JP2016066041A - Wavelength conversion member, backlight unit, liquid crystal display device, method for manufacturing wavelength conversion member, and quantum dot-containing polymerizable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength conversion member including quantum dots, which has both high visible light transmitting property and excellent durability.SOLUTION: The wavelength conversion member includes a wavelength conversion layer containing quantum dots that are excited by excitation light to emit fluorescent light. The wavelength conversion layer is a cured layer formed by curing a quantum dot-containing polymerizable composition comprising the quantum dots, a first polymerizable compound, and a second polymerizable compound. The first polymerizable compound is at least one compound selected from the group consisting of a (meth)acrylate monomer having two or more functional groups and a monomer having two or more functional groups selected from the group consisting of an epoxy group and an oxetanyl group. The second polymerizable compound is at least one compound selected from the group consisting of monomers including a functional group having a hydrogen-bonding property in the molecule and also having a polymerizable group that can polymerize with the first polymerizable compound. The present invention also provides a backlight unit, a liquid crystal display device, a method for manufacturing the wavelength conversion member, and a quantum dot-containing polymerizable composition.SELECTED DRAWING: None

Description

  The present invention relates to a wavelength conversion member and a manufacturing method thereof. The present invention also relates to a backlight unit including the wavelength conversion member and a liquid crystal display device including the backlight unit. The present invention further relates to a quantum dot-containing polymerizable composition that can be used in the production of the wavelength conversion member.

  Flat panel displays such as liquid crystal display devices (hereinafter also referred to as LCDs (Liquid Crystal Displays)) consume less power and are increasingly used as space-saving image display devices year by year. 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, color reproducibility is improving as LCD performance improvement. In this regard, in recent years, quantum dots (also referred to as quantum dots, QDs, and quantum dots) have attracted attention as light emitting materials (see Patent Document 1). For example, when excitation light enters the wavelength conversion member including quantum dots from the backlight, the quantum dots are excited and emit fluorescence. Here, by using quantum dots having different light emission characteristics, it is possible to embody white light by emitting each emission line light of red light, green light, and blue light. Since the fluorescence due to the quantum dots has a small half-value width, the white light obtained has high brightness and excellent color reproducibility. With the progress of the three-wavelength light source technology using quantum dots, the color gamut has been expanded from 72% to 100% compared to the current TV standard (FHD (Full High Definition), NTSC (National Television System Committee)). doing.

US2012 / 0113672A1

When the wavelength conversion member is processed, if the punching to a prescribed size is performed, the wavelength conversion layer including the quantum dots may be broken or cracked. Such breakage or cracks impair the function of the wavelength conversion member, for example, make the emitted light non-uniform.
Moreover, it becomes easy to produce peeling with a wavelength conversion layer and an adjacent layer depending on the fracture | rupture or crack of a wavelength conversion layer. The separation between the wavelength conversion layer and the adjacent layer may significantly reduce the light resistance of the wavelength conversion member. That is, the quantum dot has a problem that the emission intensity decreases due to a photo-oxidation reaction when it comes into contact with oxygen. In this regard, Patent Document 1 proposes laminating a barrier film on a layer containing quantum dots in order to protect the quantum dots from oxygen and the like. However, when peeling occurs as described above, the wavelength conversion layer comes into contact with oxygen, and the emission intensity of the wavelength conversion member decreases.

  The subject of this invention is providing a highly durable wavelength conversion member and its manufacturing method. Specifically, it is an object of the present invention to provide a wavelength conversion member including a wavelength conversion layer that is difficult to break or that does not easily crack, and a method for manufacturing the same. Moreover, the subject of this invention is providing the composition which can form the wavelength conversion layer which is hard to fracture | rupture or is hard to produce a crack. An object of the present invention is to provide a backlight unit and a liquid crystal display device with higher durability.

  In order to solve the above-mentioned problems, the present inventors have intensively studied a polymer compound used for a composition containing quantum dots for producing a wavelength conversion layer, and completed the present invention.

That is, the present invention provides the following [1] to [18].
[1] A wavelength conversion member having a wavelength conversion layer including quantum dots that are excited by excitation light and emit fluorescence.
The wavelength conversion layer is a cured layer formed by curing a quantum dot-containing polymerizable composition containing the quantum dots, the first polymerizable compound, and the second polymerizable compound,
The first polymerizable compound is a bifunctional or higher functional (meth) acrylate monomer and one or more compounds selected from the group consisting of monomers having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups And
The second polymerizable compound is one or more selected from the group consisting of monomers having a functional group having hydrogen bonding in the molecule and a polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound. A wavelength conversion member which is a compound of
[2] The wavelength conversion member according to [1], wherein the quantum dot-containing polymerizable composition contains a monofunctional (meth) acrylate monomer.
[3] The wavelength conversion member according to [1] or [2], wherein the quantum dot-containing polymerizable composition contains a compound having a long-chain alkyl group having 4 to 30 carbon atoms.

[4] The wavelength conversion member according to any one of [1] to [3], including a base material, wherein at least one surface of the wavelength conversion layer is in contact with the base material.
[5] The first substrate, the wavelength conversion layer, and the second substrate are included in this order, the first substrate and the wavelength conversion layer are in contact with each other, and the wavelength conversion layer and the second substrate are in contact with each other. The substrate is in contact,
Any one of [1] to [4], wherein each of the first base material and the second base material is a barrier film having an oxygen permeability of 1 cm ³ / (m ² · day · atm) or less. Wavelength conversion member.
[6] The wavelength conversion, wherein at least one of the first base material and the second base material is a barrier film having an inorganic layer containing silicon oxide, silicon nitride, silicon carbide, or aluminum oxide. The wavelength conversion member according to [5], wherein at least one surface of the layer is in direct contact with the inorganic layer.
[7] A barrier film in which at least one of the first base material and the second base material includes an inorganic layer and an organic layer containing silicon oxide, silicon nitride, silicon carbide, or aluminum oxide. The wavelength conversion member according to [5], wherein the inorganic layer and the organic layer are in direct contact, and at least one side of the wavelength conversion layer is in direct contact with the organic layer.
[8] The wavelength conversion member according to any one of [5] to [7], wherein the quantum dot-containing polymerizable composition contains an organometallic coupling agent.
[9] The wavelength conversion member according to any one of [5] to [8], wherein the quantum dot-containing polymerizable composition contains a (meth) acrylate monomer containing a boronic acid group.

[10] The quantum dot has a light emission center wavelength in a wavelength band of 600 nm to 680 nm and a half width of a light emission peak of 70 nm or less, and has a light emission center wavelength in a wavelength band of 520 nm to 560 nm. It is at least one selected from the group consisting of quantum dots having a half-value width of 60 nm or less and quantum dots having an emission center wavelength in the wavelength band of 430 nm to 480 nm and an emission peak half-value width of 50 nm or less [1] The wavelength conversion member according to any one of to [9].
[11] A backlight unit including at least the wavelength conversion member according to any one of [1] to [10] and a blue light emitting diode or an ultraviolet light emitting diode.
[12] The backlight unit according to [11], further including a light guide plate, wherein the wavelength conversion member is disposed on a path of light emitted from the light guide plate.
[13] The backlight unit according to [11] or [12], further including a prism sheet.
[14] A liquid crystal display device comprising at least the backlight unit according to any one of [11] to [13] and a liquid crystal cell.
[15] The method for producing a wavelength conversion member according to [4], wherein the quantum dot-containing polymerizable composition is cured after the quantum dot-containing polymerizable composition is applied to the surface of the substrate. The manufacturing method including forming the said wavelength conversion layer by.
[16] The method for producing a wavelength conversion member according to any one of [5] to [9], wherein a first base material and a second base material are prepared, and the first base material Applying the quantum dot-containing polymerizable composition on the surface to form a coating film, overlaying a second substrate on the coating film, and coating the coating film with the first substrate and the second substrate A production method comprising sandwiching and forming the wavelength conversion layer by curing the coating film sandwiched between the first substrate and the second substrate.

[17] The method according to [15] or [16], comprising heating the quantum dot-containing polymerizable composition before the curing of the coating film.
[18] comprising a quantum dot excited by excitation light to emit fluorescence, a first polymerizable compound, and a second polymerizable compound,
The first polymerizable compound is one or more selected from the group consisting of a bifunctional or higher functional (meth) acrylate monomer and a monomer having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups. A compound,
The second polymerizable compound is one or more selected from the group consisting of monomers having a functional group having hydrogen bonding in the molecule and a polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound. A quantum dot-containing polymerizable composition which is a compound of

  The present invention provides a highly durable wavelength conversion member. The wavelength conversion member of the present invention is less susceptible to breakage and cracking during processing, and the light emission intensity is less likely to deteriorate over time even in subsequent use.

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

  The following description may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  In the present specification, the “half width” of a peak means the width of the peak at a peak height of 1/2. Further, light having an emission center wavelength in the wavelength band of 430 to 480 nm is called blue light, light having an emission center wavelength in the wavelength band of 500 to 600 nm is called green light, and the emission center wavelength is in the wavelength band of 600 to 680 nm. The light having a color is called red light.

  In the present invention and the present specification, the “polymerizable composition” is a composition containing at least one polymerizable compound, and has a property of being cured by being subjected to a polymerization treatment such as light irradiation and heating. . Further, the “polymerizable compound” is a compound containing one or more polymerizable functional groups in one molecule. The polymerizable functional group is a group that can participate in the polymerization reaction, and will be described in detail later.

  In the present invention and this specification, “in contact” with respect to the stacked state means that the layer is in direct contact with no other layer. The same applies to “adjacent”.

[Wavelength conversion member]
The wavelength conversion member should just have the function to convert the wavelength of at least one part of incident light, and to radiate | emit the light of a wavelength different from the wavelength of incident light. The shape of the wavelength conversion member is not particularly limited, and may be any shape such as a sheet shape or a bar shape. The wavelength conversion member includes at least a wavelength conversion layer. The wavelength conversion member can be used as a constituent member of a backlight unit of a liquid crystal display device, for example.

FIG. 1 is an explanatory diagram of an example of a backlight unit 1 including a wavelength conversion member. In FIG. 1, the backlight unit 1 includes a light source 1A and a light guide plate 1B for making 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 to Fig.1 (a), the light radiate | emitted from the light-guide plate 1B injects into 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 portion of the light guide plate 1B is blue light, and the liquid crystal is applied from the surface on the liquid crystal cell (not shown) side of the light guide plate 1B. It is emitted toward the cell. The wavelength conversion member 1C disposed on the path of the light (blue light 2) emitted from the light guide plate 1B has quantum dots (A) that are excited by the blue light 2 and emit red light 4, and the blue light 2 It includes at least quantum dots (B) that are excited to emit green light 3. In this way, the backlight unit 1 emits the excited green light 3 and red light 4 and the blue light 2 transmitted through the wavelength conversion member 1C. By emitting red light, green light and blue light in this way, white light can be realized.
The example shown in FIG. 1B is the same as the embodiment shown in FIG. 1A except that the arrangement of the wavelength conversion member and the light guide plate is different. In the example shown in FIG. 1B, the excited green light 3 and red light 4 and the blue light 2 transmitted through the wavelength conversion member 1C are emitted from the wavelength conversion member 1C and enter the light guide plate, and the surface light source is Realized.

(Wavelength conversion layer)
The wavelength conversion member has at least a wavelength conversion layer including quantum dots. The wavelength conversion layer is a cured layer formed by curing a quantum dot-containing polymerizable composition containing quantum dots, a first polymerizable compound, and a second polymerizable compound. The shape of the wavelength conversion layer is not particularly limited, and may be any shape such as a sheet shape or a bar shape.
Quantum dots are excited by excitation light and emit fluorescence. The wavelength conversion layer includes at least one kind of quantum dot and can also include two or more kinds of quantum dots having different light emission characteristics. Known quantum dots include quantum dots (A) having an emission center wavelength in the wavelength band of 600 nm to 680 nm, quantum dots (B) having an emission center wavelength in the wavelength band of 500 nm to 600 nm, and 400 nm to 500 nm. There is a quantum dot (C) having a light emission center wavelength in the wavelength band, and the quantum dot (A) is excited by excitation light to emit red light, the quantum dot (B) emits green light, and the quantum dot (C). Emits blue light. For example, when blue light is incident as excitation light on a wavelength conversion layer including quantum dots (A) and quantum dots (B), red light emitted from the quantum dots (A) and quantum dots as shown in FIG. White light can be realized by the green light emitted by (B) and the blue light transmitted through the wavelength conversion layer. Alternatively, the red light emitted from the quantum dots (A) and the quantum dots (B) by making ultraviolet light incident on the wavelength conversion layer including the quantum dots (A), (B), and (C) as excitation light. White light can be realized by green light emitted by the blue light and blue light emitted by the quantum dots (C).

(Quantum dot-containing polymerizable composition)
The quantum dot-containing polymerizable composition includes a quantum dot, a first polymerizable compound, and a second polymerizable compound. The quantum dot-containing polymerizable composition may contain other components such as a polymerization initiator, an organometallic coupling agent, and a (meth) acrylate monomer containing a boronic acid group.

(Quantum dot)
Regarding quantum dots, in addition to the above description, for example, JP-A-2012-169271, paragraphs 0060 to 0066 can be referred to, but the quantum dots are not limited thereto. As the quantum dots, commercially available products can be used without any limitation. The emission wavelength of the quantum dots can usually be adjusted by the composition and size of the particles, and the composition and size. In one embodiment, the wavelength conversion layer emits light having a luminescence center wavelength in the wavelength band of 600 nm to 680 nm and a luminescence center wavelength in the wavelength band of 520 nm to 560 nm, and a luminescence peak having a half width of the emission peak of 70 nm or less. Quantum dots having a peak half-value width of 60 nm or less, and at least one quantum dot selected from the group consisting of quantum dots having an emission center wavelength in a wavelength band of 430 nm to 480 nm and an emission peak half-value width of 50 nm or less Is preferably included.

  Quantum dots may be added to the polymerizable composition in the form of particles, or may be added in the form of a dispersion dispersed in a solvent. The addition in the state of a dispersion is preferable from the viewpoint of suppressing the aggregation of the quantum dot particles. The solvent used here is not particularly limited. A quantum dot can be added about 0.01-10 mass parts with respect to 100 mass parts of whole quantity of a composition, for example.

(First polymerizable compound)
The first polymerizable compound is one or more selected from the group consisting of a bifunctional or higher functional (meth) acrylate monomer and a monomer having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups. A compound. In the present invention and the present specification, the monomer means a polymerizable compound and is not limited to the monomer, and may be a multimer including two or more repeating units that are the same or different. . A multimer means a compound containing the same or different repeating units, and is used in a sense that encompasses oligomers and polymers such as dimers, trimers, and tetramers. The same applies hereinafter.

  Among the bifunctional or higher (meth) acrylate monomers, examples of the bifunctional (meth) acrylate monomer include neopentyl glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and tripropylene glycol di (meth). ) Acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclo Pentenyloxyethyl (meth) acrylate, dicyclopentanyl di (meth) acrylate and the like are preferable examples.

  Among the bifunctional or higher functional (meth) acrylate monomers, the trifunctional or higher functional (meth) acrylate monomers include ECH (epichlorohydrin) modified glycerol tri (meth) acrylate, EO (ethylene oxide) modified glycerol tri ( (Meth) acrylate, PO (propylene oxide) modified glycerol tri (meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, EO modified phosphate triacrylate, trimethylolpropane tri (meth) acrylate, caprolactone modified trimethylolpropane tri ( (Meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, tris (acryloxy) Ethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, alkyl-modified dipentaerythritol penta (Meth) acrylate, dipentaerythritol poly (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate Etc. are mentioned as preferable examples.

The quantum dot-containing polymerizable composition contains a (meth) acrylate monomer in which the ratio of the molecular weight Mw to the number F of (meth) acryloyl groups per molecule, Mw / F is 200 or less. preferable. Mw / F is more preferably 150 or less, and most preferably 100 or less. The (meth) acrylate monomer having a small Mw / F can increase the crosslink density of the polymer in the wavelength conversion layer formed by curing the quantum dot-containing polymerizable composition, and as a result, the wavelength conversion layer is broken. It is because it can prevent. Further, by using a (meth) acrylate monomer having a small Mw / F, the oxygen permeability of the wavelength conversion layer can be reduced, and the quantum dots contained in the wavelength conversion layer are further suppressed from coming into contact with oxygen. It is preferable also in that Specific examples of (meth) acrylate monomers having Mw / F of 200 or less include pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane trimethacrylate, dipentaerythritol hexaacrylate, tricyclodecane dimethanol An acrylate etc. are mentioned.
In addition, molecular weight shall mean a weight average molecular weight about a multimer. A polymerization average molecular weight shall mean the weight average molecular weight calculated | required by converting the measured value by gel permeation chromatography (GPC) into polystyrene. As measurement conditions by GPC, for example, the following conditions can be employed.
GPC device: HLC-8120 (manufactured by Tosoh Corporation):
Column: TSK gel Multipore HXL-M (7.8 mm ID (inner diameter) x 30.0 cm, manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran (THF)

  Monomers having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups include, for example, aliphatic cyclic epoxy compounds, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, bromine Bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl 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 of polyether polyol obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin Ethers; diglycidyl esters of aliphatic long-chain dibasic acids; glycidyl esters of higher fatty acids; compounds containing epoxycycloalkanes; 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyloxetane, xylylenebisoxetane, 3 Oxetane compounds such as -ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane and the like are preferably used in the present invention.

  Examples of commercially available products that can be suitably used as monomers having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups include Daicel Chemical Industries Celoxide 2021P, Celoxide 8000, and Sigma Aldrich 4-vinyl. Examples include cyclohexene dioxide, OXT-101, OXY-121, and OXT-221 manufactured by Toa Gosei Kagaku. These can be used alone or in combination of two or more.

  In addition, a monomer having two or more functional groups selected from the group consisting of an epoxy group and an oxetanyl group may be produced by any method. For example, Maruzen KK Publishing Co., Ltd., Fourth Edition Experimental Chemistry Course 20 Organic Synthesis II, 213, 1992, Ed. By Alfred Hasfner, The chemistry of cyclic 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, No. 5, 42, 1986, Yoshimura, Adhesion, Vol. 30, No. 7, 42, 1986, Japanese Patent Laid-Open No. 11-100308, Japanese Patent No. 2906245, Japanese Patent No. 2926262, etc. Can be synthesized.

(Second polymerizable compound)
The second polymerizable compound has a functional group having hydrogen bonding properties in the molecule and a polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound.
In this specification, with respect to a functional group having hydrogen bonding property, a hydrogen bond refers to a hydrogen atom covalently bonded to an atom having a higher electronegativity than a hydrogen atom in the molecule, in the same molecule or in a different molecule. A non-covalent bond created by an attractive interaction with an atom or group of atoms. The functional group having hydrogen bonding is a functional group containing a hydrogen atom capable of generating the above hydrogen bond, and specific examples include a urethane group, a urea group, or a hydroxyl group.
As the polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound, for example, when the first polymerizable compound is a bifunctional or higher (meth) acrylate monomer, it may be a (meth) acryloyl group. When the polymerizable compound is a monomer having two or more functional groups selected from the group consisting of an epoxy group and an oxetanyl group, it may be an epoxy group or an oxetanyl group.

  Examples of the (meth) acrylate monomer containing a urethane group include diisocyanates such as TDI (tolylene diisocyanate), MDI (diphenylmethane diisocyanate), HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), and HMDI (hexamethylene diisocyanate). Propylene oxide) diol, poly (tetramethylene oxide) diol, ethoxylated bisphenol A, ethoxylated bisphenol S spiroglycol, caprolactone-modified diol, polyol such as carbonate diol, and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( Such as (meth) acrylate, glycidol di (meth) acrylate, pentaerythritol triacrylate Monomers and oligomers obtained by reacting roxyacrylate, and examples thereof include polyfunctional urethane monomers described in JP-A No. 2002-265650, JP-A No. 2002-355936, JP-A No. 2002-0667238, and the like. . Specifically, an adduct of TDI and hydroxyethyl acrylate, an adduct of IPDI and hydroxyethyl acrylate, an adduct of HDI and pentaerythritol triacrylate (PETA), and an adduct of TDI and PETA remained. Examples include, but are not limited to, compounds obtained by reacting isocyanate and dodecyloxyhydroxypropyl acrylate, adducts of 6,6 nylon and TDI, and adducts of pentaerythritol, TDI and hydroxyethyl acrylate. .

  Commercially available products that can be suitably used as a (meth) acrylate monomer containing a urethane group include AH-600, AT-600, UA-306H, UA-306T, UA-306I, UA-510H, and UF- manufactured by Kyoeisha Chemical Co., Ltd. EBECRYL series such as 8001G, DAUA-167, UA-160TM manufactured by Shin-Nakamura Chemical Co., Ltd., UV-4108F, UV-4117F manufactured by Osaka Organic Chemical Co., Ltd., EBECRYL230, EBECRYL600, EBECRYL3603 manufactured by Daicel Ornex . These can be used alone or in combination of two or more.

  Examples of the (meth) acrylate monomer containing a hydroxyl group include compounds synthesized by a reaction between a compound having an epoxy group and (meth) acrylic acid. Typical ones are classified into bisphenol A type, bisphenol S type, bisphenol F type, epoxidized oil type, phenol novolak type, and alicyclic type, depending on the compound having an epoxy group. As a specific example, (meth) acrylate obtained by reacting (meth) acrylic acid with an adduct of bisphenol A and epichlorohydrin, epichlorohydrin was reacted with phenol novolak, and (meth) acrylic acid was reacted ( (Meth) acrylate, bisphenol S and epichlorohydrin adduct was reacted with (meth) acrylic acid (meth) acrylate, bisphenol S and epichlorohydrin adduct was reacted with (meth) acrylic acid ( Examples include (meth) acrylate, (meth) acrylate obtained by reacting (meth) acrylic acid with epoxidized soybean oil, and the like. Other examples of the (meth) acrylate monomer containing a hydroxyl group include, but are not limited to, a (meth) acrylate monomer having a carboxy group or a phosphate group at the terminal.

As a commercially available product that can be suitably used as the second polymerizable compound containing a hydroxyl group, epoxy ester manufactured by Kyoeisha Chemical Co., Ltd., M-600A, 40EM, 70PA, 200PA, 80MFA, 3002M, 3002A, 3000MK, 3000A, Nippon Kasei 4-hydroxybutyl acrylate manufactured by Shin-Nakamura Chemical Co., Ltd., monofunctional acrylate A-SA manufactured by Shin-Nakamura Chemical Co., Ltd., monofunctional methacrylate SA, monofunctional acrylate β-carboxyethyl acrylate manufactured by Daicel Ornex Co., Ltd., JPA manufactured by Johoku Chemical Industry Co., Ltd. -514 etc. are mentioned. These can be used alone or in combination of two or more.
The mass ratio of the first polymerizable compound and the second polymerizable compound in the quantum dot-containing polymerizable composition may be 10:90 to 99: 1, and may be 10:90 to 90:10. preferable. It is also preferable that the content of the first polymerizable compound is larger than the content of the second polymerizable compound. Specifically, (content of the first polymerizable compound) / (of the second polymerizable compound) The content is preferably 2 to 10.

(Monofunctional (meth) acrylate monomer)
The quantum dot-containing polymerizable composition preferably further contains a monofunctional (meth) acrylate monomer. Monofunctional (meth) acrylate monomers include acrylic acid and methacrylic acid, derivatives thereof, and more specifically, monomers having one polymerizable unsaturated bond ((meth) acryloyl group) of (meth) acrylic acid in the molecule Can be mentioned. Specific examples thereof include the following compounds, but the present invention is not limited thereto.
Methyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl ( Alkyl (meth) acrylates having an alkyl group such as meth) acrylate having 1 to 30 carbon atoms; aralkyl (meth) acrylates having an aralkyl group such as benzyl (meth) acrylate having 7 to 20 carbon atoms; butoxyethyl (meta) ) An alkoxyalkyl (meth) acrylate having 2-30 carbon atoms of an alkoxyalkyl group such as acrylate; the total carbon number of a (monoalkyl or dialkyl) aminoalkyl group such as N, N-dimethylaminoethyl (meth) acrylate; 1-2 An aminoalkyl (meth) acrylate which is: (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, Octaethylene glycol monomethyl ether (meth) acrylate, nonaethylene glycol monomethyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate, heptapropylene glycol monomethyl ether (meth) acrylate, tetraethylene glycol monoethyl Alkylene chain such as ether (meth) acrylate has 1-10 carbon atoms and terminal alkyl (Meth) acrylate of polyalkylene glycol alkyl ether having 1 to 10 carbon atoms of ether; alkylene chain such as (meth) acrylate of hexaethylene glycol phenyl ether having 1 to 30 carbon atoms and terminal aryl ether having 6 carbon atoms (Meth) acrylate of -20 polyalkylene glycol aryl ethers; alicyclic structures such as cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, and methylene oxide-added cyclodecatriene (meth) acrylate (Meth) acrylate having 4 to 30 carbon atoms in total; fluorinated alkyl (meth) acrylate having 4 to 30 carbon atoms in total such as heptadecafluorodecyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, mono (meth) acrylate of triethylene glycol, tetraethylene glycol mono (meth) acrylate, hexaethylene glycol mono (meth) acrylate, octapropylene glycol mono (Meth) acrylate, (meth) acrylate having a hydroxyl group such as glycerol mono- or di (meth) acrylate; (meth) acrylate having a glycidyl group such as glycidyl (meth) acrylate; tetraethylene glycol mono (meth) acrylate, hexa Polyethylene glycol mono (methyl) having 1 to 30 carbon atoms in the alkylene chain such as ethylene glycol mono (meth) acrylate and octapropylene glycol mono (meth) acrylate. ) Acrylate; (meth) acrylamide, N, N- dimethyl (meth) acrylamide, N- isopropyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, acryloyl morpholine (meth) acrylamide and the like.
The monofunctional (meth) acrylate monomer is preferably contained in an amount of 1 to 300 parts by mass, and 50 to 150 parts by mass with respect to a total mass of 100 parts by mass of the first polymerizable compound and the second polymerizable compound. More preferably it is included.

The quantum dot-containing polymerizable composition preferably contains a compound having a long-chain alkyl group having 4 to 30 carbon atoms. Specifically, at least one of the first polymerizable compound, the second polymerizable compound, and the monofunctional (meth) acrylate monomer preferably has a long-chain alkyl group having 4 to 30 carbon atoms. The long chain alkyl group is more preferably a long chain alkyl group having 12 to 22 carbon atoms. This is because the dispersibility of the quantum dots is improved. As the dispersibility of the quantum dots improves, the amount of light that goes straight from the light conversion layer to the exit surface increases, which is effective in improving front luminance and front contrast.
Specific examples of the monofunctional (meth) acrylate monomer having a long-chain alkyl group having 4 to 30 carbon atoms include butyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, and oleyl (meth) acrylate. , Stearyl (meth) acrylate, behenyl (meth) acrylate, butyl (meth) acrylamide, octyl (meth) acrylamide, lauryl (meth) acrylamide, oleyl (meth) acrylamide, stearyl (meth) acrylamide, behenyl (meth) acrylamide, etc. preferable. Of these, lauryl (meth) acrylate, oleyl (meth) acrylate, and stearyl (meth) acrylate are particularly preferable.

(Other monomers)
The quantum dot-containing polymerizable composition includes trifluoroethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, (perfluorobutyl) ethyl (meth) acrylate, perfluorobutyl-hydroxypropyl (meth) acrylate, (perfluoro Hexyl) ethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate and other compounds having a fluorine atom may be included. By including these compounds, the coating property can be improved.
The total amount of the polymerizable compound (monomer) in the quantum dot-containing polymerizable composition is preferably 90 to 99.9 parts by mass with respect to 100 parts by mass of the total amount of the quantum dot-containing polymerizable composition, It is more preferable that it is 92-99 mass parts.

  As described above, the monomer in the present invention and the present specification means a polymerizable compound, and includes a multimer. And as a preferable aspect of another monomer, a multimer can also be mentioned. The weight average molecular weight of such a multimer is preferably 1000 or more, more preferably 2000 or more, and preferably 3000 or more from the viewpoint of suppressing polymerization shrinkage when forming the wavelength conversion layer. Is more preferable. The weight average molecular weight is preferably 1,000,000 or less from the viewpoints of solubility with the first polymerizable compound and the second polymerizable compound and applicability (viscosity) of the polymerizable composition.

  Further, when the second polymerizable compound is a multimer, it is also preferable that the repeating unit contains one or more of polar groups such as hydroxyl group and nitrile group, chlorine atom and fluorine atom. It is considered that hydroxyl groups, nitrile groups, and the like can contribute to reducing the oxygen permeability of the wavelength conversion layer by cross-linking interaction. In addition, since the chlorine atom and the fluorine atom are atoms having a large atomic radius among various atoms constituting the organic compound, the movement of the polymer is caused by filling the gap in the structure of the polymer in which the polymerizable compound is polymerized. It is thought that it can be suppressed. It is assumed that this can reduce the oxygen permeability of the wavelength conversion layer.

(resin)
The quantum dot containing polymeric composition may contain 1 or more types of resin as needed. The weight average molecular weight of the resin is preferably 1000 or more, more preferably 2000 or more, and still more preferably 3000 or more, from the viewpoint of suppressing polymerization shrinkage when forming the wavelength conversion layer. The weight average molecular weight is preferably 1,000,000 or less from the viewpoints of solubility with the first polymerizable compound and the second polymerizable compound and applicability (viscosity) of the polymerizable composition. Suitable resins include polyester resin, (meth) acrylic resin, methacrylic acid-maleic acid copolymer, polystyrene resin, fluororesin resin, polyimide resin, polyetherimide resin, urethane resin, polyetheretherketone resin, polycarbonate resin. , Polyacrylonitrile resin, polyvinyl chloride resin, polyarylate resin, polyethersulfone resin, polysulfone resin, triacetyl cellulose (TAC) resin, ABS (Acrylonitrile, butadiene (Butadiene), styrene (Styrene)) resin, nylon 6, nylon 66, polyvinylidene chloride resin, polyvinylidene fluoride resin, ethylene-vinyl alcohol (EVOH) copolymer resin, polyvinyl butyrate resin, and polyvinyl alcohol resin. Further, the resin may be a modified resin in which some of the repeating units of the resin are different. Among these, (meth) acrylic resin, polyvinyl butyrate resin, polyvinyl alcohol resin, polyvinylidene chloride resin, and ethylene-vinyl alcohol copolymer resin are preferable from the viewpoint of reducing the oxygen permeability of the wavelength conversion layer.

  Commercially available products include Kuraray Mobital, Kuraray Poval, Nippon Synthetic Chemical Soarnol, Gohsenol, Mitsubishi Rayon Acrypet, Dianar, Toa Gosei Chemical ARUFON UP Series, UC Series, UF Series Is mentioned.

  In addition, for the same reason as described above for the multimer that can be used as the other monomer, the resin is a hydroxyl group, a polar group such as a nitrile group, a chlorine atom and a fluorine atom in the repeating unit, It is also preferable that 2 or more types are included.

(Organic metal coupling agent)
The quantum dot-containing polymerizable composition may contain an organometallic coupling agent as an adhesion improver. The organometallic coupling agent is effective because it also has the effect of promoting the thermosetting reaction. As the organometallic coupling agent, for example, various coupling agents such as a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, and a tin coupling agent can be used. These organometallic coupling agents have a great effect of improving adhesion, particularly when a metal, metal oxide, metal nitride itself, or a substrate containing these materials in a resin is used.

  Examples of the silane coupling agent that can be added to the quantum dot-containing polymerizable composition include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidyl Sidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxy Propyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N 2- (Aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propyl Amine and its partial hydrolyzate, 3-trimethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine and its partial hydrolyzate, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyl Methyldimethoxysilane, 3-mercaptopropyltrimethoxy Silane, 3-isocyanate propyl triethoxysilane and the like. Of these, vinyl, epoxy, (meth) acryloyloxy, amino, and isocyanate-modified silane coupling agents are preferable, and (meth) acryloyloxy-modified silane coupling agents are particularly preferable. These silane coupling agents can be used alone or in combination of two or more.

  Examples of commercially available silane coupling agents that can be suitably used include those manufactured by Shin-Etsu Chemical Co., Ltd. Examples include KBM-502, KBM-503, KBM-5103, KBE-502, KBE-503, KBM-903, KBM-9103, and the like manufactured by Shin-Etsu Chemical Co., Ltd.

  Moreover, as a silane coupling agent, the silane coupling agent represented by General formula (1) as described in Unexamined-Japanese-Patent No. 2013-43382 can be mentioned. For details, the description of Unexamined-Japanese-Patent No. 2013-43382 Paragraphs 0011-0016 can be referred.

  Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) Titanate, tetra (2,2-diallyloxymethyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl Titanate, isopropyl isostearoyl diacryl titanate, isop Pirutori (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N- aminoethyl-aminoethyl) titanate, dicumyl phenyloxy acetate titanate, diisostearoyl ethylene titanate.

  Examples of the zirconium coupling agent include tetra-n-propoxyzirconium, tetra-butoxyzirconium, zirconium tetraacetylacetonate, zirconium dibutoxybis (acetylacetonate), zirconium tributoxyethyl acetoacetate, zirconium butoxyacetylacetonate bis. (Ethyl acetoacetate) and the like.

  Examples of the aluminum coupling agent include aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec-butyrate, aluminum ethylate, ethylacetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate), alkylacetate Acetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethyl acetoacetate), aluminum tris (acetylacetoacetate) and the like can be mentioned.

  As the titanium coupling agent, zirconium coupling agent, and zirconium coupling agent described above, commercially available products or those synthesized by a known method can be used without any limitation. The same applies to tin coupling agents.

  From the viewpoint of further improving the adhesion to the inorganic layer, the organometallic coupling agent can be used to calculate the mass of the quantum dots and the solvent from the total mass of the quantum dot-containing polymerizable composition in the quantum dot-containing polymerizable composition. It is preferably included in the range of 1 to 30% by mass, more preferably 3 to 30% by mass, and further preferably 5 to 25% by mass with respect to the excluded mass.

((Meth) acrylate monomer containing boronic acid group)
Examples of the (meth) acrylate monomer containing a boronic acid group include a (meth) acrylate monomer having a boronic acid group represented by the following formula (1).

In formula (1), R ¹ and R ² each independently represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group.
Examples of the aliphatic hydrocarbon group include a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms (for example, a methyl group, an ethyl group, an iso-propyl group, etc.), and a 3 to 20 carbon atom. Examples thereof include a substituted or unsubstituted cyclic alkyl group (for example, cyclohexyl group) and an alkenyl group having 2 to 20 carbon atoms (for example, vinyl group).
Examples of the aryl group include substituted or unsubstituted phenyl groups having 6 to 20 carbon atoms (for example, phenyl group and tolyl group), substituted or unsubstituted naphthyl groups having 10 to 20 carbon atoms, and the like.
The heterocyclic group is, for example, a substituted or unsubstituted 5-membered or 6-membered ring group containing at least one heteroatom (for example, a nitrogen atom, an oxygen atom, a sulfur atom, etc.), such as a pyridyl group, Examples include imidazolyl group, furyl group, piperidyl group, morpholino group and the like. R ¹ and R ² may be linked to each other to form a ring. For example, the isopropyl groups of R ¹ and R ² are linked to form 4,4,5,5-tetramethyl-1,3,2- A dioxaborolane ring may be formed.
In formula (1), R ¹ and R ² are preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, and R ¹ and R ² connected to form a ring, Preferably, it is a hydrogen atom.
In formula (1), Z represents a (meth) acryloyl group.
The number of boronic acid groups represented by formula (1) is not particularly limited, and may be one or plural (two or more).
From the viewpoint of further improving the adhesion with the inorganic layer, the (meth) acrylate monomer containing a boronic acid group is incorporated into the quantum dot-containing polymerizable composition from the total mass of the quantum dot-containing polymerizable composition. It is preferably included in the range of 1 to 30% by mass, more preferably 3 to 30% by mass, and further preferably 5 to 25% by mass with respect to the mass excluding the mass of the solvent.

(Rubber particles)
The quantum dot-containing polymerizable composition may contain rubber particles. By including the rubber particles, the wavelength conversion layer can be prevented from becoming brittle. Examples of the rubber particles include a rubbery polymer having acrylate as a main constituent monomer, a rubbery polymer having butadiene as a main constituent monomer, and an ethylene-vinyl acetate copolymer. A rubber particle may be used individually by 1 type, and 2 or more types may be mixed and used for it. Regarding the rubber particles, reference can be made to the descriptions in 0061 to 0069 of JP-A-2014-35393.

(Polymerization initiator)
The quantum dot-containing polymerizable composition may contain a known radical photopolymerization initiator or cationic polymerization initiator as a polymerization initiator. About a polymerization initiator, JP, 2013-043382, A paragraph 0037 and JP, 2011-159924, A paragraphs 0040-0042 can be referred to, for example. The polymerization initiator is preferably 0.1 mol% or more, more preferably 0.5 to 5 mol% of the total amount of the polymerizable compounds contained in the polymerizable composition. Moreover, when a polymerization initiator contains a volatile solvent, except it, it is preferable to contain 0.1-10 mass parts per 100 mass parts of the whole quantity of a polymeric compound, More preferably, 0.2-8. It is preferable to contain 0.2 parts by mass, more preferably 0.2-5 parts by mass.

(solvent)
The quantum dot containing polymeric composition may contain the solvent as needed. In this case, the type and amount of the solvent used are not particularly limited. For example, one or a mixture of two or more organic solvents can be used as the solvent.

(Viscosity modifier)
The quantum dot-containing polymerizable composition may contain a viscosity modifier as necessary. The viscosity modifier is preferably a filler having a particle size of 5 nm to 300 nm. The viscosity modifier is also preferably a thixotropic agent. In the present specification, thixotropic property refers to the property of reducing the viscosity with respect to an increase in shear rate in a liquid composition, and the thixotropic agent refers to a thixotropy in a composition by including it in the liquid composition. It refers to a material having a function of imparting sex. Specific examples of thixotropic agents include fumed silica, alumina, silicon nitride, titanium dioxide, calcium carbonate, zinc oxide, talc, mica, feldspar, kaolinite (kaolin clay), pyrophyllite (waxite clay), and sericite. (Sericite), bentonite, smectite vermiculites (montmorillonite, beidellite, nontronite, saponite, etc.), organic bentonite, organic smectite and the like.
In one aspect, the quantum dot-containing polymerizable composition has a viscosity of 3 to 100 mPa · s when the shear rate is 500 s ⁻¹ , and preferably 300 mPa · s or more when the shear rate is 1 s ⁻¹ . In order to adjust the viscosity in this way, it is preferable to use a thixotropic agent. The reason why the viscosity of the quantum dot-containing polymerizable composition is preferably 3 to 100 mPa · s when the shear rate is 500 s ⁻¹ and preferably 300 mPa · s or more when the shear rate is 1 s ⁻¹ is as follows. is there.
As an example of the manufacturing method of a wavelength conversion member, after apply | coating a quantum dot containing polymeric composition to a 1st base material so that it may mention later, it is a 2nd base material on a quantum dot containing polymeric composition. And a manufacturing method including a step of forming a wavelength conversion layer by curing the quantum dot-containing polymerizable composition. In the above production method, it is desirable to uniformly coat the first substrate so that coating stripes do not occur when the quantum dot polymerizable compound is applied, so that the coating thickness is uniform. The viscosity of the coating liquid (quantum dot-containing polymerizable composition) is preferably low from the viewpoints of properties and leveling properties. On the other hand, in order to uniformly bond the second substrate onto the coating solution applied to the first substrate, it is preferable that the resistance to pressure at the time of bonding is high. A coating solution is preferred. The shear rate 500 s ⁻¹ is a representative value of the shear rate applied to the coating liquid applied to the first substrate, and the shear rate 1 s ⁻¹ is immediately before the second substrate is bonded to the coating liquid. This is a representative value of the shear rate applied to the coating solution. The shear rate 1 s ⁻¹ is merely a representative value. When the second substrate is bonded onto the coating solution applied to the first substrate, the first substrate and the second substrate are bonded to each other while being transported at the same speed. The shear rate applied is approximately ^{0 s −1} , and the shear rate applied to the coating solution in the actual manufacturing process is not limited to 1 s ⁻¹ . Similarly, the shear rate of 500 s ⁻¹ is merely a representative value, and the shear rate applied to the coating solution in the actual manufacturing process is not limited to 500 s ⁻¹ . From the viewpoint of uniform application and bonding, the viscosity of the quantum dot-containing polymerizable composition is 3 when the representative value of the shear rate applied to the coating liquid is 500 s ⁻¹ when the coating liquid is applied to the first substrate. ˜100 mPa · s, and 300 mPa · s or more when the representative value of the shear rate applied to the coating solution is 1 s ⁻¹ immediately before the second substrate is bonded onto the coating solution applied to the first substrate. It is preferable to adjust so that.

(Method for forming wavelength conversion layer)
The wavelength conversion layer can be formed by applying the quantum dot-containing polymerizable composition to the substrate surface and then curing it by light irradiation or heating.
Application methods include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, wire bar method, etc. A well-known coating method is mentioned.
Curing conditions can be appropriately set according to the type of polymerizable compound used and the composition of the polymerizable composition. Moreover, when a quantum dot containing polymeric composition is a composition containing a solvent, you may give a drying process for solvent removal before hardening.

  The quantum dot-containing polymerizable composition may be cured in a state where the quantum dot-containing polymerizable composition is sandwiched between two substrates. One aspect of the manufacturing process of the wavelength conversion member including such a curing process will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.

  FIG. 2 is a schematic configuration diagram of an example of a wavelength conversion member manufacturing apparatus, and FIG. 3 is a partial enlarged view of the manufacturing apparatus shown in FIG. The manufacturing process of the wavelength conversion member using the manufacturing apparatus shown in FIGS. 2 and 3 applies the quantum dot-containing polymerizable composition to the surface of the first substrate (hereinafter referred to as “first film”) that is continuously conveyed. The step of applying and forming a coating film, and laminating (overlapping) a second substrate (hereinafter also referred to as “second film”) continuously conveyed on the coating film, the first film A step of sandwiching the coating film between the first film and the second film, and a state where the coating film is sandwiched between the first film and the second film, and either the first film or the second film is a backup roller And irradiating with light while continuously transporting, polymerizing and curing the coating film to form a wavelength conversion layer (cured layer). By using a barrier film having a barrier property against oxygen or moisture as either the first film or the second film, a wavelength conversion member having one surface protected by the barrier film can be obtained. Moreover, the wavelength conversion member by which the both surfaces of the wavelength conversion layer were protected by the barrier film can be obtained by using a barrier film as a 1st film and a 2nd film, respectively.

  More specifically, first, the first film 10 is continuously conveyed to the coating unit 20 from a delivery machine (not shown). For example, the 1st film 10 is sent out from the sending machine with the conveyance speed of 1-50 m / min. However, it is not limited to this conveyance speed. When delivered, for example, a tension of 20 to 150 N / m, preferably a tension of 30 to 100 N / m, is applied to the first film 10.

  In the application unit 20, a quantum dot-containing polymerizable composition (hereinafter also referred to as “application liquid”) is applied to the surface of the first film 10 that is continuously conveyed, and a coating film 22 (see FIG. 3) is formed. Is done. In the coating unit 20, for example, a die coater 24 and a backup roller 26 disposed to face the die coater 24 are installed. 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 the coating liquid is applied from the discharge port of the die coater 24 onto the surface of the first film 10 that is continuously conveyed. As a result, the coating film 22 is formed. Here, the coating film 22 refers to a quantum dot-containing polymerizable composition before being applied on the first film 10.

  In the present embodiment, the die coater 24 to which the extrusion coating method is applied is shown as the coating apparatus, but the present invention is not limited to this. 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 are applied can be used.

  The first film 10 that has passed through the coating unit 20 and has the coating film 22 formed thereon is continuously conveyed to the laminating unit 30. In the laminating unit 30, the second film 50 that is 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 addition, when a quantum dot containing polymeric composition contains a solvent, you may provide the drying zone which is not illustrated in the arbitrary positions before the laminate part 30 for solvent removal. The drying treatment in the drying zone can be performed by a known method such as passing through a heated atmosphere or blowing dry air.

  The laminating unit 30 is provided with a laminating roller 32 and a heating chamber 34 surrounding the laminating roller 32. The heating chamber 34 is provided with an opening 36 for allowing the first film 10 to pass therethrough and an opening 38 for allowing the second film 50 to pass therethrough.

  A backup roller 62 is disposed at a position facing the laminating roller 32. The first film 10 on which the coating film 22 is formed is wound around the backup roller 62 on the surface opposite to the surface on which the coating film 22 is formed, and is continuously conveyed to the laminating position P. The laminating position P means a position where the contact between the second film 50 and the coating film 22 starts. The first film 10 is preferably wound around the backup roller 62 before reaching the laminating position P. This is because even if wrinkles occur in the first film 10, the wrinkles are corrected and removed by the backup roller 62 before reaching the laminate 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 lamination position P are preferably long, for example, 30 mm or more is preferable, and the upper limit is usually It is determined by the diameter of the backup roller 62 and the pass line.

  In the present embodiment, the second film 50 is laminated by the backup roller 62 and the laminating roller 32 used in the curing unit 60. That is, the backup roller 62 used in the curing unit 60 is also used as a roller used in the laminating unit 30. However, the present invention is not limited to the above form, and a laminating roller may be installed in the laminating unit 30 in addition to the backup roller 62 so that the backup roller 62 is not used.

  By using the backup roller 62 used in the curing unit 60 in the laminating unit 30, the number of rollers can be reduced. The backup roller 62 can also be used as a heat roller for the first film 10.

  The second film 50 sent from a sending machine (not shown) is wound around the laminating roller 32 and continuously conveyed between the laminating 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 laminating position P. Accordingly, the coating film 22 is sandwiched between the first film 10 and the second film 50. Lamination refers to laminating the second film 50 on the coating film 22.

  The distance L2 between the laminating roller 32 and the backup roller 62 is the total thickness of the first film 10, the wavelength conversion layer (cured layer) 28 obtained by polymerizing and curing the coating film 22, and the second film 50. It is preferable that it is more than a value. Moreover, it is preferable that L2 is below the length which added 5 mm to the total thickness of the 1st film 10, the coating film 22, and the 2nd film 50. FIG. By setting the distance L2 to be equal to or less than the total thickness plus 5 mm, it is possible to prevent bubbles from entering between the second film 50 and the coating film 22. Here, the distance L <b> 2 between the laminating roller 32 and the backup roller 62 refers to the shortest distance between the outer peripheral surface of the laminating roller 32 and the outer peripheral surface of the backup roller 62.

  The rotational accuracy of the laminating roller 32 and the backup roller 62 is 0.05 mm or less, preferably 0.01 mm or less in radial runout. The smaller the radial runout, the smaller the thickness distribution of the coating film 22.

  Further, in order to suppress thermal deformation after the coating film 22 is sandwiched between the first film 10 and the second film 50, the difference between the temperature of the backup roller 62 of the curing unit 60 and the temperature of the first film 10. The difference between the temperature of the backup roller 62 and the temperature of the second film 50 is preferably 30 ° C. or less, more preferably 15 ° C. or less, and most preferably the same.

  In order to reduce the difference from the temperature of the backup roller 62, when the heating chamber 34 is provided, it is preferable to heat the first film 10 and the second film 50 in the heating chamber 34. For example, hot air is supplied to the heating chamber 34 by a hot air generator (not shown), and the first film 10 and the second film 50 can be heated.

  The first film 10 may be heated by the backup roller 62 by being wound around the temperature-controlled backup roller 62.

On the other hand, the second film 50 can be heated by the laminating roller 32 by using the laminating roller 32 as a heat roller.
However, the heating chamber 34 and the heat roller are not essential and can be provided as necessary.

  Next, the film 22 is continuously conveyed to the curing unit 60 in a state where the coating film 22 is sandwiched between the first film 10 and the second film 50. In the embodiment shown in the drawing, curing in the curing unit 60 is performed by light irradiation. However, when the polymerizable compound contained in the quantum dot-containing polymerizable composition is polymerized by heating, such as spraying warm air. Curing can be performed by heating.

A light irradiation device 64 is provided at a position facing the backup roller 62 and the backup roller 62. The first film 10 and the second film 50 sandwiching the coating film 22 are continuously conveyed between the backup roller 62 and the light irradiation device 64. What is necessary is just to determine the light irradiated by a light irradiation apparatus according to the kind of photopolymerizable compound contained in a quantum dot containing polymeric composition, and an ultraviolet-ray is mentioned as an example. Here, the ultraviolet light refers to light having a wavelength of 280 to 400 nm. As a light source that generates ultraviolet rays, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. What is necessary is just to set the light irradiation amount to the range which can advance the polymerization hardening of a coating film, for example, the ultraviolet-ray of the irradiation amount of 100-10000mJ / cm < ² > can be irradiated toward the coating film 22 as an example.

  In the curing unit 60, the first film 10 is wound around the backup roller 62 in a state where the coating film 22 is sandwiched between the first film 10 and the second film 50, and is continuously transported from the light irradiation device 64. The wavelength conversion layer (cured layer) 28 can be formed by performing light irradiation to cure the coating film 22.

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

  Wrapping around the backup roller 62 refers to 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 wrap angle. Accordingly, the first film 10 and the second film 50 move in synchronization with the rotation of the backup roller 62 while being continuously conveyed. Winding around the backup roller 62 may be at least during the irradiation of ultraviolet rays.

  The backup roller 62 includes a cylindrical body and rotation shafts disposed at both ends of the body. The main body of the backup roller 62 has a diameter of φ200 to 1000 mm, for example. There is no restriction on the diameter φ of the backup roller 62. In consideration of curl deformation of the laminated film, equipment cost, and rotational accuracy, the diameter is preferably 300 to 500 mm. The temperature of the backup roller 62 can be adjusted by attaching a temperature controller to the main body of the backup roller 62.

  The temperature of the backup roller 62 takes into consideration 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. Can be determined. For example, the backup roller 62 is preferably set to a temperature range of 10 to 95 ° C, and more preferably 15 to 85 ° C. Here, the temperature related to the roller refers to the surface temperature of the roller.

  A distance L3 between the laminate position P and the light irradiation device 64 can be set to, for example, 30 mm or more.

  The coating film 22 becomes the hardened layer 28 by light irradiation, and the wavelength conversion member 70 including the first film 10, the hardened 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 to a winder (not shown), and then the wavelength conversion member 70 is wound into a roll by the winder.

  As mentioned above, although the one aspect | mode of the manufacturing process of the wavelength conversion member was demonstrated, this invention is not limited to the said aspect. For example, a quantum dot-containing polymerizable composition is applied on a base material, and a wavelength conversion layer ( A hardened layer) may be produced. One or more other layers such as an inorganic layer may be laminated on the prepared wavelength conversion layer by a known method.

  The thickness of the wavelength conversion layer is preferably in the range of 1 to 500 μm, more preferably in the range of 10 to 250 μm, and still more preferably in the range of 30 to 150 μm. A thickness of 1 μm or more is preferable because a high wavelength conversion effect can be obtained. Further, it is preferable that the thickness is 500 μm or less because the backlight unit can be thinned when incorporated in the backlight unit.

(Base material)
The wavelength conversion member may have a base material for strength improvement, film formation ease, and the like. The substrate may be in direct contact with the wavelength conversion layer. One or two or more base materials may be included in the wavelength conversion member, and the wavelength conversion member may have a structure in which the base material, the wavelength conversion layer, and the base material are laminated in this order. Good. When the wavelength conversion member includes two or more base materials, the base materials may be the same or different. The substrate is preferably transparent to visible light. Here, being transparent to visible light means that the light transmittance in the visible light region is 80% or more, preferably 85% or more. The light transmittance used as a measure of transparency is measured by measuring the total light transmittance and the amount of scattered light using the method described in JIS-K7105, that is, using an integrating sphere light transmittance measuring device, and diffusing transmission from the total light transmittance. It can be calculated by subtracting the rate.

  The thickness of the substrate is preferably in the range of 10 μm to 500 μm, more preferably in the range of 20 to 400 μm, and particularly preferably in the range of 30 to 300 μm, from the viewpoint of gas barrier properties, impact resistance and the like.

  Moreover, a base material can also be used as either the above-mentioned 1st film and 2nd film, or both.

  The substrate can also be a barrier film. The barrier film is a film having a gas barrier function of blocking oxygen molecules. It is also preferable that the barrier film has a function of blocking water vapor.

The barrier film that can be used as the substrate may be any known barrier film, for example, a barrier film described below.
The barrier film usually only needs to include at least an inorganic layer, and may be a film including a support film and an inorganic layer. Regarding the support film, reference can be made, for example, to paragraphs 0046 to 0052 of JP-A-2007-290369 and paragraphs 0040 to 0055 of JP-A-2005-096108. The barrier film may include a barrier laminate including at least one inorganic layer and at least one organic layer on the support film. It is preferable to stack a plurality of layers in this way because the barrier property can be further improved. On the other hand, as the number of layers to be stacked increases, the light transmittance of the wavelength conversion member tends to decrease. Therefore, it is desirable to increase the number of layers within a range in which good light transmittance can be maintained. Specifically, the substrate preferably has an oxygen permeability of 1.00 cm ³ / (m ² · day · atm) or less. Moreover, it is preferable that the total light transmittance in the visible light region of description is 80% or more. Here, the oxygen permeability is a value measured using an oxygen gas permeability measuring device (OX-TRAN 2/20: trade name, manufactured by MOCON) under the conditions of a measurement temperature of 23 ° C. and a relative humidity of 90%. is there. The visible light region means a wavelength region of 380 to 780 nm, and the total light transmittance indicates an average value of light transmittance over the visible light region.
The oxygen permeability of the substrate is more preferably 0.10 cm ³ / (m ² · day · atm) or less, and still more preferably 0.01 cm ³ / (m ² · day · atm) or less. The total light transmittance in the visible light region is more preferably 90% or more. The lower the oxygen permeability, the better, and the higher the total light transmittance in the visible light region, the better.

-Inorganic layer-
The “inorganic layer” is a layer mainly composed of an inorganic material, and is preferably a layer formed only from an inorganic material. On the other hand, the organic layer is a layer mainly composed of an organic material, and preferably refers to a layer in which the organic material occupies 50% by mass or more, more preferably 80% by mass or more, and particularly 90% by mass or more. To do.
The inorganic material constituting the inorganic layer is not particularly limited, and for example, various inorganic compounds such as metals or inorganic oxides, nitrides, oxynitrides, and the like can be used. As an element constituting the inorganic material, silicon, aluminum, magnesium, titanium, tin, indium and cerium are preferable, and one or two or more of these may be included. 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. 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. Since the inorganic layer made of these materials has good adhesion to the organic layer, even when the inorganic layer has pinholes, the organic layer can effectively fill the pinholes, and the barrier property is further improved. This is because it can be further increased.
A method for forming the inorganic layer is not particularly limited, and various film forming methods that can evaporate or scatter the film forming material and deposit it on the deposition surface can be used.

  Examples of the method for forming the inorganic layer include a vacuum vapor deposition method in which an inorganic material such as an inorganic oxide, an inorganic nitride, an inorganic oxynitride, or a metal is heated and vapor-deposited; Oxidation reaction vapor deposition method for oxidizing and vapor deposition; sputtering method using inorganic material as target raw material, introducing argon gas and oxygen gas and performing sputtering; plasma generated on inorganic material with plasma gun Physical vapor deposition method (physical vapor deposition method) such as ion plating method, which is heated by a beam for vapor deposition, and plasma chemical vapor deposition method using an organosilicon compound as a raw material when depositing a silicon oxide vapor deposition film (Chemical Vapor Deposition method) and the like. The vapor deposition may be performed on the surface of the substrate film, the wavelength conversion layer, the organic layer or the like as a substrate.

  The silicon oxide film is preferably formed by using a low temperature plasma chemical vapor deposition method using an organosilicon compound as a raw material. Specific examples of the organosilicon compound include 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, and propyl. Examples thereof include silane, phenylsilane, vinyltriethoxysilane, tetramethoxysilane, phenyltriethoxysilane, methyltriethoxysilane, and octamethylcyclotetrasiloxane. Among the organosilicon compounds, tetramethoxysilane (TMOS) and hexamethyldisiloxane (HMDSO) are preferably used. This is because these are excellent in handleability and vapor deposition film characteristics.

  The thickness of the inorganic layer may be 1 nm to 500 nm, preferably 5 nm to 300 nm, and particularly preferably 10 nm to 150 nm. Providing a wavelength conversion member that can suppress reflection in the inorganic layer and achieve higher light transmittance while realizing good barrier properties when the thickness of the adjacent inorganic layer is within the above-described range. Because you can.

  In the wavelength conversion member, the layer in the barrier film adjacent to the wavelength conversion layer may be an inorganic layer or an organic layer, and is not particularly limited. In the present specification, the two layers are “adjacent” means that they are adjacent to each other through other layers or are in direct contact with each other without passing through other layers. Alternatively, “directly contacting” means directly contacting without any other layer.

-Organic layer-
JP, 2007-290369, A paragraphs 0020-0042 and JP, 2005-096108, A paragraphs 0074-0105 can be referred to as an organic layer. The organic layer preferably contains a cardo polymer. Thereby, the adhesiveness between the organic layer and the adjacent layer, particularly the adhesiveness with the inorganic layer is improved, and a further excellent gas barrier property can be realized. For details of the cardo polymer, reference can be made to paragraphs 0085 to 0095 of the above-mentioned JP-A-2005-096108. The thickness of the organic layer is preferably in the range of 0.05 μm to 10 μm, and more preferably in the range of 0.5 to 10 μm. When the organic layer is formed by a wet coating method, the thickness of the organic layer is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 1 μm to 5 μm. Moreover, when formed by the dry coating method, it is preferable that it exists in the range of 0.05 micrometer-5 micrometers, especially in the range of 0.05 micrometer-1 micrometer. This is because when the thickness of the organic layer formed by the wet coating method or the dry coating method is within the above-described range, the adhesion with the inorganic layer can be further improved.

  As for other details of the inorganic layer and the organic layer, reference can be made to the descriptions in JP-A-2007-290369, JP-A-2005-096108, and US2012 / 0113672A1.

[Scattering particles]
The wavelength conversion member can have a light scattering function in order to efficiently extract the fluorescence of the quantum dots to the outside. The light scattering function may be provided inside the wavelength conversion layer, or a layer having a light scattering function may be separately provided as the light scattering layer.
As one aspect, it is also preferable to add scattering particles inside the wavelength conversion layer.
As another aspect, it is also preferable to provide a light scattering layer on the surface of the wavelength conversion layer. Scattering in the light scattering layer may depend on scattering particles or surface irregularities.

[Backlight unit]
The wavelength conversion member can be used as a constituent member of the backlight unit. The backlight unit includes at least a wavelength conversion member and a light source.

(Emission wavelength of backlight unit)
From the viewpoint of realizing high luminance and high color reproducibility, it is preferable to use a backlight unit that has been converted to a multi-wavelength light source. For example, 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 an emission center wavelength in a wavelength band of 500 to 600 nm and a half width of It is preferable to emit green light having an emission intensity peak that is 100 nm or less and red light having an emission center wavelength in the wavelength band of 600 to 680 nm and having an emission intensity peak that is 100 nm or less. .
From the viewpoint of further improving luminance and color reproducibility, the wavelength band of the blue light emitted from the backlight unit is preferably 430 to 480 nm, and more preferably 440 to 460 nm.
From the same viewpoint, the wavelength band of the green light emitted from the backlight unit is preferably 520 to 560 nm, and more preferably 520 to 545 nm.
From the same viewpoint, the wavelength band of red light emitted from the backlight unit is preferably 600 to 680 nm, and more preferably 610 to 640 nm.

  From the same viewpoint, the half-value widths of the emission intensity of blue light, green light, and red light emitted from the backlight unit are all preferably 80 nm or less, more preferably 70 nm or less, and 60 nm or less. Is more preferably 50 nm or less, still more preferably 40 nm or less, and even more preferably 30 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 a light source together with at least the wavelength conversion member. In one embodiment, a light source that emits blue light having an emission center wavelength in a wavelength band of 430 nm to 480 nm, for example, a blue light emitting diode that emits blue light can be used. In the case of using a light source that emits blue light, the wavelength conversion layer preferably includes at least quantum dots A that are excited by excitation light and emit red light, and quantum dots B that emit green light. Thereby, white light can be embodied 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 aspect, a light source that emits ultraviolet light having an emission center wavelength in a wavelength band of 300 nm to 430 nm, for example, an ultraviolet light emitting diode can be used. In this case, it is preferable that the wavelength conversion layer includes quantum dots C that are excited by excitation light and emit blue light together with quantum dots A and B. Thereby, white light can be embodied by red light, green light, and blue light emitted from the wavelength conversion member.
In another embodiment, a laser light source can be used instead of the light emitting diode.

(Configuration of backlight unit)
The configuration of the backlight unit may be an edge light system using a light guide plate, a reflection plate, or the like as a constituent member. Although FIG. 1 shows an example of an edge light type backlight unit, the backlight unit may be a direct type. Any known light guide plate can be used without any limitation.

  The backlight unit can also include a reflecting member at the rear of the light source. There is no restriction | limiting in particular as such a reflecting member, A well-known thing can be used, and it is described in patent 3416302, patent 3363565, patent 4091978, patent 3448626, etc., The content of these gazettes is this Incorporated into the invention.

  In addition, the backlight unit preferably includes a known diffusion plate, diffusion sheet, prism sheet (for example, BEF series manufactured by Sumitomo 3M Limited), 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, and the contents of these publications are incorporated in the present invention.

[Liquid Crystal Display]
The above backlight unit can be applied to a liquid crystal display device. The liquid crystal display device may include at least the backlight unit and the liquid crystal cell.

(Configuration of liquid crystal display device)
The driving mode of the liquid crystal cell is not particularly limited, and twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically compensated bend cell (OCB) Various modes such as can be used. The liquid crystal cell is preferably VA mode, OCB mode, IPS mode, or TN mode, but is not limited thereto. As an example of the configuration of the VA mode liquid crystal display device, the configuration shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2008-262161 is given as an example. However, the specific configuration of the liquid crystal display device is not particularly limited, and a known configuration can be adopted.

  In one embodiment of the liquid crystal display device, a liquid crystal cell having a liquid crystal layer sandwiched between substrates provided with electrodes on at least one of the opposite sides is provided, and the liquid crystal cell is arranged between two polarizing plates. The liquid crystal display device includes a liquid crystal cell in which liquid crystal is sealed between upper and lower substrates, and displays an image by changing the alignment state of the liquid crystal by applying a voltage. Furthermore, it has an accompanying functional layer such as a polarizing plate protective film, an optical compensation member that performs optical compensation, and an adhesive layer as necessary. Along with (or instead of) a color filter substrate, thin layer transistor substrate, lens film, diffusion sheet, hard coat layer, antireflection layer, low reflection layer, antiglare layer, etc., forward scattering layer, primer layer, antistatic layer Further, a surface layer such as an undercoat layer may be disposed.

FIG. 4 illustrates an example of a liquid crystal display device according to one embodiment of the present invention. The liquid crystal display device 51 shown in FIG. 4 has the 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 include the polarizing plate protective film 11 on the backlight-side surface of the backlight-side polarizer 12, but it is preferably included.
The backlight side polarizing plate 14 preferably has a configuration in which the polarizer 12 is sandwiched between two polarizing plate protective films 11 and 13.
In this specification, the polarizing plate protective film on the side closer to the liquid crystal cell with respect to the polarizer is referred to as the inner side polarizing plate protective film, and the polarizing plate protective film on the side farther from the liquid crystal cell with respect to the polarizer is referred to as the outer side polarizing plate. It is called a protective film. In the example shown in FIG. 4, 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 includes a display side polarizing plate 44 on the surface of the liquid crystal cell 21 opposite to the surface on the backlight side. The display-side polarizing plate 44 has a configuration in which a 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.

  A liquid crystal cell, a polarizing plate, a polarizing plate protective film and the like constituting the liquid crystal display device are not particularly limited, and those prepared by known methods and commercially available products can be used without any limitation. It is of course possible to provide a known intermediate layer such as an adhesive layer between the layers.

  Since the liquid crystal display device described above includes a backlight unit including a wavelength conversion member that can exhibit excellent light resistance, high luminance and high color reproducibility can be realized over a long period of time.

1. Production of Barrier Film 10 A barrier laminate was formed on one side of a polyethylene terephthalate film (PET film, manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine (registered trademark) A4300, thickness 50 μm) by the following procedure.
Trimethylolpropane triacrylate (manufactured by Daicel Cytec Co., Ltd., TMPTA) and a photopolymerization initiator (Lamberti Co., Ltd., ESACURE KTO46) were prepared and weighed so that the mass ratio was 95: 5, and these were dissolved in methyl ethyl ketone. A coating solution having a solid content concentration of 15% was obtained. This coating solution was applied onto the PET film by a roll-to-roll using a die coater, and passed through a drying zone having an atmospheric temperature of 50 ° C. for 3 minutes. Thereafter, ultraviolet rays were irradiated in a nitrogen atmosphere (accumulated dose: about 600 mJ / cm ² ), cured by UV curing, and wound up. The thickness of the first organic layer formed on the support film was 1 μm.

  Next, an inorganic layer (silicon nitride layer) was formed on the surface of the organic layer by using a roll-to-roll CVD (Chemical Vapor Deposition) apparatus. 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 source gases. A high frequency power supply having a frequency of 13.56 MHz was used as the power supply. The film forming pressure was 40 Pa, and the reached thickness was 50 nm. Thus, the barrier film 10 in which the inorganic layer was laminated on the surface of the organic layer was produced.

2. Production of Barrier Film 11 A second organic layer was laminated on the surface of the inorganic layer of the barrier film 10.
Acrylic polymer (Acrit 8BR500 manufactured by Taisei Fine Chemical Co., Ltd.) and a photopolymerization initiator (Irgacure 184 manufactured by BASF Co., Ltd.) are weighed to a mass ratio of 95: 5 and dissolved in methyl ethyl ketone to obtain a solid content concentration. The coating solution was 15%. This coating solution was applied to the surface of the inorganic layer of the barrier film 10 by a roll toe roll using a die coater, passed through a drying zone at an ambient temperature of 100 ° C. for 3 minutes, and wound up. The thickness of the second organic layer formed on the support film was 1 μm. Thus, the barrier film 11 in which the inorganic layer was laminated on the surface of the first organic layer and the second organic layer was further laminated was produced.

3. Preparation of Barrier Film 12 Barrier film “A-OP BH # 20” manufactured by Mitsui Chemicals, Inc. Toro Corporation was used as barrier film 12.

(Production of Quantum Dot-Containing Polymerizable Composition Used in Example 1)
The following quantum dot-containing polymerizable composition 1 was prepared, filtered through a polypropylene filter having a pore size of 0.2 μm, dried under reduced pressure for 30 minutes, and used as a coating solution.

──────────────────────────────────────
Quantum dot-containing polymerizable composition 1 (used in Example 1)
──────────────────────────────────────
Quantum dot 1 in toluene dispersion (emission maximum: 530 nm) 10 parts by mass Quantum dot 1: INP530-10 manufactured by NN-labs
Toluene dispersion of quantum dots 2 (light emission maximum: 620 nm) 1 part by mass Quantum dots 2: INP620-10 manufactured by NN-labs
Lauryl methacrylate 40 parts by mass Bifunctional methacrylate (4G, Shin-Nakamura Chemical Co., Ltd.) 20 parts by mass Trifunctional acrylate (TMPTA, manufactured by Daicel Cytec) 20 parts by mass Urethane acrylate (UA-160TM, Shin-Nakamura Chemical Co., Ltd.) 10 parts by mass silane Coupling agent (KBE-5103 manufactured by Shin-Etsu Chemical Co., Ltd.) 10 parts by mass photopolymerization initiator (Irgacure (registered trademark) 819 manufactured by BASF) 1 part by mass ──────────────── ──────────────────────
(In the above, the quantum dot concentration of the toluene dispersion of quantum dots 1 and 2 is 1% by mass.)

(Preparation of a quantum dot-containing polymerizable composition used in other examples and comparative examples)
A quantum dot-containing polymerizable composition was prepared at a composition ratio (mass ratio) shown in Table 1, filtered through a polypropylene filter having a pore size of 0.2 μm, dried under reduced pressure for 30 minutes, and used as a coating solution.

(Preparation of wavelength conversion member of Example 1)
The first barrier film 10 is prepared, and the quantum dot-containing polymerizable composition 1 is applied on the surface of the inorganic layer with a die coater while continuously transporting at a tension of 1 m / min and 60 N / m, and having a thickness of 50 μm. A coating film was formed. Next, the first barrier film 10 on which the coating film is formed is wound around a backup roller, and the second barrier film 10 is laminated on the coating film so that the inorganic layer surface is in contact with the coating film. While continuously transporting the coating film with the barrier film 10 of No. 2, the heating zone having an atmospheric temperature of 100 ° C. was passed for 3 minutes. Thereafter, using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.), it was cured by irradiating with ultraviolet rays to form the wavelength conversion layer 1 containing quantum dots. The irradiation amount of ultraviolet rays was 2000 mJ / cm ² .

(Production of wavelength conversion members of Examples 2 to 13 and Comparative Examples 1 to 5)
The wavelength conversion member was produced like Example 1 using the barrier film of Table 1, and the quantum dot containing polymeric composition (coating liquid) of the composition shown in Table 1. At this time, when the coating solution did not contain the organometallic coupling agent, the second barrier film was laminated, and then cured by irradiation with ultraviolet rays without passing through the heating zone at 100 ° C.

(Production of wavelength conversion members of Examples 14 and 15)
Using the barrier film described in Table 1, using the quantum dot-containing polymerizable composition (coating liquid) having the composition shown in Table 1, and in the production of the wavelength conversion member, the thickness of 100 μm is applied by coating with a die coater. After forming the coating film, the solvent is removed by passing through a drying zone at an ambient temperature of 60 ° C. and 90 ° C. at a conveyance speed of 1 m / min, and then the first film (barrier film 10) having the coating film formed thereon is a backup roller A wavelength conversion member was produced in the same manner as in Example 1 except that the wire was wound around the wire.

(Evaluation of peelability)
After putting the wavelength conversion member of each produced Example and Comparative Example in a constant temperature and humidity chamber with an internal atmosphere temperature of 80 ° C. for 24 hours, humidity control was performed for 1 hour in a room at a temperature of 25 ° C. and a relative humidity of 60%, and then 4 cm Five sheets were punched by a punching machine with a × 4 cm Thomson blade.
For the punched 4 cm × 4 cm sample, the degree of peeling of each side was scored based on the following criteria, with 4 points per sample being the highest score. The results shown in Table 1 are 0.00 points: no peeling or cracking occurs.
0.25 point: The area of peeling and cracking is 25% or less of one side.
0.50 point: The area of peeling and cracking is more than 25% of one side and 50% or less.
0.75 point: The area of peeling and cracking is more than 50% and 75% or less on one side.
1.00 point: The area of peeling and cracking exceeds 75% of one side.
The scores for the five samples were totaled and evaluated as follows, and the results are shown in Table 1 below.
A: Peelability score of 0.00 point or more and less than 5.00 point B: Peelability score of 5.00 point or more and less than 10.00 point C: Peelability score of 10.00 point or more and less than 15.00 point D: Peelability score 15.00 to 20.00

(Evaluation of peeling interface)
In the peelability evaluation, when the peelability score was B or less (peeling occurred), the peeled portion was observed with an optical microscope to identify the peel interface. The peeling interface was classified into the following A or B and listed in Table 1.
A: The interface between the barrier film and the wavelength conversion layer is peeled off.
B: The inside of the wavelength conversion layer is destroyed.

(Evaluation of luminance reduction in the outer peripheral area)
The wavelength conversion member of each example and comparative example was punched out by a puncher with a 4 cm × 4 cm Thomson blade, and a commercially available blue light source (OPSM-H150X142B manufactured by OPTEX-FA) was used in a room maintained at a temperature of 25 ° C. and a relative humidity of 60%. ) Placed side by side, the wavelength conversion member was irradiated with blue light continuously for 100 hours.
Next, a commercially available tablet terminal (Kindle (registered trademark) Fire HDX 7 ″ manufactured by Amazon) is disassembled to take out the backlight unit, and the wavelength conversion member after continuously irradiating blue light on the light guide plate for 100 hours is used. The two prism sheets taken out from the Kindle Fire HDX 7 ″ were placed on top of each other so that the directions of the surface unevenness patterns were orthogonal to each other. The backlight unit was turned on, and the luminance was measured with an imaging color luminance meter (manufactured by Prometric Radiant Imaging) installed at a distance of 740 mm from the surface of the backlight unit. From the measurement results, in the outer peripheral area (the area from the edge of the four sides of the screen to the inside 1 cm), the ratio of the area where the luminance is reduced by 15% or more from the luminance measured at the center of the screen is obtained. evaluated. The results are shown in Table 1 below.
(Evaluation criteria)
AA: The area where the luminance is reduced by 15% or more is less than 10% of the outer peripheral area.
A: The region where the luminance decrease of 15% or more occurs is 10% or more and less than 25% of the outer peripheral region.
B: The region where the luminance is reduced by 15% or more is 25% or more and less than 50% of the outer peripheral region.
C: The region where the luminance decrease of 15% or more occurs is 50% or more and less than 75% of the outer peripheral region.
D: The area where the luminance decrease of 15% or more occurs is 75% or more of the outer peripheral area.

1 Backlight unit 1
DESCRIPTION OF SYMBOLS 1A Light source 1B Light-guide plate 100 Manufacturing equipment 10 1st film 20 Application | coating part 22 Coating film 24 Die coater 26 Backup roller 28 Curing layer 30 Laminating part 32 Laminating roller 34 Heating chamber 50 Second film 60 Curing part 62 Backup roller 64 Ultraviolet Irradiation device 70 Laminated film 80 Peeling roller

Claims (18)

A wavelength conversion member having a wavelength conversion layer including quantum dots that are excited by excitation light to emit fluorescence,
The wavelength conversion layer is a cured layer formed by curing a quantum dot-containing polymerizable composition containing the quantum dots, the first polymerizable compound, and the second polymerizable compound,
The first polymerizable compound is a bifunctional or higher functional (meth) acrylate monomer and one or more compounds selected from the group consisting of monomers having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups And
The second polymerizable compound is one or more selected from the group consisting of monomers having a functional group having hydrogen bonding in the molecule and a polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound. A wavelength conversion member which is a compound of The wavelength conversion member according to claim 1, wherein the quantum dot-containing polymerizable composition contains a monofunctional (meth) acrylate monomer. The wavelength conversion member according to claim 1 or 2, wherein the quantum dot-containing polymerizable composition contains a compound having a long-chain alkyl group having 4 to 30 carbon atoms. The wavelength conversion member according to any one of claims 1 to 3, comprising a base material, wherein at least one surface of the wavelength conversion layer is in contact with the base material. The first substrate, the wavelength conversion layer, and the second substrate are included in this order, the first substrate and the wavelength conversion layer are in contact, and the wavelength conversion layer and the second substrate are in contact with each other. Touching,
The first base material and the second base material are both barrier films having an oxygen permeability of 1.00 cm ³ / (m ² · day · atm) or less. Wavelength conversion member. At least one of the first substrate and the second substrate is a barrier film having an inorganic layer containing silicon oxide, silicon nitride, silicon carbide, or aluminum oxide, and at least of the wavelength conversion layer The wavelength conversion member according to claim 5, wherein one surface is in direct contact with the inorganic layer. At least one of the first base material and the second base material is a barrier film including an inorganic layer and an organic layer containing silicon oxide, silicon nitride, silicon carbide, or aluminum oxide, and the inorganic The wavelength conversion member according to claim 5, wherein the layer and the organic layer are in direct contact, and at least one side of the wavelength conversion layer is in direct contact with the organic layer. The wavelength conversion member according to any one of claims 5 to 7, wherein the quantum dot-containing polymerizable composition contains an organometallic coupling agent. The wavelength conversion member according to claim 5, wherein the quantum dot-containing polymerizable composition contains a (meth) acrylate monomer containing a boronic acid group. The quantum dot has an emission center wavelength in a wavelength band of 600 nm to 680 nm and a half width of an emission peak of 70 nm or less, an emission center wavelength in a wavelength band of 520 nm to 560 nm, and a half width of an emission peak. The quantum dot having a wavelength of 60 nm or less and at least one selected from the group consisting of a quantum dot having an emission center wavelength in a wavelength band of 430 nm to 480 nm and a half width of an emission peak of 50 nm or less. The wavelength conversion member of any one of Claims 1. A backlight unit comprising at least the wavelength conversion member according to claim 1 and a blue light emitting diode or an ultraviolet light emitting diode. The backlight unit according to claim 11, further comprising a light guide plate, wherein the wavelength conversion member is disposed on a path of light emitted from the light guide plate. The backlight unit according to claim 11, further comprising a prism sheet. A liquid crystal display device comprising at least the backlight unit according to claim 11 and a liquid crystal cell. It is a manufacturing method of the wavelength conversion member of Claim 4, Comprising: After apply | coating the said quantum dot containing polymeric composition to the surface of the said base material, the said wavelength is made by hardening the said quantum dot containing polymeric composition. A manufacturing method comprising forming a conversion layer. It is a manufacturing method of the wavelength conversion member given in any 1 paragraph of Claims 5-9, Comprising: Preparing the 1st substrate and the 2nd substrate, The quantum dot on the surface of the 1st substrate Applying the polymerizable composition to form a coating film, overlaying a second substrate on the coating film, and sandwiching the coating film between the first substrate and the second substrate; and The manufacturing method including forming the said wavelength conversion layer by hardening | curing the said coating film clamped by the 1st base material and the 2nd base material. The manufacturing method according to claim 15 or 16, comprising heating the quantum dot-containing polymerizable composition before the curing of the coating film. Comprising a quantum dot excited by excitation light to emit fluorescence, a first polymerizable compound, and a second polymerizable compound;
The first polymerizable compound is one or more selected from the group consisting of a bifunctional or higher functional (meth) acrylate monomer and a monomer having two or more functional groups selected from the group consisting of epoxy groups and oxetanyl groups. A compound,
The second polymerizable compound is one or more selected from the group consisting of monomers having a functional group having hydrogen bonding in the molecule and a polymerizable group capable of undergoing a polymerization reaction with the first polymerizable compound. A quantum dot-containing polymerizable composition which is a compound of