, an antireflection function, a light diffusion function, an antistatic function, and a scratch prevention function. ..

Next, the fluorophore protective film with a release film of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a cross-sectional explanatory view illustrating the layer structure of the phosphor protective film 10 with a release film of the present invention.
FIG. 2 illustrates the layer structure of the phosphor protective film 10-1 with a release film of the present invention in the case where the phosphor protective film 1 in FIG. 1 is a laminate of the barrier film 9 and the functional layer 4. It is a thing.
In FIG. 3, the functional layer 4 in FIG. 2 is a matte layer 4-1 and the barrier film 9 is a release film which is a laminate of a barrier film base material 5, an adhesion layer 6, an inorganic thin film layer 7, and an organic coating layer 8. The attached phosphor protective film 10-2 is illustrated.

The functional layer 4 may be a layer exhibiting at least one function selected from the group consisting of an interference fringe prevention function, an antireflection function, a light diffusion function, an antistatic function, and a scratch prevention function. ..

(Laminated film)
The phosphor protective film 1 (FIGS. 1 and 2) used in the phosphor protective film with a release film of the present invention is a laminate provided with a barrier film 9 and a functional layer 4 as illustrated in FIG. Can be.
Further, the barrier film 9 of FIG. 2 is a laminated body including the barrier film base material 5, the adhesion layer 6, the inorganic thin film layer 7, and the organic coating layer 8 as illustrated in FIG. Can be done.

(Release film)
The release film 2 is preferably a resin film capable of smoothing wrinkles generated in the manufacturing process of the phosphor protective film with a release film and having a sufficient elastic modulus to suppress the occurrence of further wrinkles. .. From this point of view, as the release film 2, a polyethylene terephthalate film, a polyethylene naphthalate film, a polypropylene film or the like can be used. Among these, polyethylene terephthalate film is preferable because it can suppress the occurrence of wrinkles more sufficiently. The release film 2 may be composed of a resin film having a single layer structure, or may be composed of a resin film having a multilayer structure in which a plurality of resin films are laminated. The release film 2 also has a protective function of protecting the laminated film 1 from damage such as scratches. Therefore, the release film 2 can prevent the phosphor protection film 1 from being damaged when the phosphor protective film 10 with the release film is used or when the wavelength conversion sheet is manufactured.

The release film 2 may be colored. In this case, the visibility of the release film 2 can be improved, it can be easily peeled off when the wavelength conversion sheet is manufactured, and it is possible to prevent forgetting to peel it off. Since the release film 2 is finally peeled off and does not need to be transparent, it has an advantage that it can be colored. Further, from the same viewpoint, the release film 2 may be opaque or translucent, may be printed, or may have a pattern or pattern drawn on it.

The thickness of the release film 2 is such that the ratio of the thickness of the release film 2 alone to the total thickness of the fluorescent film protective films 10, 10-1 and 10-2 with the release film is 50% or more. It is preferable to be adjusted. The thickness of the release film 2 in the fluorescent film protective films 10, 10-1 and 10-2 with the release film is, for example, 25 to 250 μm, preferably 50 to 230 μm, more preferably 60 to 200 μm, and further. It is preferably 75 to 180 μm. When the thickness of the release film 2 occupies 50% or more of the total thickness of the release film protective film 10, 10-1, 10-2, the release film-attached phosphor protective film 10, 10-1, 10- Sufficient strength to obtain the effect of improving the wrinkles of 2 can be secured, and when the thickness of the release film 2 is 250 μm or less, the phosphor protective film with the release film 10, 10-1, 10- It is easy to prevent the total thickness of 2 from becoming excessively thick.

The tensile elastic modulus of the release film 2 is preferably 290 MPa or more, and is 290 to 290 to
It is more preferably 380 MPa. When the tensile elastic modulus is 290 MPa or more, the effect of improving the wrinkles of the phosphor protective films 10, 10-1, and 10-2 with a release film can be more sufficiently obtained. In the present specification, the tensile elastic modulus of the release film 2 is measured using a test piece obtained by punching the release film 2 into a size of 15 mm in width and 100 mm in length. As the measuring device, Autograph AG-X (manufactured by Shimadzu Corporation) is used for measurement under the conditions of a tensile speed of 300 mm / min, a temperature of 25 ° C., and a humidity of 40% RH.

The release film 2 may contain additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, and a slip agent, if necessary. Further, at least one surface of the release film 2 may be subjected to corona treatment, frame treatment, plasma treatment or the like.

(Adhesive layer)
Examples of the adhesive or adhesive constituting the adhesive layer 3 include acrylic adhesives, epoxy adhesives, urethane adhesives and the like. The adhesive preferably contains an epoxy resin. Examples of the pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, and a starch paste-based pressure-sensitive adhesive. The thickness of the adhesive layer 3 is preferably 0.5 to 50 μm, more preferably 1 to 20 μm, and even more preferably 2 to 6 μm.

The oxygen permeability of the adhesive layer 3 is, for example, 1000 cm ³ / (m ² · day · atm) or less in the thickness direction at a thickness of 5 μm. Preferably the oxygen permeability is ^{500cm 3 / (m 2 · day} · atm) or ^less, 100 cm ³ / more preferably (m 2 · day · atm) or ^{less, 50cm 3 / (m 2 ·} day -Atm) or less is more preferable, and 10 cm ³ / (m ² · day · atm) or less is particularly preferable. By having the oxygen permeability of the adhesive layer 3 of 1000 cm ³ / (m ² · day · atm) or less, even if the inorganic thin film layer 7 and the organic coating layer 8 have defects, dark spots can be suppressed. A possible phosphor protective film can be obtained. The lower limit of the oxygen permeability is not particularly limited, but is, for example, 0.1 cm ³ / (m ² · day · atm).

(Functional layer)
As the functional layer 4, for example, a coating film composed of a binder resin and fine particles can be used. Then, by embedding the fine particles in the binder resin so that a part of the fine particles is exposed from the surface of the functional layer 4, fine irregularities may be generated on the surface of the functional layer 4. By providing the functional layer 4 on the surface of the laminated film 1, that is, on the surface of the wavelength conversion sheet in this way, it is possible to more sufficiently prevent the occurrence of interference fringes such as Newton rings. Further, the incident light can be scattered to exert a light diffusion function, and at the same time, an antireflection function can be exerted.

The binder resin is not particularly limited, but a resin having excellent optical transparency can be used. More specifically, for example, polyester resin, acrylic resin, acrylic urethane resin, polyester acrylate resin, polyurethane acrylate resin, urethane resin, epoxy resin, polycarbonate resin, polyamide resin, polyimide resin. , Thermoplastic resins such as melamine resins and phenolic resins, thermosetting resins, ionizing radiation curable resins and the like can be used. In addition to the organic resin, a silica binder can also be used. Among these, it is desirable to use an acrylic resin or a urethane resin because of the wide range of materials, and it is more desirable to use an acrylic resin because of its excellent light resistance and optical characteristics. These can be used not only as one type but also in combination of a plurality of types. Further, by using a thermosetting resin, an ionizing radiation curable resin, or the like, it is possible to exert a scratch prevention function.

The fine particles are not particularly limited, but are, for example, inorganic fine particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, titanium oxide, and alumina, as well as styrene resin, urethane resin, and silicone resin. Organic fine particles such as acrylic resin and polyamide resin can be used. Among these, as the fine particles, it is preferable to use fine particles having a refractive index of 1.40 to 1.55 made of silica, acrylic resin, urethane resin, polyamide resin or the like in terms of transmittance. Fine particles with a low index of refraction are expensive, while fine particles with an excessively high index of refraction tend to impair the transmittance. These can be used not only as one type but also in combination of a plurality of types.

The average particle size of the fine particles (average particle size based on the volume by the laser diffraction / scattering method) is preferably 0.1 to 30 μm, more preferably 0.5 to 10 μm. When the average particle size of the fine particles is 0.1 μm or more, an excellent interference fringe prevention function tends to be obtained, and when it is 30 μm or less, the transparency tends to be further improved. The content of the fine particles in the functional layer 4 is preferably 0.5 to 30% by mass, more preferably 3 to 10% by mass, based on the total amount of the functional layer 4. When the content of the fine particles is 0.5% by mass or more, the light diffusion function and the effect of preventing the occurrence of interference fringes tend to be further improved, and when it is 30% by mass or less, the reduction in brightness is sufficiently suppressed. There is a tendency to be able to do it.

The thickness of the functional layer 4 is preferably 0.1 to 20 μm, more preferably 0.3 to 10 μm. When the thickness of the functional layer 4 is 0.1 μm or more, a uniform film can be easily obtained, and it is selected from the group consisting of an interference fringe prevention function, an antireflection function, a light diffusion function, an antistatic function, and a scratch prevention function. It tends to be sufficiently easy to obtain at least one function to be performed. On the other hand, when the thickness of the functional layer 4 is 20 μm or less, when the fine particles are used for the functional layer 4, the fine particles are exposed on the surface of the functional layer 4, and the effect of imparting unevenness tends to be easily obtained.

(Mat layer)
One embodiment of the functional layer 4 in FIG. 2 is the matte layer 4-1 in FIG. The mat layer 4-1 is provided on the surface of the barrier film base material 5 in order to exert one or more optical functions and antistatic functions. Here, the optical function is not particularly limited, and examples thereof include an interference fringe (moire) prevention function, an antireflection function, a light diffusion function, and an antistatic function. Among these, the matte layer 4-1 preferably has at least an interference fringe prevention function as an optical function.

The mat layer 4-1 may be composed of a binder resin and fine particles. Then, the surface of the mat layer 4-1 may have fine irregularities by embedding the fine particles in the binder resin so that a part of the fine particles is exposed from the surface of the mat layer 4-1. By providing such a mat layer 4-1 on the surface of the gas barrier laminated film, it is possible to more sufficiently prevent the occurrence of interference fringes such as Newton rings, and as a result, light emission with high efficiency, high definition, and long life. It becomes possible to obtain a device.

The mat layer 4-1 includes, for example, 100 parts by mass of an acrylic polyol resin (manufactured by DIC, trade name: Acrydic A-814) and an isocyanate-based curing agent (manufactured by DIC, trade name: Barnock DN-980). , Hexamethylene diisocyanate compound) 8.5 parts by mass, fine particles (polyurethane, average particle size 2 μm) 10 parts by mass, solvent (ethyl acetate) 70 parts by mass is applied, and 1 at 80 ° C. It may be carried out by heating and drying for a minute and curing to form a mat layer having a thickness of 3 μm.

(Barrier film base material)
The barrier film base material 5 in FIG. 3 is not particularly limited, but a base material having a total light transmittance of 85% or more is desirable. For example, a polyethylene terephthalate film, a polyethylene naphthalate film, or the like can be used as a base material having high transparency and excellent heat resistance. Its thickness is, for example, 9 to 50 μm, preferably 12 to 30 μm, and more preferably 12 to 25 μm. If the thickness of the barrier film base material 5 is 9 μm or more, the strength of the barrier film base material 5 can be sufficiently secured, while if it is 50 μm or less, a long roll can be efficiently and economically produced. be able to.

(Adhesion layer)
The adhesion layer 6 in FIG. 3 is a layer provided for the purpose of improving the adhesion between the inorganic thin film layers 7 when the inorganic thin film layer 7 is formed on the barrier film base material 5. Therefore, when the adhesion of the inorganic thin film layer 7 is good, the adhesion layer 6 does not necessarily have to be provided.
The film thickness and material of the adhesion layer 6 are not particularly limited, but for example, the film thickness can be 1 nm or more and 10,000 nm or less. Further, the material can be selected from one or more of a thermoplastic resin, a thermosetting resin, and a photocurable resin. For example, it may contain a water-soluble polymer and an alkoxysilane or a hydrolysis product thereof.

(Inorganic thin film layer)
The inorganic thin film layer 7 in FIG. 3 is not particularly limited, but for example, aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof can be used. Among these, it is desirable to use aluminum oxide or silicon oxide from the viewpoint of barrier properties and productivity.

The thickness (film thickness) of the inorganic thin film layer 7 is preferably in the range of 5 to 500 nm, and more preferably in the range of 10 to 100 nm. When the film thickness is 5 nm or more, a uniform film is likely to be formed, and the function as a gas barrier material tends to be more sufficiently fulfilled. On the other hand, when the film thickness is 500 nm or less, the thin film can maintain sufficient flexibility, and it is possible to more reliably prevent the thin film from cracking due to external factors such as bending and pulling after the film formation. There is a tendency to be able to do it.

(Organic coating layer)
The organic coating layer 8 of FIG. 3 is provided to prevent various secondary damages in the subsequent process and to impart high barrier properties. From the viewpoint of obtaining excellent barrier properties, the organic coating layer 8 contains at least one selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a metal alkoxide hydrolyzate, and a metal alkoxide polymer as a component. Is preferable. Further, the organic coating layer 8 may further contain a silane coupling agent.

Specific examples of the hydroxyl group-containing polymer compound include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and starch, and the barrier property is most excellent especially when polyvinyl alcohol is used.

The metal alkoxide has a general formula: M (OR) _n (M represents a metal atom such as Si, Ti, Al, Zr, R represents an alkyl group such as -CH ₃ , -C ₂ H ₅ , and n is M. It is a compound represented by (indicating an integer corresponding to the valence of). Specific examples thereof include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [Al (O-iso-C ₃ H ₇ ) ₃ ]. Tetraethoxysilane and triisopropoxyaluminum are preferable because they are relatively stable in an aqueous solvent after hydrolysis. As the hydrolyzate and polymer of the metal alkoxide, for example, silicic acid (Si (OH) ₄ ) as the hydrolyzate and polymer of tetraethoxysilane can be used as the hydrolyzate and polymer of tripropoxyaluminum. Examples thereof include aluminum hydroxide (Al (OH) ₃ ). Examples of the silane coupling agent include compounds represented by the general formula: R ¹ Si (OR ² ) _n (R ¹ : organic functional group, R ² : alkyl group such as CH ₃ , C ₂ H ₅ ). Specifically, ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- Examples thereof include silane coupling agents such as methacryloxypropylmethyldimethoxysilane. Further, an isocyanate compound or a known additive such as a dispersant, a stabilizer, a viscosity modifier, or a colorant is added to the gas barrier coating layer 13 as necessary, as long as the gas barrier property is not impaired. Is also possible.

The thickness (film thickness) of the organic coating layer 8 is preferably in the range of 50 to 1000 nm, and more preferably in the range of 100 to 500 nm. When the film thickness is 50 nm or more, a more sufficient gas barrier property tends to be obtained, and when the film thickness is 1000 nm or less, the thin film tends to maintain sufficient flexibility.

<Wavelength conversion sheet>
Next, the wavelength conversion sheet of the present invention will be described.
The wavelength conversion sheet of the present invention has two phosphor protective films of the present invention, and is configured by sandwiching a phosphor layer containing a phosphor between the two phosphor protective films. Here, the phosphor layer refers to a layer made of a fluorescent material such as a quantum dot (QD) layer.
In the wavelength conversion sheet of the present invention, first, the two protective films with a release film are arranged so that the release film is the outermost layer. After that, the release film and the adhesive layer are separated from the functional layer to complete the wavelength conversion sheet of the present invention.

FIG. 4 is a cross-sectional explanatory view illustrating the method for producing the wavelength conversion sheet of the present invention. Using the phosphor protective film 10-1 with a release film (FIG. 2) of the present invention, the barrier film 9 side thereof is inside each other, and the QD (quantum dot) layer is sandwiched and laminated (FIG. 4 (FIG. 4). The wavelength conversion of the present invention is performed by peeling the release film 2 and the adhesive layer 3 of the phosphor protective layer 10-1 with the release film on the front and back surfaces from the functional layer 4 through a)) (FIG. 4 (b)). A sheet (functional layer / barrier film / QD layer / barrier film / functional layer) is obtained (FIG. 4 (c)).

In the fluorescent film protective film 10, 10-1, 10-2 with a release film of the present invention, the phosphor protective film 1 composed of the barrier film 9 and the functional layer 4 is adhered to the release film 2 via the adhesive layer 3. It is a composition. Therefore, even when the phosphor protective film 1 is thin enough to generate heat wrinkles and the mechanical strength is weak, the fluorescent protective film 1 is in a state of being supported by the release film 2 and handled in that state. Therefore, wrinkles do not occur. Since the QD layer is laminated as shown in FIG. 4A in that state, heat wrinkles do not occur. Next, as shown in FIG. 4B, the release film and the adhesive layer are peeled from the functional layer, but since the barrier film and the functional layer are already laminated on the QD layer, wrinkles and unevenness may occur. A wavelength conversion sheet can be obtained without it (Fig. 4 (c)).
A functional layer is arranged on the outermost surface of the wavelength conversion sheet of the present invention thus obtained.

Next, examples of the present invention will be described.

<Example 1>
A phosphor protective film with a release film having a layer structure as shown in FIG. 5 (PET base material 50 μm / adhesive layer 5 μm / matte layer 3 μm / barrier film 23.5 μm) was prepared, and between the PET base material and the matte layer. The peel strength was measured and the state of the peel interface was confirmed.

First, a barrier film was prepared as follows. First, silicon oxide was provided as an inorganic thin film layer by a vacuum vapor deposition method on one side of a PET film as a barrier film base material, and a gas barrier coating layer was further formed on the inorganic thin film layer. This gas barrier coating layer was formed by applying a coating liquid obtained by mixing tetraethoxysilane and polyvinyl alcohol at a mass ratio of 1: 1 by a wet coating method, and then heating and drying at 180 ° C. for 1 minute. As a result, a barrier film having an inorganic thin film layer and a gas barrier coating layer provided on one surface of the base material was obtained. The thickness of this barrier film is 23.5 μm, the thickness of the barrier film base material is 23 μm, the thickness of the inorganic thin film layer is 30 nm, and the thickness of the gas barrier coating layer is 0.5 μm. is there.

Next, on the barrier film base material of the barrier film, 100 parts by mass of an acrylic polyol resin (manufactured by DIC, trade name: Acrydic A-814) and an isocyanate-based curing agent (manufactured by DIC, trade name: Barnock DN). A composition for forming a mat layer consisting of -980, hexamethylene diisocyanate compound) 8.5 parts by mass, fine particles (polyurethane, average particle size 2 μm) 10 parts by mass, and solvent (ethyl acetate) 70 parts by mass was applied, and the temperature was 80 ° C. The mixture was heat-dried for 1 minute and cured to form a matte layer having a thickness of 3 μm. As a result, a phosphor protective film in which a barrier film and a matte layer were laminated was obtained.

On the other hand, 100 parts by mass of an acrylic adhesive (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol MS-3999) and an isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name) are placed on one side of a PET film having a thickness of 50 μm as a release film. : After applying the pressure-sensitive adhesive layer forming composition consisting of 1.1 parts by mass of Cybinol K-315), 2 parts by mass of stabilizer (acetylacetone), and 221 parts by mass of solvent (ethyl acetate), it is used at 120 ° C. for 1 minute. An adhesive layer having a thickness of 5 μm was formed by heating and drying. As a result, a release film with an adhesive layer was obtained. The sample thus prepared was allowed to stand at room temperature (25 ° C.) for 3 days, and then the peel strength was measured according to the T-shaped peeling test method based on JIS K 6854-3. As a result, the peel strength was 0.158 N / 25 mm. In addition, no peeling of the mat layer or peeling of the adhesive layer was observed by visual observation.

The phosphor protective film and the release film with the adhesive layer are laminated in the direction in which the mat layer and the adhesive layer are in contact with each other, and pressure-bonded with a heat laminator (lamination temperature 40 ° C., transport speed 1 m / min, lamination pressure 0.5 MPa). A phosphor protective film with a release film was obtained. The obtained phosphor protective film with a release film does not have a support film between the barrier film and the release film, and the thickness of the release film is 61% of the total thickness of the phosphor protective film with a release film. It became.

<Example 2>
The same applies to Example 1 except for the following.
100 parts by mass of acrylic adhesive (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol MS-3999) and isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol) on one side of a PET film having a thickness of 50 μm as a release film. K-315) After applying a pressure-sensitive adhesive layer forming composition consisting of 2.2 parts by mass of a stabilizer (acetylacetone) and 221 parts by mass of a solvent (ethyl acetate), heat-drying at 120 ° C. for 1 minute. By doing so, an adhesive layer having a thickness of 5 μm was formed. As a result, a release film with an adhesive layer was obtained. The sample thus prepared was allowed to stand at room temperature (25 ° C.) for 3 days, and then the peel strength was measured according to the T-shaped peeling test method based on JIS K 6854-3. As a result, the peel strength was 0.097 N / 25 mm. In addition, no peeling of the mat layer or peeling of the adhesive layer was visually observed.

<Example 3>
The same applies to Example 1 except for the following.
100 parts by mass of acrylic adhesive (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol MS-3999) and isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol) on one side of a PET film having a thickness of 50 μm as a release film. K-315) After applying a pressure-sensitive adhesive layer-forming composition consisting of 7.5 parts by mass of a stabilizer (acetylacetone) and 221 parts by mass of a solvent (ethyl acetate), heat-drying at 80 ° C. for 1 minute. By doing so, an adhesive layer having a thickness of 5 μm was formed. As a result, a release film with an adhesive layer was obtained. The sample thus prepared was allowed to stand at room temperature (25 ° C.) for 3 days, and then the peel strength was measured according to the T-shaped peeling test method based on JIS K 6854-3. As a result, the peel strength was 0.982N / 25mm. In addition, no peeling of the mat layer or peeling of the adhesive layer was visually observed.

<Comparative example 1>
The same applies to Example 1 except for the following.
100 parts by mass of acrylic adhesive (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol MS-3999) and isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol) on one side of a PET film having a thickness of 50 μm as a release film. K-315) After applying a pressure-sensitive adhesive layer forming composition consisting of 0.5 parts by mass of a stabilizer (acetylacetone) and 221 parts by mass of a solvent (ethyl acetate), heat-drying at 80 ° C. for 1 minute. By doing so, an adhesive layer having a thickness of 5 μm was formed. As a result, a release film with an adhesive layer was obtained. The sample thus prepared was allowed to stand at room temperature (25 ° C.) for 3 days, and then the peel strength was measured according to the T-shaped peeling test method based on JIS K 6854-3. As a result, the peel strength was 0.020 N / 25 mm. In addition, agglomeration failure of the adhesive layer was visually observed.

<Comparative example 2>
The same applies to Example 1 except for the following.
100 parts by mass of acrylic adhesive (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol MS-3999) and isocyanate-based curing agent (manufactured by Saiden Chemical Co., Ltd., trade name: Cybinol) on one side of a PET film having a thickness of 50 μm as a release film. K-315) After applying a composition for forming a pressure-sensitive adhesive layer consisting of 8.5 parts by mass of a stabilizer (acetylacetone) and 221 parts by mass of a solvent (ethyl acetate), heat-drying at 80 ° C. for 1 minute. By doing so, an adhesive layer having a thickness of 5 μm was formed. As a result, a release film with an adhesive layer was obtained. The sample thus prepared was allowed to stand at room temperature (25 ° C.) for 3 days, and then the peel strength was measured according to the T-shaped peeling test method based on JIS K 6854-3. As a result, the peel strength was 1.652 N / 25 mm. In addition, the adhesive layer and the mat layer became strongly adhered, and the mat layer was peeled off.

The above results are summarized in Table 1.

1 ... Fluorescent protective film 2 ... Release film 3 ... Adhesive layer 4 ... Functional layer 5 ... Barrier film base material 6 ... Adhesive layer 7 ... Inorganic barrier layer 8 ... -Organic coating layer 9 ... Barrier film 10, 10-1, 10-2 ... Fluorescent protective film with release film

Claims (4)

It is provided with a fluorophore protective film having a barrier property and a release film provided on one surface of the fluorophore protective film and peelable from the fluorophore protective film.
The release film has an adhesive layer on the contact surface with the phosphor protective film.
A phosphor protective film with a release film, characterized in that the release strength between the phosphor protective film and the release film based on JIS K 6854-3 is 0.05 to 1.0 N / 25 mm. The fluorescent protective film with a release film according to claim 1, wherein the fluorescent protective film includes a barrier film including a barrier film base material and an inorganic thin film layer. The phosphor protective film has a functional layer on the surface on the release film side.
The functional layer is characterized in that it exhibits at least one function selected from the group consisting of an interference fringe prevention function, an antireflection function, a light diffusion function, an antistatic function, and a scratch prevention function. The fluorescent material protective film with a release film according to claim 1 or 2. The two fluorescent material protective films according to claim 3 are provided, and a fluorescent material layer containing a phosphor is sandwiched between the two fluorescent material protective films, and the two fluorescent material protective films are formed. , A wavelength conversion sheet, characterized in that the functional layer is arranged so as to be the outermost layer.