KR102236516B1 - Polymerizable composition containing quantum dot, wavelength conversion member, backlight unit, liquid crystal display device and method for manufacturing wavelength conversion member - Google Patents

Abstract

An object of the present invention is to provide a wavelength conversion member having excellent adhesion between a wavelength conversion layer containing quantum dots and an adjacent layer.
As a means to solve these problems, it contains quantum dots that are excited by excitation light to emit fluorescence, polymerizable compounds, silane coupling agents, and an acid generator that generates protonic acid by imparting energy. A quantum dot-containing polymerizable composition, a wavelength conversion layer formed by simultaneously or sequentially applying energy to generate the protonic acid and polymerization treatment to the quantum dot-containing polymerizable composition, and one main surface of the wavelength conversion layer A wavelength conversion member including at least an adjacent layer adjacent to the main surface, a manufacturing method of the wavelength conversion member, a backlight unit including the wavelength conversion member, and a liquid crystal display device including the backlight unit are provided.

Description

TECHNICAL FIELD BACKGROUND OF THE INVENTION [0001] BACKGROUND ART POLYMERIZABLE COMPOSITION CONTAINING QUANTUM DOT, WAVELENGTH CONVERSION MEMBER, BACKLIGHT UNIT, LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR MANUFACTURING WAVELENGTH CONVERSION MEMBER }

The present invention relates to a polymerizable composition containing quantum dots that are excited by excitation light to emit fluorescence, a wavelength conversion member, a backlight unit, a liquid crystal display device, and a method of manufacturing a wavelength conversion member.

BACKGROUND ART Flat panel displays such as a liquid crystal display device (hereinafter, also referred to as an LCD (Liquid Crystal Display)) have low power consumption and are widely used year by year as a space-saving image display device. The liquid crystal display device is composed of at least a backlight and a liquid crystal cell, and usually further includes members such as a backlight-side polarizing plate and a viewing-side polarizing plate.

In the flat panel display market, improvement in color reproducibility is advancing as an improvement in LCD performance. In this regard, in recent years, as a light emitting material, quantum dots (also referred to as quantum dots, QDs, and quantum dots) are attracting attention (see Patent Document 1). For example, when excitation light enters a wavelength conversion member containing quantum dots from a backlight, the quantum dots are excited to emit fluorescence. Here, by using quantum dots having different light emission characteristics, red light, green light, and blue light may be emitted to realize white light. Fluorescence by quantum dots has a small half-value width, so the obtained white light has high luminance and is excellent in color reproducibility. With the progress of the three-wavelength light source technology using quantum dots, the color reproduction range has been expanded from 72% to 100% of the current television standards (FHD (Full High Definition), NTSC (National Television System Committee)).

US2012/0113672A1

As the wavelength conversion member, a laminated structure in which one or more other layers are provided on one or both of the main surfaces (the main surface will be described later) of the wavelength conversion layer containing quantum dots is proposed. However, if the close contact between the wavelength conversion layer and the adjacent layer adjacent to this layer is insufficient, during processing such as cutting the wavelength conversion member into a specified size (for example, punching by a punching machine) to ship the wavelength conversion member as a product. Thus, peeling occurs at the end of the interface between the wavelength conversion layer and the adjacent layer. For example, as an example, in the case where the adjacent layer is a layer having oxygen barrier properties, if such separation of the interface ends occurs, there is a concern that the luminous efficiency of the quantum dots decreases due to intrusion of oxygen from the interface ends. In addition, insufficient adhesion between the wavelength conversion layer and the adjacent layer is a cause of a decrease in durability of the member due to partial peeling between the layers.

Therefore, an object of the present invention is to provide a wavelength conversion member having excellent adhesion between a wavelength conversion layer containing quantum dots and an adjacent layer.

The present inventors, as a result of repeated careful examination in order to achieve the above object,

Quantum dots that are excited by excitation light to emit fluorescence,

Polymerizable compounds,

A silane coupling agent, and,

Acid generator that generates protonic acid by imparting energy,

It was newly discovered that the above object could be achieved by using the quantum dot-containing polymerizable composition (hereinafter, also simply referred to as "composition" or "polymerizable composition") containing. That is, by using such a composition, it has become possible to provide a wavelength conversion member including an adjacent layer and a wavelength conversion layer having excellent adhesion to the adjacent layer, as a result of intensive examination by the present inventors, newly discovered.

In the wavelength conversion layer formed using the composition, quantum dots are present in a matrix in which a polymerizable compound is polymerized by polymerization treatment such as light irradiation or heating. On the other hand, the adhesion between the wavelength conversion layer formed in this way and the adjacent layer can be improved by the silane coupling agent contained in the said composition. This is considered to be due to the fact that the silane coupling agent forms a covalent bond with the surface of the adjacent layer or the constituent components of the adjacent layer by a hydrolysis reaction, a condensation reaction, or the like.

However, the wavelength conversion layer is formed through polymerization treatment of the polymerizable composition as described above. If the formation of the polymer by this polymerization treatment proceeds with priority over the reaction of the silane coupling agent, the reactivity of the silane coupling agent decreases in the layer cured by the polymerization, so that the improvement of the adhesion with the adjacent layer by the silane coupling agent is sufficiently improved. It becomes difficult to get.

In contrast, the acid generator contained in the composition generates protonic acid by applying energy such as light irradiation or heating. The acceleration of the reaction of the silane coupling agent by this protonic acid contributes to enhancing the adhesion between the wavelength conversion layer formed through the polymerization treatment of the polymerizable compound and the adjacent layer adjacent to this layer by the silane coupling agent. As there is, the inventors are thinking.

However, the above does not limit the present invention at all as speculation by the present inventors.

In one aspect, the acid generator includes a photoacid generator that generates protonic acid by application of energy by light irradiation, and a thermal acid generator that generates protonic acid by application of energy by heating. It is at least one selected from the group consisting of 酸發生劑).

In one embodiment, the molecular weight of the protonic acid is 500 or less and 300 or less.

In one aspect, the composition further contains a polymerization initiator capable of initiating polymerization of the above-described polymerizable compound.

In one aspect, the polymerization initiator is a photopolymerization initiator.

In one aspect, the polymerizable compound is selected from the group consisting of a radical polymerizable compound and a cationic polymerizable compound.

In one aspect, the polymerizable compound includes a monofunctional (meth)acrylate compound and a polyfunctional (meth)acrylate compound.

In one aspect, the polymerizable compound contains an epoxy compound.

In one aspect, the quantum dot,

Quantum dot A having an emission center wavelength in a wavelength band in the range of 600 nm to 680 nm,

Quantum dot B having an emission center wavelength in a wavelength band ranging from 500 nm to 600 nm, and

Quantum dot C having an emission center wavelength in a wavelength band ranging from 400 nm to 500 nm,

It is at least one member selected from the group consisting of.

A further aspect of the invention,

A wavelength conversion layer formed by simultaneously or sequentially performing energy imparting and polymerization treatment for generating protonic acid from the above-described acid generator to the quantum dot-containing polymerizable composition, and

An adjacent layer adjacent to one major surface of the wavelength conversion layer,

A wavelength conversion member comprising at least a,

It is about. Here, the "main surface" refers to the surface (front surface, back surface) of the wavelength conversion layer disposed on the visible side or the backlight side when the wavelength conversion member is used. The same applies to the main surface to the adjacent layer described later.

In one aspect, the adjacent layer is an inorganic layer.

In one aspect, the wavelength conversion member has an adjacent layer adjacent to one major surface of the wavelength conversion layer and an adjacent layer adjacent to the other major surface.

In one aspect, both of the two adjacent layers are inorganic layers.

In one aspect, the thickness of the wavelength conversion layer is in the range of 10 to 300 µm.

A further aspect of the present invention relates to a backlight unit including at least the wavelength conversion member and a light source.

In one aspect, the light source has a light emission center wavelength in a wavelength band of 430 nm to 480 nm.

A further aspect of the present invention relates to a liquid crystal display device including at least the backlight unit and a liquid crystal cell.

A further aspect of the present invention is a method of manufacturing the wavelength conversion member,

A production method comprising applying energy to generate a protonic acid from an acid generator and performing polymerization treatment simultaneously or sequentially to the quantum dot-containing polymerizable composition after contacting the main surface of the adjacent layer with the quantum dot-containing polymerizable composition ,

It is about.

A further aspect of the present invention is a method of manufacturing the wavelength conversion member having adjacent layers on both main surfaces of the wavelength conversion layer,

After bringing the quantum dot-containing polymerizable composition into contact with at least one of the two adjacent layers, energy is applied to the quantum dot-containing polymerizable composition to generate a protonic acid from an acid generator, and polymerization treatment is performed simultaneously or sequentially. A manufacturing method comprising that,

It is about.

In one aspect, the energy application is performed after contacting the respective main surfaces of the two adjacent layers with the quantum dot-containing polymerizable composition.

According to an aspect of the present invention, it is possible to provide a wavelength conversion member including a wavelength conversion layer having excellent adhesion to an adjacent layer, a backlight unit including the wavelength conversion member, and a liquid crystal display device.

1A and 1B are explanatory diagrams of an example of a backlight unit including a wavelength conversion member according to an aspect of the present invention.
2 is a diagram showing an example of a liquid crystal display device according to an aspect of the present invention.
3 is a schematic configuration diagram of an example of an apparatus for manufacturing a wavelength conversion member.
4 is a partially enlarged view of the manufacturing apparatus shown in FIG. 3.

Although the following description may be made based on a representative embodiment of the present invention, the present invention is not limited to such an embodiment. In addition, in the present invention and this specification, the numerical range indicated by using "-" means a range including the numerical values described before and after "-" as a lower limit value and an upper limit value.

In addition, in the present invention and this specification, the "half width" of the peak means the width of the peak at 1/2 of the peak height. In addition, light having an emission center wavelength in a wavelength band of 400 to 500 nm, preferably 430 to 480 nm, is referred to as blue light, and light having an emission center wavelength in a wavelength band of 500 to 600 nm is referred to as green light. , Light having an emission center wavelength in the wavelength band of 600 to 680 nm is referred to as red light.

[Polymerable composition containing quantum dots]

The quantum dot-containing polymerizable composition according to an aspect of the present invention is a quantum dot that is excited by excitation light to emit fluorescence, a polymerizable compound, a silane coupling agent, and an acid generator that generates a protonic acid by imparting energy. Contains.

Hereinafter, the composition will be described in more detail.

<quantum dot>

The composition contains at least one type of quantum dot, and may contain two or more types of quantum dots having different luminescence properties. Known quantum dots include quantum dot A having a light emission center wavelength in a wavelength range of 600 nm to 680 nm, quantum dot B having a light emission center wavelength in a wavelength range of 500 nm to 600 nm, and 400 nm to 500 nm. There is a quantum dot C having an emission center wavelength in the wavelength band of nm. Quantum dot A is excited by excitation light to emit red light, quantum dot B emits green light, and quantum dot C emits blue light. For example, when blue light is incident on the wavelength conversion layer containing quantum dot A and quantum dot B as excitation light, red light emitted by quantum dot A, green light emitted by quantum dot B, and wavelength conversion layer are transmitted through. With one blue light, white light can be realized. Alternatively, red light emitted by quantum dot A, green light emitted by quantum dot B, and quantum dot C by injecting ultraviolet light as excitation light into a wavelength conversion layer containing quantum dots A, B, and C. White light can be realized by the blue light emitted by the. As quantum dots, those prepared by known methods and commercially available products can be used without any limitation. Regarding the quantum dot, for example, paragraphs 0060 to 0066 of Japanese Unexamined Patent Application Publication No. 2012-169271 can be referred to, but the present invention is not limited thereto. The emission wavelength of the quantum dot can usually be adjusted according to the composition and size of the particles, and the composition and size.

The quantum dots may be mixed in the form of particles with other components at the time of preparing the composition, or may be mixed in the form of a dispersion liquid dispersed in a solvent. Addition in the form of a dispersion is preferable from the viewpoint of suppressing agglomeration of the particles of quantum dots. The solvent used here is not particularly limited. Quantum dots can be added, for example, about 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the quantum dot-containing polymerizable composition.

A specific aspect of wavelength conversion in the wavelength conversion member containing the above quantum dots will be described below with reference to the drawings. However, this invention is not limited to the following specific aspect.

1 is an explanatory diagram of an example of a backlight unit 1 including a wavelength conversion member according to an aspect of the present invention. In FIG. 1, the backlight unit 1 includes a light source 1A and a light guide plate 1B used as a surface light source. In the example shown in Fig. 1A, the wavelength conversion member is disposed on the path of light emitted from the light guide plate. On the other hand, in the example shown in Fig. 1B, the wavelength conversion member is disposed between the light guide plate and the light source.

And in the example shown in Fig. 1A, light emitted from the light guide plate 1B enters the wavelength conversion member 1C. In the example shown in Fig. 1A, the light 2 emitted from the light source 1A disposed at the edge of the light guide plate 1B is blue light, and is on the side of the liquid crystal cell (not shown) of the light guide plate 1B. It is emitted from the surface toward the liquid crystal cell. In the wavelength conversion member 1C disposed on the path of the light (blue light 2) emitted from the light guide plate 1B, the quantum dot A is excited by the blue light 2 to emit red light 4, and the blue light 2 ), and at least a quantum dot B that emits green light (3). In this way, the excited green light 3 and the red light 4 and the blue light 2 transmitted through the wavelength conversion member 1C are emitted from the backlight unit 1. In this way, by emitting red light, green light, and blue light, white light can be realized.

The example shown in FIG. 1(b) is the same as the mode shown in FIG. 1(a) except that the arrangement|positioning of a wavelength conversion member and a light guide plate is different. In the example shown in Fig. 1(b), the excited green light 3 and the red light 4, and the blue light 2 transmitted through the wavelength conversion member 1C are emitted from the wavelength conversion member 1C, and are emitted to the light guide plate. Incidentally, a surface light source is realized.

<Polymerizable compound>

In the wavelength conversion layer formed using the above composition, quantum dots are contained in a matrix (polymer) in which a polymerizable compound is polymerized by light irradiation or the like. The shape of the wavelength conversion layer is not particularly limited. For example, the wavelength conversion layer and the wavelength conversion member including this layer are in the form of a sheet or a film.

As the polymerizable compound, a radical polymerizable compound, a cationic polymerizable compound, an anionic polymerizable compound, or other polymerizable compounds according to various types of polymerization can be used. Moreover, 1 type may be used for a polymeric compound, and 2 or more types may be mixed and used for it. The content of the polymerizable compound to the total amount of the composition is preferably about 10 to 99.99% by mass. As an example of a preferred polymerizable compound, from the viewpoint of transparency and adhesion of the cured film after curing, a monofunctional or polyfunctional (meth)acrylate monomer, a polymer thereof, or a polyfunctional (meth)acrylate compound such as a prepolymer. Can be mentioned. Moreover, in this invention and this specification, the description of "(meth)acrylate" shall be used by the meaning of at least one of an acrylate and a methacrylate, or any one. The same applies to "(meth)acryloyl" and the like.

Examples of monofunctional (meth)acrylate compounds include acrylic acid and methacrylic acid, their derivatives, and more specifically, compounds having one polymerizable unsaturated bond ((meth)acryloyl group) of (meth)acrylic acid in a molecule. I can. Although the following compounds are mentioned as a specific example of these, this invention is not limited to this.

Methyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, n-octyl (meth) acrylate , An alkyl (meth)acrylate having 1 to 30 carbon atoms in an alkyl group such as lauryl (meth)acrylate and stearyl (meth)acrylate; Aralkyl (meth)acrylate having 7 to 20 carbon atoms of an aralkyl group such as benzyl (meth)acrylate; Alkoxyalkyl (meth)acrylates having 2 to 30 carbon atoms in an alkoxyalkyl group such as butoxyethyl (meth)acrylate; Aminoalkyl (meth)acrylates having 1 to 20 carbon atoms in total (monoalkyl or dialkyl) aminoalkyl groups such as N,N-dimethylaminoethyl (meth)acrylate; (Meth)acrylate of diethylene glycol ethyl ether, (meth) acrylate of triethylene glycol butyl ether, (meth) acrylate of tetraethylene glycol monomethyl ether, (meth) acrylate of hexaethylene glycol monomethyl ether, Monomethyl ether (meth)acrylate of octaethylene glycol, monomethyl ether (meth)acrylate of nonaethylene glycol, monomethyl ether (meth)acrylate of dipropylene glycol, monomethyl ether (meth)acrylic of heptapropylene glycol (Meth)acrylates of polyalkylene glycol alkyl ethers having 1 to 10 carbon atoms in the alkylene chain and 1 to 10 carbon atoms in the terminal alkyl ether, such as monoethyl ether (meth)acrylate of tetraethylene glycol; (Meth)acrylates of polyalkylene glycol aryl ethers having 1 to 30 carbon atoms in the alkylene chain and 6 to 20 carbon atoms in the terminal aryl ether, such as (meth)acrylate of hexaethylene glycol phenyl ether; Cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, methylene oxide-added cyclodecatriene (meth) acrylate having an alicyclic structure having a total carbon number of 4 to 30 (Meth)acrylate; Fluorinated alkyl (meth)acrylates having 4 to 30 carbon atoms, such as heptadecafluorodecyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) ) (Meth)acrylate having a hydroxyl group such as acrylate, hexaethylene glycol mono(meth)acrylate, octapropylene glycol mono(meth)acrylate, and mono or di(meth)acrylate of glycerol; (Meth)acrylates having a glycidyl group such as glycidyl (meth)acrylate; Polyethylene glycol mono(meth)acrylate having 1 to 30 carbon atoms in the alkylene chain such as tetraethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, and octapropylene glycol mono(meth)acrylate; (Meth)acrylamides such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, 2-hydroxyethyl (meth)acrylamide, and acryloylmorpholine And the like.

As the monofunctional (meth)acrylate compound, it is preferable to use an alkyl (meth) acrylate having 4 to 30 carbon atoms, and using an alkyl (meth) acrylate having 12 to 22 carbon atoms is a dispersibility of quantum dots. From the viewpoint of improvement, it is more preferable. As the dispersibility of the quantum dots increases, the amount of light that passes directly from the wavelength conversion layer to the emission surface increases, which is effective in improving the front luminance and the front contrast. Specifically, as a monofunctional (meth)acrylate compound, butyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, stearyl (meth)acrylic Rate, behenyl (meth)acrylate, butyl (meth)acrylamide, octyl (meth)acrylamide, lauryl (meth)acrylamide, oleyl (meth)acrylamide, stearyl (meth)acrylamide, behenyl (Meth)acrylamide and the like are preferred. Among them, lauryl (meth)acrylate, oleyl (meth)acrylate, and stearyl (meth)acrylate are particularly preferred.

A polyfunctional (meth)acrylate compound having two or more (meth)acryloyl groups in a molecule with a monomer having one polymerizable unsaturated bond ((meth)acryloyl group) of the (meth)acrylic acid in a molecule You can also use together. As a specific example, although a compound is mentioned below, this invention is not limited to this.

Alkylene having 1 to 20 carbon atoms in an alkylene chain such as 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, and 1,9-nonanedioldi(meth)acrylate Glycol di(meth)acrylate; Polyalkylene glycol di(meth)acrylate having 1 to 20 carbon atoms in the alkylene chain such as polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate; Tri(meth)acrylates having a total carbon number of 10 to 60, such as trimethylolpropane tri(meth)acrylate and ethylene oxide added trimethylolpropane tri(meth)acrylate; Tetra(meth)acrylate having a total carbon number of 10 to 100, such as ethylene oxide added pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and pentaerythritol tetra(meth)acrylate; Dipentaerythritol hexa(meth)acrylate, etc. are mentioned.

The amount of the polyfunctional (meth)acrylate compound such as bifunctional or trifunctional is preferably 5 parts by mass or more from the viewpoint of coating film strength with respect to 100 parts by mass of the total amount of the polymerizable compound contained in the polymerizable composition. And, from the viewpoint of suppressing gelation of the composition, it is preferable to use 95 parts by mass or less. In addition, from the same viewpoint, the amount of monofunctional (meth)acrylate compound used is preferably 5 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the total amount of the polymerizable compound contained in the polymerizable composition. Do.

As a preferred polymerizable compound, a compound having a cyclic group such as a ring-opening polymerizable cyclic ether group such as an epoxy group and an oxetanyl group is mentioned. As such a compound, more preferably, a compound having a compound having an epoxy group (epoxy compound) is exemplified.

Examples of the epoxy compound include alicyclic epoxy compounds, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F di Glycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl Ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether; Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin; Diglycidyl esters of aliphatic long-chain dibasic acids; Monoglycidyl ethers of aliphatic higher alcohols; Monoglycidyl ethers of phenol, cresol, butylphenol, or polyether alcohols obtained by adding alkylene oxide to these; Glycidyl esters of higher fatty acids, etc. can be illustrated.

Examples of the epoxy compound further include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl ethers of aromatic polyols, and aromatics. Hydrogenated compounds of polyglycidyl ethers of polyols, urethane polyepoxy compounds, epoxidized polybutadienes, and the like can also be mentioned.

Among these components, alicyclic epoxy compounds, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 1,4-butanediol digly Cidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol Diglycidyl ether is preferred.

Commercial products that can be suitably used as a glycidyl group-containing compound include UVR-6216 (manufactured by Union Carbide), glycidol, AOEX24, Cychroma A200, (above, manufactured by Daicel Chemical Industries, Ltd.), and Epicoat 828, Epicoat 812, Epicoat 1031, Epicoat 872, Epicoat CT508 (above, manufactured by Yucca Shell), KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2720, KRM-2750 (above, Asahi Tenka Kogyo Corporation), etc. are mentioned. These can be used alone or in combination of two or more.

In addition, the manufacturing method of these epoxy compounds is irrelevant. For example, Maruzen KK Shootpan, 4th Edition Experimental Chemistry Lecture 20 Organic Synthesis II, 213-, 1992, Ed. by Alfred Hasfner, The chemistry of heterocyclic compounds-Small Ring Heterocycles part3 Oxiranes, John & Wiley and Sons, An Interscience Publication, New York, 1985, Yoshimura, Adhesion, Vol. 29, No. 12, 32, 1985, Yoshimura, Adhesion, Vol. 30 5, 42, 1986, Yoshimura, Adhesion, Vol. 30, No. 7, 42, 1986, Japanese Patent Laid-Open No. 11-100378, Japanese Patent No. 2906245, Japanese Patent No. 2926262, etc. It can be synthesized as.

As the epoxy compound, a commercially available epoxy composition in which two or more components are mixed and prepared in advance according to the conditions of use may be used. These are commercially available as adhesives or sealing agents. Commercially available products can be obtained from, for example, Three Bond Corporation, EMI Corporation, Desksha, and the like. Specifically, OPTOCAST (trade name) 3505 manufactured by EMI, 3506, 3553, A-1771 (trade name) manufactured by Desk Corporation, and the like are exemplified. However, the present invention is not limited to these.

The polymerizable composition may contain a polymerization initiator. Specifically, as a polymerization initiator, a known radical polymerization initiator or a cationic polymerization initiator may be contained. Regarding the polymerization initiator, for example, Japanese Unexamined Patent Application Publication No. 2013-043382, paragraph 0037, and Japanese Patent Application Publication No. 2011-159924, paragraphs 0040 to 0042 can be referred to. The polymerization initiator is preferably 0.1 mol% or more of the total amount of the polymerizable compound contained in the polymerizable composition, and more preferably 0.5 to 5 mol%. However, as described later, since the acid generator may act as a polymerization initiator with respect to the polymerizable compound, the use of a polymerization initiator is not essential. As the polymerization initiator, a photopolymerization initiator or a thermal polymerization initiator may be appropriately selected and used according to the kind of the polymerizable compound. The polymerization treatment is preferably performed by light irradiation from the point that the polymerization treatment is completed in a short time. Therefore, in this respect, as a polymerization initiator, a photoinitiator is preferable.

Some of the acid generators described later function as a cationic polymerization initiator capable of initiating polymerization of a cationic polymerizable compound. In the case of using such an acid generator, when the polymerizable compound contained in the composition is a cationic polymerizable compound capable of initiating a polymerization reaction by release of a protonic acid from the acid generator, a polymerization initiator is separately added and used in combination. It is not necessary to do it. On the other hand, from the viewpoint of further improvement of adhesion, it is preferable that the polymerizable compound is a radical polymerizable compound. Preferable polymerizable compounds from this point of view include monofunctional (meth)acrylate compounds and polyfunctional (meth)acrylate compounds described above.

<Silane coupling agent>

The composition contains a silane coupling agent. From such a composition, a wavelength conversion layer can be formed by, for example, a coating method. Specifically, a wavelength conversion layer can be obtained by applying a quantum dot-containing polymerizable composition (curable composition) on a substrate or the like, followed by curing treatment by light irradiation or the like. Here, a wavelength conversion layer containing a silane coupling agent can be formed by using a composition containing a silane coupling agent together with a quantum dot and a polymerizable compound as the polymerizable composition. The wavelength conversion layer formed from the polymerizable composition containing a silane coupling agent can be made to have strong adhesion to an adjacent layer by means of a silane coupling agent. This is considered mainly because the silane coupling agent contained in the wavelength conversion layer forms a covalent bond with the surface of the adjacent layer or the constituent components of the adjacent layer by a hydrolysis reaction or a condensation reaction. In addition, when the silane coupling agent has a reactive functional group such as a radical polymerizable group, forming a crosslinked structure with the polymerizable compound used for forming the wavelength conversion layer can also contribute to improving the adhesion between the wavelength conversion layer and the adjacent layer. I think there will be. From this point of view, it is also preferable to use a silane coupling agent having a reactive functional group having good crosslinking reactivity with the polymerizable compound contained in the composition. Examples of the reactive functional group that the silane coupling agent may have include a vinyl group, an epoxy group, a styryl group, a (meth)acrylic group, an amino group, a ureido group, a mercapto group, a sulfide group, an isocyanate group, and the like.

However, as previously described, the fact that the polymerization reaction of the polymerizable compound proceeds in preference to the reaction of the silane coupling agent is considered to be a hindrance to the reaction of the silane coupling agent as described above and contributing to the improvement of adhesion with the adjacent layer. . On the other hand, by forming a wavelength conversion layer through a step of adding an acid generator, which will be described in detail later, to the composition to impart energy to generate protonic acid, adhesion with an adjacent layer can be improved. This is because the reaction of the silane coupling agent is accelerated by the protonic acid generated by the acid generator, and the present inventors speculate.

As the silane coupling agent, a known silane coupling agent can be used without any limitation. Preferred silane coupling agents from the viewpoint of adhesion include vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropyl Trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyl Triethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldimethoxysilane Acryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltri Methoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-( 1,3-dimethyl-butylidene)propylamine and its partial hydrolyzate, 3-trimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine and its partial hydrolyzate, N-phenyl- 3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanate propyltriethoxysilane, etc. are mentioned. Among them, vinyl, epoxy, (meth)acryloyloxy, amino, and isocyanate-modified silane coupling agents are preferred, and particularly preferably (meth)acryloyloxy-modified silane coupling agents. These silane coupling agents can be used, for example, manufactured by Shin-Etsu Chemical Co., Ltd.

Moreover, as a silane coupling agent, the silane coupling agent represented by General formula (1) described in Unexamined-Japanese-Patent No. 2013-43382 is mentioned. For details, reference can be made to the description of Japanese Unexamined Patent Application Publication No. 2013-43382, paragraphs 0111 to 0016.

From the viewpoint of further improving the adhesion to the adjacent layer, the silane coupling agent is preferably contained in the range of 1 to 30% by mass, more preferably 3 to 30% by mass, and still more preferably in the polymerizable composition. It is 5 to 25 mass %.

<Acid Generator>

The composition contains, together with the components described above, an acid generator that generates protonic acid by imparting energy. Such an acid generator is usually an ionic compound or salt containing an anion moiety ^{X −} and a cation ^{moiety Y +,} and decomposes by imparting energy to extract the ^{proton H + from the solvent or the acid generator itself.} Acid XH can be generated. Here, protonic acid refers to a compound capable of releasing ^{proton H +.}

The method of imparting energy for generating the protonic acid from the acid generator is not particularly limited, and examples thereof include light irradiation, heat treatment, radiation, and irradiation of active energy rays such as electromagnetic waves. Preferably, they are light irradiation and heat treatment. That is, the acid generator is preferably selected from the group consisting of a photoacid generator and a thermal acid generator. The light irradiated to impart energy to the photoacid generator is, for example, ultraviolet light, but if the acid generator contained in the composition can perform light irradiation capable of generating protonic acid, the wavelength of the irradiated light is limited. no. In addition, conditions for applying energy, such as light irradiation conditions and heating conditions, may also be conditions in which the acid generator contained in the composition can generate protonic acid, and are not particularly limited.

(Mine generator)

Examples of the photoacid generator include onium salts such as diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, and arsenium salts, organic halogen compounds, organic metal/organic halides, o -A photoacid generator having a nitrobenzyl-type protecting group, a compound that generates sulfonic acid by photolysis, such as iminosulfonate, etc., a disulfone compound, a diazoketosulfone, a diazodisulfone compound, and the like. Further, triazines, quaternary ammonium salts, diazomethane compounds, imide sulfonate compounds, and oxime sulfonate compounds are also mentioned.

In addition, a group that generates an acid by light or a compound in which a compound is introduced into the main chain or side chain of the polymer can be used.

In addition, V. N. R. Pillai, Synthesis, (1), 1 (1980), A. Abad et al., Tetrahedron Lett., (47) 4555 (1971), D. H. R. Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Patent No. 3,779,778, European Patent No. 126,712 and the like described in the compound that generates an acid by light can also be used.

Moreover, as a specific example of a photoacid generator, the following <A-1>-<A-4> are mentioned.

<A-1>: An oxazole derivative represented by the following general formula (PAG1) substituted by a trihalomethyl group or an S-triazine derivative represented by the following general formula (PAG2).

In the formula, R ²⁰¹ represents a substituted or unsubstituted aryl group or an alkenyl group, and R ²⁰² represents a substituted or unsubstituted aryl group, an alkenyl group, an alkyl group, or -C(Y) ₃ . Y represents a chlorine atom or a bromine atom.

Specifically, although the following compounds are mentioned, it is not limited to these.

<A-2>: An iodonium salt represented by the following general formula (PAG3), or a sulfonium salt represented by the general formula (PAG4).

In the formula, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Each of R ²⁰³ , R ²⁰⁴ , and R ²⁰⁵ independently represents a substituted or unsubstituted alkyl group or an aryl group.

Z ^- is a pair denotes an anion, for _{^{example, BF 4 -, AsF 6 -}} , PF 6 -, SbF 6 -, SiF 6 2 -, ClO 4 -, CF 3 SO 3 - , such as alkane sulfonic acid perfluoro Condensation of aromatic sulfonic acid anions such as anions, camphorsulfonic acid anions, alkylsulfonic acid anions, pentafluorobenzenesulfonic acid anions, benzenesulfonic acid anions, and triisopropylbenzenesulfonic acid anions Polynuclear aromatic sulfonic acid anions, anthraquinonesulfonic acid anions, sulfonic acid group-containing dyes, etc. are mentioned, but the present invention is not limited thereto. In addition, these anionic species may further have a substituent.

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ , and Ar ¹ and Ar ² may be bonded via respective single bonds or substituents.

Although the compounds shown below are mentioned as a specific example, it is not limited to these.

The onium salts represented by the general formulas (PAG3) and (PAG4) are known and, for example, J. W. Knapczyk et al., J. Am. Chem. Soc., 91, 145 (1969), A. L. Maycok et al., J. Org. Chem., 35, 2532, (1970), E. Goethas et al., Bull. Soc. Chem. Belg., 73, 546, (1964), H. M. Leicester, J. Ame. Chem. Soc., 51, 3587 (1929), J. V. Crivello et al., J. Polym. Chem. Ed., 18, 2677 (1980), U.S. Patent Nos. 2,807,648 and 4,247,473, and Japanese Patent Laid-Open No. 53-101,331, etc., can be synthesized.

<A-3>: A disulfone derivative represented by the following general formula (PAG5) or an iminosulfonate derivative represented by the general formula (PAG6).

In the formula, Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or an aryl group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group.

Although the compounds shown below are mentioned as a specific example, it is not limited to these.

<A-4>: Diazodisulfone derivative represented by the following general formula (PAG7).

In the formula, R represents a linear, branched or cyclic alkyl group, or an optionally substituted aryl group.

Although the compounds shown below are mentioned as a specific example, it is not limited to these.

(Heat acid generator)

Examples of the thermal acid generator include salts composed of an acid and an organic base.

Examples of the acid include organic acids such as sulfonic acid, phosphonic acid, and carboxylic acid, and inorganic acids such as sulfuric acid and phosphoric acid. From the viewpoint of compatibility with the matrix, organic acids are more preferable, sulfonic acid and phosphonic acid are more preferable, and sulfonic acid is most preferable. Preferred sulfonic acids include p-toluenesulfonic acid (PTS), benzenesulfonic acid (BS), p-dodecylbenzenesulfonic acid (DBS), p-chlorobenzenesulfonic acid (CBS), and 1,4-naphthalenedisulfonic acid ( NDS), methanesulfonic acid (MsOH), nonafluorobutane-1-sulfonic acid (NFBS), and the like, and any can be preferably used (abbreviated in ()).

About the basicity of an organic base forming a salt with an acid, when expressed using the pKa of a conjugated acid, the pKa is preferably 5.0 to 10.5, more preferably 6.0 to 10.0, and 6.5 to 10.0. More preferable. The pKa value of the organic base in the aqueous solution is described on pages Ⅱ-334 to 340 of Vol. 2 of the Basic Chemistry Handbook (Revised 5th edition, Japanese Chemical Society edition, Maruzen, 2004). It is possible to select an organic base having Further, a compound which can be estimated to have an appropriate pKa structurally even if there is no description in the above document can also be preferably used. In the following table, compounds having a suitable pKa described in the above documents are shown, but the present invention is not limited thereto.

[Table 1]

On the other hand, the lower the boiling point of the organic base is, the higher the acid generation efficiency during heating, and is preferable from the viewpoint of promoting the reaction of the silane coupling agent. Therefore, it is preferable to use an organic base having an appropriate boiling point. As the boiling point of the organic base, it is preferably 120°C or less, more preferably 80°C or less, and still more preferably 70°C or less.

Specific examples of the thermal acid generator include, for example, the following compounds, but are not limited thereto. () Indicates the boiling point.

b-3: pyridine (115°C), b-14: 4-methylmorpholine (115°C), b-20: diallylmethylamine (111°C), b-19: triethylamine (88.8°C), b -21: t-butylmethylamine (67 to 69°C), b-22: dimethylisopropylamine (66°C), b-23: diethylmethylamine (63 to 65°C), b-24: dimethylethylamine (36-38°C).

The boiling point of the organic base is preferably 35°C or more and 120°C or less, and more preferably 40°C or more and 115°C or less.

The above-described thermal acid generator may be used by isolating a salt composed of an acid and an organic base, or may be used by mixing an acid and an organic base to form a salt in a solution. In addition, both of an acid and an organic base may be used alone, or a plurality of types may be mixed and used. When an acid and an organic base are mixed and used, the mixture is preferably mixed so that the equivalent ratio of the acid and the organic base is 1: 0.9 to 1.5, more preferably 1: 0.95 to 1.3, and 1: 1.0 to 1.1. It is more preferable to do it.

(Molecular weight of acid generator)

The molecular weight of the protonic acid (described above XH) generated by the application of energy to the acid generator is not particularly limited. Although it is thought that the reaction of the silane coupling agent will be accelerated by the generated protonic acid, it is preferable that the reaction proceeds at the interface with the adjacent layer in order to improve the adhesion of the interface between the wavelength conversion layer and the adjacent layer. For this purpose, the present inventors speculate that it is preferable that the generated protonic acid has a relatively low molecular weight and has good mobility in the wavelength conversion layer. In this respect, the molecular weight of the protonic acid to be generated is preferably 500 or less, more preferably 300 or less, further preferably 200 or less, and even more preferably 100 or less. The lower limit of the molecular weight is, for example, 30 or more, but is not particularly limited.

(Amount of acid generator added)

The acid generator described above may be contained in the composition, for example, 0.01 to 30 parts by mass, preferably 0.1 to 20 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable compound. I can.

<Other ingredients>

The quantum dot-containing polymerizable composition according to an aspect of the present invention can be prepared by using the components described above and a known additive that can be optionally added, if necessary. For example, a quantum dot-containing polymerizable composition can be prepared by simultaneously or sequentially mixing the above components and one or more known additives added as necessary. The amount of the additive used is not particularly limited and can be set appropriately. Further, for the viscosity of the quantum dot-containing polymerizable composition, etc., a solvent may be added as necessary. The type and amount of the solvent used in this case are not particularly limited. For example, as a solvent, organic solvents can be used alone or in combination of two or more.

As described above, the composition contains an acid generator that generates protonic acid by application of energy. On the other hand, adding the protonic acid itself to the composition is not preferable from the viewpoint of liquid stability of the composition. When protonic acid is added to the composition, protons are released, and as a result of the rapid reaction of the silane coupling agent, there is a concern that bulky foreign matters are generated in the composition (liquid stability decreases). In addition, since the silane coupling agent solidifies into a mass before contributing to the improvement of the adhesion at the interface with the adjacent layer, there is a concern that the improvement of the adhesion with the adjacent layer by the silane coupling agent may be hindered. On the other hand, if an acid generator that generates protonic acid by application of energy (trigger), for example, protonic acid can be generated by applying energy after bringing the composition into contact with the surface of the adjacent layer. As a result of the reaction of the silane coupling agent being accelerated by the protonic acid generated from the acid generator in this way, the present inventors speculate that it is possible to improve the adhesion with the adjacent layer.

From the above point of view, it is preferable that the composition does not contain a large amount of protonic acid in a state in which protonic acid is not generated by application of energy. Specifically, the content of such a protonic acid is preferably 20 parts by mass or less, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and most preferably 0 parts by mass with respect to 100 parts by mass of the silane coupling agent. Do.

[Wavelength conversion member]

A further aspect of the invention,

A wavelength conversion layer formed by simultaneously or sequentially subjecting the quantum dot-containing polymerizable composition to energy for generating a protonic acid from an acid generator and performing polymerization treatment, and,

An adjacent layer adjacent to one major surface of the wavelength conversion layer,

A wavelength conversion member comprising at least a,

It is about.

Hereinafter, the wavelength conversion member will be described in more detail.

<Method of forming a wavelength conversion layer>

The wavelength conversion layer is a layer formed by simultaneously or sequentially subjecting the quantum dot-containing polymerizable composition to energy for generating protonic acid from the above-described acid generator and polymerization treatment. For example, in an embodiment in which the acid generator is a photoacid generator and the polymerization treatment of the polymerizable composition is performed by light irradiation, energy application and polymerization treatment can be performed simultaneously, that is, as one step. This point is also the same for an aspect in which the acid generator is a thermal acid generator, and the polymerization treatment is performed by heating. On the other hand, in a mode in which the acid generator is a thermal acid generator, and the polymerization treatment is performed by light irradiation, energy application (heating) and polymerization treatment (light irradiation) are sequentially performed as different steps. This point is also the same for a mode in which the acid generator is a photoacid generator, and the polymerization treatment is performed by heating. In the case where the energy application and the polymerization treatment are performed in different steps, it is preferable to perform the polymerization treatment after the energy application is performed. This is because it is considered that performing polymerization treatment after accelerating the reaction of the silane coupling agent by application of energy will further improve the adhesion between the wavelength conversion layer and the adjacent layer. In addition, in the case where the energy application and the polymerization treatment are performed together by light irradiation, even when the light irradiation conditions for energy application (e.g., the wavelength of the irradiated light) are different from those of the polymerization treatment, energy is provided for the same reason. After light irradiation for, it is preferable to perform light irradiation for polymerization treatment. This point is a case where the energy application and the polymerization treatment are performed by heating together, and the same applies to the case where the heating conditions for energy application and the heating conditions for the polymerization treatment are different.

In addition, from the viewpoint of further improving the adhesion between the wavelength conversion layer and the adjacent layer, it is preferable to impart energy after the quantum dot-containing polymerizable composition comes into contact with the main surface of the adjacent layer. This is because it is thought that advancing the reaction of the silane coupling agent, particularly in the vicinity of the interface of both layers, will greatly contribute to the improvement of the adhesiveness of both layers. In this respect, in the formation of a wavelength conversion member having adjacent layers on both major surfaces of the wavelength conversion layer, it is preferable to impart energy after contact between at least one of the major surfaces of the adjacent layer and the quantum dot-containing polymerizable composition. , It is preferable to impart energy after the main surfaces of both adjacent layers and the quantum dot-containing polymerizable composition come into contact with each other.

As a coating method of the quantum dot-containing polymerizable composition, the curtain coating method, dip coating method, spin coating method, printing coating method, spray coating method, slot coating method, roll coating method, slide coating method, blade coating method, gravure coating method And a known coating method such as a wire bar method. In addition, curing conditions can be appropriately set according to the kind of the polymerizable compound to be used or the composition of the polymerizable composition. In addition, when the quantum dot-containing polymerizable composition is a composition containing a solvent, before performing the polymerization treatment, a drying treatment may be performed in order to remove the solvent.

In one embodiment, the polymerization treatment of the quantum dot-containing polymerizable composition can be performed in a state where the composition is sandwiched between two substrates. An aspect of the manufacturing process of the wavelength conversion member including such a polymerization treatment will be described below with reference to the drawings. However, this invention is not limited to the following aspect.

3 is a schematic configuration diagram of an example of a manufacturing apparatus 100 for a wavelength conversion member, and FIG. 4 is a partially enlarged view of the manufacturing apparatus shown in FIG. 3. The manufacturing process of the wavelength conversion member using the manufacturing apparatus 100 shown in FIGS. 3 and 4,

A step of forming a coating film by applying a quantum dot-containing polymerizable composition to the surface of the first substrate (hereinafter, also referred to as “first film”) to be continuously conveyed;

A process of laminating (overlapping) a second base material (hereinafter also referred to as ``second film'') to be continuously conveyed on the coating film, and holding the coating film with the first film and the second film, and

In the state where the coating film is sandwiched between the first film and the second film, any one of the first film and the second film is wound around a backup roller, and light irradiation is performed while continuously conveying, and the coating film is polymerized and cured to form a wavelength conversion layer (cured The process of forming a layer),

It includes at least. By using a barrier film having barrier properties to oxygen and moisture as either of the first substrate and the second substrate, a wavelength conversion member having one side protected by a barrier film (barrier layer) can be obtained. Further, by using a barrier film as the first substrate and the second substrate, respectively, it is possible to obtain a wavelength converting member in which both surfaces of the wavelength converting layer are protected by a barrier film (barrier layer).

More specifically, first, the first film 10 is continuously conveyed to the coating unit 20 from an unillustrated delivery machine. From the delivery machine, for example, the first film 10 is delivered at a conveying speed of 1 to 50 m/min. However, it is not limited to this conveyance speed. When delivered, a tension of 20 to 150 N/m, preferably 30 to 100 N/m, is applied to the first film 10, for example.

In the coating unit 20, a quantum dot-containing polymerizable composition (hereinafter, also referred to as “coating solution”) is applied to the surface of the first film 10 to be continuously conveyed, and the coating film 22 (refer to FIG. 2) is formed. Is formed. In the coating unit 20, for example, a die coater 24 and a backup roller 26 disposed opposite to the die coater 24 are provided. The surface opposite to the surface on which the coating film 22 of the first film 10 is formed is wound around the backup roller 26 and applied from the discharge port of the die coater 24 on the surface of the first film 10 to be continuously conveyed. The liquid is applied, and the coating film 22 is formed. Here, the coating film 22 refers to a composition containing quantum dots before polymerization treatment applied on the first film 10.

In this embodiment, although the die coater 24 to which the extrusion coating method was applied was shown as the coating device, it is not limited thereto. For example, a coating apparatus to which various methods such as a curtain coating method, an extrusion coating method, a rod coating method, or a roll coating method can be used can be used.

The 1st film 10 which passed through the coating part 20 and formed the coating film 22 on it is continuously conveyed to the laminate part 30. In the laminate portion 30, the second film 50 continuously conveyed is laminated on the coating film 22, and the coating film 22 is sandwiched between the first film 10 and the second film 50.

In the laminate part 30, a laminate roller 32 and a heating chamber 34 surrounding the laminate roller 32 are provided. The heating chamber 34 is provided with an opening 36 for passing the first film 10 and an opening 38 for passing the second film 50.

A backup roller 62 is disposed at a position facing the laminate roller 32. In the first film 10 on which the coating film 22 is formed, the surface opposite to the formation surface of the coating film 22 is wound around the backup roller 62 and continuously conveyed to the lamination position P. The lamination position (P) refers to a position where the contact between the second film 50 and the coating film 22 starts. It is preferable that the first film 10 is wound around the backup roller 62 before reaching the lamination position P. This is because even when wrinkles occur in the first film 10, the wrinkles are corrected and removed by the backup roller 62 until they reach the lamination position P. Therefore, the position (contact position) where the first film 10 is wound around the backup roller 62 and the distance L1 to the laminate position P are preferably longer, for example, 30 mm or more. And, the upper limit value is usually determined by the diameter of the backup roller 62 and the pass line.

In this embodiment, the second film 50 is laminated by the backup roller 62 and the lamination roller 32 used in the polymerization treatment unit 60. In other words, the backup roller 62 used in the polymerization treatment unit 60 is also used as a roller used in the laminate unit 30. However, it is not limited to the above form, and a roller for lamination may be provided in the laminate part 30 separately from the backup roller 62 so that the backup roller 62 may not be used at the same time.

By using the backup roller 62 used in the polymerization treatment unit 60 in the laminate unit 30, the number of rollers can be reduced. Moreover, the backup roller 62 can also be used as a heat roller for the 1st film 10.

The second film 50 delivered from a delivery machine (not shown) is wound around the laminate roller 32 and continuously conveyed between the laminate roller 32 and the backup roller 62. The second film 50 is laminated on the coating film 22 formed on the first film 10 at the lamination position P. Accordingly, the coating film 22 is pinched by the first film 10 and the second film 50. Lamination refers to superimposing and laminating the second film 50 on the coating film 22.

The distance L2 between the laminate roller 32 and the backup roller 62 is a wavelength conversion layer (cured layer) 28 obtained by polymerizing and curing the first film 10 and the coating film 22, and the second film ( It is preferable that it is more than the value of the total thickness with 50). Moreover, it is preferable that L2 is less than or equal to the length which added 5 mm to the total thickness of the 1st film 10, the coating film 22, and the 2nd film 50. By making the distance L2 less than or equal to the length obtained by adding 5 mm to the total thickness, it is possible to prevent air bubbles from entering between the second film 50 and the coating film 22. Here, the distance L2 between the laminate roller 32 and the backup roller 62 refers to the shortest distance between the outer circumferential surface of the laminate roller 32 and the outer circumferential surface of the backup roller 62.

The rotational accuracy of the laminate roller 32 and the backup roller 62 is 0.05 mm or less, preferably 0.01 mm or less due to radial vibration. The smaller the radial vibration, the smaller the thickness distribution of the coating film 22 can be.

In addition, in order to suppress thermal deformation after the coating film 22 is pinched with the first film 10 and the second film 50, the temperature of the backup roller 62 of the polymerization treatment unit 60 and the first film 10 ), and the difference between the temperature of the backup roller 62 and the temperature of the second film 50 are preferably 30° C. or less, more preferably 15° C. or less, and most preferably the same.

In order to reduce the difference with the temperature of the backup roller 62, when the heating chamber 34 is provided, heating the first film 10 and the second film 50 in the heating chamber 34 It is desirable. For example, hot air is supplied to the heating chamber 34 by a hot air generating device (not shown) to heat the first film 10 and the second film 50.

The first film 10 may be heated by the backup roller 62 by winding the first film 10 around the temperature-adjusted backup roller 62.

On the other hand, about the 2nd film 50, the 2nd film 50 can be heated with the lamination roller 32 by using the lamination roller 32 as a heat roller.

However, the heating chamber 34 and the heat roller are not essential, and can be provided as needed.

Next, in the state where the coating film 22 is pinched by the 1st film 10 and the 2nd film 50, it is conveyed continuously to the superposition|polymerization processing part 60. In the embodiment shown in the drawing, the polymerization treatment in the polymerization treatment unit 60 is performed by light irradiation, but in the case of polymerization of the polymerizable compound contained in the quantum dot-containing polymerizable composition by heating, spraying of warm air, etc. The polymerization treatment can be performed by heating of. In addition, when energy is applied in one step with the polymerization treatment, energy is applied in the polymerization treatment unit 60. On the other hand, when energy application and polymerization treatment are performed in different steps, it is preferable to perform energy application before the polymerization treatment for the reasons described above.

A light irradiation device 64 is provided at a position opposite the backup roller 62 and the backup roller 62. Between the backup roller 62 and the light irradiation device 64, the 1st film 10 and the 2nd film 50 which pinched the coating film 22 are conveyed continuously. The light irradiated by the light irradiation device may be determined according to the kind of the photopolymerizable compound contained in the quantum dot-containing polymerizable composition, and an example thereof is ultraviolet rays. Ultraviolet rays here shall mean light having a wavelength of 280 to 400 nm. As a light source for generating ultraviolet rays, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, and the like can be used. The amount of light irradiation may be set in a range capable of advancing polymerization and curing of the coating film. For example, an ultraviolet ray having an irradiation amount of 100 to 10000 mJ/cm 2 can be irradiated toward the coating film 22 as an example.

In the polymerization treatment unit 60, the first film 10 is wound around the backup roller 62 in a state where the coating film 22 is sandwiched by the first film 10 and the second film 50, and is continuously conveyed. While doing light irradiation from the light irradiation apparatus 64, the coating film 22 is hardened, and the wavelength conversion layer (cured layer) 28 can be formed.

In the present embodiment, the first film 10 side is wound around the backup roller 62 and continuously conveyed, but the second film 50 is wound around the backup roller 62 and continuously conveyed.

Winding over the backup roller 62 means a state in which either the first film 10 or the second film 50 is in contact with the surface of the backup roller 62 at a certain lap angle. Therefore, during continuous conveyance, the first film 10 and the second film 50 move in synchronization with the rotation of the backup roller 62. It is sufficient that it is wound around the backup roller 62 while being irradiated with ultraviolet rays at least.

The backup roller 62 includes a main body having a cylindrical shape and a rotation shaft disposed at both ends of the main body. The main body of the backup roller 62 has a diameter of 200 to 1000 mm, for example. There is no limitation on the diameter φ of the backup roller 62. In consideration of curl deformation of the laminated film, equipment cost, and degree of rotation, it is preferable to have a diameter of 300 to 500 mm. By attaching a temperature controller to the main body of the backup roller 62, the temperature of the backup roller 62 can be adjusted.

The temperature of the backup roller 62 is the heat generation during light irradiation, the curing efficiency of the coating film 22, and the occurrence of wrinkle deformation on the backup roller 62 of the first film 10 and the second film 50. In consideration of, you can decide. It is preferable to set the backup roller 62 in the temperature range of 10 to 95 degreeC, for example, and it is more preferable that it is 15 to 85 degreeC. Here, the temperature related to the roller shall mean the surface temperature of the roller.

The distance L3 between the lamination position P and the light irradiation device 64 can be, for example, 30 mm or more.

The coating film 22 becomes a cured layer 28 by light irradiation, and a wavelength conversion member 70 including the first film 10, the cured layer 28, and the second film 50 is manufactured. The wavelength conversion member 70 is peeled from the backup roller 62 by the peeling roller 80. The wavelength conversion member 70 is continuously conveyed by a winding machine (not shown), and the wavelength conversion member 70 is then wound up in a roll shape by a winding machine.

As mentioned above, although one aspect of the manufacturing process of a wavelength conversion member was demonstrated, this invention is not limited to the said aspect. For example, a wavelength conversion layer (cured layer) may be produced by applying a quantum dot-containing composition on a substrate, followed by a polymerization treatment after drying treatment performed as necessary without laminating an additional substrate thereon. On the produced wavelength conversion layer, one or more other layers, such as a barrier layer, may be laminated by a known method.

The total thickness of the wavelength conversion layer is preferably in the range of 1 to 500 µm, more preferably in the range of 100 to 400 µm. Further, the wavelength conversion layer may have a stacked structure of two or more layers, or may contain two or more types of quantum dots exhibiting different light emission characteristics in the same layer. When the wavelength conversion layer is a laminate of two or more layers, the film thickness of one layer is preferably in the range of 1 to 300 µm, more preferably in the range of 10 to 250 µm, and more preferably 30 It is in the range of -150 μm.

<Other layers and supports>

As described above, the wavelength conversion member has an adjacent layer on at least one main surface of the wavelength conversion layer. For example, you may have at least one layer selected from the group consisting of an inorganic layer and an organic layer on at least one main surface of the wavelength conversion layer. As such an inorganic layer and an organic layer, an inorganic layer and an organic layer which comprise a barrier film mentioned later are mentioned. From the viewpoint of maintaining luminous efficiency, it is preferable that at least one layer selected from the group consisting of an inorganic layer and an organic layer, respectively, is included on both main surfaces of the wavelength conversion layer. This is because the intrusion of oxygen, moisture, and the like from the main surface into the wavelength conversion layer can be prevented by such a layer, and it is possible to prevent the quantum dots from deteriorating due to the invasion, and the luminous efficiency decrease. In addition, in one aspect, it is preferable that the inorganic layer and the organic layer are included as an adjacent layer in direct contact with the main surface of the wavelength conversion layer. In addition, by using a quantum dot-containing polymerizable composition containing a silane coupling agent and an acid generator, the adhesion of the interface between the wavelength conversion layer and the adjacent layer can be improved without using the adhesive layer, but the use of the adhesive layer is eliminated. It is not. For example, in the case of laminating an adjacent layer on one main surface of the wavelength conversion layer after energy application and polymerization treatment, a known adhesive layer may be bonded to the adjacent layer and the wavelength conversion layer.

(Support)

The wavelength converting member may have a support for improving strength, easiness of film formation, and the like. The support may be included as a layer adjacent to or in direct contact with the wavelength conversion layer, or may be included as a base film for a barrier film described later. In the wavelength conversion member, the support may be included so that an inorganic layer to be described later and a support may be in this order, and a wavelength conversion layer, an inorganic layer to be described later, an organic layer to be described later, and a support may be included in this order. . A support may be disposed between the organic layer and the inorganic layer, between two organic layers, or between two inorganic layers. Further, one or two or more of the supports may be included in the wavelength conversion member, and the wavelength conversion member may have a structure in which a support, a wavelength conversion layer, and a support are stacked in this order. The support is preferably a transparent support transparent to visible light. Here, the term "transparent with respect to visible light" means that the line transmittance in the visible region is 80% or more, preferably 85% or more. The light transmittance used as a measure of transparency is calculated by measuring the total light transmittance and the amount of scattered light using the method described in JIS-K7105, that is, an integral spherical light transmittance measuring device, and subtracting the diffuse transmittance from the total light transmittance. I can. For the support, Japanese Patent Application Laid-Open No. 2007-290369, paragraphs 0046 to 0052, and Japanese Patent Application Publication No. 2005-096108, paragraphs 0040 to 0055, can be referred to. The thickness of the support is preferably in the range of 10 to 500 µm, particularly in the range of 20 to 400 µm, particularly in the range of 30 to 300 µm, from the viewpoints of gas barrier properties and impact resistance.

The support can also be used as the above-described substrate. In addition, the support may be used for either or both of the first film and the second film described above. When both the first film and the second film are a support, they may be the same or different.

(Barrier film)

It is preferable that the wavelength conversion member contains a barrier film. The barrier film is a film having a gas barrier function to block oxygen. It is also preferable that the barrier film has a function of blocking water vapor.

It is preferable that the barrier film is included in the wavelength conversion member as a layer adjacent to or in direct contact with the wavelength conversion layer. In addition, one or two or more barrier films may be included in the wavelength conversion member, and it is preferable that the wavelength conversion member has a structure in which a barrier film, a wavelength conversion layer, and a barrier film are laminated in this order.

In the wavelength conversion member, the wavelength conversion layer may be formed of a barrier film as a substrate. In addition, the barrier film may be used for either or both of the first film and the second film described above. When both the first film and the second film are barrier films, they may be the same or different.

As the barrier film, any known barrier film may be used, and for example, a barrier film described below may be used.

The barrier film usually needs to contain at least an inorganic layer, and may be a film containing a base film and an inorganic layer. About the base film, the base material of the said support body can be referred to. The barrier film may include a barrier laminate comprising at least one inorganic layer and at least one organic layer on the base film. Laminating a plurality of layers in this way is because the barrier property can be further improved. On the other hand, since the light transmittance of the wavelength conversion member tends to decrease as the number of layers to be laminated increases, it is preferable to increase the number of laminates within a range that can maintain a good light transmittance. Specifically, it is preferable that the barrier film has a total light transmittance of 80% or more in a visible light region and an oxygen transmittance of 1 cm 3 /(m 2 ·day·atm) or less. Here, the oxygen permeability is a value measured using an oxygen gas permeability measuring device (manufactured by MOCON, OX-TRAN 2/20: brand name) under conditions of a measurement temperature of 23°C and a relative humidity of 90%. In addition, the visible light region refers to a wavelength region of 380 to 780 nm, and the total light transmittance refers to the average value of the light transmittance over the visible light region.

The oxygen permeability of the barrier film is more preferably 0.1 cm 3 /(m 2 ·day·atm) or less, and more preferably 0.01 cm 3 /(m 2 ·day·atm) or less. The total light transmittance in the visible region is more preferably 90% or more. The lower the oxygen transmittance is, the more preferable it is, and the higher the total light transmittance in the visible region is, the more preferable.

(Inorganic layer)

The "inorganic layer" is a layer mainly composed of an inorganic material, and is preferably a layer formed only of an inorganic material. In contrast, the organic layer is a layer containing an organic material as a main component, and preferably refers to a layer in which the organic material occupies 50% by mass or more, 80% by mass or more, and particularly 90% by mass or more.

The inorganic material constituting the inorganic layer is not particularly limited, and for example, a metal or various inorganic compounds such as inorganic oxides, nitrides and oxynitrides can be used. As the elements constituting the inorganic material, silicon, aluminum, magnesium, titanium, tin, indium, and cerium are preferable, and one or two or more of them may be contained. Specific examples of the inorganic compound include silicon oxide, silicon oxynitride, aluminum oxide, magnesium oxide, titanium oxide, tin oxide, indium oxide alloy, silicon nitride, aluminum nitride, and titanium nitride. Further, as the inorganic layer, a metal film such as an aluminum film, a silver film, a tin film, a chromium film, a nickel film, or a titanium film may be provided.

Among the above materials, silicon nitride, silicon oxide, or silicon oxynitride is particularly preferable. This is because the inorganic layer made of these materials has good adhesion to the organic layer, so that the barrier property can be further increased.

The method of forming the inorganic layer is not particularly limited, and for example, various film forming methods capable of evaporating or scattering the film-forming material to be deposited on the surface to be deposited can be used.

Examples of the method for forming the inorganic layer include a vacuum vapor deposition method in which inorganic materials such as inorganic oxides, inorganic nitrides, inorganic oxynitrides, and metals are heated to evaporate; An oxidation reaction vapor deposition method in which an inorganic material is used as a raw material, oxidized by introducing oxygen gas, and deposited; A sputtering method in which an inorganic material is used as a target raw material, argon gas and oxygen gas are introduced and sputtered to evaporate; Plasma using an organosilicon compound as a raw material for physical vapor deposition (Physical Vapor Deposition method) such as an ion plating method in which an inorganic material is heated by a plasma beam generated by a plasma gun to evaporate, and when a vapor-deposited film of silicon oxide is formed. The chemical vapor deposition method, etc. are mentioned. The vapor deposition may be performed on the surface using a support, a base film, a wavelength conversion layer, an organic layer, or the like as a substrate.

The silicon oxide film is preferably formed using an organosilicon compound as a raw material and using a low-temperature plasma chemical vapor deposition method. As this organosilicon compound, specifically, 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, Propylsilane, phenylsilane, vinyl triethoxysilane, tetramethoxysilane, phenyl triethoxysilane, methyl triethoxysilane, octamethylcyclotetrasiloxane, and the like. In addition, among the above organosilicon compounds, it is preferable to use tetramethoxysilane (TMOS) and hexamethyldisiloxane (HMDSO). These are because they are excellent in handling properties and properties of a vapor-deposited film.

The thickness of the inorganic layer is, for example, 1 nm to 500 nm, preferably 5 nm to 300 nm, and more preferably 10 nm to 150 nm. This is because, when the film thickness of the inorganic layer is within the above-described range, reflection in the inorganic layer can be suppressed while realizing good barrier properties, and a wavelength converting member having a higher light transmittance can be provided.

In the wavelength conversion member, it is preferable that at least one inorganic layer adjacent to the wavelength conversion layer, preferably in direct contact with the wavelength conversion layer, is included. It is also preferable that the inorganic layer is in direct contact with both surfaces of the wavelength conversion layer. However, as for the inorganic layer, it tends to be difficult to ensure adhesion with the wavelength conversion layer generally formed of a polymerizable composition containing an organic compound. On the other hand, in the wavelength conversion member formed using the composition containing the silane coupling agent and the acid generator, good adhesion to the inorganic layer and the wavelength conversion layer can be obtained.

(Organic layer)

As the organic layer, Japanese Patent Application Laid-Open No. 2007-290369, paragraphs 0020 to 042, and Japanese Patent Application Publication No. 2005-096108, paragraphs 0704 to 0105, can be referred to. Moreover, it is preferable that an organic layer contains a cardo polymer. This is because the adhesion between the organic layer and the adjacent layer, in particular, the adhesion to the inorganic layer is improved, and further superior gas barrier properties can be realized. For details of the cardo polymer, reference can be made to Japanese Patent Application Laid-Open No. 2005-096108, paragraphs 0085 to 0095. The thickness of the organic layer is preferably in the range of 0.05 µm to 10 µm, and particularly preferably in the range of 0.5 to 10 µm. When the organic layer is formed by the wet coating method, the film thickness of the organic layer is preferably in the range of 0.5 to 10 µm, especially in the range of 1 µm to 5 µm. Further, in the case of forming by a dry coating method, it is preferably in the range of 0.05 µm to 5 µm, and particularly, in the range of 0.05 µm to 1 µm. This is because the adhesion with the inorganic layer can be made more favorable when the film thickness of the organic layer formed by the wet coating method or the dry coating method is within the above-described range.

For other details of the inorganic layer and the organic layer, Japanese Unexamined Patent Publication No. 2007-290369, Japanese Unexamined Patent Publication No. 2005-096108, and further description of US2012/0113672A1 can be referred to.

Between an organic layer and an inorganic layer, between two organic layers, or between two inorganic layers, you may bond with a well-known adhesive layer. From the viewpoint of improving the light transmittance, the smaller the adhesive layer is, the more preferable it is, and it is more preferable that no adhesive layer is present.

[Method of manufacturing wavelength conversion member]

A further aspect of the present invention relates to a method of manufacturing the wavelength conversion member.

In one aspect, in the above production method, after bringing the main surface of the adjacent layer into contact with the quantum dot-containing polymerizable composition, the quantum dot-containing polymerizable composition is simultaneously applied with energy to generate protonic acid from an acid generator and a polymerization treatment. Or sequentially. In addition, the sequence here is not necessarily limited to that the polymerization treatment is continuously performed as the next step of the energy application treatment, and the polymerization treatment is performed after energy application, for example, after other treatment such as drying treatment. It shall be included as well.

In another aspect, in order to manufacture the wavelength conversion member having adjacent layers on both major surfaces of the wavelength conversion layer,

After bringing the quantum dot-containing polymerizable composition into contact with at least one of the two adjacent layers, the quantum dot-containing polymerizable composition is simultaneously or sequentially subjected to energy imparting and polymerization treatment for generating protonic acid from an acid generator. . In a further aspect, the energy application is performed after the main surfaces of the two adjacent layers and the quantum dot-containing polymerizable composition are brought into contact with each other.

Details of the above manufacturing method are as described above.

[Backlight unit]

A backlight unit according to an aspect of the present invention includes at least the above-described wavelength conversion member and a light source. The details of the wavelength conversion member are as described above.

(Light emission wavelength of backlight unit)

From the viewpoint of realization of high luminance and high color reproducibility, it is preferable to use a multi-wavelength light source as the backlight unit. As a preferred aspect,

Blue light having an emission center wavelength in a wavelength band of 430 to 480 nm and a peak of emission intensity with a half width of 100 nm or less; and

Green light having an emission center wavelength in a wavelength band of 500 to 600 nm and a peak of emission intensity with a half width of 100 nm or less, and

Red light having a luminous intensity peak having an emission center wavelength in a wavelength band of 600 to 680 nm and a half width of 100 nm or less,

And a backlight unit that emits light.

From the viewpoint of further improving luminance and color reproducibility, the wavelength band of blue light emitted by the backlight unit is preferably in the range of 440 to 480 nm, and more preferably in the range of 440 to 460 nm.

From the same viewpoint, the wavelength band of green light emitted by the backlight unit is preferably in the range of 510 to 560 nm, and more preferably in the range of 510 to 545 nm.

In addition, from the same viewpoint, the wavelength band of the red light emitted by the backlight unit is preferably in the range of 600 to 650 nm, and more preferably in the range of 610 to 640 nm.

Further, from the same point of view, the half width of each light emission intensity of blue light, green light, and red light emitted by the backlight unit is preferably 80 nm or less, more preferably 50 nm or less, further preferably 40 nm or less, and 30 It is even more preferable that it is nm or less. Among these, it is particularly preferable that the half-value width of each emission intensity of blue light is 25 nm or less.

The backlight unit includes at least a light source together with the wavelength conversion member. In one embodiment, as a light source, one emitting blue light having a light emission center wavelength in a wavelength band of 430 nm to 480 nm, for example, a blue light emitting diode emitting blue light can be used. When a light source emitting blue light is used, it is preferable that the wavelength conversion layer contains at least quantum dots A that are excited by excitation light to emit red light, and quantum dots B that emit green light. Accordingly, white light may be realized by blue light emitted from the light source and transmitted through the wavelength conversion member, and red light and green light emitted from the wavelength conversion member.

Alternatively, in another embodiment, as a light source, an ultraviolet light emitting diode having an emission center wavelength in a wavelength band of 300 nm to 430 nm can be used, for example, an ultraviolet light emitting diode. In this case, it is preferable that the wavelength conversion layer contains quantum dots C that are excited by excitation light and emit blue light together with quantum dots A and B. Accordingly, white light may be realized by red light, green light, and blue light emitted from the wavelength conversion member.

In another aspect, two types of light sources selected from the group consisting of a blue laser emitting blue light, a green laser emitting green light, and a red laser emitting red light are used. White light can also be realized by two types of light emitted from the light source and light emitted from the quantum dots of the wavelength conversion layer by presenting quantum dots emitting fluorescence having fluorescence in the wavelength conversion layer.

Further, in another aspect, the light emitting diode can be substituted as a laser light source.

(Configuration of backlight unit)

The configuration of the backlight unit may be an edge light system in which a light guide plate, a reflection plate, or the like is used as a constituent member, or a direct type system. In Fig. 1, as an embodiment, an example of an edge light type backlight unit is shown. As the light guide plate, a known one can be used without any limitation.

Further, the backlight unit may include a reflective member at the rear of the light source. As such a reflective member, there is no particular limitation, and known ones can be used, and are described in Japanese Patent 3416302, 363565, Japanese Patent 4091978, Japanese Patent 3448626, and the like. Is introduced into the invention.

It is also preferable that the backlight unit includes other known diffusion plates, diffusion sheets, prism sheets (eg, BEF series manufactured by Sumitomo 3M, etc.), and a light guide. Other members are also described in Japanese Patent No. 3416302, Japanese Patent No. 3363565, Japanese Patent No. 4091978, Japanese Patent No. 3448626, etc., and the contents of these publications refer to the present invention. Is introduced.

[Liquid crystal display device]

A liquid crystal display device according to an aspect of the present invention includes at least the above-described backlight unit and a liquid crystal cell.

(Configuration of liquid crystal display device)

There is no particular limitation on the driving mode of the liquid crystal cell, and twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically compensated band cell (OCB) Various modes such as can be used. The liquid crystal cell is preferably in a VA mode, an OCB mode, an IPS mode, or a TN mode, but is not limited thereto. As an example of the configuration of a liquid crystal display device in VA mode, the configuration shown in Fig. 2 of Japanese Unexamined Patent Application Publication No. 2008-262161 is exemplified. However, there is no particular limitation on the specific configuration of the liquid crystal display device, and a known configuration can be adopted.

In one embodiment of a liquid crystal display device, a liquid crystal cell is provided in which a liquid crystal layer is sandwiched between substrates provided with electrodes on at least one of the opposite sides, and this liquid crystal cell is configured by being disposed between two polarizing plates. A liquid crystal display device includes a liquid crystal cell filled with a liquid crystal between upper and lower substrates, and displays an image by changing the alignment state of the liquid crystal by applying a voltage. In addition, it has an accompanying functional layer such as a polarizing plate protective film, an optical compensation member for performing optical compensation, and an adhesive layer, if necessary. In addition, with (or instead of) a color filter substrate, a thin layer transistor substrate, a lens film, a diffusion sheet, a hard coating layer, an antireflection layer, a low reflection layer, an anti-glare layer, etc., a front scattering layer, a primer layer, an antistatic layer, an undercoat layer, etc. The surface layer of may be disposed.

2 shows an example of a liquid crystal display device according to an aspect of the present invention. The liquid crystal display device 51 shown in FIG. 2 has a backlight-side polarizing plate 14 on the surface of the liquid crystal cell 21 on the backlight side. The backlight-side polarizing plate 14 may or may not contain the polarizing plate protective film 11 on the surface of the backlight-side polarizer 12 on the backlight side, but is preferably included.

It is preferable that the backlight-side polarizing plate 14 has a configuration in which the polarizer 12 is sandwiched between two polarizing plate protective films 11 and 13.

In the present specification, the polarizing plate protective film on the side close to the liquid crystal cell with respect to the polarizer is referred to as the inner polarizing plate protective film, and the polarizing plate protective film on the side far from the liquid crystal cell with respect to the polarizer is referred to as the outer polarizing plate protective film. In the example shown in FIG. 2, the polarizing plate protective film 13 is an inner-side polarizing plate protective film, and the polarizing plate protective film 11 is an outer-side polarizing plate protective film.

The backlight-side polarizing plate may have a retardation film as an inner-side polarizing plate protective film on the liquid crystal cell side. As such a retardation film, a known cellulose acylate film or the like can be used.

The liquid crystal display device 51 has a display-side polarizing plate 44 on a surface of the liquid crystal cell 21 on the side opposite to the surface on the backlight side. The display-side polarizing plate 44 has a configuration in which the polarizer 42 is sandwiched between two polarizing plate protective films 41 and 43. The polarizing plate protective film 43 is an inner-side polarizing plate protective film, and the polarizing plate protective film 41 is an outer-side polarizing plate protective film.

The backlight unit 1 included in the liquid crystal display device 51 is as described above.

There is no particular limitation on a liquid crystal cell, a polarizing plate, a polarizing plate protective film, and the like constituting the liquid crystal display according to an aspect of the present invention, and a product manufactured by a known method or a commercially available product may be used without any limitation. In addition, it is of course possible to provide a known intermediate layer such as an adhesive layer between the respective layers.

[Example]

Hereinafter, the present invention will be described in more detail based on examples. Materials, amounts used, ratios, treatment contents, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific examples shown below.

(Example 1)

1. Fabrication of the barrier film 10

An organic layer and an inorganic layer were sequentially formed on one side of a polyethylene terephthalate film (PET film, manufactured by Toyobo Corporation, trade name: Cosmo Shine (registered trademark) A4300, thickness 50 µm, width 1000 mm, length 100 m) by the following procedure.

Trimethylolpropane triacrylate (TMPTA manufactured by Daicel Cytech Co., Ltd.) and a photoinitiator (manufactured by Lamberti, ESACURE KTO46) were prepared and weighed so that the former: the latter = 95:5 as a mass ratio, and these were added to methyl ethyl ketone. It was dissolved and set as a coating liquid having a solid content concentration of 15%. This coating liquid was applied on the PET film by roll-to-roll using a die coater, and passed through a drying zone at 50°C for 3 minutes. Thereafter, ultraviolet rays were irradiated under a nitrogen atmosphere (accumulated irradiation amount of about 600 mJ/cm 2 ), cured by ultraviolet curing, and wound up. The thickness of the first organic layer formed on the support was 1 µm.

Next, an inorganic layer (silicon nitride layer) was formed on the surface of the first organic layer using a roll-to-roll CVD (Chemical Vapor Deposition) device. As the raw material gas, silane gas (flow rate 160 sccm), ammonia gas (flow rate 370 sccm), hydrogen gas (flow rate 590 sccm), and nitrogen gas (flow rate 240 sccm) were used. As the power source, a high-frequency power source with a frequency of 13.56 MHz was used. The film forming pressure was 40 Pa and the resulting film thickness was 50 nm. In this way, the barrier film 10 in which the inorganic layer was laminated on the surface of the first organic layer was produced.

2. Fabrication of wavelength conversion layer

As a quantum dot-containing polymerizable composition, the following quantum dot dispersion liquid 1 was prepared, filtered through a filter made of polypropylene having a pore diameter of 0.2 µm, dried under reduced pressure for 30 minutes, and used as a coating liquid. The quantum dot concentration in the following toluene dispersion was 1% by mass.

As quantum dots 1 and 2, nanocrystals having the following core-shell structure (InP/ZnS) were used.

Quantum dot 1: INP530-10 (manufactured by NN-labs)

Quantum dot 2: INP620-10 (manufactured by NN-labs)

The viscosity of the quantum dot dispersion 1 was 50 mPa·s.

Silane coupling agent A

Photoacid generator a

The barrier film 10 produced by the above-described procedure was used as the first and second films, and the wavelength conversion member 1 was obtained by the manufacturing process described with reference to FIGS. 3 and 4. Specifically, while continuously conveying the barrier film 10 as a first film at a tension of 1 m/min and 60 N/m, a coating liquid was applied to the surface of the first film from a die coater to form a 50 μm thick coating Formed. Next, the 1st film on which the coating film was formed was wound over a backup roller, and the 2nd film which is another barrier film 10 was laminated on the coating film. In the state where the coating film was sandwiched between the first film and the second film, it was wound on a backup roller and irradiated with ultraviolet rays while continuously conveying. The diameter of the backup roller was 300 mm, and the temperature of the backup roller was 50°C. The irradiation amount of ultraviolet rays was 2000 mJ/cm 2. In addition, L1 was 50 mm, L2 was 1 mm, and L3 was 50 mm.

The coating film was cured by irradiation of ultraviolet rays to form a wavelength conversion layer (cured layer), and a wavelength conversion member 1 was manufactured. The thickness of the cured layer of the wavelength conversion member was about 50 µm. In this way, a wavelength converting member 1 having the barrier films 10 on both surfaces of the wavelength converting layer, and in which both main surfaces of the wavelength converting layer are in direct contact with the inorganic layer of the barrier film 10 was obtained.

(Example 2)

In Example 1, except that the photoacid generator a was changed to the following photoacid generator b (a mixture of the following two salts: UVI-6990 manufactured by Dow Chemical, where n is the number of repeating units), the wavelength The conversion member 2 was produced.

Photoacid generator b

(Example 3)

In Example 1, the wavelength conversion member 3 was produced in the same manner except that the photoacid generator a was changed to the photoacid generator c (triphenylsulfonium-trifluoromethanesulfonate).

(Example 4)

In Example 1, the photoacid generator was changed to the thermal acid generator d (paratoluene sulfonic acid triethylamine salt), except that the method of lamination was changed as follows, and a wavelength conversion member 4 was produced. .

While continuously conveying the first film at a tension of 1 m/min and 60 N/m, a coating liquid was applied from a die coater to the surface of the first film (barrier film 10) to form a coating film having a thickness of 50 μm. Next, the 1st film on which the coating film was formed was heated for 2 minutes at 100 degreeC by zone heating by warm air. Thereafter, it was wound around a backup roller, and another barrier film 10 was laminated on the coating film as a second film. In the state where the coating film was sandwiched between the first film and the second film, it was wound around a backup roller and irradiated with ultraviolet rays while continuously conveying. The diameter of the backup roller was 300 mm, and the temperature of the backup roller was 50°C. The irradiation amount of ultraviolet rays was 2000 mJ/cm 2. In addition, L1 was 50 mm, L2 was 1 mm, and L3 was 50 mm.

The coating film was cured by irradiation of ultraviolet rays to form a wavelength conversion layer (cured layer), and a wavelength conversion member 4 was manufactured. The thickness of the cured layer of the wavelength conversion member was about 50 µm. In this way, a wavelength converting member 4 having the barrier films 10 on both surfaces of the wavelength converting layer, and in which both main surfaces of the wavelength converting layer are in direct contact with the inorganic layer of the barrier film 10 was obtained.

(Example 5)

As the quantum dot-containing polymerizable composition, a wavelength conversion member 5 was produced in the same manner as in Example 1 except that the following quantum dot dispersion 5 was used. The toluene dispersions of the following quantum dots 1 and 2 are the same as those used in the quantum dot dispersion 1.

Silane coupling agent B

(Example 6)

In Example 1, a wavelength conversion member 6 was produced in the same manner except that the photoacid generator a was changed to the photoacid generator e shown below (PAG3-1 described above).

Photoacid generator e

(Example 7)

In Example 1, the wavelength conversion member 7 was produced in the same manner except that the photo-acid generator a was changed to the photo-acid generator f shown below.

Mine generator f (T1608 manufactured by Kasei Kogyo, Tokyo)

(Example 8)

In Example 5, the wavelength conversion member 8 was produced in the same manner except that the photo-acid generator a was changed to the above-described photo-acid generator f.

(Comparative Example 1)

In Example 1, a wavelength conversion member 11 was produced in the same manner except that a photoacid generator was not added.

(Comparative Example 2)

As the quantum dot-containing polymerizable composition, a wavelength conversion member 12 was produced in the same manner as in Example 1 except that the following quantum dot dispersion liquid 12 was used. The toluene dispersions of the following quantum dots 1 and 2 are the same as those used in the quantum dot dispersion 1.

(Comparative Example 3)

As the quantum dot-containing polymerizable composition, a wavelength conversion member 13 was produced in the same manner as in Example 1 except that the following quantum dot dispersion liquid 13 was used. The toluene dispersions of the following quantum dots 1 and 2 are the same as those used in the quantum dot dispersion 1.

Protonic acid2

(Comparative Example 4)

In Example 5, a wavelength conversion member 14 was produced in the same manner as in Example 5 except that the same amount of protonic acid 1 (paratoluenesulfonic acid) was added instead of the photoacid generator a (Irgacure 250 manufactured by BASF).

The photoacid generator and thermal acid generator used in the examples generate protonic acid by imparting energy (light irradiation, heating). The generated protonic acid ^{has a structure in which proton H +} is added to the anion portion in the above structure. The molecular weight of the protonic acid generated in this way is shown in Table 2 described later. In addition, the molecular weight of the protonic acid mentioned later used in the comparative example is also shown in Table 2.

<Evaluation method of adhesion (existence of interface peeling off after punching)>

The prepared wavelength conversion member is placed in a room maintained at a temperature of 25°C and 60% relative humidity, humidity is controlled for 1 hour, and then punched by a punching machine using a 4cm×4cm Thomson cutter, and five sheets of sheet. A sample was obtained.

With respect to the punched 4cm×4cm square sheet sample, the peeling state of the interface between the wavelength conversion layer and the barrier film on each side of the square was determined per 1 sample based on the following criteria. The score was scored with 4 as the highest score.

0.00 points: no occurrence of peeling of the interface

0.25 points: The area where peeling of the interface occurs is 25% or less of one side

0.50 points: The area where peeling of the interface occurs is more than 25% to 50% of one side

0.75 points: The area where peeling of the interface occurs is more than 50% to less than 75% of one side

1.00 points: The area where peeling of the interface occurs is more than 75% of one side

The scores were totaled for five sheet samples, and evaluation was performed as follows, and the results are shown in Table 2 below.

A: Score 0 or more and 5 or less

B: More than 5 points and 10 points or less

C: More than 10 points and 15 points or less

D: More than 15 points and 20 points or less

<Method of evaluating liquid stability (existence of foreign matter)>

In the case where the wavelength conversion member (sheet sample) of Examples and Comparative Examples was prepared immediately (within 1 hour) of the quantum dot dispersion solution, and after the solution was prepared in a room at a temperature of 25°C and a relative humidity of 60%, in the same room. In the case of production after storage for 3 days, the number of increase in bulk foreign matter per square meter (after storage-immediately after the crude liquid) was measured and ranked. The number of lump-shaped foreign matters was measured by visually observing the sheet sample between two polarizing plates having a 1-square-meter cross-Nicol arrangement. The size of the foreign material was about 10 µm to 500 µm.

The liquid stability was evaluated according to the following evaluation criteria from the increase number of the bulky foreign matter per 1 square meter. The results are shown in Table 2 below.

(Evaluation standard)

A: less than 1

B: 1 or more and less than 5

C: 5 or more

<Manufacture of liquid crystal display device>

A commercially available tablet terminal (Amazon's Kindle (registered trademark) Fire HDX 7") was disassembled, and the backlight unit was taken out. On the light guide plate of the taken out backlight unit, the wavelength conversion members of Examples and Comparative Examples were placed on the light guide plate. Then, two prism sheets in which the directions of the surface irregularities pattern were orthogonal were stacked on top of each other to produce a liquid crystal display device.

<Evaluation method of luminance decrease in the outer circumferential region>

By turning on the manufactured liquid crystal display, the luminance of the entire screen is imaged from the true surface from a far enough distance (at least 2m away) to reduce the angle of view. It measured with a luminance meter (manufactured by Prometric Radiant Imaging). From the measurement result, in the outer circumferential area (area from the edge of the 4 sides of the screen to 1 cm inside), the ratio of the area in which the luminance has decreased by 15% or more from the luminance measured at the center of the screen is calculated, and evaluated according to the following evaluation criteria. did. The results are shown in Table 2 below.

(Evaluation standard)

A: The area where the luminance decrease of 15% or more has occurred is 25% or less of the outer circumferential area.

B: The area where the luminance decrease of 15% or more has occurred is more than 25% and 50% or less of the outer circumference area

C: The area where the luminance decrease of 15% or more has occurred is more than 50% and less than 75% of the outer circumference area

D: The area in which the luminance decrease by 15% or more has occurred exceeds 75% of the outer circumferential area.

[Table 2]

Evaluation results

From the results shown in Table 2, it can be confirmed that the wavelength conversion member of the example exhibits little peeling at the end of the interface between the wavelength conversion layer and the barrier film by punching, and has good adhesion between the wavelength conversion layer and the barrier film.

As shown in Table 2, in the liquid crystal display device provided with the wavelength conversion member of the example, for the fact that the decrease in luminance in the outer circumferential region was suppressed, the present inventors found that the peeling of the interface end between the wavelength conversion layer and the barrier film It is considered that this is a result showing that the invasion of oxygen from the interface end to the wavelength conversion layer is suppressed so that the luminous efficiency of the quantum dot is well maintained at the end.

In addition, as shown in Table 2, the quantum dot-containing polymerizable composition used in Examples also had good liquid stability. In this regard, the present inventors speculate that the use of an acid generator that generates protonic acid by application of energy such as light irradiation or heating, unlike in the comparative examples, contributes to this point.

The present invention is useful in the field of manufacturing a liquid crystal display device.

Claims (21)

In a quantum dot-containing polymerizable composition containing a quantum dot excited by excitation light to emit fluorescence, a polymerizable compound, a silane coupling agent, and an acid generator that generates a protonic acid by imparting energy , A wavelength conversion layer formed by simultaneously or sequentially performing energy application and polymerization treatment to generate the protonic acid, and,
Adjacent layer adjacent to one main surface of the wavelength conversion layer
The cut-out wavelength conversion member containing at least. The method of claim 1,
The acid generator is a photoacid generator that generates protonic acid by imparting energy by light irradiation, and a thermal acid generator that generates protonic acid by imparting energy by heating. At least one selected from the group consisting of, the cut-out wavelength conversion member. The method according to claim 1 or 2,
The adjacent layer is a wavelength conversion member which is an inorganic layer. The method according to claim 1 or 2,
A wavelength conversion member having an adjacent layer adjacent to one major surface of the wavelength conversion layer and an adjacent layer adjacent to the other major surface. The method of claim 4,
The two adjacent layers are both inorganic layers. The method according to claim 1 or 2,
The wavelength conversion member has a thickness of the wavelength conversion layer in the range of 10 to 300 µm. The wavelength conversion member according to claim 1 or 2, and
Light source,
A backlight unit comprising at least. The method of claim 7,
The light source is a backlight unit having a light emission center wavelength in a wavelength band of 430 nm to 480 nm. The backlight unit according to claim 7,
Liquid crystal cell
A liquid crystal display device comprising at least. As the manufacturing method of the wavelength conversion member according to claim 1 or 2,
After bringing the main surface of the adjacent layer into contact with the quantum dot-containing polymerizable composition,
In the quantum dot-containing polymerizable composition,
It is roll-to-roll until energy imparting and polymerization treatment for generating protonic acid from the acid generator are performed simultaneously or sequentially,
Thereafter, the manufacturing method comprising cutting to a specified size. As the manufacturing method of the wavelength conversion member according to claim 4,
After contacting at least one of the main surfaces of the two adjacent layers with the quantum dot-containing polymerizable composition,
In the quantum dot-containing polymerizable composition,
It is roll-to-roll until energy imparting and polymerization treatment for generating protonic acid from the acid generator are performed simultaneously or sequentially,
The manufacturing method comprising cutting to a prescribed size. The method of claim 11,
The production method, wherein the energy application is performed after the main surfaces of each of the two adjacent layers and the quantum dot-containing polymerizable composition are brought into contact with each other. delete delete delete delete delete delete delete delete delete

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