JP2021081493A - Phosphor protective film with release film, wavelength conversion sheet using the same and manufacturing method thereof - Google Patents

Abstract

To provide a phosphor protective film capable of preventing the phosphor protective film from causing heat wrinkles or an adhesive layer of a release film from remaining, after a protective film having a barrier layer is bonded onto a phosphor in a state with the release film laminated thereon and a heat treatment applied, in a formation process of the barrier layer in manufacturing a phosphor light-emitting unit.SOLUTION: A phosphor protective film with a release film includes: a protective film (1) including a protective base material layer (12), a barrier layer (13) and a phosphor adhesion layer (14) from outside; and a release film (2) composed of a weak adhesive layer (22) and a protection film (21) releasably adhered on an outside of the protective film. The weak adhesive layer includes an isocyanate adhesive agent containing a photoinitiator.SELECTED DRAWING: Figure 1

Description

The present invention relates to a protective film used to produce a phosphor representing a quantum dot.

A phosphor, which is a wavelength conversion sheet that changes the wavelength of the laser light by incident the laser light generated from the LED, is used in the backlight unit of the liquid crystal display and the light emitting unit such as the electroluminescence light emitting unit. Since the color of a phosphor changes with a change in wavelength, it is possible to display a color screen using light that has changed to various wavelengths and various colors as display light.

The performance of the phosphor may deteriorate due to contact with oxygen, water vapor, or the like for a long time. In order to prevent such a decrease, a protective film is laminated on the phosphor layer containing the phosphor, or a phosphor light emitting unit is formed by sandwiching the phosphor layer with the protective film.

For example, in Patent Document 1,
A color conversion member including a pair of base materials arranged to face each other and a plurality of color conversion layers provided between the pair of base materials and having different types of phosphors for each layer.
Each of the pair of base materials is a barrier film that protects the plurality of color conversion layers.
Each of the plurality of color conversion layers has different types of phosphors and a resin layer that holds the phosphors.
For each resin layer in the plurality of color conversion layers, a color conversion member containing a different adhesive for each type of the phosphor, that is, a so-called phosphor light emitting unit is proposed.

By the way, for the phosphor light emitting unit used for television and the like, a phosphor protective film having a thickness of about 100 μm is used for reasons such as handling. In the case of a phosphor protective film having a large thickness of about 100 μm, since the bulky film of the protective film has a high Young's modulus, stable production is possible even if there is a heating step. However, in mobile applications, thinness is an important item, and a configuration as thin as about 20 to 30 μm is required.

However, since high heat is applied in the process of forming the barrier layer, there arises a problem that heat wrinkles generated by high temperature in the flow direction are generated in a thin fluorescent protective film for mobile use.
When a phosphor light emitting unit is manufactured using a protective film in a state where heat wrinkles are generated, it becomes difficult to form a phosphor layer having a uniform thickness when laminating, and problems such as uneven light emission of the phosphor become difficult. There was a problem such as the occurrence of.

Japanese Unexamined Patent Publication No. 2011-13567

Therefore, in the process of forming the barrier layer for manufacturing the phosphor light emitting unit, the release film is laminated on the protective film having the barrier layer, and the release film is attached to the phosphor, and after heat treatment, heat wrinkles are generated on the phosphor protective film. It is an object of the present invention to obtain a phosphor protective film in which the adhesive layer of the release film does not remain.

The present invention comprises a protective film provided with a protective base material layer, a barrier layer, and a phosphor adhesive layer from the outside, and a release film composed of a slightly adhesive layer and a protective film that can be adhered to and peeled off from the outer surface of the protective film.
In the fluorophore protective film with a release film
A phosphor protective film with a release film, wherein the slightly adhesive layer is made of an isocyanate-based adhesive containing a photopolymerization initiator.

The fluorophore protective film with a release film of the present invention is easily exposed to ultraviolet rays because the isocyanate-based adhesive containing a photopolymerization initiator is the main component of the slightly adhesive layer after being attached to the phosphor and heated. The adhesiveness of the slightly adhesive layer is lowered, and the release film can be peeled off without causing residual fine adhesive layer or heat wrinkles to obtain a wavelength conversion sheet with a protective film.

It is sectional drawing which shows the structure of the fluorescent substance protective film with a release film in the Example of Embodiment of this invention. It is sectional drawing which shows the state which attached the fluorescent substance protective film with a release film of this invention to a fluorescent substance. It is sectional drawing which shows the state in which the release film was peeled off after the fluorescent substance protective film with a release film of this invention was attached to a fluorescent substance.

Hereinafter, the fluorescent protective film with a release film of the present invention will be described in detail.
FIG. 1 is a cross-sectional view showing the configuration of a phosphor protective film with a release film according to an example of the embodiment of the present invention.
The phosphor protective film with a release film of the present invention is composed of a phosphor protective film 1 and a release film 2.
The phosphor protective film 1 is composed of a functional layer 11, a protective base material layer 12, a barrier layer 13, and a phosphor adhesive layer 14 in this order from the outside.
Further, the release film 2 is composed of a protective film 21 and a slightly adhesive layer 22 in this order from at least the outside.

The functional layer 11 is a layer having at least one or more functions for preventing interference fringes, antireflection, light diffusion, antistatic, scratch prevention, and the like.
A coating film composed of, for example, a binder resin and fine particles may be used to impart functions such as interference fringe prevention, reflection prevention, and light diffusion.
A coating film mixed with an antistatic agent, acrylic resin particles, or the like may be used to impart functions such as antistatic and scratch prevention.
In this case, fine irregularities may be generated on the surface by embedding the fine particles in the binder resin so that a part of the fine particles is exposed from the surface of the layer.

As the binder resin used for the functional layer 11, a resin having excellent optical transparency is used. Specifically, polyethylene terephthalate resin, acrylic resin, acrylic urethane resin, polyester acrylate resin, polyurethane acrylate resin, urethane resin, epoxy resin, polycarbonate resin, polyamide resin, polyimide resin, melamine resin. Thermoplastic resins such as resins, phenolic resins and cyclic polyolefin resins, thermosetting resins, ionizing radiation curable resins and the like can be used. Above all, an acrylic resin having excellent light resistance and optical characteristics is desirable. Of course, not only these single resins but also a plurality of resins can be used in combination.

The fine particles for light diffusion used in the functional layer 11 include 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 can also be used. Fine particles having a refractive index as far as possible from the refractive index of the binder resin are preferable.
The particle size of the fine particles is preferably 0.1 to 30 μm, more preferably 0.5 to 10 μm. If it is less than 0.1 μm, it is fine and embedded in a binder, and it is difficult to obtain the effect of light diffusion.
On the other hand, if the thickness is 30 μm or more, the surface is too rough and it is difficult to obtain an appropriate adhesive force with the release film, and the effect of peeling during heating cannot be obtained.

The protective base material layer 12 is a layer that supports the entire phosphor protective film 1, and is a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a biaxially stretched polybutylene terephthalate film, and a biaxially stretched polypropylene film. Polyethylene-2,6-naphthalate films and their copolymer films can be used. The thickness of the protective base material layer 12 can be determined in consideration that the total thickness of the protective base material and the release film is 60% or more of the total thickness of the phosphor protective film with the release film. desirable.
The thickness of the protective base material layer 12 alone is 9 to 30 μm. If the thickness of the protective base material layer 12 is less than 9 μm, the strength of the entire protective film cannot be maintained. On the other hand, if the thickness is less than 30 μm, the production can be performed efficiently, and the thickness of the entire light emitting unit can be reduced to maintain the weight in a low state.

The barrier layer 13 includes, for example, at least one component selected from the group consisting of a metal alkoxide, a metal alkoxide hydrolyzate, and a metal alkoxide polymer, a hydroxyl group-containing polymer compound, and a silane coupling agent, if necessary. It can be formed by applying an aqueous solution containing the above or a water / alcohol mixed solution to the surface of the inorganic thin film layer and heating and drying at, for example, 80 to 250 ° C.
Even in this gas barrier layer forming step, tension acts on the protective base material layer. And this tension and heat drying may cause wrinkles of the protective film.
By setting the drying temperature to 120 ° C. or higher, the water vapor barrier property can be improved.

The phosphor adhesive layer 14 is an adhesive layer that adheres a protective film to the surface of the phosphor.
As the adhesive or adhesive used for the phosphor adhesive layer, an acrylic adhesive, an epoxy adhesive, a urethane adhesive, or the like can be used. The adhesive preferably contains an epoxy resin.
As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a starch-based pressure-sensitive adhesive, and the like can be used.
The thickness of the fluorescent adhesive layer is 0.5 to 50 μm. If it is less than 0.5 μm, adhesion cannot be obtained. Further, if the thickness is 50 μm or more, there is a problem that the gas barrier property is lowered. Of these, 2 to 6 μm is particularly preferable.

The protective film 21 is a film for suppressing wrinkles that are likely to occur in the manufacturing process of the protective film 1 so as not to occur.
Therefore, a film having high heat resistance and rigidity and sufficient elasticity is required.
Specifically, a film such as a biaxially stretched polyethylene terephthalate film can be used. In addition, as the transparent film, a polyethylene naphthalate film, a polysulfone film, a polyimide film, a biaxially stretched polypropylene film and the like can be considered.
Among the above, a biaxially stretched polyethylene terephthalate film that is heat-fixed at a high temperature is particularly preferable.

The protective film may be composed of a resin film having a single-layer structure, or may be composed of a resin film having a multi-layer structure in which a plurality of resin films are laminated.
The protective film also has a protective function that protects the protective film from damage such as scratches.
Further, the protective film may be a colored film. When it is colored, the visibility is increased, it is easy to peel off when the phosphor is manufactured, and it is possible to prevent forgetting to peel off the release film.

The slightly adhesive layer is a layer that adheres the protective film to the protective film in the manufacturing process, and is held in a state of being attached to the protective film on the phosphor.
The main component of the slightly adhesive layer is an isocyanate-based adhesive containing a photopolymerization initiator, and the adhesiveness is lowered by irradiation with ultraviolet light, so that the release film can be easily peeled off from the protective film.
As the photopolymerization initiator, an alkylphenone-based photopolymerization initiator is added.
The thickness of the slightly adhesive layer is set to 3 μm to 5 μm so that the functional layer 11 and the protective film 21 can be adhered to each other and can be easily peeled off in a later process.

It is required that the slightly adhesive layer does not completely peel off from the protective film and does not remain after being manufactured by heat treatment, and does not cause problems such as distortion in the protective film and the phosphor during peeling.
As the pressure-sensitive adhesive used for the slightly pressure-sensitive adhesive layer, an acrylic pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a starch-based pressure-sensitive adhesive, and the like can be used.

A photopolymerization initiator is added to the slightly adhesive layer so that it can be easily peeled off from the functional layer 11.
Radical species are generated from the photopolymerization initiator, and the polymerization reaction between the oligomers proceeds to form a network structure. By forming the mesh structure, the flow of the micro-adhesive polymer is restricted, the elastic modulus is increased, the adhesiveness is lowered, and the residue of the micro-adhesive layer can be eliminated.
The composition of the pressure-sensitive adhesive forming the slightly pressure-sensitive adhesive layer is as follows: pressure-sensitive adhesive: curing agent: stabilizer (acetylacetone): ethyl acetate: photopolymerization initiator, 30 to 32: 0.3 to 0.7: 0.3 to 0. It can be used in the ratio range of 7.: 66 to 69: 0.2 to 1.2,
Adhesive base: Hardener: Stabilizer (Acetylacetone): Ethyl acetate: Photopolymerization initiator, 30 to 31: 0.35 to 0.6: 0.3 to 0.5: 67.5 to 68.5: 0 A ratio of .6 to 1.2 is preferred.

As the adhesive main agent to be used, a material in which the terminal functional group reacts with the isocyanate-based curing agent and is cured is used. For example, Cybinol MS-3999, Cybinol OC-3405, etc. manufactured by Saiden Chemical Co., Ltd., which are acrylic adhesives, can be used.

As the curing agent, a material whose terminal functional group is cured with the main agent having a hydroxyl group is used. For example, the isocyanate-based curing agents Cybinol K-315 and Cybinol K-341 manufactured by Saiden Chemical Co., Ltd. can be used.

As the photopolymerization initiator to be used, an alkylphenone-based photopolymerization initiator can be used. For example
Benzyldimethylketal-based photopolymerization initiators such as 2,2-dimethoxy-1,2-diphenylethane-1-one;
1-Hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one,
1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one,
2-Hyrodoxy-1- {4- [4- (2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one and other α-hydroxyalkylphenone-based photopolymerization initiators ;
2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one,
Α-Aminoacetophenone system such as 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone Examples include photopolymerization initiators.
Examples of commercially available benzyl dimethyl ketal-based photopolymerization initiators include Irgacure 651 manufactured by BASF Japan Ltd.
Examples of commercially available α-hydroxyalkylphenone-based photopolymerization initiators include Irgacure 184, DaroCure 1173, Irgacure 2959, and Irgacure 127 manufactured by BASF Japan Ltd.
Examples of commercially available α-aminoacetophenone-based photopolymerization initiators include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan Ltd.

FIG. 2 is a cross-sectional view showing a state in which the phosphor protective film 1 with the release film 2 of the present invention is attached to the phosphor 3.
The release film 2 is manufactured by wrapping the release film 2 with a fluorescent substance adhesive layer facing each other on the front and back surfaces of the phosphor 3 while slightly adhering to the fluorescent substance protective film 1, sandwiching the film, and heating and pressure-bonding the film with a heat laminator. ..

FIG. 3 is a cross-sectional view showing a state in which the release film 2 is peeled off after the phosphor protective film with a release film of the present invention is attached to the phosphor 3.
A phosphor protective film 1 with a release film 2 attached to a phosphor is heated and pressure-bonded, cooled sufficiently, and then the release film 2 is peeled off.

At this time, the slightly adhesive layer 22 is cured by irradiating with ultraviolet rays before peeling so as not to generate the adhesive residue.
The ultraviolet irradiation differs depending on the photopolymerization initiator, but for example, a high-pressure mercury lamp containing a wavelength of 243 to 331 nm is used, and an irradiation amount of about ^{180 mJ / cm 2 is applied to cure the ultraviolet light.}

As the phosphor 3, quantum dots or the like are used. Examples of the quantum dots include those in which the core of the light emitting portion is covered with a shell as a protective film.
Examples of the core include cadmium selenium, and examples of the shell include zinc sulfide.
The core may be doubly covered by a first shell and a second shell. Cadmium selenium is used for the core, zinc selenide is used for the first shell, and zinc sulfide is used for the second shell.
Further, yttrium aluminum garnet (YAG): selenium or the like can be used as a phosphor other than the quantum dots.

The phosphor 3 is used with the protective film 1 attached.
When the protective film 1 is bonded, the release film is also bonded together, so that the protective film 1 can be manufactured with a structure that is elastic and has sufficiently high heat resistance.
However, in order to actually incorporate the phosphor 3 into a mobile device or the like, the release film 2 having no wall thickness or transparency is peeled off and then incorporated, so that a thin, light and high-quality fluorescent substance that can be used for mobile devices can be obtained. Be done.

A thin-walled prototype experiment for mobile was conducted by attaching a protective film to the light diffusion layer side of the barrier film for phosphors with a peelable slight adhesive.
To evaluate the experimental product, samples with different amounts of photopolymerization initiator of the slight adhesive were prepared, and the peeling force was measured before and after UV irradiation, and the peeling after UV irradiation was performed. It was confirmed whether or not the adhesive layer was removed on the functional layer side.

<Experimental example 1>
By attaching a protective film to the light diffusing layer side of the barrier film for phosphors with a peelable slight adhesive, we made a prototype of a thin heat wrinkle countermeasure product for mobile use.
A biaxially stretched polyethylene terephthalate film (thickness 23.5 μm) is used as the protective base material layer. The protective film was a biaxially stretched polyethylene terephthalate film (thickness 75 μm).
As the barrier layer, first, silicon oxide was vacuum-deposited to provide an inorganic thin film layer with a thickness of 30 nm.
The light diffusion layer is coated by adding an isocyanate-based curing agent, a polyurethane fine particle size of 2 μm, and ethyl acetate as a solvent to an acrylic polyol resin, drying at 80 ° C. for 1 minute, and light-diffusing to the outer surface side of the protective base material layer. A layer was formed.
The fluorescent material adhesive layer is coated with a 1: 1 mixed solution of traethoxysilane and polyvinyl alcohol and dried at 180 ° C. for 1 minute to make 0.5 μm, and is placed on the 30 nm side of the inorganic thin film layer inside the protective base material layer. A phosphor adhesive layer was provided.
As the fine pressure-sensitive adhesive layer, 30.56 parts of the pressure-sensitive adhesive was an acrylic pressure-sensitive adhesive of Cybinol (registered trademark) MS-3999 manufactured by Saiden Chemical Co., Ltd.
The isocyanate curing agent was Cybinol (registered trademark) K-315 manufactured by Saiden Chemical Co., Ltd., and 0.67 parts.
0.61 part of acetylacetone as a stabilizer,
68.15 parts of ethyl acetate was added as a solvent.
However, no photopolymerization initiator was added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 4.0 μm on the protective film side of the protective film.

<Experimental example 2>
For the slightly pressure-sensitive adhesive layer, 30.51 parts of the pressure-sensitive adhesive is an acrylic pressure-sensitive adhesive of Cybinol (registered trademark) MS-3999 manufactured by Saiden Chemical Co., Ltd.
The isocyanate curing agent was Cybinol (registered trademark) K-315 manufactured by Saiden Chemical Co., Ltd., and 0.62 parts.
0.56 parts of acetylacetone as a stabilizer,
0.20 copies of Irgacure (registered trademark) I-184 manufactured by BASF Japan Ltd. as a photopolymerization initiator.
68.10 parts of ethyl acetate was added as a solvent.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental example 3>
The micro-adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.46 parts, the isocyanate curing agent is 0.57 parts, the stabilizer is 0.51 parts, and the photopolymerization initiator is 0. 40 parts and 68.05 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental Example 4>
The fine pressure-sensitive adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.41 parts, the isocyanate curing agent is 0.52 parts, the stabilizer is 0.46 parts, and the photopolymerization initiator is 0. 60 parts and 68.00 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental Example 5>
The fine pressure-sensitive adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.36 parts, the isocyanate curing agent is 0.47 parts, the stabilizer is 0.41 parts, and the photopolymerization initiator is 0. 80 parts and 67.95 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental example 6>
The micro-adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.31 parts, the isocyanate curing agent is 0.42 parts, the stabilizer is 0.36 parts, and the photopolymerization initiator is 0. 99 parts and 67.90 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental Example 7>
The micro-adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.26 parts, the isocyanate curing agent is 0.37 parts, the stabilizer is 0.31 parts, and the photopolymerization initiator is 1. 19 parts and 67.85 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental Example 8>
The micro-adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.16 parts, the isocyanate curing agent is 0.27 parts, the stabilizer is 0.21 parts, and the photopolymerization initiator is 1. 59 parts and 67.75 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Experimental Example 9>
The micro-adhesive layer is made of the same material as in Experimental Example 2, but the composition is changed. The pressure-sensitive adhesive is 30.06 parts, the isocyanate curing agent is 0.18 parts, the stabilizer is 0.11 parts, and the photopolymerization initiator is 1. 99 parts and 67.65 parts of the solvent were added.
These were sufficiently mixed and applied, and dried at 80 ° C. for 1 minute to form a slightly adhesive layer having a thickness of 3.5 μm on the protective film side of the protective film.
The other protective base material layer, barrier layer, light diffusing layer, and phosphor adhesive layer were prepared in the same manner as in Experimental Example 1.

<Evaluation content>
The phosphor protective film with a release film of the above experimental example was used as a phosphor for quantum dots in which a light emitting portion such as cadmium selenium was coated with a zinc sulfide shell.
Quantum dots are wrapped with a fluorescent protective film with a release film of the experimental example on the front and back, with the fluorescent adhesive layers facing each other, sandwiched between them, and wrapped with a heat laminator at a laminating temperature of 40 ° C., a speed of 1 m / min, and a laminating pressure of 0. It was crimped at 5 MPa.
For ultraviolet irradiation, a high-pressure mercury lamp containing a wavelength of 243 to 331 nm was used, and ^{an irradiation amount of about 180 mJ / cm 2} was applied to cure the slightly adhesive layer.
After crimping to the phosphor and leaving it at room temperature for 30 minutes before UV irradiation, and after leaving it at room temperature for 30 minutes after UV irradiation, make a cut with a knife to a width of 25 mm and peel off the T-shape of JIS K 6854-1. The peeling strength was measured with the peeling speed set to 50 mm / min according to the peeling adhesive strength test method.
After measuring the peel strength, the transition of the adhesive layer at the peeled portion was observed with a magnifying glass to confirm the presence or absence of the transition.

<Peeling evaluation result>
When the amount of the photopolymerization initiator added to the slightly adhesive layer was less than 0.20% by weight, a transition occurred in a part of the slightly adhesive layer.
Further, when the photopolymerization initiator was 1.20% by weight or more, a problem occurred in adhesion.
From the above, the photopolymerization initiator added to the slightly adhesive layer is an alkylphenone-based photopolymerization initiator, and when the addition amount is 0.2 to 1.2% by weight, transfer and adhesion problems occur. It is judged not to.

The fluorophore protective film with a release film of the present invention is produced by preparing two sheets, wrapping the fluorophore adhesive layers with the phosphor adhesive layers facing each other, sandwiching the fluorophore in the film, and heating and pressure-bonding the fluorophore protective film with a heat laminator.
At this time, since the elastic release film is adhered, it can be heat-bonded without causing wrinkles. Then, after the phosphor protective film with the release film is attached, by irradiating with ultraviolet rays, the photopolymerization initiator inside the slightly adhesive layer works, the adhesive strength is lowered, and the release film is easy without transfer. It becomes easy to peel off from the functional layer of the protective film.
By peeling off the release film, the phosphor with the protective film became a thin and light wavelength conversion sheet, and it was possible to make a wavelength conversion sheet suitable for use in mobile devices and the like.
In the thin-walled phosphor manufacturing process, heat wrinkles are prevented by temporarily using the fluorescent protective film with a release film of the present invention, and by peeling after processing, stable supply with high production efficiency is possible. Became.
In particular, since a wavelength conversion sheet without adhesive transition can be obtained only by irradiating with ultraviolet rays, it is very effective in producing a lightweight and thin wavelength conversion sheet, and the merit of the present invention is great.

1 ・ ・ ・ ・ ・ ・ ・ ・ Fluorescent protective film 11 ・ ・ ・ ・ ・ ・ ・ Functional layer 12 ・ ・ ・ ・ ・ ・ Protective base layer 13 ・ ・ ・ ・ ・ ・ Barrier layer 14 ・ ・ ・ ・ ・ ・・ ・ ・ Fluorescent adhesive layer 2 ・ ・ ・ ・ ・ ・ ・ ・ Release film 21 ・ ・ ・ ・ ・ ・ Protect film 22 ・ ・ ・ ・ ・ ・ Slightly adhesive layer 3 ・ ・ ・ ・ ・ ・ ・ ・ Fluorescent

Claims (8)

A protective film having a protective base material layer, a barrier layer, and a phosphor adhesive layer from the outside,
A release film composed of a slightly adhesive layer and a protective film that can be adhered to and peeled off from the outer surface of the protective film.
In the fluorophore protective film with a release film
A phosphor protective film with a release film, wherein the slightly adhesive layer is made of an isocyanate-based adhesive containing a photopolymerization initiator. The phosphor protective film with a release film according to claim 1, wherein the slightly adhesive layer has reduced adhesiveness by irradiation with ultraviolet rays, and the release film can be easily peeled from the protective film. The phosphor protective film with a release film according to claim 1 or 2, wherein the photopolymerization initiator is an alkylphenone-based photopolymerization initiator. The fluorescence with a release film according to claim 3, wherein the micro-adhesive layer is a micro-adhesive layer to which 0.2 to 1.2% by weight of an alkylphenone-based photopolymerization initiator as a photopolymerization initiator is added. Body protection film. A functional layer is provided on the outside of the protective base material layer, and the functional layer is a layer having at least one or more functions for preventing interference fringes, antireflection, light diffusion, antistatic, scratch prevention, and the like. The fluorescent protective film with a release film according to any one of claims 1 to 4. It is characterized in that two fluorescent film protective films with a release film according to any one of claims 1 to 5 are used, the respective fluorescent film adhesive layers are opposed to each other, the fluorescent film is sandwiched between them, and the film is pressure-bonded. Wavelength conversion sheet with release film. A wavelength conversion sheet obtained by peeling the front and back release films from the wavelength conversion sheet with a release film according to claim 6. A protective film having a protective base material layer, a barrier layer, and a phosphor adhesive layer from the outside,
A release film composed of a slightly adhesive layer composed of an isocyanate-based adhesive containing a photopolymerization initiator as a main component and a protective film, and a protective film.
The process of facing the fluorescent adhesive layers of the fluorescent protective film with a release film and crimping with the fluorescent material sandwiched between them.
The process of irradiating ultraviolet rays and
A method for manufacturing a wavelength conversion sheet, which comprises a step of peeling a release film on the front and back surfaces and a step of peeling off the release film.

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