JP7000763B2 - Barrier film laminate - Google Patents

Description

The present invention relates to a barrier film laminate.

In a light emitting unit such as a backlight unit and an electroluminescence light emitting unit of a liquid crystal display, the performance of the light emitting body may deteriorate due to the contact of the light emitting body with oxygen, water vapor, or the like for a long time. For this reason, in these light emitting units, a barrier film laminate in which a gas barrier film having a gas barrier layer formed on a polymer film is laminated via an adhesive layer is often used as a protective film for the light emitting body (for example, Patent Documents). 1).

Japanese Unexamined Patent Publication No. 2012-76288

In the barrier film laminate as described above, the gas barrier film has a gas barrier property that prevents oxygen, water vapor, or the like from invading mainly from the upper surface (or lower surface) of the barrier film laminate in the thickness direction (lamination direction). Since the gas barrier film is laminated, the barrier film laminate can further suppress the intrusion of oxygen, water vapor, etc. as compared with the case of the gas barrier film single layer, and if there is a defect such as a pinhole in one of the gas barrier films. However, the gas barrier property of the barrier film laminate is not easily impaired.

On the other hand, in the barrier film laminate, oxygen, water vapor, etc. may invade from the side surface of the barrier film laminate through the adhesive layer in the surface direction (direction perpendicular to the laminate direction), and if a defect occurs in the gas barrier film. , The gas barrier property as a gas barrier film laminate is impaired, and the performance of the light emitting body to be protected may be deteriorated. Therefore, in the barrier film laminate, not only the gas barrier film but also the adhesive layer may have high gas barrier properties. As a result, it is possible to suppress the intrusion of oxygen, water vapor, etc. through the adhesive layer, and even if a defect occurs in the barrier film, it becomes easy to maintain the gas barrier property as the barrier film laminate.

However, in the barrier film laminate using such an adhesive layer having gas barrier properties, the peel strength between the barrier films changes depending on the peel angle, and in particular, one barrier film is parallel to the plane direction of the other barrier film. There was a problem that peeling was likely to occur when pulled in the (180 degree direction). The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a barrier film laminate having excellent peel strength when the barrier film is pulled in a direction of 180 degrees.

The present invention is formed on a first barrier film including a first base material layer and a first barrier layer formed on the first base material layer, and on the second base material layer and the second base material layer. Provided is a barrier film laminate comprising a second barrier film including a second barrier layer and an adhesive layer. In the barrier film laminate, the first barrier film and the second barrier film are bonded to each other so that the first barrier layer and the second barrier layer face each other via the adhesive layer. Further, the first barrier layer includes a first inorganic thin film layer and a first gas barrier coating layer, the second barrier layer includes a second inorganic thin film layer and a second gas barrier coating layer, and the adhesive layer is , The epoxy resin is formed from an adhesive containing an epoxy resin and a curing agent having an amino group, and the epoxy resin contains a chain aliphatic type bifunctional epoxy resin.

In a barrier film laminate using an adhesive layer having gas barrier properties, the state of peeling when one barrier film was pulled parallel to the surface direction of the other barrier film (180 degree direction) was confirmed. Was found to be not the adhesive layer / barrier film interfacial peeling or the agglomeration peeling of the adhesive layer, but the agglomeration peeling of the base material layer near the barrier layer. The barrier film laminate is a laminate of a large number of layers, and stress generated during and after the production thereof may be accumulated inside. This is because the adhesive layer having a gas barrier property generally has a hard property and often lacks flexibility, so that it is difficult to disperse the stress generated in the barrier film laminate provided with such an adhesive layer. be. As a result, stress is concentrated in the vicinity of the barrier layer of the base material layer, and the base material layer is likely to be agglomerated and peeled off. It is thought that it was. When cohesive peeling of the base material layer occurred, the peeling strength may decrease. In particular, when a stretched polyethylene terephthalate film was used as the base material layer, the surface was peeled off in layers (surface layer peeling), and it was found that the peeling strength tended to decrease more significantly.

Therefore, the present inventors have given flexibility to the adhesive layer by using a chain aliphatic type bifunctional epoxy resin as the epoxy resin used for the adhesive, and peeling when the barrier film is pulled in the 180 degree direction. It was found that the decrease in strength can be suppressed. According to the present invention, since the barrier film laminate includes an adhesive layer formed from the adhesive, the barrier films are excellent in peel strength (hereinafter referred to as 180 degree peel strength) when the barrier films are pulled in the 180 degree direction. A barrier film laminate can be obtained.

In the barrier film laminate, the chain aliphatic type bifunctional epoxy resin is preferably hexanediol diglycidyl ether. This makes it possible to further improve the gas barrier property while obtaining an excellent 180-degree peel strength between the barrier films.

The ratio ( _ME / _MC ) of the content ME of the epoxy resin to the content _MC of the curing agent in the adhesive used for forming the adhesive layer is 0.05 to ₀ . It is preferably 5. This makes it easy to obtain excellent peel strength between the barrier films.

The adhesive preferably further contains a silane coupling agent having an amino group. This tends to improve the peel strength between the barrier films.

The ratio ( _{ME / MSCA )} of the epoxy resin content _ME to the content _MSCA of the silane coupling agent having an amino group in the adhesive shall be 1.0 or more in terms of mass ratio. Is preferable. This makes it easier to improve the peel strength between the barrier films.

The adhesive preferably further contains a silane coupling agent having an epoxy group. This tends to improve the peel strength between the barrier films.

The oxygen permeability of the adhesive layer is preferably 1000 cm ³ / (m ² · day · atm) or less at a thickness of 5 μm. This tends to further improve the gas barrier property of the barrier film laminate.

According to the present invention, it is possible to provide a barrier film laminate having excellent peel strength when the barrier film is pulled in the 180-degree direction.

It is a schematic sectional drawing of the barrier film laminated body which concerns on one Embodiment of this invention. It is schematic cross-sectional view of the wavelength conversion sheet obtained by using the barrier film laminated body which concerns on one Embodiment of this invention. It is a schematic sectional drawing of the backlight unit obtained by using the barrier film laminated body which concerns on one Embodiment of this invention. It is a schematic sectional drawing of the electroluminescence light emitting unit obtained by using the barrier film laminated body which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments.

[Barrier film laminate]
FIG. 1 is a schematic cross-sectional view of a barrier film laminate according to an embodiment of the present invention. In FIG. 1, the barrier film laminate 10 includes a first barrier film 16a, a second barrier film 16b, and an adhesive layer 15, and the first barrier film 16a and the second barrier film 16b are bonded to each other via the adhesive layer 15. ing.

The adhesive layer 15 is formed of an adhesive containing an epoxy resin and a curing agent having an amino group. More specifically, the above adhesive is applied and dried on one barrier film, the other barrier film is bonded via the coating film, and these are aged to obtain an epoxy resin in the coating film and the like. An adhesive layer is formed through a curing reaction with a curing agent. In other words, the adhesive layer 15 contains a reaction product of an epoxy resin and a curing agent having an amino group. Further, the epoxy resin contains a chain aliphatic type bifunctional epoxy resin. As a result, the formed adhesive layer 15 becomes flexible. Since the adhesive layer 15 has flexibility, it is possible to disperse the stress generated during and after the production of the barrier film laminate and suppress the stress from being applied to a specific place. Therefore, in the barrier film laminate 10 provided with the adhesive layer 15, excellent 180-degree peel strength between the barrier films can be obtained.

In the present specification, the chain aliphatic type epoxy resin refers to an epoxy resin having a chain aliphatic hydrocarbon group as a main skeleton, and the above main skeleton is, for example, a portion of the epoxy resin excluding the epoxy group introduction site. Point to. Further, the bifunctional epoxy resin refers to an epoxy resin having two epoxy groups as functional groups in the molecule. The chain aliphatic hydrocarbon group is an aliphatic hydrocarbon group having no ring structure (including an aromatic ring and an aliphatic ring).

The chain aliphatic type bifunctional epoxy resin can be obtained, for example, by allowing epichlorohydrin to act on an alkylene diamine, an alkylene diol, or the like. In this case, the portion of the obtained epoxy resin containing the nitrogen atom derived from the amino group of the alkylenediamine or the oxygen atom derived from the hydroxyl group of the alkylene diol to the terminal epoxy group is the epoxy group introduction site. Further, the portion derived from the alkylene group in the alkylene diamine or the alkylene diol becomes the main skeleton of the epoxy resin.

Specific examples of the chain aliphatic type bifunctional epoxy resin include hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, and diethylene glycol diglycidyl ether. Among these, the chain aliphatic type bifunctional epoxy resin is preferably hexanediol diglycidyl ether or neopentyl glycol diglycidyl ether, and more preferably hexanediol diglycidyl ether. When the chain aliphatic type bifunctional epoxy resin is hexanediol diglycidyl ether, the gas barrier property of the barrier film laminate tends to be improved.

The epoxy resin may contain other epoxy resins other than the chain aliphatic type bifunctional epoxy resin as long as the effects of the present invention are not impaired. Examples of the other epoxy resin include aromatic type epoxy resin, cyclic aliphatic type epoxy resin, monofunctional epoxy resin, and trifunctional or higher functional epoxy resin. The other epoxy resin can be a trifunctional or higher functional epoxy resin. When the epoxy resin contains a trifunctional or higher functional epoxy resin, the ratio of the content of the trifunctional or higher epoxy resin _MEM to the content _ME2 of the chain aliphatic type bifunctional epoxy resin ( _MEM / _ME2 ) is The mass ratio of the non-volatile content is preferably 1.0 or less, more preferably 0.5 or less, and further preferably 0.3 or less. By containing an epoxy resin having a trifunctional or higher adhesive at a content of the above-mentioned content below a certain level with respect to a chain aliphatic type bifunctional epoxy resin, the effect of imparting flexibility to the adhesive layer and 180-degree peel strength is achieved. There is a tendency to improve the gas barrier property without damaging the gas barrier property.

The curing agent having an amino group is not particularly limited as long as it can be mixed with an epoxy resin and cured by heating.

The ratio ( _ME / _MC ) of the epoxy resin content _ME to the content MC of the curing agent having an amino group in the above adhesive is the mass ratio of the non _- volatile content, preferably 1.0 or less. It is more preferably 0.05 to 0.5, still more preferably 0.2 to 0.5, and particularly preferably 0.3 to 0.5. When the adhesive contains an epoxy resin and a curing agent having an amino group within the above range, the adhesiveness of the barrier film can be further easily obtained.

The adhesive preferably further contains a silane coupling agent, more preferably a silane coupling agent having an amino group or an epoxy group, and even more preferably a silane coupling agent having an amino group. .. The silane coupling agent having an amino group preferably further has two or more hydrolyzable functional groups. The silane coupling agent having an epoxy group preferably further has two or more hydrolyzable functional groups.

Examples of the silane coupling agent having an amino group include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane and N-2- (aminoethyl) -3-aminopropylmethyldiethoxysilane, 3-. Aminopropyldimethoxysilane, N-2- (aminoethyl) -3-aminobutylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminohexylmethyldimethoxysilane, N-2- (aminoethyl) -3- Examples thereof include aminooctylmethyldimethoxysilane and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane.

Examples of the silane coupling agent having an epoxy group include 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl. Examples thereof include triethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.

When the adhesive contains a silane coupling agent having an amino group, the ratio of the epoxy resin content _{ME to the content MSCA of} the silane coupling agent having an amino group ( _ME / M) in the adhesive. _SCA ) is preferably 1.0 or more, and more preferably 2.0 or more, in terms of the mass ratio of the non-volatile content. By containing the silane coupling agent having an amino group in the adhesive in the above ratio, the peel strength of the barrier film can be easily improved.

When the adhesive contains a silane coupling agent having an epoxy group, the content of the curing agent having an amino group in the adhesive is _{MC, and the content of the silane coupling agent having an epoxy group is M SCE .} The ratio (MC / M _SCE ) is preferably 10.0 or more in terms of the mass ratio of the non _- volatile content. By containing the silane coupling agent having an epoxy group in the adhesive in the above ratio, the peel strength of the barrier film can be easily improved.

The oxygen permeability of the adhesive layer 15 is preferably 1000 cm ³ / (m ² · day · atm) or less in the thickness direction at a thickness of 5 μm. The oxygen permeability is more preferably 500 cm ³ / (m ² · day · atm) or less, and even more preferably 200 cm ³ / (m ² · day · atm) or less. Since the oxygen permeability of the adhesive layer 15 is 1000 cm ³ / (m ² · day · atm) or less, even if the barrier layer has a defect when used in a light emitting unit, the area around the defect It becomes easier to suppress the occurrence of dark spots. The lower limit of the oxygen permeability is not particularly limited, but is, for example, 0.1 cm ³ / (m ² · day · atm).

The thickness of the adhesive layer 15 is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and even more preferably 2 to 6 μm. When the thickness of the adhesive layer 15 is 0.5 μm or more, the adhesion between the first barrier film 16a and the second barrier film 16b can be easily obtained, and when the thickness is 20 μm or less, the gas barrier property can be obtained. Is easy to obtain.

In FIG. 1, the first barrier film 16a includes a first base material layer 11a and a first barrier layer 14a formed on the first base material layer 11a, and the second barrier film 16b includes a second base material layer 11b. It includes a second barrier layer 14b formed on the second base material layer 11b.

The first base material layer 11a and the second base material layer 11b are layers for suppressing damage in processing, distribution, and the like. Examples of the first base material layer 11a and the second base material layer 11b include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyamides such as nylon; polyolefins such as polypropylene and cycloolefin polymers; polycarbonates; and birds. Examples include, but are not limited to, films such as acetyl cellulose. The first base material layer 11a and the second base material layer 11b are preferably a polyester film, a polyamide film or a polyolefin film, more preferably a polyester film or a polyamide film, and are a polyethylene terephthalate film or a polyethylene naphthalate film. It is more preferable to have. Further, it is preferable that the first base material layer 11a and the second base material layer 11b are biaxially stretched. The first base material layer 11a and the second base material layer 11b may be the same or different. When the first base material layer 11a or the second base material layer 11b is a stretched polyethylene terephthalate film, when the first barrier film 16a or the second barrier film 16b is pulled in the 180 degree direction, the first base material layer 11a Alternatively, the surface of the second base material layer 11b may be peeled off in layers (surface layer peeling), but since the barrier film laminate 10 according to the present embodiment includes the adhesive layer 15, the peeling strength is reduced by 180 degrees. The stretched polyethylene terephthalate film can fully exert its function without occurring.

The thickness of the first base material layer 11a and the second base material layer 11b is not particularly limited, but is preferably 3 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

A first barrier layer 14a and a second barrier layer 14b are formed on the first base material layer 11a and the second base material layer 11b, respectively, via an anchor coat layer (not shown), if necessary. Examples of the anchor coat layer include polyester resin, and the thickness of the anchor coat layer is about 0.01 to 1 μm.

The first barrier film 16a and the second barrier film 16b are bonded so that the first barrier layer 14a and the second barrier layer 14b face each other. As a result, more excellent gas barrier properties can be obtained, and since the first barrier layer 14a and the second barrier layer 14b can be protected from external forces, more stable gas barrier properties can be obtained.

The first barrier film 16a may contain two or more first barrier layers 14a, and the second barrier film 16b may contain two or more second barrier layers 14b. When the first barrier film 16a includes two or more first barrier layers 14a, the configurations of the plurality of first barrier layers 14a may be the same or different. When the second barrier film 16b includes two or more second barrier layers 14b, the configurations of the plurality of second barrier layers 14b may be the same or different. When the barrier film laminate 10 is used in the light emitting unit, the barrier film laminate 10 is arranged so that the first barrier film 16a is in contact with the light emitting body layer. Since the barrier film laminate 10 is a barrier film laminate in which the first barrier film 16a and the second barrier film 16b are laminated, damage to the light emitting body layer due to an external force is suppressed when used in a light emitting unit, and the barrier film laminate 10 is suppressed. , The gas barrier property can be improved.

The first barrier layer 14a includes a first inorganic thin film layer 12a and a first gas barrier coating layer 13a, and the first inorganic thin film layer 12a and the first gas barrier coating layer 13a are arranged in this order on the first base material layer 11a. It is laminated. The second barrier layer 14b includes a second inorganic thin film layer 12b and a second gas barrier coating layer 13b, and the second inorganic thin film layer 12b and the second gas barrier coating layer 13b are arranged in this order on the second base material layer 11b. It is laminated.

The first inorganic thin film layer 12a and the second inorganic thin film layer 12b contain an inorganic compound, and preferably contain a metal oxide. Examples of the metal oxide include oxides of metals such as aluminum, copper, silver, ittrium, tantalum, silicon, and magnesium. The metal oxide is preferably silicon oxide (SiO _x , x is 1.0 to 2.0) because it is inexpensive and has excellent barrier performance. When x is 1.0 or more, good gas barrier properties tend to be easily obtained.

The method for forming the first inorganic thin film layer 12a and the second inorganic thin film layer 12b is preferably vacuum film formation. Examples of the vacuum film formation include a physical vapor deposition method and a chemical vapor deposition method. Examples of the physical vapor deposition method include a vapor deposition method, a sputtering method, an ion plating method, and the like. Moreover, as a chemical vapor deposition method, for example, a thermal CVD method, a plasma CVD method, an optical CVD method and the like can be mentioned. From the viewpoint of manufacturing cost, the first inorganic thin film layer 12a or the second inorganic thin film layer 12b is preferably an inorganic vapor deposition film layer formed by a vapor deposition method.

The thickness of the first inorganic thin film layer 12a and the second inorganic thin film layer 12b is preferably 10 to 300 nm, more preferably 20 to 100 nm. When the thickness of the first inorganic thin film layer 12a and the second inorganic thin film layer 12b is 10 nm or more, a uniform film tends to be easily obtained, and gas barrier properties tend to be easily obtained. On the other hand, when the thickness of the first inorganic thin film layer 12a and the second inorganic thin film layer 12b is 300 nm or less, the first inorganic thin film layer 12a and the second inorganic thin film layer 12b can maintain flexibility. There is a tendency that cracks and the like are less likely to occur due to external forces such as bending and tension after the film.

The first gas barrier coating layer 13a and the second gas barrier coating layer 13b are formed from a composition containing at least one selected from the group consisting of a metal alkoxide represented by the following formula (1) and a hydrolyzate thereof. Is preferable.
M (OR ¹ ) _m (R ² ) _nm ... (1)

In the above formula (1), R ¹ and R ² are independently monovalent organic groups having 1 to 8 carbon atoms, and are preferably alkyl groups such as a methyl group and an ethyl group. M represents an n-valent metal atom such as Si, Ti, Al, Zr and the like. m is an integer from 1 to n. Examples of the metal alkoxide include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [Al (O-iso-C ₃ H ₇ ) ₃ ]. The metal alkoxide is preferably tetraethoxysilane or triisopropoxyaluminum because it is relatively stable in an aqueous solvent after hydrolysis. Examples of the hydrolyzate of the metal alkoxide include silicic acid (Si (OH) ₄ ), which is a hydrolyzate of tetraethoxysilane, and aluminum hydroxide (Al (OH) ₃ ), which is a hydrolyzate of tripropoxyaluminum. ) Etc. can be mentioned. These are not limited to one type, but can be used in combination of a plurality of types. The content of the metal alkoxide and its hydrolyzate in the above composition is, for example, 10 to 90% by mass.

The composition may further contain a hydroxyl group-containing polymer compound. Examples of the hydroxyl group-containing polymer compound include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone and starch. The hydroxyl group-containing polymer compound is preferably polyvinyl alcohol from the viewpoint of barrier properties. These are not limited to one type, but can be used in combination of a plurality of types. The content of the hydroxyl group-containing polymer compound in the above composition is, for example, 10 to 90% by mass.

The thickness of the first gas barrier coating layer 13a and the second gas barrier coating layer 13b is preferably 50 to 1000 nm, more preferably 100 to 500 nm. When the thickness of the first gas barrier coating layer 13a and the second gas barrier coating layer 13b is 50 nm or more, more sufficient gas barrier properties tend to be obtained, and when the thickness is 1000 nm or less, sufficient flexibility is provided. Tends to be retained.

The barrier film laminate 10 may further include a coating layer (not shown) on the surface on the second barrier film 16b side in order to exert a light scattering function. By providing the barrier film laminate 10 with a coating layer, it is possible to obtain an interference fringe (moire) prevention function, an antireflection function, and the like in addition to the light scattering function.

The barrier film laminate 10 can be suitably used as a protective film for a light emitting body (light emitting body protective film) that may deteriorate due to contact with oxygen, water vapor, or the like. Examples of the illuminant include a fluorescent substance such as a quantum dot, an electroluminescence illuminant, and the like.

A method for manufacturing the barrier film laminate according to the present embodiment will be described. First, the first barrier film 16a and the second barrier film 16b are prepared. The method for producing the first barrier film 16a and the second barrier film 16b is as described above. Next, the adhesive is applied onto the surface of the first barrier film 16a on the first barrier layer 14a side (or the second barrier layer 14b side of the second barrier film 16b) to form a coating film. Examples of the method for applying the adhesive include a reverse gravure coating method. The coating film may be dried, if necessary. The drying temperature is about 70 to 130 ° C., and the drying time is about 10 to 60 seconds. After that, the first barrier film 16a and the second barrier film 16b are bonded to each other so that the first barrier layer 14a and the second barrier layer 14b face each other via the coating film. By heat-curing the coating film after bonding, the coating film becomes the adhesive layer 15, and the barrier film laminate 10 can be manufactured. The heating (aging) temperature for curing the coating film is, for example, 40 to 60 ° C., and the heating time is, for example, 1 to 4 days.

[Wavelength conversion sheet]
FIG. 2 is a schematic cross-sectional view of a wavelength conversion sheet obtained by using the barrier film laminate according to the embodiment of the present invention. The wavelength conversion sheet is a sheet capable of converting a part of the wavelength of light from the light source of the backlight unit for a liquid crystal display. As shown in FIG. 2, the wavelength conversion sheet 20 is provided separately from the barrier film laminate 10 described above, the phosphor layer 21 formed on the barrier film laminate 10, and the phosphor layer 21. It is roughly configured with the barrier film laminate 10 of the above. The wavelength conversion sheet 20 has a structure in which the phosphor layer 21 is wrapped (that is, sealed) between the two barrier film laminates 10. In the wavelength conversion sheet 20, a protective film different from the above-mentioned barrier film laminate 10 may be used for one of the barrier film laminates arranged on the light source side of the backlight unit. Further, the wavelength conversion sheet 20 does not necessarily have to have a protective film on the light source side. That is, the wavelength conversion sheet 20 may include a barrier film laminate 10 and a phosphor layer 21 formed on the first barrier film 16a of the barrier film laminate 10.

The fluorescent material layer 21 contains a resin and a fluorescent material. The thickness of the phosphor layer 21 is several tens to several hundreds μm. As the resin, for example, a photocurable resin or a thermosetting resin can be used. The phosphor layer 21 preferably contains two types of phosphors composed of quantum dots. Further, the phosphor layer 21 may be a stack of two or more layers of a phosphor layer containing one type of phosphor and a phosphor layer containing another type of phosphor. As the two types of phosphors, those having the same excitation wavelength are selected. The excitation wavelength is selected based on the wavelength of the light emitted by the light source of the backlight unit. The fluorescent colors of the two types of phosphors are different from each other. When a blue light emitting diode (blue LED) is used as a light source, each fluorescent color is red and green. The wavelength of each fluorescence and the wavelength of the light emitted by the light source are selected based on the spectral characteristics of the color filter. The peak wavelength of fluorescence is, for example, 610 nm for red and 550 nm for green.

Next, the particle structure of the phosphor will be described. As the phosphor, core-shell type quantum dots having particularly good luminous efficiency are preferably used. The core-shell type quantum dot is a semiconductor crystal core as a light emitting portion coated with a shell as a protective film. For example, cadmium selenide (CdSe) can be used for the core, and zinc sulfide (ZnS) can be used for the shell. The quantum yield is improved by covering the surface defects of the particles of CdSe with ZnS having a large bandgap. Further, the fluorescent material may have a core double-coated with a first shell and a second shell. In this case, CdSe can be used for the core, zinc selenide (ZnSe) can be used for the first shell, and ZnS can be used for the second shell.

The fluorescent substance layer 21 may have a single-layer structure in which all the fluorescent substances are dispersed in a single layer, or a multilayer structure in which each fluorescent substance is separately dispersed in a plurality of layers and these are laminated. You may have.

Next, a method of manufacturing the wavelength conversion sheet 20 will be described with reference to FIG. The method for forming the fluorescent layer 21 is not particularly limited, and examples thereof include the methods described in Japanese Patent Application Laid-Open No. 2013-544018. A fluorescent substance is dispersed in a binder resin, and the prepared fluorescent substance dispersion is applied onto the surface of the barrier film laminate 10 on the first barrier film 16a side, and then another barrier film laminate 10 is attached to the coated surface. By curing the phosphor layer 21, the wavelength conversion sheet 20 can be manufactured.

[Backlight unit]
A backlight unit can be obtained by using the wavelength conversion sheet 20. FIG. 3 is a schematic cross-sectional view of a backlight unit obtained by using the barrier film laminate. In FIG. 3, the backlight unit 30 includes a light source 32 and the wavelength conversion sheet 20, and the barrier film laminate 10 is arranged on the light source 32 side and the opposite side thereof with the phosphor layer 21 interposed therebetween. Specifically, in the backlight unit 30, the light guide plate 34 and the reflector 36 are arranged in this order on the surface of the barrier film laminate 10 of the wavelength conversion sheet 20, and the light source 32 is lateral to the light guide plate 34. It is arranged (in the plane direction of the light guide plate 34).

The light guide plate 34 and the reflector 36 efficiently reflect and guide the light emitted from the light source 32, and known materials are used. As the light guide plate 34, for example, acrylic, polycarbonate, cycloolefin film and the like are used. The light source 32 is provided with, for example, a plurality of blue light emitting diode elements. The light emitting diode element may be a purple light emitting diode or a light emitting diode having a lower wavelength. The light emitted from the light source 32 is incident on the light guide plate 34 (D1 direction), and then is incident on the phosphor layer 21 (D2 direction) with reflection and refraction. The light that has passed through the phosphor layer 21 becomes white light by mixing the yellow light generated in the phosphor layer 21 with the light before passing through the phosphor layer 21.

[Electroluminescence light emitting unit]
FIG. 4 is a schematic cross-sectional view of an electroluminescence light emitting unit obtained by using the barrier film laminate. The electroluminescence light emitting unit 50 according to the present embodiment includes an electroluminescence light emitting body layer 56 and a barrier film laminate 10. The electroluminescence light emitting unit 50 includes, for example, a transparent electrode layer 54, an electroluminescence light emitting body layer 56 provided on the transparent electrode layer 54, and a dielectric layer 58 provided on the electroluminescence light emitting body layer 56. It is obtained by sandwiching and sealing the electrode element including the back electrode layer 60 provided on the dielectric layer 58 between the barrier film laminate 10 and the protective film 62. The electroluminescence illuminant layer 56 is formed on the first barrier film 16a of the barrier film laminate 10.

Hereinafter, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

[Preparation of barrier film laminate]
(Example 1)
Acrylic polyol and tolylene diisocyanate are mixed so that the number of NCO groups of tolylene diisocyanate is equal to the number of OH groups of acrylic polyol, and the total solid content is 5% by mass with ethyl acetate. Diluted. Β- (3,4 Epoxycyclohexyl) trimethoxysilane was further added to the diluted mixture so as to be 5% by mass with respect to the total solid content, and these were mixed to obtain an anchor coat layer composition. Made.

The anchor coat layer composition is applied on one surface of a biaxially stretched polyethylene terephthalate film (first substrate layer, thickness: 25 μm) by the bar coat method, and dried and cured at 100 ° C. for 1 minute to increase the thickness. An anchor coat layer having a size of 50 nm was formed.

Using an electron beam heating type vacuum vapor deposition apparatus, the silicon oxide material (SiO, manufactured by Canon Optron Optron Co., Ltd.) is evaporated by electron beam heating under a pressure of 1.5 × ^10-2 Pa, and is placed on the anchor coat layer. A SiO _x film (first inorganic thin film layer) having a thickness of 30 nm was formed. The acceleration voltage in the vapor deposition was 40 kV, and the emission current was 0.2 A.

Next, 10.4 parts by mass of tetraethoxysilane and 89.6 parts by mass of hydrochloric acid (concentration: 0.1N) were mixed, and the mixed solution was stirred for 30 minutes to obtain a hydrolyzed solution of tetraethoxysilane. On the other hand, polyvinyl alcohol was dissolved in a mixed solvent of water / isopropyl alcohol (water / isopropyl alcohol (mass ratio) = 90:10) to obtain a 3% by mass polyvinyl alcohol solution. 60 parts by mass of the hydrolyzed solution of tetraethoxysilane and 40 parts by mass of the polyvinyl alcohol solution were mixed to obtain a gas barrier coating layer composition.

The gas barrier coating layer composition was applied onto the first inorganic thin film layer and dried to form a first gas barrier coating layer having a thickness of 300 nm. Further, another first inorganic thin film layer having a thickness of 30 nm is formed on the first gas barrier coating layer in the same manner as described above, and another first inorganic thin film layer having a thickness of 300 nm is formed on the other first inorganic thin film layer. A first gas barrier coating layer was formed. As described above, the first base material layer, the anchor coat layer, the first inorganic thin film layer, the first gas barrier coating layer, the first inorganic thin film layer, and the first gas barrier coating layer are laminated in this order. Obtained a barrier film.

The anchor coat layer composition is applied on one surface of a biaxially stretched polyethylene terephthalate film (second substrate layer, thickness: 25 μm) by the bar coat method, and dried and cured at 100 ° C. for 1 minute to increase the thickness. An anchor coat layer having a size of 50 nm was formed.

Using an electron beam heating type vacuum vapor deposition apparatus, the silicon oxide material (SiO, manufactured by Canon Optron Co., Ltd.) is evaporated by electron beam heating under a pressure of 1.5 × ^10-2 Pa, and is placed on the anchor coat layer. A SiO _x film (second inorganic thin film layer) having a thickness of 30 nm was formed. The acceleration voltage in the vapor deposition was 40 kV, and the emission current was 0.2 A.

The gas barrier coating layer composition was applied onto the second inorganic thin film layer and dried to form a second gas barrier coating layer having a thickness of 300 nm. As described above, a second barrier film was obtained in which the second base material layer, the anchor coat layer, the second inorganic thin film layer, and the second gas barrier coating layer were laminated in this order.

Bifunctional chain aliphatic type epoxy resin-based main agent (hexanediol diglycidyl ether, manufactured by Mitsubishi Chemical Corporation, trade name: YED-216, non-volatile content: 100% by mass), 5 parts by mass, curing agent having an amino group (Manufactured by Mitsubishi Gas Chemicals Co., Ltd., trade name: C-93, non-volatile content: 65% by mass) 16 parts by mass and a silane coupling agent having an amino group (N-2- (aminoethyl) -3-aminopropyl) Methyldimethoxysilane, manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: KBM-602) 1 part by mass was dissolved in a solvent consisting of 23 parts by mass of methanol and 47 parts by mass of ethyl acetate to prepare an adhesive. The composition of the adhesive is summarized in Table 1.

The above adhesive was applied onto the surface of the first gas barrier coating layer of the obtained first barrier film using a reverse gravure device, and then dried at 82 ° C. for 1 minute to cover the coated surface of the adhesive and the second gas barrier coating. The second barrier film was bonded so as to face the layer, and aged at 50 ° C. for 2 days. As described above, the first barrier film and the second barrier film were bonded together via an adhesive layer having a thickness of 5 μm to prepare a barrier film laminate.

(Example 2)
A barrier film laminate was produced in the same manner as in Example 1 except that the blending amount of the epoxy resin-based main agent was changed from 5 parts by mass to 1 part by mass in the preparation of the adhesive. The composition of the adhesive is summarized in Table 1.

(Example 3)
A barrier film laminate was produced in the same manner as in Example 1 except that the content of the epoxy resin-based main agent was changed from 5 parts by mass to 2.5 parts by mass in the preparation of the adhesive. The composition of the adhesive is summarized in Table 1.

(Example 4)
Same as Example 3 except that the epoxy resin-based main agent was changed to neopentyl glycol diglycidyl ether (manufactured by ADEKA Co., Ltd., trade name: ED-523T, non-volatile content: 100% by mass) in the preparation of the adhesive. To prepare a barrier film laminate. The composition of the adhesive is summarized in Table 1.

(Example 5)
Same as Example 3 except that the silane coupling agent having an amino group was changed to 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-903) in the preparation of the adhesive. To prepare a barrier film laminate. The composition of the adhesive is summarized in Table 1.

(Example 6)
In the preparation of adhesives, a silane coupling agent having an amino group is used as a silane coupling agent having an epoxy group (3-glycidoxypropylmethyldimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-402). A barrier film laminate was produced in the same manner as in Example 3 except that the changes were made. The composition of the adhesive is summarized in Table 1.

(Example 7)
A barrier film laminate was produced in the same manner as in Example 1 except that the blending amount of the silane coupling agent having an amino group was changed from 1 part by mass to 0.1 part by mass in the preparation of the adhesive. The composition of the adhesive is summarized in Table 1.

(Example 8)
A barrier film laminate was produced in the same manner as in Example 1 except that the blending amount of the silane coupling agent having an amino group was changed from 1 part by mass to 0.05 part by mass in the preparation of the adhesive. The composition of the adhesive is summarized in Table 1.

(Example 9)
A barrier film laminate was produced in the same manner as in Example 3 except that a silane coupling agent having an amino group was not blended in the preparation of the adhesive. The composition of the adhesive is summarized in Table 1.

(Example 10)
In the preparation of the adhesive, the epoxy resin-based main agent is 4 parts by mass of hexanediol diglycidyl ether (manufactured by Mitsubishi Chemical Corporation, trade name: YED-216, non-volatile content: 100% by mass), and a polyfunctional epoxy resin (Mitsubishi). A barrier film laminate was produced in the same manner as in Example 1 except that it was changed to 1 part by mass (manufactured by Gas Chemical Corporation, trade name: M-100, non-volatile content: 100% by mass). The composition of the adhesive is summarized in Table 1.

(Comparative Example 1)
Examples in the preparation of the adhesive, except that the epoxy resin-based main agent was changed to 5 parts by mass of a polyfunctional epoxy resin (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: M-100, non-volatile content: 100% by mass). A barrier film laminate was produced in the same manner as in 1. The composition of the adhesive is summarized in Table 2.

(Comparative Example 2)
In the preparation of the adhesive, the epoxy resin-based main agent is a bifunctional aromatic epoxy resin (resorcinol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trade name: EX-201, non-volatile content: 100% by mass) by 5 mass. A barrier film laminate was produced in the same manner as in Example 1 except that the parts were changed. The composition of the adhesive is summarized in Table 2.

(Comparative Example 3)
In the preparation of adhesives, the epoxy resin-based main agent is a bifunctional cyclic aliphatic type epoxy resin (3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Co., Ltd., trade name: celoxide. A barrier film laminate was produced in the same manner as in Example 1 except that the amount was changed to 2021P (nonvolatile content: 100% by mass) to 5 parts by mass. The composition of the adhesive is summarized in Table 2.

[Evaluation of adhesive layer]
(Oxygen permeability)
The adhesive used in Examples and Comparative Examples was applied onto a CPP (non-stretched polypropylene film) having a thickness of 70 μm, and the CPP having a thickness of 70 μm was attached to the coated surface of the adhesive for 2 days at 50 ° C. Aging was done. As described above, a sample (laminated body) for measuring oxygen permeability was obtained, in which a CPP having a thickness of 70 μm, an adhesive layer having a thickness of 5 μm, and a CPP having a thickness of 70 μm were laminated in this order. The obtained sample is placed in a differential pressure type gas permeability measuring device (GTR-30X, manufactured by GTR Tech Co., Ltd.), and the temperature is 40 ° C. and the relative humidity is 0 according to the method described in JIS K7126-1 (Annex 1). The test gas was oxygen in an environment of%, and the oxygen permeability of the above sample was measured by a differential pressure method at a differential pressure of 101 kPa (1 atm). The measurement results of the oxygen permeability are shown in Tables 1 and 2. In the above measurement method, a film having a higher oxygen permeability than the adhesive layer (for example, an oxygen permeability higher than 1000 cm ³ / ( ^m2・ day ・ atm)) is used as the film bonded with the adhesive. Therefore, the oxygen permeability of the laminated body can be regarded as the oxygen permeability of the adhesive layer. That is, in the above measurement method, since CPP having an oxygen transmittance of 2500 cm ³ / (m ²・ day ・ atm) is used as the film bonded with the adhesive, 2500 cm ³ / (m ²・ day) is used. -Atm) The measurement result of the oxygen permeability of the sample below can be regarded as the oxygen permeability of the adhesive layer.

[Evaluation of barrier film laminate]
(180 degree peel strength and peeling mode)
The barrier film laminates obtained in Examples and Comparative Examples were cut into strips having a width of 1 cm, and the first barrier film side of the barrier film laminate was fixed on a glass plate. The second barrier film of the fixed strip-shaped barrier film laminate was subjected to a tencilon tensile tester (manufactured by Orientec) in a direction parallel to the glass plate (180 degrees) at a speed of 300 mm / min. Then, it was peeled off from the first barrier film, and the strength required for peeling (180 degree peeling strength) was measured. The above strength was measured in an environment of temperature 23 ° C. and humidity 65% RH. Further, the peeled surfaces of the first barrier film and the second barrier film were observed visually and by microscopic observation, and the mode of peeling was evaluated. Tables 1 and 2 show the measurement results of the 180-degree peel strength and the peel surface.

(90 degree peel strength and peeling mode)
The barrier film laminates obtained in Examples and Comparative Examples were cut into strips having a width of 1 cm, and the first barrier film side of the barrier film laminate was fixed on a glass plate. The second barrier film, which is a fixed strip-shaped barrier film laminate, is subjected to a tencilon tensile tester (manufactured by Orientec) in a direction perpendicular to the glass plate (90 degrees) at a speed of 300 mm / min. Then, it was peeled off from the first barrier film, and the strength required for peeling (90 degree peeling strength) was measured. The above strength was measured in an environment of temperature 23 ° C. and humidity 65% RH. Further, the peeled surfaces of the first barrier film and the second barrier film were observed visually and by microscopic observation, and the mode of peeling was evaluated. Tables 1 and 2 show the measurement results of the 90-degree peel strength and the peel surface.

In both the barrier film laminates of Examples 1 to 10 and Comparative Examples 1 to 3, when the second barrier film is peeled off in a direction perpendicular to the first barrier film fixed to the glass plate (90 degrees). Good peel strength was obtained. Further, in the barrier film laminates of Examples 1 to 10, when the second barrier film is peeled off in a direction parallel to (180 degrees) with respect to the first barrier film fixed to the glass plate, the peeling is also good. Strength was obtained. Looking at the 180-degree peeled surface of the barrier film laminates of Examples 1 to 10, it was confirmed that the adhesive layer was agglomerated and peeled. On the other hand, in Comparative Example 1, when the second barrier film was peeled off in a direction parallel to (180 degrees) with respect to the first barrier film fixed to the glass plate, similarly good peel strength could not be obtained. Looking at the peeled surface of the barrier film laminates of Comparative Examples 1 to 3, it was confirmed that the base material layer in the vicinity of the barrier layer was peeled in a layered manner. The reason why such an evaluation result was obtained is that the adhesive layer became hard by using only an epoxy resin other than the chain aliphatic type bifunctional epoxy resin as the epoxy resin, and during the production of the barrier film laminate and It is conceivable that the stress generated after manufacturing was concentrated on the base material layer. In Example 5, cloudiness was observed when the adhesive was left for several hours before application, but the peel strength was not affected.

10 ... Barrier film laminate, 11a ... First base material layer, 11b ... Second base material layer, 12a ... First inorganic thin film layer, 12b ... Second inorganic thin film layer, 13a ... First gas barrier coating layer, 13b ... Second gas barrier coating layer, 14a ... first barrier layer, 14b ... second barrier layer, 15 ... adhesive layer, 16a ... first barrier film, 16b ... second barrier film, 20 ... wavelength conversion sheet, 21 ... phosphor Layer, 30 ... Backlight unit, 50 ... Electroluminescence light emitting unit.

Claims (7)

A first barrier film containing a first base material layer and a first barrier layer formed on the first base material layer,
A second barrier film including a second base material layer and a second barrier layer formed on the second base material layer, and a second barrier film.
With an adhesive layer,
Equipped with
The first barrier film and the second barrier film are bonded to each other via the adhesive layer so that the first barrier layer and the second barrier layer face each other.
The first barrier layer includes a first inorganic thin film layer and a first gas barrier coating layer.
The second barrier layer includes a second inorganic thin film layer and a second gas barrier coating layer.
A barrier film laminate in which the adhesive layer is formed of an adhesive containing an epoxy resin and a curing agent having an amino group, and the epoxy resin contains a chain aliphatic type bifunctional epoxy resin. The barrier film laminate according to claim 1, wherein the chain aliphatic type bifunctional epoxy resin is hexanediol diglycidyl ether. The ratio ( _ME / _MC ) of the content _ME of the epoxy resin to the content _MC of the curing agent in the adhesive is 0.05 to 0.5 by mass ratio, claim 1. Or the barrier film laminate according to 2. The barrier film laminate according to any one of claims 1 to 3, wherein the adhesive further contains a silane coupling agent having an amino group. The ratio ( _{ME / MSCA )} of the epoxy resin content _ME to the content _MSCA of the silane coupling agent having an amino group in the adhesive is 1.0 or more by mass ratio. The barrier film laminate according to claim 4. The barrier film laminate according to any one of claims 1 to 3, wherein the adhesive further contains a silane coupling agent having an epoxy group. The barrier film laminate according to any one of claims 1 to 6, wherein the oxygen permeability of the adhesive layer is 1000 cm ³ / (m ² · day · atm) or less at a thickness of 5 μm.

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