WO2016125482A1 - Composition having fluorescent bodies dispersed therein, fluorescent molded body obtained using said composition, wavelength conversion film, wavelength conversion member, backlight unit, and liquid crystal display device - Google Patents

Abstract

[Problem] To provide a composition that has fluorescent bodies dispersed therein, can form a thermally curable film, and can be used to manufacture a fluorescent molded body exhibiting little warpage or curing unevenness and excellent light fastness and long-term reliability. And to provide a fluorescent molded body which exhibits little warpage or curing unevenness and which has excellent light fastness and long term reliability in terms of the tone and intensity of emitted light, a wavelength conversion film, a wavelength conversion member comprising the same, a backlight unit, and a liquid crystal display device. [Solution] This composition having fluorescent bodies dispersed therein forms a fluorescent molded body and comprises at least one type of fluorescent body dispersed in a binder having a three-dimensional mesh structure. The composition comprises fluorescent bodies, and a binder precursor that forms a binder upon a thermal curing reaction. The binder precursor contains at least one thermally curable compound that forms a three-dimensional mesh structure upon a thermal curing reaction, and the combined total content of the polyfunctional primary amine and the polyfunctional secondary amine that serve as thermally curable compounds is at most 0.1 mass% relative to the total mass of the composition having fluorescent bodies dispersed therein.

Description

Phosphor dispersion composition and fluorescent molded body, wavelength conversion film, wavelength conversion member, backlight unit, and liquid crystal display device obtained by using the same

The present invention relates to a phosphor dispersion composition used for forming a fluorescent molded body such as a wavelength conversion film that emits fluorescence when irradiated with excitation light, and a fluorescent molded body and a wavelength conversion film obtained using the same. The present invention also relates to a wavelength conversion member having a wavelength conversion film, a backlight unit including the wavelength conversion member, and a liquid crystal display device.

Flat panel displays such as liquid crystal display devices (hereinafter also referred to as LCDs) 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 recent years, for the purpose of improving the color reproducibility of LCDs, a wavelength conversion film (wavelength conversion layer) containing quantum dots (also referred to as Quantum Dot, QD, or quantum dots) as a light emitting material on a wavelength conversion member of a backlight unit. Attention has been focused on a configuration provided with (Patent Document 1, Patent Document 2, etc.). The wavelength conversion member is a member that converts the wavelength of light incident from the planar light source and emits it as white light. In the wavelength conversion film containing the quantum dots as the light emitting material, two or three of different light emission characteristics are used. White light can be realized by using fluorescence in which a seed quantum dot is excited by light incident from a planar light source and emits light.

Fluorescence due to quantum dots has high brightness and a small half-value width, so that LCDs using quantum dots are excellent in color reproducibility. With the progress of the three-wavelength light source technology using such quantum dots, the color gamut is expanded from 72% to 100% of the current TV standard (FHD, NTSC (National Television System Committee)) ratio.

As described in Patent Documents 1 to 3, a wavelength conversion film (wavelength conversion film) containing quantum dots as a light emitting material is an aspect in which quantum dots are dispersed substantially uniformly in an organic matrix (polymer matrix). Is common. The polymer matrix of the wavelength conversion film is formed by applying a coating solution in which the polymer matrix is dissolved in a solvent to the substrate, then casting to remove the solvent from the coating film, and pouring the molten polymer matrix onto the substrate. After forming a film with a melt film-forming method to form a film by lowering the temperature, a binder precursor such as a monomer is applied on the substrate, and then the coating film is heated or irradiated with light without causing volatilization of the solvent or the like. It is generally performed by any one of a thermosetting film forming method and a photocuring film forming method.

The thermosetting film-forming method can uniformly cure even a thick film of several tens to several hundreds of μm. In particular, a thermosetting polymer matrix formed by crosslinking to form a three-dimensional network structure is tough. Nevertheless, there is an advantage that a good quality sheet or film can be obtained with small warpage and unevenness of curing. In Patent Document 2, a composition for forming a wavelength conversion layer in which quantum dots formed by coordination of a polyfunctional amine compound on a surface are dispersed in a binder precursor containing an epoxide by a thermosetting film forming method. To form a wavelength conversion layer.

Patent Document 2 discloses that a polyfunctional amine compound that is a ligand of a quantum dot is excessively added to the composition for forming a wavelength conversion layer, and a thermosetting reaction between the polyfunctional amine compound and an epoxide is performed. The formation of a polymer matrix having a three-dimensional network structure is described.

Patent Document 3 describes that a crosslinked polymer or a thermosetting epoxy material is used as a polymer matrix formed by a thermosetting film forming method.

US Patent Application Publication No. 2012/0113672 Special table 2013-544018 gazette Special table 2014-531762 gazette

The polymer matrix obtained by the thermosetting reaction of the polyfunctional amine compound and epoxide described in Patent Document 2 has a three-dimensional network structure of the polymer matrix formed of the polyfunctional amine compound. Polyfunctional amine compounds have the advantage of high nucleophilicity and excellent reaction activity with epoxy compounds, isocyanates, etc., and have the advantage of being easy to cure even at low temperatures. It is known that a polymer matrix in which a three-dimensional network structure of a polymer matrix is formed by an amine compound has a high possibility of yellowing over time. The wavelength conversion film is formed by dispersing phosphors in a polymer matrix, and emits white light using fluorescence emitted by excitation of the phosphors by excitation light incident on the layer. Yellowing of the polymer matrix of the film may cause changes in the intensity and color of the emitted light.

In Patent Document 3, as described above, a crosslinked polymer or a thermosetting epoxy material is exemplified as a polymer matrix. However, a suitable polymer matrix material is not a crosslinked polymer or a thermosetting epoxy material, but a linear polymer matrix. There is no description of the specific composition of the polymer matrix using the cross-linked polymer or the thermosetting epoxy material or the examples.

Further, the above yellowing due to aging can cause not only the polymer matrix as the wavelength conversion film but also the polymer molded body using the fluorescence of the phosphor to cause deterioration of its performance.

The present invention has been made in view of the above circumstances, and is a phosphor dispersion capable of producing a thermoformed film and capable of producing a fluorescent molded body having small warpage and curing unevenness and excellent in light resistance and long-term reliability. The object is to provide a composition.
The present invention also provides a fluorescent molded body, a wavelength conversion film, a wavelength conversion member provided with the same, a back surface having a small warpage and unevenness in curing, excellent light resistance, and excellent long-term reliability of emitted light intensity and color, An object of the present invention is to provide a light unit and a liquid crystal display device.

The present inventor is a phosphor dispersion composition in which a phosphor is dispersed in a binder precursor that is thermally cured without volatilization of a solvent or the like, and a thermosetting property that forms a three-dimensional network structure of the binder by a thermosetting reaction. It has been found that the above object can be achieved by suppressing the contents of polyfunctional primary amines and polyfunctional secondary amines as compounds low or by not using these amines as thermosetting compounds.

That is, the phosphor dispersion composition of the present invention is
A phosphor dispersion composition for forming a phosphor molded body comprising at least one phosphor dispersed and contained in a binder having a three-dimensional network structure,
Comprising at least one phosphor and a binder precursor that forms a binder by a thermosetting reaction;
The binder precursor includes at least one thermosetting compound that forms a three-dimensional network structure by a thermosetting reaction;
The total content of the polyfunctional primary amine and polyfunctional secondary amine as the thermosetting compound is 0.1% by mass or less based on the total mass of the phosphor dispersion composition.

Here, “the total content of the polyfunctional primary amine and the polyfunctional secondary amine as the thermosetting compound is 0.1% by mass or less with respect to the total mass of the phosphor dispersion composition” means that thermosetting It is assumed that the total content of the polyfunctional primary amine and the polyfunctional secondary amine as the active compound is 0% by mass with respect to the total mass of the phosphor dispersion composition.
Further, in the present specification, “having a three-dimensional network structure” means having at least a three-dimensional network structure constituted only by covalent bonds, but in a three-dimensional network structure constituted only by covalent bonds. In addition, a more complicated three-dimensional network structure may be formed with non-covalent bonds such as hydrogen bonds and ionic bonds. Whether or not it has a three-dimensional network structure composed only of covalent bonds is detected by not dissolving the binder in any solvent (provided that it does not involve decomposition of the chemical structure) and not causing melting. can do.

A preferred embodiment of the phosphor dispersion composition of the present invention includes an embodiment in which the thermosetting compound contains a polyvalent isocyanate and a polyol. In such a configuration, the polyvalent isocyanate is preferably a cyclic aliphatic (alicyclic) isocyanate and / or a chain aliphatic isocyanate. In such a configuration, it is more preferable that the binder precursor includes a reaction accelerator that accelerates the thermosetting reaction between the polyvalent isocyanate and the polyol.

As another preferred embodiment of the phosphor dispersion composition of the present invention, the thermosetting compound contains an epoxide and a carboxylic acid anhydride, and the binder precursor has a thermosetting reaction between the epoxide and the carboxylic acid anhydride. The aspect containing the reaction promoter which accelerates | stimulates is mentioned.

Moreover, as a preferable aspect when the thermosetting reaction of the phosphor dispersion composition of the present invention is a thermopolymerization reaction, the thermosetting compound contains an epoxide, and the binder precursor is a thermopolymerization initiator for the thermopolymerization reaction. The aspect containing is mentioned.

The fluorescent molded body of the present invention is formed by thermosetting the phosphor dispersion composition of the present invention.

The wavelength conversion film of the present invention is formed by applying the phosphor dispersion composition of the present invention on a base material to form a coating film of the phosphor dispersion composition and thermally curing the coating film. .
The wavelength conversion member of the present invention includes the wavelength conversion film of the present invention.

The backlight unit of the present invention is
A planar light source that emits primary light;
The wavelength conversion member of the present invention provided on a planar light source;
A retroreflective member disposed opposite to the planar light source across the wavelength conversion member;
A backlight unit including a wavelength conversion member and a reflector disposed opposite to a surface light source,
The wavelength conversion member emits fluorescence using at least a part of the primary light emitted from the planar light source as excitation light, and emits at least light including secondary light composed of fluorescence.

The liquid crystal display device of the present invention comprises the backlight unit of the present invention described above,
And a liquid crystal unit disposed opposite to the retroreflective member side of the backlight unit.

The phosphor-dispersed composition of the present invention is used for forming a fluorescent molded body in which a phosphor that emits fluorescence when irradiated with excitation light is dispersed in a binder, and is formed by a thermosetting reaction. The binder precursor contains at least one thermosetting compound that forms a three-dimensional network structure by a thermosetting reaction, and contains a total of polyfunctional primary amines and polyfunctional secondary amines as thermosetting compounds. The amount is 0.1% by mass or less based on the total mass of the phosphor dispersion composition. According to such a configuration, yellowing due to the reaction of the amine compound caused by long-time light irradiation can be prevented in advance, so that even a thick film of several tens μm to several hundred μm has little warping and uneven curing. It is possible to produce a fluorescent molded article having the advantages of thermosetting film formation that can be formed into a film, having excellent light resistance, and excellent long-term reliability. According to the present invention, the fluorescent molded body, the wavelength conversion film, and the wavelength conversion member provided with the same, which have small warpage and unevenness in curing, excellent light resistance, and excellent long-term reliability of emitted light intensity and color, A backlight unit and a liquid crystal display device can be provided.

It is a schematic structure sectional view of the backlight unit of one embodiment concerning the present invention. It is a schematic structure sectional view of the wavelength conversion member of one embodiment concerning the present invention. It is a schematic block diagram which shows an example of the wavelength conversion member manufacturing apparatus of one Embodiment concerning this invention. It is the elements on larger scale of the manufacturing apparatus shown in FIG. It is a schematic structure sectional view of a liquid crystal display provided with the back light unit of one embodiment concerning the present invention.

"Phosphor dispersion composition and fluorescent molded body"
The phosphor dispersion composition of the present invention comprises:
A phosphor dispersion composition for forming a phosphor molded body comprising at least one phosphor dispersed and contained in a binder having a three-dimensional network structure,
Comprising at least one phosphor and a binder precursor that forms a binder by a thermosetting reaction;
The binder precursor includes at least one thermosetting compound that forms a three-dimensional network structure by a thermosetting reaction;
The total content of the polyfunctional primary amine and polyfunctional secondary amine as the thermosetting compound is 0.1% by mass or less based on the total mass of the phosphor dispersion composition.

[Binder precursor]
As described above, in the present invention, the binder precursor includes at least one thermosetting compound that forms a three-dimensional network structure of the polymer by a thermosetting reaction, and includes a polyfunctional primary amine as the thermosetting compound and The total content of the polyfunctional secondary amine is 0.1% by mass or less based on the total mass of the phosphor dispersion composition.
The thermosetting compound is not particularly limited as long as the total content of the polyfunctional primary amine and the polyfunctional secondary amine is within the above range, but an embodiment including a combination of a polyvalent isocyanate and a polyol, epoxide and carvone An embodiment including a combination with an acid anhydride and an embodiment in which the thermosetting reaction is a thermal polymerization reaction, the thermosetting compound includes an epoxide, and the binder precursor includes a thermal polymerization initiator of the thermal polymerization reaction are included. .

<Combination of polyvalent isocyanate and polyol>
When a binder precursor containing a combination of a polyvalent isocyanate and a polyol as a thermosetting compound is used, a urethane bond is formed by a reaction between an isocyanate group and a hydroxyl group of the polyol, and a urethane polymer is generated as a binder. At this time, if there are more polyfunctional primary amines and polyfunctional secondary amines than 0.1% by mass with respect to the total mass of the phosphor dispersion composition, the amine generation reaction by the de-CO reaction of the isocyanate group is promoted. Competing with the urethane bond forming reaction, the amine group concentration in the wavelength conversion film increases beyond the original addition amount of the polyfunctional primary amine and polyfunctional secondary amine. Therefore, when using a binder precursor containing a combination of a polyvalent isocyanate and a polyol as a thermosetting compound, the total content of the polyfunctional primary amine and polyfunctional secondary amine as the thermosetting compound is the phosphor dispersion. It is 0.1 mass% or less with respect to the composition total mass.

Examples of the polyvalent isocyanate (bifunctional or higher functional isocyanate) suitable for the phosphor dispersion composition of the present invention include phenylene-1,3-diisocyanate, phenylene-1,4-diisocyanate, and 1-methoxyphenylene-2,4-diisocyanate. 1-methylphenylene-2,4-diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, biphenylene-4,4- Diisocyanate, 3,3-dimethoxybiphenylene-4,4-diisocyanate, 3,3-dimethylbiphenylene-4,4-diisocyanate, diphenylmethane-2,4-diisocyanate, diphenylmethane-4,4-diisocyanate, 3,3-dimethoxy Phenylmethane-4,4-diisocyanate, 3,3-dimethyldiphenylmethane-4,4-diisocyanate, naphthylene-1,5-diisocyanate, cyclobutylene-1,3-diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohex Silene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, 1-methylcyclohexylene-2,4-diisocyanate, 1-methylcyclohexylene-2,6-diisocyanate, 1-isocyanate-3,3,5 -Trimethyl-5-isocyanate methylcyclohexane, cyclohexane-1,3-bis (methylisocyanate), cyclohexane-1,4-bis (methylisocyanate), isophorone diisocyanate, dicyclohexylmethane 2,4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, ethylene diisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, dodecamethylene-1,12-diisocyanate, or organic diisocyanates thereof And a bifunctional isocyanate prepolymer obtained by the reaction of a bifunctional active hydrogen-containing compound.

Optionally, together with the diisocyanate, for example, phenyl-1,3,5-triisocyanate, diphenylmethane-2,4,4-triisocyanate, diphenylmethane-2,5,4-triisocyanate, triphenylmethane-2,4, 4 "-triisocyanate, triphenylmethane-4,4,4" -triisocyanate, diphenylmethane-2,4,2,4-tetraisocyanate, diphenylmethane-2,5,2,5-tetraisocyanate, cyclohexane-1, 3,5-triisocyanate, cyclohexane-1,3,5-tris (methyl isocyanate), 3,5-dimethylcyclohexane-1,3,5-tris (methyl isocyanate), 1,3,5-trimethylcyclohexane-1 , 3,5-Tris (methyli Cyanate), dicyclohexylmethane-2,4,2-triisocyanate, dicyclohexylmethane-2,4,4-triisocyanate and other trifunctional organic polyisocyanates, and these trifunctional and higher organic polyisocyanates You may use together the terminal isocyanate prepolymer etc. which are obtained by reaction with a chemical excess amount and the polyfunctional active hydrogen containing compound more than bifunctional. The polyvalent isocyanate mentioned above may be used individually by 1 type, and may mix and use 2 or more types. In addition, from the viewpoint of adjusting the viscosity of the binder precursor and adjusting the physical properties of the resulting urethane polymer, an appropriate monofunctional isocyanate such as alkyl monoisocyanate, cycloalkyl monoisocyanate, aromatic monoisocyanate and derivatives thereof are added. May be.

From the viewpoint of preventing yellowing under light irradiation for a long period of time, cycloaliphatic (alicyclic) isocyanates and chain aliphatic isocyanates are preferable, and those in which the isocyanate group is bonded to primary carbon are particularly preferable. preferable. Moreover, from the viewpoint of imparting coating suitability to the composition, the polyvalent isocyanate or a mixture thereof is preferably liquid in the range of about 20 ° C to 60 ° C.

Examples of the polyol (compound having a bifunctional or higher functional alcoholic hydroxyl group) suitable for the phosphor dispersion composition of the present invention include aliphatic polyols and alicyclic rings from the viewpoint of preventing yellowing under long-term light irradiation. Group polyols are more preferred. Such polyols include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,4-butanediol, polytetramethylene glycol, glycerin, trimethylolpropane, and pentaerythritol.
Di-, tri-, or tetra-alcohol compounds such as glycerin, trimethylolpropane, pentaerythritol modified with polyethylene glycol, polypropylene glycol modified, polytetramethylene glycol modified,
Known as various polyester polyols derived by esterification reaction with dicarboxylic acid,
Examples also include linear alkylene terminal diols such as hexanediol, heptanediol, octanediol, decanediol, and dodecanediol.

The above polyols may be used alone or in combination of two or more. Further, from the viewpoint of imparting coating suitability to the composition, the liquid is preferably in the range of about 20 ° C to 60 ° C. In addition, from the viewpoint of adjusting the viscosity of the binder precursor and adjusting the physical properties of the obtained urethane polymer, monoalcohols such as alkyl monoalcohols, cycloalkyl monoalcohols, monofunctional phenols, and derivatives thereof are appropriately added. May be.

The binder precursor containing the combination of the polyvalent isocyanate and polyol described above as a thermosetting compound has a 1: 1 ratio of isocyanate groups and hydroxyl groups, so the mixing ratio is equivalent ratio of each functional group. When the ratio is 1: 1, the reaction is considered to be completed without excess or deficiency, but the equivalent ratio may be adjusted in order to appropriately adjust various physical properties of the obtained urethane polymer. Preferably, the equivalent ratio of the isocyanate equivalent of the polyvalent isocyanate and the hydroxyl equivalent of the polyol is preferably in the range of 1: 0.8 to 1: 1.2, and preferably 1: 0.9 to 1: 1. A range of 1 is more preferable.

A function of capturing the moisture by reacting with the moisture that has entered the molded body by the isocyanate group contained in the molded body by making the phosphor dispersion composition having an excess of isocyanate groups (getter function) It is possible to form a fluorescent molded body having In addition, by forming a phosphor dispersion composition having an excess of hydroxyl groups, it is possible to increase the cohesive force of the polymer matrix (binder) of the formed molded body to form a fluorescent molded body having a high barrier property. .

Further, in an embodiment in which a combination of a polyvalent isocyanate and a polyol is included as a thermosetting compound, it is more preferable that the binder precursor includes a reaction accelerator that promotes a thermosetting reaction between the polyvalent isocyanate and the polyol. By adding a reaction accelerator, the reaction between the isocyanate and the hydroxyl group is accelerated, and a good urethane polymer can be produced even at a low temperature. Preferred reaction accelerators include tetraalkylammonium salts, cyclic amidines such as diazabicycloundecene (DBU) and diazabicyclononene (DBN) and their salts, 1,4-diazabicyclo [2.2.2]. Cyclic amines such as octane (DABCO), pyridines, nitrogen-containing heteroaromatic compounds and salts thereof such as imidazoles, alkyltin compounds and salts thereof, alkylzinc compounds and salts thereof, zirconium compounds, titanium compounds, alkylaluminums And boric acids are preferably used. Since the reaction accelerator acts catalytically and is not consumed in the reaction, the effect can be sufficiently exerted even in a trace amount. The specific addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, and still more preferably 1 to 3% by mass with respect to the total mass of the binder precursor.

When an ammonium salt or a cyclic amine is used as a reaction accelerator, a trace amount of primary and secondary amines may be contained as impurities. Therefore, when these compounds are used as reaction accelerators, it is preferable to use them after purification so that the amount of impurities is as small as possible. The amount of impurities contained in the reaction accelerator is quantitatively determined with respect to the total mass of the composition. It is preferable to adjust so that it may become 0.1 mass% or less, and it is more preferable to adjust to 0.05 mass% or less. If it is below this content, when reacting the binder precursor, the isocyanate and the amine of the impurity react quickly and convert to a urea bond, the primary amine and the secondary amine disappear, under long-term light irradiation. Yellowing can be prevented in advance, and the urethane polymer production process and the physical properties thereof due to the reaction between the polyvalent isocyanate and the polyol that should occur can be prevented from being significantly affected.

<Combination of epoxide and carboxylic anhydride>
In the case of using a binder precursor containing a combination of an epoxide and a carboxylic acid anhydride as a thermosetting compound, a mode in which a reaction accelerator that accelerates a thermosetting reaction between an epoxide and a carboxylic acid anhydride is simultaneously included in the binder precursor And In this combination, heating at 100 ° C. may be necessary to promote the reaction. At this time, if more than 0.1% by mass of polyfunctional primary amine and polyfunctional secondary amine are present, they are activated by heat. Since rapid coloring due to amine may be observed, the total content of the polyfunctional primary amine and polyfunctional secondary amine as the thermosetting compound is 0 with respect to the total mass of the phosphor dispersion composition. .1% by mass or less.

When a combination of an epoxide, a carboxylic acid anhydride, and a reaction accelerator is used as the binder precursor of the present invention, an epoxide and a carboxylic acid anhydride undergo an ester condensation reaction to form a polyester polymer. . When epoxide is used excessively, chain polymerization of epoxides may occur in parallel, and a mixture of epoxide polymer and polyester polymer may be formed.

The epoxide in the present invention refers to general cyclic ether compounds (epoxy compounds, oxirane compounds, etc.) capable of ring-opening polymerization reaction of epoxy groups. These can be obtained by synthesis using epichlorohydrin as a starting material, or can be obtained by oxidizing the carbon-carbon double bond of an unsaturated hydrocarbon. Specific examples include compounds containing a glycidyl group or a cyclohexene oxide group. For example, bisphenol A type epoxy resin derived from bisphenol A and epichlorohydrin, bisphenol F type epoxy resin derived from bisphenol F and epichlorohydrin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A A novolac type epoxy resin, a bisphenol F novolac type epoxy resin, an alicyclic epoxy resin, a diphenyl ether type epoxy resin, and a hydroquinone type epoxy resin. In order to more effectively suppress yellowing under long-term light irradiation, it is preferable that the epoxide does not contain an aromatic ring. For example, an epoxide composed of a saturated hydrocarbon-only skeleton or an epoxide containing an aromatic An epoxide obtained by hydrogenating the aromatic ring to form a cyclic alkyl is preferable.

Specific examples include glycidyl ethers such as diglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, 1,4-bis (2,3-epoxypropoxyperfluoroisopropyl) cyclohexane, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl. Ether, resorcin diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, dibromophenyl glycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1 , 2,7,8-diepoxyoctane, 1,6-dimethylol perfluorohexane diglycidyl Ethers and polyethylene oxide modified products of these compounds, polypropylene oxide modified products, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetrahydrofuran diglycidyl ether, polyethylene glycol triol triglycidyl ether, polypropylene glycol triol triglycidyl ether, etc. Is mentioned.

Glycidyl esters such as tetrahydrophthalic acid, hexahydrophthalic acid, methylated hexahydrophthalic acid, hexahydroterephthalic acid, hexahydropyromellitic acid glycidyl ester, succinic acid, alkenyl succinic acid , Glycidyl ester compounds of aliphatic dicarboxylic acids such as nadic acid, methyl nadic acid, maleated fatty acid, dodecenyl succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, eicosane dicarboxylic acid, and modified polyethylene oxides thereof , Modified polypropylene oxide and the like.

As the alkyl oxides synthesized by oxidation of unsaturated hydrocarbons, cyclohexene oxide or cyclopentene oxide-containing compounds are preferable. Specific examples include 4,4-bis (2,3-epoxypropoxyperfluoroisopropyl) diphenyl ether, 3, 4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexyloxirane, 1,2,5,6-diepoxy-4,7-methanoperhydroindene, 2- (3,4-epoxy Cyclohexyl) -3,4-epoxy-1,3-dioxane-5-spirocyclohexane, 1,2-ethylenedioxy-bis (3,4-epoxycyclohexylmethane), 4,5-epoxy-2. -Methylcyclohexylmethyl-4,5-epoxy-2-methylcyclohexanecarboxylate, ethylene glycol-bis (3,4-epoxycyclohexanecarboxylate), bis- (3,4-epoxycyclohexylmethyl) adipate, di-2, Examples thereof include 3-epoxycyclopentyl ether and the following compounds. These compounds may be used alone or in combination of two or more.

Carboxylic anhydrides include tetrahydrophthalic anhydride, methylated tetrahydrophthalic anhydride, hexahydrotrimellitic anhydride, hexahydropyromellitic anhydride, hexahydrophthalic anhydride, methylated hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, Aliphatic polycarboxylic acid anhydrides such as methylbutenyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, succinic anhydride, methylcyclohexenedicarboxylic anhydride, maleic anhydride, linolenic anhydride, linoleic anhydride, Examples thereof include aliphatic polycarboxylic acid anhydrides such as eleostearic acid anhydride, polyadipic acid anhydride, polyazeline acid anhydride, polysebacic acid anhydride, dodecane dicarboxylic acid anhydride, and eicosane dicarboxylic acid anhydride. From the viewpoint of reactivity, alicyclic polycarboxylic acid anhydrides are preferred. This is because the greater the distortion of the cyclic structure formed by the carboxylic acid anhydride, the better the reactivity, and the reaction between the carboxylic acid anhydride and the epoxide proceeds at a lower temperature and in a shorter time.

Since the reaction between epoxide and carboxylic acid anhydride has a high activation energy and requires a high temperature for the progress of the reaction, it is necessary to add a reaction accelerator to lower the activation energy. Therefore, a reaction accelerator is added in the present invention. As a result, the reaction between the epoxide and the carboxylic acid anhydride can be completed within a range of suitable treatment temperature and treatment time, and coloring and impurity generation due to thermal deterioration of the components are suppressed, and the effects of the present invention are more preferred. It can be demonstrated.

Preferred reaction accelerators include organic complex salts of various metals that can be used as a curing catalyst for epoxy compounds, metal salts, enamines, ammonium salts, diazabicycloundecene (DBU), diazabicyclononene (DBN), and the like. Cyclic amidines and salts thereof, cyclic amines such as 1,4-diazabicyclo [2.2.2] octane (DABCO), pyridines, nitrogen-containing heteroaromatic compounds of imidazoles and their salts, tertiary amino acids Phenols, borates, imidazolium salts, phosphorus compounds and the like can be used. In particular, those known as latent catalysts are preferred. Details are described in “New Epoxy Resin” (edited by Akihiro Kakiuchi, Shosendo). Since the reaction accelerator acts catalytically and is not consumed in the reaction, the effect can be sufficiently exerted even in a trace amount. The specific addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and still more preferably 1 to 5% by mass with respect to the total mass of the binder precursor.

When ammonium salts, amidines, and cyclic amines are used as reaction accelerators, trace amounts of primary and secondary amines may be included as impurities. Therefore, when these compounds are used as reaction accelerators, it is preferable to use them after purification so that the amount of impurities is as small as possible. The amount of impurities contained in the reaction accelerator is quantified and 0% of the total amount of the composition. It is preferable to adjust so that it may become 1 mass% or less, and it is more preferable to adjust to 0.05 mass% or less. If it is less than this content, when reacting the binder precursor, the epoxide and impurity amines react rapidly to convert to urea bonds, and the primary amine and secondary amine disappear, under prolonged light irradiation. Yellowing can be prevented in advance, and it is possible to prevent the binder formation process and the physical properties of the binder from forming due to the reaction between the epoxide and the carboxylic acid anhydride, which should originally occur. In addition, for the purpose of activating the reaction at the initial stage of the reaction, in the range of addition amount of 0.1% by mass or less, a polyfunctional primary amine or polyfunctional secondary amine compound is intentionally added to assist the reaction accelerator. It may be an agent.

The binder precursor containing the above-mentioned combination of epoxide and carboxylic acid anhydride as a thermosetting compound has a one-to-one quantitative ratio of the epoxide and carboxylic acid anhydride group. When the equivalent ratio of groups is 1: 1, the reaction is considered to be completed without excess or deficiency, but the equivalent ratio can be adjusted in order to appropriately adjust various physical properties of the resulting binder. Preferably, the equivalent ratio of the functional group equivalent of the epoxide and the functional group equivalent of the acid anhydride is preferably 1: 0.8 to 1: 1.1, more preferably 1: 0.9 to 1: 1.

Moreover, although the above demonstrated the case where the binder precursor containing the combination of an epoxide and a carboxylic acid anhydride was used as a thermosetting compound, it replaced with the epoxide, and the cyclic ether compound which can perform the ring-opening polymerization reaction of an oxetanyl group ( A binder precursor containing a combination of oxetane compounds) as a thermosetting compound can also be suitably used as described above.

<Combination of epoxide and thermal polymerization initiator>
In a preferred embodiment of the phosphor dispersion composition of the present invention, when the thermosetting reaction is a thermopolymerization reaction, the thermosetting compound contains an epoxide, and the binder precursor contains a thermopolymerization initiator for the thermopolymerization reaction. Is mentioned.
As the epoxide to be used, the epoxides already described are preferably used. In particular, cycloaliphatic epoxides are more preferable because they are excellent in reaction rate and excellent in oxygen barrier property and water vapor barrier property of the resulting binder.
In this combination, the polymerization reaction becomes ionic polymerization, and the inside of the film is biased to acidic or basic. In this case, the polyfunctional primary that is more than 0.1% by mass with respect to the total mass of the phosphor dispersion composition. If an amine or a polyfunctional secondary amine is present, if the thermal polymerization initiator is a cationic polymerization initiator, a large amount of initiator is required to suppress the polymerization reaction. It becomes. Further, when the thermal polymerization initiator is an anionic polymerization initiator, hydrogen atoms on the polyfunctional primary amine and polyfunctional secondary amine are likely to be pulled out, which may cause coloring to be accelerated. Therefore, the total content of the polyfunctional primary amine and polyfunctional secondary amine as the thermosetting compound is 0.1% by mass or less based on the total mass of the phosphor dispersion composition.

As thermal polymerization initiators, iodonium salts, sulfonium salts, onium salt compounds such as phosphonium salts, boron trifluoride,
Complex salts of Lewis acid compounds such as zinc halides, tin halides, aluminum halides and iron halides with tertiary amines and nitrogen-containing heteroaromatics,
Illustrative are the imidazoles, cyclic amidines, and salts thereof with organic acids described above.

Polymerization may be cationic polymerization (example of thermal polymerization initiator: onium salt compounds) or anionic polymerization (example of thermal polymerization initiator: imidazoles). When these thermal polymerization initiators contain at least a part of their components, or substances with high nucleophilicity in impurities and decomposition products, they are adsorbed on the surface of the phosphor, reducing the reaction rate of epoxides, At the same time, the luminous efficiency of the phosphor contained in the phosphor dispersion composition may be affected. Therefore, it is preferable that the thermal polymerization initiator has a low content of highly nucleophilic components, particularly primary amines and secondary amines.

Also, from the viewpoint of preventing yellowing under long-term light irradiation, it is preferable to design so that the content of primary amines and secondary amines is reduced. Specifically, primary amines and secondary amines are prepared with respect to the total mass of the prepared composition by preventing or removing impurities in advance or suppressing the addition amount of the thermal polymerization initiator to a small amount. The content is preferably 2% by mass or less, and more preferably 1% by mass or less. Furthermore, the thermal polymerization initiator preferably has a small number of aromatic rings. A thermal polymerization initiator having no aromatic ring (eg, cyclic amidines and salts thereof) is particularly preferred.

Since the thermal polymerization initiator acts catalytically and is not consumed by the reaction, the effect can be sufficiently exhibited even in a trace amount. The specific addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and still more preferably 1 to 5% by mass with respect to the total mass of the binder precursor.

Moreover, although the above demonstrated the case where the binder precursor which contains the combination of an epoxide and a thermal-polymerization initiator as a thermosetting compound was used, it replaced with the epoxide, and the cyclic ether compound in which the ring-opening polymerization reaction of an oxetanyl group ( A binder precursor containing a combination of oxetane compounds) as a thermosetting compound can also be suitably used as described above.

[Phosphor]
Various known phosphors can be used in the phosphor dispersion composition of the present invention. For example, rare earth doped garnet, silicate, aluminate, phosphate, ceramic phosphor, sulfide phosphor, nitride phosphor and other inorganic phosphors, and organic fluorescent dyes and organic fluorescent pigments Organic fluorescent materials. Further, a phosphor obtained by doping a semiconductor fine particle with a rare earth, and a semiconductor nanoparticle (quantum dot, quantum rod) are also preferably used.

Inorganic phosphors and quantum dots are preferred as the phosphors contained in the phosphor dispersion composition of the present invention in that they have good durability that can withstand long-term light irradiation. In particular, when the composition of the present invention is used for a wavelength conversion film or the like used for a light source for a display device, the intensity half-value width of the emission spectrum is preferably narrow from the viewpoint of providing a light source with excellent color reproducibility. Quantum dots are particularly preferred phosphors.

The phosphor is added in a dispersed manner to the binder precursor, and when the binder precursor is converted into the binder by reaction, the dispersed state is maintained to realize a state in which the phosphor is dispersed in the binder. To do.
When adding the phosphor to the binder precursor, the phosphor prepared as fine particles is added to either the binder precursor or its constituent materials and dispersed by an appropriate method to obtain the phosphor dispersion composition of the present invention. Alternatively, the phosphor dispersion composition of the present invention may be prepared by preparing a dispersion in which phosphor fine particles are dispersed in a solvent, adding the dispersion to the binder precursor, and then reducing or removing the solvent in the dispersion as appropriate. You may get things.

Phosphors can be used alone, but in order to obtain a desired fluorescence spectrum, a plurality of phosphors having different wavelengths may be used in combination, or a combination of phosphors having different material configurations (for example, A combination of a rare earth-doped garnet and quantum dots may be used.

The phosphor content in the phosphor dispersion composition of the present invention is adjusted so that a desired fluorescence intensity is obtained with respect to the total mass of the phosphor dispersion composition. The range of 0.01 to 30% by mass is preferable, 0.05 to 20% by mass is more preferable, and 0.1 to 10% by mass is still more preferable.

Regarding quantum dots, for example, JP 2012-169271 A paragraphs 0060 to 0066 can be referred to, but are not limited to those described here. 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 the case where the quantum dot is used as a phosphor, the inventors, in addition to the above yellowing problem, in the phosphor molded body obtained using a phosphor dispersion composition containing a conventional primary amine or secondary amine, It has been found that the emission efficiency of fluorescence may decrease from the beginning. Regarding this phenomenon, the inventors presume the following mechanism.

Quantum dots are generally used together with an electron donating ligand for the purpose of adjusting light emission characteristics and imparting dispersibility (preventing aggregation). Examples of these electron donating ligands include substituted phosphine oxides such as trioctylphosphine oxide (TOPO), substituted phosphinic acids such as octylphosphinic acid, substituted phosphonic acids such as octylphosphonic acid, primary amines, 2 It is known to use monodentate ligands such as secondary amines. However, when primary amines or secondary amines are used as the thermosetting compounds contained in the binder precursor, these must be polyfunctional amines in order to constitute three-dimensional crosslinking, and these compounds are inevitable. Therefore, the coordinating ability is higher than that of the monodentate ligand. As a result of the above-mentioned action, the present inventor has obtained a quantum dot dispersion composition containing a binder precursor containing a polyfunctional primary amine or a thermosetting compound of a polyfunctional secondary amine. It is thought that the secondary amine unintentionally caused ligand exchange with the ligand originally coordinated to the quantum dot, thereby impairing the original light emission performance of the quantum dot.

As already described, the phosphor dispersion composition of the present invention contains 0.1% by mass or less of polyfunctional primary amine or polyfunctional secondary amine as the thermosetting compound of the binder precursor with respect to the total mass. Since it is configured to include, the electron donating property is low, and the influence of ligand exchange and ligand exchange originally coordinated to the quantum dot can be suppressed to a small extent. Therefore, even when quantum dots are used as the phosphor, the influence of the ligand exchange can be suppressed to be small, and the original light emission performance of the quantum dots can be expressed. From the above, when quantum dots are used as the phosphor, the phosphor dispersion composition of the present invention is a fluorescent molded body capable of expressing the original light emission performance of the quantum dots in addition to the effect of solving the above-mentioned problems of the present invention, The wavelength conversion layer and the wavelength converter can be obtained. As a measure of coordination ability, acid dissociation constant (pKa) can be used as an index. That is, it is one preferred mode to use a binder precursor having an acid dissociation constant lower than that of the quantum dot ligand.

[Other additives]
Various functional additives can be added to the phosphor dispersion composition of the present invention as necessary. For example, improve adhesion to base materials such as viscosity modifiers (thixotropic agents), specific gravity modifiers, reactive diluents, solvents, leveling agents, antifoaming agents, etc. For obtaining a desired fluorescence emission spectrum such as an adhesion improver, a surface energy adjusting agent, an antioxidant for preventing deterioration under long-term light irradiation, a radical scavenger, a moisture getter agent, an oxygen getter agent, etc. UV absorbers, visible light absorbers, IR absorbers, etc., dispersion aids for assisting the dispersion of phosphors, micellar agents, viscosity modifiers, etc., mechanical properties when forming molded articles such as films, surface These include plasticizers for adjusting properties, brittleness improving agents, antistatic agents, antifouling agents, fillers, etc., refractive index adjusting agents for adjusting optical properties of molded articles, light scattering agents, and the like.

<Method for Preparing Phosphor Dispersion Composition>
The phosphor dispersion composition of the present invention can be obtained by mixing the aforementioned materials. However, such as an isocyanate group and a hydroxyl group, an epoxide and a carboxylic anhydride group, and a thermal polymerization initiator and an epoxide, the thermosetting compound and a reaction accelerator and a thermal polymerization initiator that contribute to the thermosetting reaction. The reaction starts little by just mixing, and the reaction heat is further accelerated by the reaction heat generated at that time, and the reaction may proceed unintentionally. Therefore, it is preferable that the time from mixing these combinations to applying heat to advance the reaction is short. Or it is preferable to suppress the progress of the unintended reaction by cooling.

A preferred embodiment of the method for preparing the phosphor dispersion composition includes a method in which the above combinations are individually prepared and mixed immediately before the film forming step (coating step). For example, in the combination of a polyvalent isocyanate and a polyol, a polyvalent isocyanate liquid and a polyol liquid are prepared and mixed immediately before use. The phosphor and other additives added by the above-described method may be mixed in advance in either one or both of a polyvalent isocyanate liquid and a polyol liquid. When a reaction accelerator is used, the reaction accelerator is active on an isocyanate group, so it is preferable to mix only on the polyol liquid side. Mixing may be carried out using a mixing tank or by stirring and mixing, or may be carried out in a liquid feed line using a static mixer.

In addition, since the moisture and oxygen may inhibit the reaction of the binder precursor preferably used in the present invention and may cause deterioration of the binder and the phosphor in the cured film, the phosphor dispersion composition It is preferable to remove from the inside. Therefore, the steps from preparation to mixing are preferably performed in an environment in which moisture and oxygen are sufficiently removed using an airtight tank. For example, such a process can be realized by using an airtight automatic liquid preparation device (trade name: Posilatio) available from Liquid Control (USA). By flowing an inert gas, for example, a dry nitrogen gas, into the system and appropriately removing dissolved oxygen and dissolved moisture, oxygen and moisture can be removed from the system.

Similarly, when using an epoxide and a carboxylic acid anhydride, prepare an epoxide solution and a carboxylic acid anhydride solution, respectively. At this time, the reaction accelerator is active with respect to the epoxide, and it is desirable to mix only on the carboxylic anhydride liquid side. In addition, when using an epoxide and a thermal polymerization initiator, if the thermal polymerization initiator is in a liquid state, a liquid diluted with a reactive diluent or the like and an epoxide liquid may be separately prepared as necessary. When the polymerization initiator is in a solid state, a sub-epoxide solution that is dissolved in a small amount of epoxide and sufficiently cooled, and a main epoxide solution may be prepared separately.

Also, it is a preferable aspect that the binder precursor after mixing is sufficiently cooled. At this time, it is necessary to set the cooling temperature with sufficient care so that the phosphor dispersed by cooling and various added functional additives do not aggregate or precipitate.

[Fluorescent molded body]
The phosphor dispersion composition of the present invention can be converted into a binder by thermosetting the binder precursor to obtain a fluorescent molded body. By forming the shape of the fluorescent molded body into sheets, films, rods, strips, dice, lenses, and other various shapes, and combining with base materials and other functional layers, various wavelength conversion members Can be used. Further, it may be formed and used so as to form a dot-like or lattice-like pattern on the substrate, or may be formed by filling the cavity.

As described above, the phosphor dispersion composition of the present invention is used for forming a fluorescent molded body in which a phosphor that emits fluorescence when irradiated with excitation light is dispersed in a binder, by a thermosetting reaction, The binder precursor formed by the thermosetting reaction contains at least one thermosetting compound that forms a three-dimensional network structure by the thermosetting reaction, and is a polyfunctional primary amine or polyfunctional as a thermosetting compound. The total content of secondary amine is 0.1% by mass or less based on the total mass of the phosphor dispersion composition. According to such a configuration, yellowing due to the reaction of the amine compound caused by long-time light irradiation can be prevented in advance, so that even a thick film of several tens μm to several hundred μm has little warping and uneven curing. It is possible to produce a fluorescent molded article having the advantages of thermosetting film formation that can be formed into a film, having excellent light resistance, and excellent long-term reliability.
Therefore, the fluorescent molded body formed by heat-curing the phosphor dispersion composition of the present invention has small warpage and curing unevenness, excellent light resistance, and long-term reliability of emitted light intensity and color. Are better.

"Wavelength conversion member and backlight unit"
A sheet-like or film-like fluorescent molded body formed by thermosetting the phosphor dispersion composition of the present invention is suitable as a wavelength conversion layer provided in a wavelength conversion member constituting a backlight of a liquid crystal display device. It is.

With reference to the drawings, a wavelength conversion member according to an embodiment of the present invention and a backlight unit including the same will be described. FIG. 1 is a schematic cross-sectional view of a backlight unit including the wavelength conversion member of the present embodiment, and FIG. 2 is a schematic cross-sectional view of the wavelength conversion member of the present embodiment. In the drawings of this specification, the scale of each part is appropriately changed and shown for easy visual recognition. 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.

As shown in FIG. 1, the backlight unit 2 includes a light source 1A that emits primary light (blue light L _B ) and a light guide plate 1B that guides and emits the primary light emitted from the light source 1A. A planar light source 1C, a wavelength conversion member 1D provided on the planar light source 1C, a retroreflective member 2B disposed opposite to the planar light source 1C across the wavelength conversion member 1D,
Across the surface light source 1C and a reflecting plate 2A disposed opposite and the wavelength converting member 1D, the wavelength conversion member 1D, at least a portion of the primary light L _B emitted from the surface light source 1C excitation light as it emits fluorescence, in which emits this fluorescence consists secondary light _{(L G,} L _R) and the primary light L _B having passed through the wavelength conversion member 1D.

As shown in FIG. 2, the wavelength conversion member 1 </ b> D includes a wavelength conversion layer 30 including quantum dots that are excited by excitation light to emit fluorescence, and substrates 11 and 21 provided on both surfaces of the wavelength conversion layer 30. The barrier layers 12 and 22 having the organic barrier layers 12a and 22a and the inorganic barrier layers 12b and 22b are formed on the base materials 11 and 21 on the surface of the base materials 11 and 21 on the wavelength conversion layer 30 side. It is formed in contact. Moreover, the base material 11 is equipped with the uneven | corrugated provision layer 13 which provides an uneven | corrugated structure in the surface on the opposite side to the surface at the wavelength conversion layer 30 side. In the present embodiment, the unevenness imparting layer (matte layer) 13 also has a function as a light diffusion layer.

In FIG. 1, L _B , L _G , and L _R emitted from the wavelength conversion member 1D are incident on the retroreflective member 2B, and each incident light is transmitted between the retroreflective member 2B and the reflector 2A. The reflection is repeated and passes through the wavelength conversion member 1D many times. As a result, in the wavelength conversion member 1D, a sufficient amount of excitation light (blue light L _B ) is absorbed by the quantum dots 30A and 30B in the wavelength conversion layer 30, and a necessary amount of fluorescence (L _G , L _R ) is emitted. The white light _LW is embodied and emitted from the retroreflective member 2B.
Hereinafter, each component of the wavelength conversion member 1D will be described.

[Wavelength conversion layer (wavelength conversion film)]
In the present embodiment, the wavelength conversion layer (wavelength conversion film) 30 is a barrier film 10 including the barrier layer 12 on the surface of the substrate 11 (or a barrier film including the barrier layer 22 on the surface of the substrate 21). 20) The phosphor dispersion composition of the present invention is applied to form a coating film of the phosphor dispersion composition, and the coating film is thermally cured, and blue light is formed in the organic matrix 30P. are excited by L _B fluorescence (red light) quantum dots (phosphor) which emits _{L R} 30A and is excited by the blue light _{L B} fluorescence (green light) quantum dots (phosphor) which emits _{L G} 30B Is distributed. In FIG. 2, the quantum dots 30A and 30B are greatly illustrated for easy visual recognition, but in actuality, for example, the diameter of the quantum dots is about 2 to 7 nm with respect to the thickness of the wavelength conversion layer 30 of 50 to 100 μm. It is.

As already described, in the wavelength conversion film used for the light source for the display device, from the viewpoint of providing a light source excellent in color reproducibility, a quantum dot having a narrow half-value width of the emission spectrum is preferable as a phosphor.

The quantum dots can contain different two or more quantum dot emission characteristics, in the present embodiment, the quantum dots 30A for emitting quantum dots is excited by the blue light L _B fluorescence (red light) L _R When a quantum dot 30B that emits when excited by the blue light _{L B} fluorescence (green light) _{L G.} Moreover, the quantum dots 30A are excited by ultraviolet light LUV that emits fluorescence (red light) _{L R,} and the quantum dots 30B that emits fluorescence (green light) _{L G} is excited by ultraviolet light LUV, by ultraviolet light LUV is excited can also comprise a fluorescent quantum dots 30C that emits (blue light) L _B (not shown).

The known quantum dots include a quantum dot 30A having an emission center wavelength in a wavelength band ranging from 600 nm to 680 nm, a quantum dot 30B having an emission center wavelength in a wavelength band ranging from 520 nm to 560 nm, and from 400 nm to 500 nm. A quantum dot 30C (emitting blue light) having an emission center wavelength in a wavelength band is known.

Regarding quantum dots, in addition to the above description, for example, JP 2012-169271 A 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.

Quantum dots may be added to the phosphor dispersion 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. The quantum dots can be added in an amount of, for example, about 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the phosphor dispersion composition.

In the phosphor dispersion composition, the content of the quantum dots is preferably 0.01 to 10% by mass, and more preferably 0.05 to 5% by mass with respect to the total mass of the curable compound contained in the polymerizable composition.

Since the wavelength conversion layer 30 is formed by thermosetting the phosphor dispersion composition of the present invention, the warpage and curing unevenness are small, the light resistance is excellent, the long-term reliability of the intensity and color of emitted light. Excellent in properties.

In the form of a sheet or film, the wavelength conversion layer 30 is preferably strong. That is, it is preferable not to cause permanent deformation due to breakage or cracking or elongation even in tension or bending. In order to evaluate these characteristics of the wavelength conversion layer already laminated on the base material, etc., after unnecessary components such as the base material are physically removed by cutting or polishing, etc., to make only the wavelength conversion layer. You can test it. In addition, when the phosphor dispersion composition itself or its raw material can be obtained, it can be peeled off after forming a film on a peelable and removable support, and only the wavelength conversion layer can be obtained and tested and measured. it can.

The tensile strength of the wavelength conversion layer is preferably in the range of 20 to 7000 MPa, more preferably in the range of 30 to 2000 MPa in the measurement method based on JIS K-7113. Within this range, the wavelength conversion layer is not distorted even when shear stress is applied, and both flexibility and flexibility required for winding and processing can be achieved. Further, the breaking elongation is preferably in the range of 5% to 200%, more preferably 10% to 100%. When the elongation at break is within this range, it is not broken by a bending test described later, or tensile stress generated by the tension during transportation or wet heat expansion of the substrate, and it does not stretch excessively and cause permanent deformation.

As bending resistance, a shopper folding test is performed based on JIS P-8114: 2003, and it is preferable to withstand 10 times or more until breakdown, and more preferably 50 times or more.

Martens hardness (when measured on quartz glass) is preferably in the range of 70 to 300 MPa, more preferably in the range of 100 to 200 MPa. Within this range, dents in the wavelength conversion layer due to contact with other members or during manufacturing are unlikely to occur, and damage to the base material due to moderate cushioning of the wavelength conversion layer can be suppressed.

[Barrier film]
The barrier films 10 and 20 that sandwich the wavelength conversion layer 30 are films having a function of suppressing the transmission of moisture and / or oxygen. In this embodiment, the barrier layers 12 and 22 are respectively formed on the base materials 11 and 21. It has the composition provided. In such an embodiment, due to the presence of the base material, the strength of the wavelength conversion member 1D is improved, and film formation can be easily performed.
In this embodiment, the barrier films 10 and 20 in which the barrier layers 12 and 22 are supported by the base materials 11 and 21 are provided on both main surfaces of the wavelength conversion layer 30 so that the barrier layers 12 and 22 are adjacent to each other. However, the barrier layers 12 and 22 may not be supported by the base materials 11 and 21, and if the base materials 11 and 21 have sufficient barrier properties, The barrier layer may be formed only from the materials 11 and 21.

Further, the barrier films 10 and 20 are preferably provided on both sides of the wavelength conversion layer 30 as in the present embodiment, but may be provided only on one side.

The barrier film preferably has a total light transmittance of 80% or more in the visible light region, and more preferably 90% or more. The visible light region refers to 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 barrier films 10 and 20 is preferably 1.00 cm ³ / (m ² · day · atm) or less. Oxygen permeability of the barrier film 10 and 20, more ^{preferably, 0.10cm 3 / (m 2 ·} day · atm) or less, more ^preferably is ^{0.01cm 3 / (m 2 · day} · atm) or less . In this specification, the oxygen permeability is measured using an oxygen gas permeability measuring device (manufactured by MOCON, OX-TRAN 2/20: trade name) under the conditions of a measurement temperature of 23 ° C. and a relative humidity of 90%. It is a measured value. In this specification, the unit of oxygen permeability is [cm ³ / (m ² · day · atm)]. The oxygen permeability of 1.0 cm ³ / (m ² · day · atm) corresponds to an oxygen permeability of 1.14 × 10 ⁻¹ fm / (s · Pa) in the SI unit system.

The barrier films 10 and 20 have a function of blocking moisture (water vapor) in addition to a gas barrier function of blocking oxygen. In the wavelength conversion member 1D, the moisture permeability (water vapor transmission rate) of the barrier films 10 and 20 is 0.10 g / (m ² · day · atm) or less. The moisture permeability of the barrier films 10 and 20 is preferably 0.01 g / (m ² · day · atm) or less. In this specification, the moisture permeability of the barrier layer is described in G. NISATO, PCPBOUTEN, PJSLIKKERVEER et al., SID Conference Record of the International Display Research Conference, pages 1435-1438, at a measurement temperature of 40 ° C. and a relative humidity of 90% RH. It is the value measured using the method (calcium method). In this specification, the unit of moisture permeability is [g / (m ² · day · atm)]. A moisture permeability of 0.1 g / (m ² · day · atm) corresponds to a moisture permeability of 1.14 × 10 ⁻¹¹ g / (m ² · s · Pa) in the SI unit system.

<Base material>
The average film thickness of the substrates 11 and 21 is preferably 10 μm to 500 μm, more preferably 20 μm to 400 μm, and more preferably 30 μm to 300 μm from the viewpoint of impact resistance of the wavelength conversion member. It is preferable. In an aspect in which retroreflection of light is increased, such as when the concentration of the quantum dots 30A and 30B included in the wavelength conversion layer 30 is reduced, or when the thickness of the wavelength conversion layer 30 is reduced, absorption of light having a wavelength of 450 nm is performed. Since the rate is preferably lower, the average film thickness of the base materials 11 and 21 is preferably 40 μm or less, and more preferably 25 μm or less from the viewpoint of suppressing a decrease in luminance.

In order to further reduce the concentration of the quantum dots 30A and 30B included in the wavelength conversion layer 30, or to further reduce the thickness of the wavelength conversion layer 30, the retroreflective member of the backlight unit is used to maintain the display color of the LCD. It is necessary to increase the number of times the excitation light passes through the wavelength conversion layer by providing means for increasing retroreflection of light, such as providing a plurality of prism sheets in 2B. Therefore, the substrate is preferably a transparent substrate that is 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 type light transmittance measuring device. It can be calculated by subtracting the rate. Regarding the base material, paragraphs 0046 to 0052 of JP-A-2007-290369 and paragraphs 0040 to 0055 of JP-A-2005-096108 can be referred to.

The base materials 11 and 21 preferably have an in-plane retardation Re (589) at a wavelength of 589 nm of 1000 nm or less. More preferably, it is 500 nm or less, and further preferably 200 nm or less.
After the wavelength conversion member 1D is manufactured, when inspecting for the presence of foreign matter or defects, two polarizing plates are placed in the extinction position, and the wavelength conversion member is inserted between them for observation, making it easy to find foreign matters and defects. . It is preferable that the Re (589) of the base material is in the above range because foreign matters and defects can be found more easily during inspection using a polarizing plate.
Here, Re (589) is measured with KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of 589 nm incident in the normal direction of the film. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like.

The base materials 11 and 21 are preferably base materials having a barrier property against oxygen and moisture. Preferred examples of the substrate include thin glass, polyethylene terephthalate film, a film made of a polymer having a cyclic olefin structure, and a polystyrene film.

<Barrier layer>
The base materials 11 and 21 are preferably provided with barrier layers 12 and 22 including at least one inorganic barrier layer 12b and 22b formed in contact with the surface on the wavelength conversion layer 30 side.
As shown in FIG. 2, the barrier layers 12 and 22 may include at least one organic barrier layer 12a and 22a between the base materials 11 and 21 and the inorganic barrier layers 12b and 22b. The organic barrier layers 12 a and 22 a may be provided between the inorganic barrier layers 12 b and 22 b and the wavelength conversion layer 30. Constructing the barrier layer from a plurality of layers is preferable from the viewpoint of improving the weather resistance since the barrier property can be further enhanced. The organic barrier layer is also preferably provided between the inorganic barrier layers 12 b and 22 b and the wavelength conversion layer 30. In this case, the organic barrier layer may be referred to as a barrier coating layer (overcoat layer).

The barrier layers 12 and 22 are formed by forming a film on the surface of the base material 11 or 21 as a support. Therefore, the barrier films 10 and 20 are comprised by the base materials 11 and 21 and the barrier layers 12 and 22 provided on it. When providing the barrier layers 12 and 22, it is preferable that the base material has high heat resistance. In the wavelength conversion member 1D, the layer in the barrier films 10 and 20 adjacent to the wavelength conversion layer 30 may be an inorganic barrier layer or an organic barrier layer, and is not particularly limited.

The barrier layers 12 and 22 are preferably composed of a plurality of layers, since the barrier property can be further enhanced. Therefore, the barrier layers 12 and 22 are preferable from the viewpoint of improving the weather resistance. However, the light transmission of the wavelength conversion member increases as the number of layers increases. Since the rate tends to decrease, it is preferable to design in consideration of good light transmittance and barrier properties.

(Inorganic barrier layer)
The “inorganic layer” is a layer mainly composed of an inorganic material, and is preferably a layer formed only from an inorganic material.
The inorganic barrier layers 12b and 22b suitable for the barrier layers 12 and 22 are not particularly limited, and various inorganic compounds such as metals, inorganic oxides, nitrides, and oxynitrides can be used. As an element constituting the inorganic material, silicon, aluminum, magnesium, titanium, tin, indium and cerium are preferable, and one 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 barrier 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, an inorganic barrier layer containing silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or aluminum oxide is particularly preferable. Since the inorganic barrier layer made of these materials has good adhesion with the organic barrier layer, even when the inorganic barrier layer has pinholes, the organic barrier layer can effectively fill the pinholes, The barrier property can be further increased.
Further, silicon nitride is most preferable from the viewpoint of suppressing light absorption in the barrier layer.

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

Examples of the method for forming the inorganic barrier 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 that oxidizes and deposits by introducing; sputtering method in which inorganic material is used as target raw material, argon gas and oxygen gas are introduced and sputtered by sputtering; generated in inorganic material by plasma gun When chemical vapor deposition methods (Physical Vapor Deposition method, PVD method) such as ion plating, which is heated by a plasma beam, and vapor deposition is performed, plasma chemistry using an organic silicon compound as a raw material Vapor phase growth (Chemical Vapor Deposition) method And the like.

The thickness of the inorganic barrier layer may be 1 nm to 500 nm, preferably 5 nm to 300 nm, and more preferably 10 nm to 150 nm. When the film thickness of the inorganic barrier layer is within the above-described range, it is possible to suppress absorption of light in the inorganic barrier layer while realizing good barrier properties, and to provide a wavelength conversion member with higher light transmittance. This is because it can be provided.

(Organic barrier layer)
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. JP, 2007-290369, A paragraphs 0020-0042 and JP, 2005-096108, A paragraphs 0074-0105 can be referred to as an organic barrier layer. The organic barrier layer preferably contains a cardo polymer. Thereby, the adhesion between the organic barrier layer and the adjacent layer, in particular, the adhesion with the inorganic barrier layer is improved, and a further excellent barrier property can be realized. For details of the cardo polymer, reference can be made to paragraphs 0085 to 0095 of JP-A-2005-096108 described above. The film thickness of the organic barrier 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 barrier layer is formed by a wet coating method, the film thickness of the organic barrier layer is preferably in the range of 0.5 to 10 μm, and more preferably in the range of 1 to 5 μm. Further, when formed by a dry coating method, it is preferably in the range of 0.05 μm to 5 μm, and more preferably in the range of 0.05 μm to 1 μm. This is because when the film thickness of the organic barrier 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.

For other details of the inorganic barrier layer and the organic barrier layer, reference can be made to the descriptions in the above-mentioned Japanese Patent Application Laid-Open Nos. 2007-290369 and 2005-096108, and further in US2012 / 0113672A1.

(Barrier film design change)
In the wavelength conversion member 1D, the wavelength conversion layer, the inorganic barrier layer, the organic barrier layer, and the base material may be laminated in this order, between the inorganic barrier layer and the organic barrier layer, and between the two organic barrier layers. Alternatively, a base material may be disposed and laminated between two inorganic barrier layers.

<Roughness imparting layer (matte layer)>
It is preferable that the barrier films 10 and 20 include an unevenness imparting layer (mat layer) 13 that imparts an uneven structure on a surface opposite to the surface on the wavelength conversion layer 30 side. It is preferable that the barrier film has a matte layer because the blocking property and slipping property of the barrier film can be improved. The mat layer is preferably a layer containing particles. Examples of the particles include inorganic particles such as silica, alumina, and metal oxide, or organic particles such as crosslinked polymer particles. The mat layer is preferably provided on the surface of the barrier film opposite to the wavelength conversion layer, but may be provided on both surfaces.

<Light scattering layer>
The wavelength conversion member 1D 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 30, or a layer having a light scattering function may be separately provided as the light scattering layer.
In addition, a light scattering layer may be provided on the surface of the substrate opposite to the wavelength conversion layer, or a light scattering function may be imparted to the unevenness providing layer to provide an unevenness providing layer having a light scattering function.

[Production method of wavelength conversion layer]
In the case where the wavelength conversion member 1D having the barrier films 10 and 20 including the barrier layers 12 and 22 on the base materials 11 and 21 on both surfaces of the wavelength conversion layer 30 is manufactured by photocuring. As an example, a method for manufacturing a wavelength conversion member of the present invention will be described with reference to FIGS. However, the present invention is not limited to the following embodiments.

In this embodiment, the wavelength conversion layer 30 can be formed by applying the prepared phosphor dispersion composition of the present invention to the surface of the barrier films 10 and 20 and then curing it by heating. Known coating methods include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, and wire bar method. The coating method is mentioned.

Curing conditions can be appropriately set according to the type of curable compound to be used and the composition of the polymerizable composition. In addition, when the phosphor dispersion composition is a composition containing a solvent, a drying treatment may be performed to remove the solvent before curing.

FIG. 3 is a schematic configuration diagram of an example of a manufacturing apparatus for the wavelength conversion member 1D, and FIG. 4 is a partially enlarged view of the manufacturing apparatus shown in FIG. The manufacturing apparatus shown in FIG. 3 laminates the barrier film 20 on the coating part 120 that coats the coating liquid such as the phosphor dispersion composition on the barrier film 10 and the coating film 30M formed by the coating part 120. The coating unit 30 includes a laminating unit 130 and a curing unit 160 that cures the coating film 30M. The coating unit 120 is configured to form the coating film 30M by an extrusion coating method using a die coater 124.

The manufacturing process of the wavelength conversion member using the manufacturing apparatus shown in FIGS. 3 and 4 applies the phosphor dispersion composition to the surface of the first barrier film 10 (hereinafter referred to as “first film”) that is continuously conveyed. Then, the step of forming the coating film 30M and the second barrier film 20 (hereinafter also referred to as “second film”) continuously conveyed are laminated (overlaid) on the coating film 30M. In the state where the coating film 30M is sandwiched between the film 10 and the second film 20, and the coating film 30M is sandwiched between the first film 10 and the second film 20, the first film 10 and the second film 20 It includes at least a step of winding one of the second films 20 around the backup roller 126 and heating it while continuously conveying it to polymerize and cure the coating film to form a wavelength conversion layer (cured layer). In this embodiment, a barrier film having a barrier property against oxygen and moisture is used for both the first film 10 and the second film 20. By setting it as this aspect, wavelength conversion member 1D by which both surfaces of the wavelength conversion layer were protected by the barrier film can be obtained.

More specifically, first, the first film 10 is continuously conveyed from the unillustrated transmitter to the coating unit 120. For example, the first film 10 is delivered from the delivery device at a conveyance speed of 1 to 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 30 to 100 N / m, is applied to the first film 10.

In the application unit 120, a phosphor dispersion 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 30M (see FIG. 4) is formed. . In the application unit 120, for example, a die coater 124 and a backup roller 126 disposed to face the die coater 124 are installed. The surface opposite to the surface on which the coating film 30M of the first film 10 is formed is wound around the backup roller 126, and the coating liquid is applied from the discharge port of the die coater 124 onto the surface of the first film 10 that is continuously conveyed. Thus, the coating film 30M is formed. Here, the coating film 30 </ b> M refers to a phosphor dispersion composition before curing applied on the first film 10.

In this embodiment, the die coater 124 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 120 and has the coating film 30M formed thereon is continuously conveyed to the laminating unit 130. In the laminating unit 130, the second film 20 continuously conveyed is laminated on the coating film 30 </ b> M, and the coating film 30 </ b> M is sandwiched between the first film 10 and the second film 20.

In the laminating unit 130, a laminating roller 132 and a heating chamber 134 surrounding the laminating roller 132 are installed. The heating chamber 134 is provided with an opening 136 for allowing the first film 10 to pass therethrough and an opening 138 for allowing the second film 20 to pass therethrough.

A backup roller 162 is disposed at a position facing the laminating roller 132. The first film 10 on which the coating film 30M is formed is wound around the backup roller 162 on the surface opposite to the surface on which the coating film 30M is formed, and is continuously conveyed to the laminating position P. Lamination position P means the position where the contact between the second film 20 and the coating film 30M starts. The first film 10 is preferably wound around the backup roller 162 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 162 before reaching the laminate position P. Therefore, the position (contact position) where the first film 10 is wound around the backup roller 162 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 162 and the pass line.

In a preferred embodiment of the present embodiment, the second film 20 is laminated by the backup roller 162 and the laminating roller 132 used in the curing unit 160. That is, the backup roller 162 used in the curing unit 160 is also used as a roller used in the laminating unit 130. However, the present invention is not limited to the above form, and a laminating roller may be installed in the laminating unit 130 in addition to the backup roller 162 so that the backup roller 162 is not used.

By using the backup roller 162 used in the curing unit 160 in the laminating unit 130, the number of rollers can be reduced. The backup roller 162 can also be used as a heat roller for the first film 10.

The second film 20 sent from a sending machine (not shown) is wound around the laminating roller 132 and continuously conveyed between the laminating roller 132 and the backup roller 162. The second film 20 is laminated on the coating film 30M formed on the first film 10 at the laminating position P. Thereby, the coating film 30 </ b> M is sandwiched between the first film 10 and the second film 20. Lamination refers to laminating the second film 20 on the coating film 30M.

The distance L2 between the laminating roller 132 and the backup roller 162 is a value of the total thickness of the first film 10, the wavelength conversion layer (cured layer) 30 obtained by polymerizing and curing the coating film 30M, and the second film 20. The above is preferable. 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 30M, and the 2nd film 20. FIG. By making the distance L2 equal to or less than the total thickness plus 5 mm, it is possible to prevent bubbles from entering between the second film 20 and the coating film 30M. Here, the distance L2 between the laminating roller 132 and the backup roller 162 is the shortest distance between the outer circumferential surface of the laminating roller 132 and the outer circumferential surface of the backup roller 162.

Rotational accuracy of the laminating roller 132 and the backup roller 162 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 30M.

Further, in order to suppress thermal deformation after the coating film 30M is sandwiched between the first film 10 and the second film 20, the difference between the temperature of the backup roller 162 of the curing unit 160 and the temperature of the first film 10 The difference between the temperature of the backup roller 162 and the temperature of the second film 20 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 162, when the heating chamber 134 is provided, it is preferable to heat the first film 10 and the second film 20 in the heating chamber 134. For example, hot air is supplied to the heating chamber 134 by a hot air generator (not shown), and the first film 10 and the second film 20 can be heated.

The first film 10 may be heated by the backup roller 162 by being wound around the temperature-adjusted backup roller 162.

On the other hand, the second film 20 can be heated with the laminating roller 132 by using the laminating roller 132 as a heat roller. However, the heating chamber 134 and the heat roller are not essential, and can be provided as necessary.

Next, the first film 10 and the second film 20 are continuously conveyed to the curing unit 160 in a state where the coating film 30M is sandwiched between the first film 10 and the second film 20. In the embodiment shown in the drawing, curing in the curing unit 160 is performed by heating.

The heating can be performed by heating the backup roller 162 or by an external heating device 164 provided in the curing unit 160. The backup roller 162 is preferably set to a temperature range of 40 to 150 ° C., for example, and more preferably 60 to 120 ° C. By attaching a temperature controller to the main body of the backup roller 162, the temperature of the backup roller 162 can be adjusted. Here, the temperature related to the roller refers to the surface temperature of the roller.
In addition to heating the backup roller 162, heat ray irradiation or hot air blowing may be performed by a heating device 164 provided at a position facing the backup roller 162. At this time, the distance L3 between the lamination position P and the heating device 164 can be set to 30 mm or more, for example.

In the curing unit 160, in a state where the coating film 30M is sandwiched between the first film 10 and the second film 20, the first film 10 is wound around the backup roller 162 and heated while being continuously conveyed. The wavelength conversion layer (cured layer) 30 can be formed by curing the film 30M.

In the present embodiment, the first film 10 side is wound around the backup roller 162 and continuously conveyed, but the second film 20 may be wound around the backup roller 162 and continuously conveyed.

Wrapping around the backup roller 162 means a state in which either the first film 10 or the second film 20 is in contact with the surface of the backup roller 162 at a certain wrap angle. Accordingly, the first film 10 and the second film 20 move in synchronization with the rotation of the backup roller 162 while being continuously conveyed.

The backup roller 162 includes a cylindrical main body and rotating shafts disposed at both ends of the main body. The main body of the backup roller 162 has a diameter of φ200 to 1000 mm, for example. There is no restriction on the diameter φ of the backup roller 162. In consideration of curl deformation of the laminated film, equipment cost, and rotational accuracy, the diameter is preferably 300 to 500 mm.

The coating film 30M becomes the cured layer 30 by heat curing, and the wavelength conversion member 1D including the first film 10, the cured layer 30, and the second film 20 is manufactured. The wavelength conversion member 1D is peeled off from the backup roller 162 by the peeling roller 180. The wavelength conversion member 1D is continuously conveyed to a winder (not shown), and then the wavelength conversion member 1D is wound into a roll by the winder. The coating film 30M may not necessarily be completely polymerized and cured at the stage of peeling from the backup roller 162, but at least a part of the coating film 30M is preferably polymerized and cured in order to facilitate subsequent conveyance. When the polymerization and curing of the coating film 30M is not completed at the stage of peeling from the backup roller 162, a post-heating means (not shown) is further provided for heating to complete the polymerization and curing. Under conditions where polymerization and curing are completed rapidly as polymerization curing is completed in less than 10 seconds, a cured layer having a distorted shape reflecting weak vibration due to conveyance, distortion of the film due to conveyance tension, distortion of the substrate due to reaction heat, etc. Therefore, it is preferable to adjust the conditions so that polymerization hardening proceeds at least for 1 minute or more. The curing step is preferably from 1 minute to 60 minutes, more preferably from 2 minutes to 30 minutes, in view of shape flatness and production efficiency.

As mentioned above, although the aspect which provided the barrier layer on both surfaces of the wavelength conversion layer was demonstrated about the manufacturing method of the wavelength conversion member of this invention, the manufacturing method of the wavelength conversion layer of this invention is a single side | surface of the wavelength conversion layer 30. It is applicable also to the aspect provided only for. The wavelength conversion member of this aspect can be manufactured by using a base material not provided with a barrier layer as the above-described second film.

Moreover, in the manufacturing method of the said wavelength conversion member, after forming the coating film 30M on the 1st film 10, before hardening the coating film 30M, the 2nd film 20 is laminated, and the coating film 30M is made into the 1st film The coating film 30M was cured while being sandwiched between the film 10 and the second film 20. On the other hand, in the aspect which provided the barrier layer only on the single side | surface of the wavelength conversion layer 30, after forming the coating film 30M on the 1st film 10, the coating film 30M is after the drying process performed as needed. Then, after forming a wavelength conversion layer (cured layer) by curing and forming a coating layer on the wavelength conversion layer as necessary, a second film made of a base material not provided with a barrier layer is bonded to the adhesive. It is also possible to form the wavelength conversion member 1D by laminating on the wavelength conversion layer via (and the coating layer). The coating layer is one or more other layers such as an inorganic layer, and can be formed by a known method.

The thickness of the wavelength conversion layer is preferably in the range of 1 to 300 μm, more preferably in the range of 10 to 200 μm, and still more preferably in the range of 20 to 100 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 300 μm or less because the backlight unit can be thinned when incorporated in the backlight unit.

"Backlight unit"
As described above, the backlight unit 2 shown in FIG. 1 includes a light source 1A that emits primary light (blue light L _B ), and a light guide plate 1B that guides and emits primary light emitted from the light source 1A. A planar light source 1C, a wavelength conversion member 1D provided on the planar light source 1C, a retroreflective member 2B disposed to face the planar light source 1C across the wavelength conversion member 1D, and a planar light source across 1C and a reflecting plate 2A disposed opposite and the wavelength converting member 1D, the wavelength conversion member 1D, at least a portion of the primary light L _B emitted from the surface light source 1C as excitation light, fluorescent emits, it is to emit the fluorescent consists secondary light _{(L G,} L _R) and the primary light L _B, which was not the excitation light.

From the viewpoint of realizing high luminance and high color reproducibility, it is preferable to use a backlight unit that is a multi-wavelength light source. For example, blue light having an emission center wavelength in a wavelength band of 430 nm or more and 480 nm or less, a peak of emission intensity having a half width of 100 nm or less, and an emission center wavelength in a wavelength band of 500 nm or more and less than 600 nm, Emits green light having an emission intensity peak with a value width of 100 nm or less, and red light having an emission center wavelength in a wavelength band of 600 nm to 680 nm and having an emission intensity peak with a half-value width of 100 nm or less. It is preferable.

From the viewpoint of further improving luminance and color reproducibility, the wavelength band of blue light emitted from the backlight unit 2 is preferably 430 nm or more and 480 nm or less, and more preferably 440 nm or more and 460 nm or less.
From the same viewpoint, the wavelength band of the green light emitted from the backlight unit 2 is preferably 520 nm or more and 560 nm or less, and more preferably 520 nm or more and 545 nm or less.
From the same viewpoint, the wavelength band of red light emitted from the backlight unit is preferably 600 nm or more and 680 nm or less, and more preferably 610 nm or more and 640 nm or less.

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 50 nm or less, and 40 nm or less. More preferably, it is 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 2 includes at least the planar light source 1C together with the wavelength conversion member 1D. Examples of the light source 1A include those that emit blue light having an emission center wavelength in a wavelength band of 430 nm to 480 nm, and those that emit ultraviolet light. As the light source 1A, a light emitting diode, a laser light source, or the like can be used.

As illustrated in FIG. 1, the planar light source 1 </ b> C may be a planar light source including a light source 1 </ b> A and a light guide plate 1 </ b> B that guides and emits primary light emitted from the light source 1 </ b> A. It may be a planar light source that is arranged in a plane parallel to the wavelength conversion member 1D and includes a diffusion plate 1E instead of the light guide plate 1B. The former planar light source is generally called an edge light system, and the latter planar light source is generally called a direct type.
In the present embodiment, a case where a planar light source is used as the light source has been described as an example. However, a light source other than the planar light source can be used as the light source.

(Configuration of backlight unit)
As the configuration of the backlight unit, the edge light method using a light guide plate, a reflection plate, or the like as a constituent member has been described in FIG. 1, but a direct type may be used. Any known light guide plate can be used without any limitation.

Further, the reflecting plate 2A is not particularly limited, and known ones can be used, and are described in Japanese Patent No. 3416302, Japanese Patent No. 3363565, Japanese Patent No. 4091978, Japanese Patent No. 3448626, etc. Incorporated into the present invention.

The retroreflective member 2B may include a known diffusion plate, diffusion sheet, prism sheet (for example, BEF series manufactured by Sumitomo 3M Limited), a light guide, or the like. The configuration of the retroreflective member 2B is 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 backlight unit 2 described above can be applied to a liquid crystal display device. As shown in FIG. 5, the liquid crystal display device 4 includes the backlight unit 2 of the above embodiment and the liquid crystal cell unit 3 disposed to face the retroreflective member side of the backlight unit.

As shown in FIG. 5, the liquid crystal cell unit 3 has a configuration in which the liquid crystal cell 31 is sandwiched between polarizing plates 32 and 33, and the polarizing plates 32 and 33 respectively have both main surfaces of the polarizers 322 and 332. The polarizing plate protective films 321 and 323, 331 and 333 are protected.

There are no particular limitations on the liquid crystal cell 31, the polarizing plates 32 and 33, and the components thereof that constitute the liquid crystal display device 4, and those produced 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.

The driving mode of the liquid crystal cell 31 is not particularly limited, and is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically compensated bend cell (OCB). ) And other modes 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.

The liquid crystal display device 4 further includes an associated functional layer such as an optical compensation member that performs optical compensation as necessary, and an adhesive layer. In addition to (or instead of) color filter substrates, thin layer transistor substrates, lens films, diffusion sheets, hard coat layers, antireflection layers, low reflection layers, antiglare layers, etc., forward scattering layers, primer layers, antistatic layers Further, a surface layer such as an undercoat layer may be disposed.

The backlight side polarizing plate 32 may have a retardation film as the polarizing plate protective film 323 on the liquid crystal cell 31 side. As such a retardation film, a known cellulose acylate film or the like can be used.

The backlight unit 2 and the liquid crystal display device 4 include the above-described wavelength conversion member with little optical loss according to the present invention. Therefore, the backlight unit and the liquid crystal display device having the same effects as those of the wavelength conversion member of the present invention, a high-brightness backlight unit and a liquid crystal display device in which the separation of the interface of the wavelength conversion layer including the quantum dots hardly occurs and the light emission intensity hardly decreases.

Hereinafter, the present invention will be described more specifically based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.

1. Barrier film (Barrier film G)
As the barrier film G, an ultra-thin glass OA-10G (thickness 50 μm) manufactured by Nippon Sheet Glass was prepared.
(Barrier film PET1)
A barrier layer 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 38 μm) by the following procedure. Cosmo Shine A4300 had a mat layer on both sides.
Trimethylolpropane triacrylate (TMPTA, manufactured by Daicel-Cytec) and a photopolymerization initiator (Lamberti, trade name: ESACURE (registered trademark) KTO46) are prepared so that the mass ratio is 95: 5. These were weighed and dissolved in methyl ethyl ketone to obtain a coating solution having a solid concentration of 15%. This coating solution was applied onto the PET film with a roll toe roll using a die coater, and passed through a drying zone at 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 substrate was 1 μm.

Next, an inorganic layer (silicon nitride layer) was formed on the surface of the organic layer using a chemical vapor deposition apparatus (CVD apparatus) of a roll toe roll. 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 film thickness was 50 nm. Thus, barrier film PET1 in which the inorganic layer was laminated on the surface of the organic layer was prepared.

2. Preparation of phosphor dispersion composition (Preparation of phosphor dispersion composition 1 used in Example 1 and Example 10)
The following dispersion was prepared in a dry nitrogen atmosphere, and toluene was removed by evaporation using an evaporator to prepare phosphor-dispersed isocyanate liquid 11. In the following, the quantum dot dispersion liquid 1 having an emission maximum wavelength of 535 nm is prepared by preparing CZ520-100 manufactured by NN-Labs Co. to a quantum dot concentration of 1% by mass, and the quantum dot dispersion liquid 2 having an emission maximum wavelength of 630 nm is NN-Labs CZ620-100 was prepared to a quantum dot concentration of 1% by mass. These quantum dots (commercially available products) are all quantum dots using CdSe as a core, ZnS as a shell, and octadecylamine as a ligand, and are dispersed in toluene at a concentration of 3% by mass. Next, the following polyol liquid 12 was prepared in a dry nitrogen atmosphere, and the phosphor dispersion composition 1 of the present invention was obtained by mixing the isocyanate liquid 11 and the polyol liquid 12 in a specified quantitative ratio. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 2 used in Example 2)
The phosphor dispersion of the present invention is the same as the phosphor dispersion composition 1 described above except that the phosphor dispersion isocyanate liquid 11 described above is used as the isocyanate liquid and the following polyol liquid 22 is prepared as the polyol liquid. Composition 2 was obtained. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 3 used in Example 3)
Under a dry nitrogen atmosphere, the following dispersion is prepared, and toluene is removed by evaporation using an evaporator to prepare the following phosphor-dispersed carboxylic acid anhydride solution 31, and 21 mass of the obtained phosphor-dispersed carboxylic acid solution. Part was mixed and stirred with 71 parts by mass of polypropylene glycol diglycidyl ether (Epolite 400P (trade name) manufactured by Kyoeisha Chemical Co., Ltd.) under a dry nitrogen atmosphere, and filtered through a polypropylene filter having a pore size of 0.2 μm to obtain a phosphor. Dispersion composition 3 was prepared.

(Preparation of phosphor dispersion composition 4 used in Example 4)
In a dry nitrogen atmosphere, the following dispersion is prepared, and toluene is removed by evaporation using an evaporator to prepare the following phosphor-dispersed carboxylic acid anhydride liquid 41. 21 mass of the obtained phosphor-dispersed carboxylic acid liquid Part was mixed and stirred with 71 parts by mass of polypropylene glycol diglycidyl ether (Epolite 400P (trade name) manufactured by Kyoeisha Chemical Co., Ltd.) under a dry nitrogen atmosphere, and filtered through a polypropylene filter having a pore size of 0.2 μm to obtain a phosphor. Dispersion composition 4 was prepared.

(Preparation of phosphor dispersion composition 5 used in Example 5 and Example 11)
The following phosphor dispersion was prepared in a dry nitrogen atmosphere, and toluene was removed by evaporation using an evaporator, followed by filtration through a polypropylene filter having a pore size of 0.2 μm to prepare phosphor dispersion composition 5. At this time, since the polymerization reaction gradually proceeds even at room temperature due to mixing, the phosphor dispersion composition 5 was sealed in a tank in a dry nitrogen atmosphere until immediately before the coating step described later, and cooled to 4 ° C. and stored.

(Preparation of phosphor dispersion composition 6 used in Example 6)
The following phosphor dispersion was prepared in a dry nitrogen atmosphere, and toluene was removed by evaporation using an evaporator, followed by filtration through a polypropylene filter having a pore size of 0.2 μm to prepare phosphor dispersion composition 6. At this time, since the polymerization reaction gradually proceeds even at room temperature due to mixing, the phosphor dispersion composition 6 was sealed in a tank in a dry nitrogen atmosphere until immediately before the coating step described later, and cooled to 4 ° C. and stored.

(Preparation of phosphor dispersion composition 7 used in Example 7)
The following dispersion was prepared in a dry nitrogen atmosphere, and the aggregates of phosphor fine particles were crushed with an ultrasonic disperser to prepare phosphor-dispersed isocyanate liquid 71. Next, the following polyol liquid 72 was prepared under a dry nitrogen atmosphere, and the phosphor dispersion composition 7 of the present invention was obtained by mixing the isocyanate liquid 71 and the polyol liquid 72 in a specified quantitative ratio. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 8 used in Example 8)
The following dispersion was prepared in a dry nitrogen atmosphere, and the aggregates of the phosphor fine particles were crushed with an ultrasonic disperser to prepare the following phosphor-dispersed carboxylic anhydride liquid 81. 21 parts by mass of the obtained phosphor-dispersed carboxylic acid solution was mixed and stirred with 71 parts by mass of polypropylene glycol diglycidyl ether (Epolite 400P (trade name), manufactured by Kyoeisha Chemical Co., Ltd.) under a dry nitrogen atmosphere. Composition 8 was prepared.

(Preparation of phosphor dispersion composition 9 used in Example 9)
The following phosphor dispersion liquid was prepared under a dry nitrogen atmosphere, and aggregates of phosphor fine particles were crushed with an ultrasonic disperser to prepare phosphor dispersion composition 9. At this time, since the polymerization reaction gradually proceeds even at room temperature, the phosphor dispersion composition 9 was sealed in a tank under a dry nitrogen atmosphere until immediately before the coating step described later, and cooled to 4 ° C. and stored.

(Preparation of phosphor dispersion composition 10 used in Comparative Example 1)
The following phosphor dispersion liquid was prepared in a dry nitrogen atmosphere, and toluene was distilled off by an evaporator to prepare phosphor dispersion epoxy curing agent liquid 101. The phosphor dispersion of the comparative example was prepared by mixing the phosphor-dispersed epoxy curing agent liquid 71 and the two-part curable epoxy main agent part 1 (epoxide, E-30CL manufactured by Loctite) so that the mixing mass ratio was 25:75. Composition 10 was obtained. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 11 used in Comparative Example 2)
The following phosphor dispersion liquid was prepared in a dry nitrogen atmosphere, and aggregates of phosphor fine particles were crushed with an ultrasonic disperser to prepare a phosphor-dispersed epoxy curing agent liquid 111. Fluorescent substance dispersion epoxy curing agent liquid 81 and two-part curable epoxy main part 1 (epoxide, manufactured by Loctite Co., Ltd., E-30CL) are mixed so that the mixing mass ratio is 25:75, and the phosphor dispersion of the comparative example Composition 11 was obtained. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 12 used in Comparative Example 3)
The phosphor dispersion of the present invention is the same as the preparation of the phosphor dispersion composition 1 except that the phosphor dispersion isocyanate liquid 11 described above is used as the isocyanate liquid and the following polyol liquid 122 is prepared as the polyol liquid. Composition 12 was obtained. At this time, since these two components started to react quickly by mixing, these two liquids were stored in separate tanks in a dry nitrogen atmosphere until immediately before the coating step described later.

(Preparation of phosphor dispersion composition 13 used in Comparative Example 4)
Under a dry nitrogen atmosphere, the following dispersion was prepared, and toluene was distilled off by an evaporator to prepare the following phosphor-dispersed carboxylic acid anhydride solution 131. 21 mass of the obtained phosphor-dispersed carboxylic acid solution Part was mixed and stirred with 71 parts by mass of polypropylene glycol diglycidyl ether (Epolite 400P (trade name) manufactured by Kyoeisha Chemical Co., Ltd.) under a dry nitrogen atmosphere, and filtered through a polypropylene filter having a pore size of 0.2 μm to obtain a phosphor. Dispersion composition 13 was prepared.

(Preparation of phosphor dispersion composition 14 used in Comparative Example 5)
The following phosphor dispersion was prepared in a dry nitrogen atmosphere, and toluene was removed by evaporation using an evaporator, followed by filtration through a polypropylene filter having a pore size of 0.2 μm to prepare phosphor dispersion composition 14. At this time, since the polymerization reaction gradually proceeds even at room temperature due to mixing, the phosphor dispersion composition 14 was sealed in a tank in a dry nitrogen atmosphere until immediately before the coating step described later, and cooled to 4 ° C. and stored.

3. Production of wavelength conversion member (Example 1)
The tank in which the phosphor-dispersed isocyanate liquid 11 is stored and the tank in which the polyol liquid 12 is stored are connected to a sealed automatic quantitative liquid feeding device (manufactured by Liquid Control, Posilatio), and the phosphor-dispersed isocyanate liquid 11 and the polyol liquid 12 are connected. Were fed to the die coater while being mixed by an in-line mixer so that the mass ratio was 35:65. By this method, the uniformly dispersed phosphor dispersion composition 1 was supplied from the die coater discharge port.

Prepare the first barrier film G, apply the phosphor dispersion composition 1 on one surface with a die coater while continuously conveying it at a tension of 1 m / min and 60 N / m, and form a coating film having a thickness of 50 μm. Formed. Next, the first barrier film G on which the coating film is formed is wound around a backup roller, the second barrier film G is laminated on the coating film, and the coating film is coated with the first and second barrier films G. While continuously transporting in the sandwiched state, the sample was heated at 80 ° C. for 30 seconds by contact-type heating on the backup roller, and then passed through a heating zone at 80 ° C. for 5 minutes. In the heating zone, the phosphor dispersion composition 1 was cured to form the wavelength conversion layer 1 containing the phosphor.

(Example 2)
A wavelength conversion layer 2 containing a phosphor was formed in the same manner as in Example 1 except that the phosphor dispersion composition 2 was used as the phosphor dispersion composition.

(Example 3)
A wavelength conversion layer 3 containing a phosphor was prepared in the same manner as in Example 1 except that the phosphor dispersion composition 3 was used as the phosphor dispersion composition, and the temperature and passage time of the heating zone were 120 ° C. and 10 minutes. Formed.

Example 4
A wavelength conversion layer 4 containing a phosphor was prepared in the same manner as in Example 1 except that the phosphor dispersion composition 4 was used as the phosphor dispersion composition, and the temperature and passage time of the heating zone were 100 ° C. and 10 minutes. Formed.

(Example 5)
A wavelength conversion layer 5 containing a phosphor was formed in the same manner as in Example 3 except that the phosphor dispersion composition 5 was used as the phosphor dispersion composition and the temperature of the heating zone was set to 80 ° C.

(Example 6)
A wavelength conversion layer 6 containing a phosphor was formed in the same manner as in Example 5 except that the phosphor dispersion composition 6 was used as the phosphor dispersion composition.

(Example 7)
A wavelength conversion layer 7 containing a phosphor was formed in the same manner as in Example 1 except that the phosphor-dispersed isocyanate liquid 71 and the polyol liquid 72 were used instead of the phosphor-dispersed isocyanate liquid 11 and the polyol liquid 12.

(Example 8)
A wavelength conversion layer 8 containing a phosphor was formed in the same manner as in Example 3 except that the phosphor dispersion composition 8 was used as the phosphor dispersion composition.

Example 9
A wavelength conversion layer 9 containing a phosphor was formed in the same manner as in Example 5 except that the phosphor dispersion composition 9 was used as the phosphor dispersion composition.

(Example 10)
A wavelength conversion layer 10 containing a phosphor was formed in the same manner as in Example 1 except that PET1 was used in place of the barrier film G as the first and second barrier films.

(Example 11)
A wavelength conversion layer 11 containing a phosphor was formed in the same manner as in Example 1 except that PET1 was used in place of the barrier film G as the first and second barrier films.

(Comparative Example 1)
A wavelength conversion layer 12 containing a phosphor was formed by performing the same process as in Example 1 except that the phosphor dispersion composition 10 was used as the phosphor dispersion composition.

(Comparative Example 2)
A wavelength conversion layer 13 containing a phosphor was formed by performing the same process as in Example 1 except that the phosphor dispersion composition 11 was used as the phosphor dispersion composition.

(Comparative Example 3)
A wavelength conversion layer 14 containing a phosphor was formed by performing the same process as in Example 1 except that the phosphor dispersion composition 12 was used as the phosphor dispersion composition.

(Comparative Example 4)
A wavelength conversion layer 15 containing a phosphor was formed by performing the same process as in Example 3 except that the phosphor dispersion composition 13 was used as the phosphor dispersion composition.

(Comparative Example 5)
A wavelength conversion layer 16 containing a phosphor was formed by performing the same process as in Example 5 except that the phosphor dispersion composition 14 was used as the phosphor dispersion composition.

4). Evaluation In order to confirm the effect of the phosphor dispersion composition of the present invention, the light resistance and long-term reliability of the wavelength conversion members of Examples and Comparative Examples were evaluated as described above. As indicators of light resistance and long-term reliability, changes in luminance with time and color changes with time were confirmed.

(Evaluation of initial luminance)
The above example in which a commercially available tablet terminal (manufactured by Amazon, Kindle (registered trademark) Fire HDX 7 ") was disassembled, QDEF (quantum dot film made by 3M) was taken out from the backlight unit, and cut into a rectangle instead of QDEF In this way, a liquid crystal display device was produced, and the produced liquid crystal display device was turned on so that the entire surface was displayed in white, and the direction perpendicular to the surface of the light guide plate was 740 mm. Is measured with a luminance meter (SR3, manufactured by TOPCON Co., Ltd.) installed at position 1. Table 1 shows the measurement results.

(Evaluation of luminance after light resistance test)
The wavelength conversion members of Examples and Comparative Examples cut out into rectangles were irradiated with a metal halide lamp (cut about 290 nm or less) (trade name: iSuper UV Tester, manufactured by Iwasaki Electric Co., Ltd.), illuminance 90 mW / cm ² , temperature 25 ° C., humidity 60%. The light resistance test was conducted by irradiating light for 1000 hours under the conditions of After the light resistance test, the same luminance evaluation as described above was performed to confirm the luminance change with time. The measurement results are shown in Table 1.

(Visual appearance evaluation)
For the wavelength conversion members of Examples and Comparative Examples, the initial appearance before the light resistance test and the appearance after the light resistance test were visually compared on a white background under a high color rendering white light source. The color of the wavelength conversion member was evaluated. The results are shown in Table 1.

As shown in Table 1, the wavelength conversion member of the example had good initial luminance, and the decrease in luminance after the light resistance test was suppressed. Whether the substrate is an ultra-thin plate glass or the barrier film PET1 in which a barrier layer is provided on a PET film, the wavelength conversion members of the examples have good results in the initial luminance and the luminance decrease after the light resistance test. Was showing.

On the other hand, the luminance conversion after the light resistance test was remarkable in the wavelength conversion member of the comparative example. In the visual evaluation, the wavelength conversion member of the comparative example after the light resistance test is colored light yellow, and it is considered that the blue light used for excitation of the phosphor is partially absorbed by this coloring and the luminance is lowered. Since the thin glass sheet of the substrate is extremely robust against light, the coloring and the accompanying decrease in luminance are attributed to the composition of the wavelength conversion layer.

Further, in Comparative Example 1, the initial luminance was lower than in the other examples. This is presumed that the amine compound used as a curing agent affects the ligand that protects the quantum dots, which are phosphors, and changes the electronic state of the quantum dots to reduce the luminous efficiency. Similarly, the wavelength conversion materials of Examples 1 to 3 using quantum dots as the phosphor maintain a suitable initial luminance, and the phosphor dispersion composition of the present invention is also suitable in terms of luminous efficiency under normal conditions. Was confirmed.

DESCRIPTION OF SYMBOLS 1C Planar light source 1D Wavelength conversion member 2 Backlight unit 2A Reflector 2B Retroreflective member 3 Liquid crystal cell unit 4 Liquid crystal display device 10,20 Barrier film 11,21 Base material 12,22 Barrier layer 13 Concavity and convexity providing layer (mat layer) , Light diffusion layer)
30 Wavelength conversion film 30A, 30B quantum dots 30P organic matrix L _B excitation light (primary light, blue light)
_LR red light (secondary light, fluorescence)
L _G the green light (secondary light, fluorescence)

Claims (11)

1. A phosphor dispersion composition for forming a phosphor molded body comprising at least one phosphor dispersed and contained in a binder having a three-dimensional network structure,
   Comprising the phosphor and a binder precursor that forms the binder by a thermosetting reaction,
   The binder precursor includes at least one thermosetting compound that forms the three-dimensional network structure by the thermosetting reaction,
   A phosphor dispersion composition in which the total content of the polyfunctional primary amine and the polyfunctional secondary amine as the thermosetting compound is 0.1% by mass or less based on the total mass of the phosphor dispersion composition.
2. The phosphor dispersion composition according to claim 1, wherein the thermosetting compound contains a polyvalent isocyanate and a polyol.
3. The phosphor dispersion composition according to claim 2, wherein the polyvalent isocyanate is a cyclic aliphatic isocyanate and / or a chain aliphatic isocyanate.
4. The phosphor dispersion composition according to claim 2 or 3, wherein the binder precursor includes a reaction accelerator that accelerates the thermosetting reaction between the polyvalent isocyanate and the polyol.
5. The fluorescence according to claim 1, wherein the thermosetting compound includes an epoxide and a carboxylic acid anhydride, and the binder precursor includes a reaction accelerator that accelerates the thermosetting reaction between the epoxide and the carboxylic acid anhydride. Body dispersion composition.
6. The phosphor dispersion composition according to claim 1, wherein the thermosetting reaction is a thermopolymerization reaction, the thermosetting compound contains an epoxide, and the binder precursor contains a thermopolymerization initiator of the thermopolymerization reaction.
7. A fluorescent molded body obtained by curing the phosphor dispersion composition according to any one of claims 1 to 6.
8. A wavelength conversion film obtained by curing a coating film of the phosphor dispersion composition according to any one of claims 1 to 6.
9. A wavelength conversion member comprising the wavelength conversion film according to claim 8.
10. A planar light source that emits primary light;
    The wavelength conversion member according to claim 9 provided on the planar light source;
    A retroreflective member disposed opposite to the planar light source with the wavelength conversion member interposed therebetween;
    A backlight unit comprising a reflection plate disposed opposite to the wavelength conversion member across the planar light source,
    The wavelength converting member emits the fluorescence using at least a part of the primary light emitted from the planar light source as excitation light, and emits at least light including secondary light composed of the fluorescence. Light unit.
11. The backlight unit according to claim 10;
    A liquid crystal display device comprising: a liquid crystal unit disposed opposite to the retroreflective member side of the backlight unit.

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