Photonic upconversion film, method for manufacturing photonic upconversion film, photonic upconversion body, laminate, and energy conversion device

Abstract

Provided are a photonic up-conversion film, a photonic up-conversion body, a laminate, and an energy conversion device capable of high-efficiency up-conversion, and a method for manufacturing the same. The photonic up-conversion film of an embodiment of the present application has a color development portion that contains at least a sensitizing component capable of absorbing light in a first wavelength range λ1 and a luminescent component capable of emitting light in a second wavelength range λ2 shorter in wavelength than the first wavelength range λ1. With respect to the photonic up-conversion film, the relaxation time measured by the spin echo method using the time-domain nuclear magnetic resonance method (pulse NMR) at 298 K is less than 210 ms.

Description

TECHNICAL FIELD

[0001] The present application relates to a photonic upconversion film, a method for manufacturing a photonic upconversion film, a photonic upconversion body, a laminate, and an energy conversion device. BACKGROUND

[0002] A photonic upconversion (hereinafter, sometimes referred to simply as "upconversion") technology of converting light of low energy into light of high energy is expected to be applied to various fields such as solar cells or solar power generation, photocatalysts, biological imaging, optical devices, and the like. As upconversion luminescence in an organic material, a technology of utilizing triplet-triplet annihilation (TTA) caused by collision of molecules in a triplet state with each other is known. In a solution system of dissolving a donor compound and an acceptor compound in a solvent, energy transfer is efficiently performed by diffusion of molecules of the donor compound and the acceptor compound. On the other hand, the solution system has a problem that the field in which it can be practically used is limited.

[0003] In view of the above circumstances, research and development of upconversion luminescence in a solid state are being conducted. However, since diffusion of molecules hardly occurs in a solid state, there is a problem that TTA cannot be efficiently utilized. For example, although a resin film into which a donor compound and an acceptor compound are introduced has been studied, upconversion luminescence efficiency thereof is insufficient.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent No. 5491408 SUMMARY

[0007] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0008] The present application has been achieved in order to solve the above-described prior problems, and a main object thereof is to provide a photonic upconversion film, a photonic upconversion body, a laminate, and an energy conversion device, which can perform upconversion with high efficiency, and a method for manufacturing the same.

[0009] In addition, a main object of the present application is to provide a photonic upconversion film, a photonic upconversion body, a laminate, and an energy conversion device, which have high transmittance by optimization of a medium and can perform upconversion with high efficiency, and a method for manufacturing the same.

[0010] [MEANS OF SOLVING THE PROBLEMS]

[0011] [1] The photonic upconversion film of one embodiment of the present invention includes a color development portion. The color development portion includes at least a sensitizing component and a light emitting component. The sensitizing component can absorb light in a first wavelength range λ1. The light emitting component can emit light in a second wavelength range λ2 that is shorter than the first wavelength range λ1. The photonic upconversion film has a spin-echo relaxation time of less than 210 ms as measured by time-domain nuclear magnetic resonance (NMR) at 298 K.

[0012] [2] The photonic upconversion film according to the above [1], can further include a matrix. The color development portion is dispersed in the matrix as a dispersed phase.

[0013] [3] The photonic upconversion film according to the above [2], wherein the matrix can include a resin.

[0014] [4] The photonic upconversion film according to the above [3], wherein the resin can include a polyethylene oxide and / or a polyvinyl alcohol-based resin.

[0015] [5] The photonic upconversion film according to any one of the above [1] to [4], wherein the color development portion can include a solvent having a boiling point of 80°C or higher.

[0016] [6] The photonic upconversion film according to any one of the above [1] to [5], wherein the color development portion can include a solvent having a viscosity of 0.6 mPa-s or higher at 23°C.

[0017] [7] The photonic upconversion film according to any one of the above [1] to [6], wherein the color development portion can include a monomolecular liquid crystal compound.

[0018] [8] The photonic upconversion film according to any one of the above [3] to [7], wherein, with respect to 1 g of the resin, 7.00 x 10 -9 mol to 5.00 x 10 -6 mol of the sensitizing component, and 5.00 x 10 -6 mol to 7.00 x 10 -5 mol of the light emitting component can be included.

[0019] [9] The method for manufacturing the photonic upconversion film according to another aspect of the present invention is the method for manufacturing the photonic upconversion film according to any one of the above [1] to [8], including the steps of preparing an emulsion from a medium in which the sensitizing component and the light emitting component are dispersed and / or dissolved, and an aqueous solution including a water-soluble resin; applying the emulsion to a substrate to form a coating film; and drying the coating film.

[0020]

[10] Another embodiment of the present invention comprises a laminate having a photon upconversion film as described in any one of [1] to [8] above.

[0021]

[11] A further embodiment of the present invention provides an energy conversion device comprising a photon upconversion membrane as described in any one of [1] to [8] above.

[0022]

[12] In another further embodiment of the present invention, the photon upconverter includes a color-developing section. The color-developing section includes at least a sensitizing component and a luminescent component. The sensitizing component is capable of absorbing light within a first wavelength range λ1. The luminescent component is capable of emitting light within a second wavelength range λ2, which has a wavelength shorter than the first wavelength range λ1. Regarding this photon upconverter, the relaxation time measured by spin echo method using time-domain nuclear magnetic resonance (pulse NMR) at 298K is less than 210 ms.

[0023] [The effects of the invention]

[0024] According to embodiments of the present invention, a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device capable of high-efficiency upconversion, as well as a method for manufacturing the same, can be realized. Furthermore, a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device, as well as a method for manufacturing the same, can be realized by optimizing the medium to achieve high transmittance and high-efficiency upconversion. Attached Figure Description

[0025] Figure 1 This is a conceptual diagram of energy levels that illustrates the mechanism of upconversion. Detailed Implementation

[0026] The following describes embodiments of the present invention, but the present invention is not limited to these embodiments.

[0027] A. Mechanism of photon upconversion

[0028] Reference Figure 1 The mechanism of photon upconversion is explained. First, the sensitized component (donor) absorbs incident light and, through self-excited singlet state S... D An excited triplet state T is generated by an intersystem crossing. D Next, a triplet-triplet energy transfer (TTET) occurs from the donor to the luminescent component (acceptor), generating the excited triplet T of the acceptor. A Next, through the excited triplet state T A The acceptors approach each other within a range where diffusion, collision, or energy transfer can occur, resulting in triplet-triplet annihilation (TTA). This results in the production of the higher excited singlet energy state S of the acceptor. A The higher excited singlet energy state S AEmitting up-converted light (light having an energy greater than that of the excitation light).

[0029] B. Overall configuration of the photonic up-conversion film

[0030] The photonic up-conversion film (hereinafter, sometimes referred to as the up-conversion film) of the embodiment of the present application has a color developing portion. The color developing portion contains at least a sensitizing component (donor) and a light emitting component (acceptor). The sensitizing component is capable of absorbing light in a first wavelength range λ1. The light emitting component is capable of emitting light in a second wavelength range λ2 which is shorter in wavelength than the first wavelength range λ1. Typically, the sensitizing component and the light emitting component are located in close proximity to each other so as to be capable of energy transfer.

[0031] With respect to such a photonic up-conversion film, if the relaxation time measured by the spin echo method using the time domain nuclear magnetic resonance method (TD-NMR, pulse NMR) is less than 210 ms (milliseconds) at 298 K (24.85°C), the absolute quantum yield of the up-conversion film can be improved. Thus, an up-conversion film capable of high efficiency up-conversion can be realized. In addition, an up-conversion film having high efficiency and improved transmittance by optimization of the medium can be produced.

[0032] In one embodiment, the photonic up-conversion film further has a matrix. The color developing portion is dispersed in the matrix in the form of a dispersed phase. Typically, the photonic up-conversion film has an island-in-sea structure.

[0033] The domain size of the color developing portion is, for example, 0.05 μm to 10 μm, preferably 0.1 μm to 10 μm, more preferably 0.1 μm to 5.0 μm, and further preferably 1.0 μm to 5.0 μm. The domain size of the color developing portion is measured, for example, by observing a cross section using a scanning electron microscope (SEM) or observing a surface using an optical microscope. If the domain size of the color developing portion is in such a range, the light emitting efficiency of the up-conversion film can be stably improved.

[0034] The content ratio of the color developing portion in the up-conversion film is, for example, 1.0 vol% to 60 vol%, and preferably 5.0 vol% to 50 vol%. The content ratio of the color developing portion is measured, for example, from a cross-sectional SEM image by any appropriate image processing. If the content ratio of the color developing portion is in such a range, the light emitting efficiency of the up-conversion film can be further stably improved.

[0035] The thickness of the up-conversion film is, for example, 5 μm to 200 μm, preferably 10 μm to 150 μm, and more preferably 15 μm to 100 μm. If the thickness of the up-conversion film is in such a range, the color developing portion can be well dispersed throughout the thickness direction of the film, and the desired up-conversion can be stably realized.

[0036] C. Detailed contents of the photonic up-conversion film

[0037] As described above, with respect to the photonic upconversion film, the relaxation time (average relaxation time) measured by TD-NMR at 298 K (24.85°C) is less than 210 ms, preferably 150 ms or less, more preferably 90 ms or less, and further preferably 80 ms or less. As a method for measuring the relaxation time (average relaxation time), for example, a spin echo method is used. The lower limit of the relaxation time (average relaxation time) measured by TD-NMR at 298 K is typically 20 μs, and is typically 6 μs. In addition, the details of the method for measuring the relaxation time (average relaxation time) will be described in the Examples to be described later.

[0038] If the relaxation time obtained by TD-NMR at 298 K is within such a range, it is presumed that the color-developing portion contained in the upconversion film exists in a form in which energy transfer can be efficiently performed at 298 K. In addition, it is presumed that a high-efficiency upconversion luminescent body can be obtained by reducing energy loss due to non-radiative deactivation in the color-developing portion. Therefore, in the color-developing portion, molecular diffusion of the sensitizing component and the luminescent component can be performed, and energy can be efficiently transmitted and received.

[0039] In one embodiment, the color-developing portion contains a medium capable of dissolving and / or dispersing the sensitizing component and the luminescent component. Therefore, in the color-developing portion, molecular diffusion of the sensitizing component and the luminescent component can be smoothly performed, and the luminescent efficiency of the upconversion film can be further improved.

[0040] D. Medium of Color-Developing Portion

[0041] As the medium, for example, a monomolecular liquid crystal compound and / or a solvent can be exemplified. The medium can be used alone or in combination.

[0042] If the color-developing portion contains a monomolecular liquid crystal compound, the absolute quantum yield of the upconversion film can be further improved.

[0043] The monomolecular liquid crystal compound can exhibit liquid crystallinity at 298 K (24.85°C), and can also exhibit crystallinity. The monomolecular liquid crystal compound can be a nematic liquid crystal compound, can be a smectic liquid crystal compound, or can be a cholesteric liquid crystal compound. The monomolecular liquid crystal compound is preferably a nematic liquid crystal compound.

[0044] The monomolecular liquid crystal compound exhibiting liquid crystallinity at 298 K (hereinafter, sometimes referred to as an ordinary temperature liquid crystal compound) typically has the ability to dissolve the sensitizing component and the luminescent component.

[0045] As the ordinary temperature liquid crystal compound, for example, cyanobiphenyls, cyanophenylcyclohexane esters, alkoxyphenyldiphenylacetylenes, and Schiff bases can be exemplified. The ordinary temperature liquid crystal compound can be used alone or in combination.

[0046] Among the room temperature liquid crystal compounds, for example, the following can be mentioned: cyanobiphenyls, cyanophenylcyclohexane esters, alkoxyphenyldiphenylacetylenes.

[0047] As the cyanobiphenyls, for example, the following can be mentioned: 4-cyano-4'-pentylbiphenyl, 4-cyano-4'-hexylbiphenyl, 4-cyano-4'-heptylbiphenyl, 4-cyano-4'-n-octylbiphenyl, and the like.

[0048] As the cyanophenylcyclohexane esters, for example, the following can be mentioned: 4-cyano-4'-pentylphenylcyclohexane ester, 4-cyano-4'-butylphenylcyclohexane ester, 4-cyano-4'-propylphenylcyclohexane ester, and the like.

[0049] As the alkoxyphenyldiphenylacetylenes, for example, the following can be mentioned: 4-ethoxy-4'-butylphenyldiphenylacetylene, 4-methoxy-4'-ethylphenyldiphenylacetylene, 4-butoxy-4'-propylphenyldiphenylacetylene, and the like.

[0050] A single molecule liquid crystal compound (hereinafter, sometimes referred to as a high temperature liquid crystal compound) which exhibits crystallinity at 298 K can be used to sensitize the sensitizing component and the light emitting component, or disperse the sensitizing component and the light emitting component at 298 K (24.85°C).

[0051] As the high temperature liquid crystal compounds, for example, the following can be mentioned: cyanophenylcyclohexanes, cyanophenyl esters, alkoxyphenyl esters, alkoxyphenylcyclohexane esters, alkoxy cyanobiphenyls. The high temperature liquid crystal compounds can be used alone or in combination.

[0052] Among the high temperature liquid crystal compounds, for example, the following can be mentioned: cyanophenylcyclohexanes, cyanophenyl esters, alkoxyphenyl esters, alkoxyphenylcyclohexane esters, alkoxy cyanobiphenyls.

[0053] As the cyanophenylcyclohexanes, for example, the following can be mentioned: 4-cyano-4'-pentylphenylcyclohexane, 4-cyano-4'-propylphenylcyclohexane, and the like.

[0054] As the cyanophenyl esters, for example, the following can be mentioned: 4-cyano-4'-nonylphenyl ester, 4-cyano-4'-ethylphenyl ester, 4-cyano-4'-butylphenyl ester, and the like.

[0055] As the alkoxyphenyl esters, for example, the following can be mentioned: 4-pentyl-4'-hexyloxyphenyl ester, 4-pentyl-4'-methoxyphenyl ester, 4-ethyl-4'-hexyloxyphenyl ester, and the like.

[0056] As the alkoxycarbonyl biphenyls, for example, 4-carbomethoxy-4'-pentyl biphenyl, 4-carboethoxy-4'-butyl biphenyl, 4-carboethoxy-4'-propyl biphenyl, and the like 4-carboalkoxy-4'-alkyl biphenyls can be exemplified.

[0057] As the alkoxycarbonyl biphenyls, for example, 4-carbomethoxy-4'-pentyl biphenyl, 4-carboethoxy-4'-butyl biphenyl, 4-carboethoxy-4'-propyl biphenyl, and the like 4-carboalkoxy-4'-alkyl biphenyls can be exemplified.

[0058] The solvent is typically in a liquid state at 298 K (24.85°C). In addition, the solvent can also be in a solid state at 298 K (24.85°C), as long as it is a material having a melting point that becomes a liquid state at the temperature involved in the production process of the upconversion film or upconversion body, or a material that can lower the melting point by mixing organic solvents, and the like can also be used. The solvent is typically capable of dissolving the sensitizing component and the luminescent component.

[0059] The viscosity of the solvent at 23°C is, for example, 0.6 mPa-s or more, and preferably 4.0 mPa-s or more. As the viscosity of the solvent, any suitable viscoelasticity measuring device (for example, a rheometer, trade name "RS-600", manufactured by HAAKE) can be used to measure the solution viscosity (mPa-s) of the coating liquid at a shear rate of 800 rpm at 23°C.

[0060] The boiling point of the solvent is, for example, 60°C or more, preferably 80°C or more, more preferably 150°C or more, and further preferably 200°C or more. The upper limit of the boiling point of the solvent is typically 300°C, and typically 400°C. In addition, in the case where a plurality of solvents are used in combination as the medium, the temperature at which the weight reduction rate is 95% when the mixed solvent is temperature- raised from 30°C to 400°C at 10°C / min in TG / DTA (Thermo gravimetry / Differential Thermal Analysis) is defined as the boiling point of the mixed solvent.

[0061] When the viscosity and / or the boiling point of the solvent contained in the color-developing portion is in such a range, the solvent is less likely to volatilize during the process, and energy loss due to non-radiative deactivation can be suppressed, and thus the absolute quantum yield of the upconversion film can be further improved.

[0062] As the solvent, for example, an organic solvent can be exemplified, and as a more specific example, benzenedicarboxylates, glycerin, triglyceride compounds, ionic liquids, and the like can be exemplified. The solvent can be used alone or in combination. Among the solvents, benzenedicarboxylates and triglyceride compounds can be preferably exemplified.

[0063] Examples of phthalate esters include dimethyl phthalate, dibutyl phthalate, and dioctyl phthalate.

[0064] Examples of triglyceride compounds include: tridecanoic acid glyceride (1,2,3-tridecanoylglycerol), triacetic acid glyceride (glycerol triacetate), tricaprylic acid glyceride (tricaprylic glycerol triacetate), and trihexanoic acid glyceride (trihexanoic glycerol triacetate).

[0065] In such a medium, room-temperature liquid crystal compounds are preferred. When the medium contains a room-temperature liquid crystal compound, the luminous efficiency of the upconversion film can be further improved.

[0066] The medium may contain additives. Examples of additives include fatty acid oils such as MCT (Medium Chain Triglyceride) oil; and saturated hydrocarbons such as hexadecane and liquid paraffin. Unlike solvents, additives are defined as materials with low pigment solubility. Low pigment solubility means that when the pigment is added to the additive and mixed at room temperature and pressure (23°C, 0.1 MPa), the pigment concentration is, for example, below 0.1 mM. By including additives in the medium, the viscosity, refractive index, or phase transition temperature of the medium can be appropriately adjusted.

[0067] E. Matrix

[0068] Materials that can be used as a matrix include, for example, resin and glass.

[0069] In one embodiment, the matrix comprises a resin. The resin is typically a water-soluble resin.

[0070] As a water-soluble resin, any suitable water-soluble resin can be used, as long as it forms a matrix. Specific examples of water-soluble resins include: polystyrene sulfonates, polyethylene oxide, polyethyleneimine, polyvinyl alcohol-based resins, and cellulose-based resins. For example, sodium polystyrene sulfonate can be used as a polystyrene sulfonate. For example, polyethyleneimine hydrochloride can be used as a polyethyleneimine. For example, polyvinyl alcohol, amine-modified polyvinyl alcohol, and carboxylic acid-modified polyvinyl alcohol can be used as polyvinyl alcohol. For example, hydroxyethyl cellulose can be used as a cellulose-based resin.

[0071] Among such water-soluble resins, preferred examples include: polyethylene oxide and polyvinyl alcohol resins, with polyvinyl alcohol resins being more preferred examples.

[0072] When the resin constituting the matrix contains polyethylene oxide and / or polyvinyl alcohol-based resins, the luminous efficiency of the upconversion membrane can be stably improved.

[0073] The distance Ra between the resin constituting the matrix and the Hansen solubility parameter (HSP) of the sensitizing and luminescent components is, for example, 10 (MPa). 1 / 2 The above, for example, is 11 (MPa). 1 / 2 The preferred value is 12 MPa. 1 / 2 The above is preferred, with 15 MPa being more ideal. 1 / 2 The above is further optimized to 18 (MPa). 1 / 2 That's all. On the other hand, the distance Ra between the resin constituting the matrix and the HSP of the sensitizing component and the luminescent component is, for example, 25 (MPa). 1 / 2 The preferred pressure is 23 MPa. 1 / 2 Hereinafter, 21 (MPa) is preferred. 1 / 2 The following applies. A HSP distance Ra within this range indicates that the resin constituting the matrix has a low affinity for both the sensitizing and luminescent components. As a result, the migration of the sensitizing and luminescent components into the matrix is ​​significantly suppressed, allowing them to exist stably in the chromogenic region.

[0074] HSP divides the Hildebrand solubility parameter into three components: dispersion force (δD), permanent dipole intermolecular force (δP), and hydrogen bonding force (δH), represented by vectors plotted in three-dimensional space. Parameters with similar vectors can be judged to have higher solubility. That is, the similarity of solubility can be determined based on their HSP distance Ra. The definition and calculation of HSP are described in Charles M. Hansen's *Hansen Solubility Parameters: A Users Handbook* (CRC Press, 2007). For HSP values, there are known values ​​for various resins and solvents, which can be used directly, or values ​​calculated using computer software, namely HSPiP (Hansen Solubility Parameters in Practice). Furthermore, HSPiP also has a database of resins and solvents.

[0075] Resin (HSP value: δD) R δP R δH R ) with sensitizing or luminescent components (HSP value: δD) C δP C δH C The HSP distance Ra of ) can be calculated using equation (1).

[0076] Ra={4×(δD R -δD C ) 2 +(δP R -δPC 2 + (δH R - δH C 2 1 / 2 ... (1)

[0077] In formula (1), δD R represents the dispersion force of the resin, δP R represents the permanent dipole intermolecular force of the resin, δH R represents the hydrogen bond force of the resin, δD C represents the dispersion force of the sensitizing component or the light-emitting component, δP C represents the permanent dipole intermolecular force of the sensitizing component or the light-emitting component, and δH C represents the hydrogen bond force of the sensitizing component or the light-emitting component.

[0078] F. Sensitizing component and light-emitting component

[0079] F-1. Sensitizing component

[0080] According to the mechanism described in item A, the sensitizing component absorbs light (incident light), becomes an excited triplet state by intersystem crossing from an excited singlet state, and undergoes triplet-triplet energy transfer to the light-emitting component. As the sensitizing component, for example, a compound having a porphyrin structure, a phthalocyanine structure, or a fullerene structure can be cited. Such a compound can contain a metal atom within the molecule. As the metal atom, for example, Pt, Pd, Zn, Ru, Re, Ir, Os, Cu, Ni, Co, Cd, Au, Ag, Sn, Sb, Pb, P, As can be cited. Pt, Pd, Os are preferred. Further, specific examples of the compound that can function as the sensitizing component are described later in item F-3.

[0081] ​​​The sensitizing component can be a quantum dot. The quantum dot can be composed of any suitable material. The quantum dot preferably can include an inorganic material, more preferably can include an inorganic conductor material or an inorganic semiconductor material. As a semiconductor material, for example, there can be cited: Group II-VI, Group III-V, Group IV-VI, and Group IV semiconductors. As specific examples, there can be cited: Si, Ge, Sn, Se, Te, B, C (including diamond), P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si3N4, Ge3N4, Al2O3, (Al, Ga, In)2(S, Se, Te)3, Al2CO, and combinations (composites) thereof.

[0082] The sensitizing component is preferably included in the up-conversion film at a ratio of 7.00 x 10 -9 mol to 5.00 x 10 -6 mol, more preferably 1.00 x 10 -8 mol to 3.00 x 10 -6 mol, further preferably 4.50 x 10 -8 mol to 2.00 x 10 -6 mol, relative to the matrix 1 g.

[0083] If the content of the sensitizing component is within such a range, triplet excitons can be sufficiently generated, and the efficiency of achieving triplet-triplet annihilation can be improved.

[0084] F-2. Luminescent Component

[0085] According to the mechanism described in item A, the light-emitting component receives the transfer of triplet-triplet energy from the sensitizing component, and generates an excited triplet state, and the light-emitting component molecules in the excited triplet state approach each other at a distance at which diffusion, collision, or energy transfer can occur, whereby triplet-triplet annihilation occurs, and an excited singlet state of a higher energy level is generated. As the light-emitting component, various compounds having a condensed aromatic ring are known. As specific examples, compounds having a naphthalene structure, an anthracene structure, a pyrene structure, a perylene structure, a tetracene structure, a Bodipy structure (boron dipyrromethene structure), a diketopyrrolopyrrole structure can be listed. Further, specific examples of compounds that can function as the light-emitting component are described later in item F-3.

[0086] The light-emitting component is contained in the upconversion film at a ratio of preferably 5.00 x 10 -6 mol to 7.00 x 10 -5 mol, more preferably 6.00 x 10 -6 mol to 6.00 x 10 -5 mol, further preferably 7.00 x 10 -6 mol to 5.00 x 10 -5 mol, relative to the matrix 1 g.

[0087] If the content of the light-emitting component is within such a range, triplet excitons received from the sensitizing dye can sufficiently diffuse among the light-emitting component molecules.

[0088] The blending ratio (molar ratio) of the sensitizing component to the light-emitting component (sensitizing component: light-emitting component) is, for example, 1:10 to 1:7000, preferably 1:25 to 1:3000, more preferably 1:30 to 1:200, further preferably 1:35 to 1:100. If the blending ratio is within such a range, triplet excitons generated from the sensitizing component efficiently move to the light-emitting dye, and deactivation among the light-emitting dyes can be suppressed as much as possible, and triplet-triplet annihilation is favorably achieved.

[0089] F-3. Combination of sensitizing component and light-emitting component

[0090] The preferred combination of the sensitizing component and the light-emitting component corresponding to the wavelengths of the incident light and the upconverted light is as shown below.

[0091] The sensitizing component that absorbs light of a wavelength range λ1 of 510 nm to 550 nm is the following compound, and the light-emitting component that emits (radiates) light of a wavelength range λ2 of 400 nm to 500 nm is the following compound. This combination can upconvert green light into blue light.

[0092] <Sensitizing component>

[0093] [Chemical Formula 1]

[0094]

[0095] <Light-emitting component>

[0096] [Chemical Formula 2]

[0097]

[0098] [Chemical Formula 3]

[0099]

[0100] The sensitizing component that absorbs light in the wavelength range λ1 of 610 nm to 650 nm is the following compound, and the light-emitting component that emits light in the wavelength range λ2 of 500 nm to 600 nm is the following compound. This combination can up-convert red light into yellow-green light.

[0101] <Sensitizing component>

[0102] [Chemical Formula 4]

[0103]

[0104] <Light-emitting component>

[0105] [Chemical Formula 5]

[0106]

[0107] The sensitizing component that absorbs light in the wavelength range λ1 of 700 nm to 810 nm is the following compound, and the light-emitting component that emits light in the wavelength range λ2 of 500 nm to 700 nm is the following compound. This combination can up-convert near-infrared light into visible light (red light to green light).

[0108] <Sensitizing component>

[0109] [Chemical Formula 6]

[0110]

[0111] <Light-emitting component>

[0112] [Chemical Formula 7]

[0113]

[0114] [Chemical Formula 8]

[0115]

[0116] The sensitizing component that absorbs light in the wavelength range λ1 of 700 nm to 730 nm is the following compound, and the luminescent component that emits light in the wavelength range λ2 of 400 nm to 500 nm is the following compound. This combination can up-convert near-infrared light into visible light (blue light).

[0117] < Sensitizing component >

[0118] [Chemical Formula 9]

[0119]

[0120] < Luminescent component >

[0121] [Chemical Formula 10]

[0122]

[0123] The sensitizing component that absorbs light in the wavelength range λ1 of 410 nm to 500 nm is the following compound, and the luminescent component that emits light in the wavelength range λ2 of 300 nm to 400 nm is the following compound. This combination can up-convert blue light into ultraviolet light.

[0124] < Sensitizing component >

[0125] [Chemical Formula 11-1]

[0126]

[0127] [Chemical Formula 11-2]

[0128]

[0129] < Luminescent component >

[0130] [Chemical Formula 12-1]

[0131]

[0132] [Chemical Formula 12-2]

[0133]

[0134] [Chemical Formula 12-3]

[0135]

[0136] The sensitizing component that absorbs light in the wavelength range λ1 in the vicinity of 630 nm to 640 nm (for example, 635 nm) is a quantum dot (CdSe, CdSe / ZnS), and the luminescent component that emits light in the wavelength range λ2 in the vicinity of 440 nm to 460 nm (for example, 450 nm) is the following compound. This combination can up-convert near-infrared light into visible light (blue light).

[0137] < Luminescent component >

[0138] [Chemical Formula 13]

[0139]

[0140] The sensitizing component that absorbs light in the wavelength range λ1 in the vicinity of 970 nm to 990 nm (for example, 980 nm) is a quantum dot (PbSe, PbS / CdS), and the luminescent component that emits light in the wavelength range λ2 in the vicinity of 550 nm to 570 nm (for example, 560 nm) is the following compound. This combination can up-convert near-infrared light into visible light (green light).

[0141] < Luminescent component >

[0142] [Chemical Formula 14]

[0143]

[0144] G. Surfactant

[0145] The photonic up-conversion film can further contain a surfactant. When the photonic up-conversion film contains a surfactant, the dispersibility of the color-developing portion in the matrix can be improved. As the surfactant, for example, a cationic surfactant such as cetyltrimethylammonium bromide (CTAB), an anionic surfactant, a nonionic surfactant can be exemplified, and CTAB can be preferably exemplified.

[0146] The addition ratio of the surfactant is, for example, 0 parts by mass to 200 parts by mass, and is preferably 1 part by mass to 50 parts by mass, with respect to 100 parts by mass of the medium.

[0147] H. Method for manufacturing photonic up-conversion film

[0148] In one embodiment, the method for manufacturing a photonic up-conversion film includes the following steps: preparing an emulsion from an aqueous solution containing a water-soluble resin, and a solution or dispersion of a sensitizing component and a luminescent component (hereinafter, sometimes collectively referred to as "pigment solution or the like"); applying the emulsion to a substrate to form a coating film; and drying the coating film. Hereinafter, each step is described in detail.

[0149] < Preparation of emulsion >

[0150] In the preparation of the emulsion, first, a pigment solution or the like according to the up-conversion film to be prepared is prepared.

[0151] In the case where the up-conversion film (UC film) is prepared using a medium having fluidity at 298 K (24.85°C), the medium (specifically, the room-temperature liquid crystal compound and / or the solvent) described in the above item C is added with an organic solvent as necessary, and then the sensitizing component and the light-emitting component described in the above item F are added, followed by stirring.

[0152] By adding the organic solvent to the medium, the solubility of the sensitizing component and the light-emitting component can be improved. In particular, in the case where the fluid medium is the room-temperature liquid crystal compound, it is preferable to add the organic solvent to the room-temperature liquid crystal compound.

[0153] As the organic solvent, for example, a solvent having volatility can be used. As specific examples of such a solvent, ethers such as tetrahydrofuran; halogenated hydrocarbons such as chloroform and dichloromethane; and toluene can be listed. The organic solvent can be used alone or in combination. Among such organic solvents, ethers can be preferably listed, and tetrahydrofuran can be more preferably listed.

[0154] The addition ratio of the organic solvent is, for example, 0 parts by mass to 200 parts by mass, and preferably 80 parts by mass to 120 parts by mass, with respect to 100 parts by mass of the fluid medium.

[0155] In addition, the above additive can also be added to the medium. The additive can be added to the medium together with the organic solvent, or the additive can be added to the medium alone. When the additive is added to the medium, the viscosity, the refractive index, and / or the phase transition temperature of the medium can be appropriately adjusted.

[0156] The addition ratio of the additive is, for example, 0 parts by mass to 200 parts by mass, and preferably 5 parts by mass to 100 parts by mass, with respect to 100 parts by mass of the medium.

[0157] In addition, a plurality of liquid crystal compounds, organic solvents, and other additives can be mixed in an arbitrary mixing ratio.

[0158] In addition, in the case where the up-conversion film is prepared using the high-temperature liquid crystal compound (UC film containing the high-temperature liquid crystal compound), the high-temperature liquid crystal compound described in the above item C is heated to be in a liquid crystal state, and then the above organic solvent is added as necessary, and the above sensitizing component and the above light-emitting component are added, followed by stirring.

[0159] The heating temperature of the high-temperature liquid crystal compound can be arbitrarily and appropriately adjusted depending on the high-temperature liquid crystal compound. The heating temperature of the high-temperature liquid crystal compound is, for example, the phase transition temperature T K-N above, and the phase transition temperature T N-I below.

[0160] By adding an organic solvent to the high-temperature liquid crystal compound in the liquid crystal state, the solubility of the sensitizing component and the light-emitting component can be improved. The addition ratio of the organic solvent is, for example, 0 parts by mass to 200 parts by mass, and preferably 80 parts by mass to 120 parts by mass, with respect to 100 parts by mass of the high-temperature liquid crystal compound.

[0161] By these, a pigment solution or the like suitable for manufacturing a UC film having a relaxation time of less than 210 ms can be prepared. The pigment solution or the like is typically a medium in which the sensitizing component and the light-emitting component are dissolved and / or dispersed.

[0162] The sensitizing component concentration in these pigment solutions or the like can be, for example, 0.001 mM to 1 mM, and the light-emitting component concentration can be, for example, 1 mM to 50 mM.

[0163] In addition, an aqueous solution of the water-soluble resin described in the above item E is prepared. The concentration of the aqueous solution can be, for example, 3% by weight to 20% by weight, and for example, 5% by weight to 10% by weight.

[0164] Next, the aqueous solution of the water-soluble resin is mixed with the pigment solution or the like in such a manner that the blending amount of the sensitizing component and the light-emitting component with respect to the water-soluble resin (matrix) is within the desired range described in the above item F. More specifically, the aqueous solution of the water-soluble resin is mixed with the pigment solution or the like, and the mixture is emulsified with a homogenizer. At this time, if necessary, the above surfactant is added. By this, the pigment solution or the like droplets are suitably dispersed in the aqueous solution of the water-soluble resin, and an emulsion can be prepared. The obtained emulsion can also be deaerated if necessary. In addition, the volatile component (for example, the organic solvent) contained in the obtained emulsion can be removed by distillation under reduced pressure. By this, the concentration of the sensitizing component and the light-emitting component in the emulsion can be improved. The volume fraction of the emulsion particles is, for example, 5% to 60%. The average particle diameter of the emulsion particles is, for example, 0.1 μm to 10 μm. If the volume fraction and / or the average particle diameter of the emulsion particles are within such ranges, a color-developing portion having a desired size can be formed in the form of a dispersed phase in the up-conversion film.

[0165] <Formation and drying of the coating film>

[0166] Next, the emulsion obtained above is applied to a substrate to form a coating film. As the substrate, resin sheets or glass can be typically exemplified. As the resin constituting the resin sheet, any suitable resin can be used. As specific examples, transparent resins such as polyimide-based resins, cellulose-based resins such as triacetyl cellulose (TAC), or polyester-based resins such as polyethylene terephthalate (PET), polyvinyl alcohol-based resins, polycarbonate-based resins, polyamide-based resins, polyethersulfone-based resins, polysulfone-based resins, polystyrene-based resins, polynorbornene-based resins, polyolefin-based resins, (meth)acrylic-based resins, and acetate-based resins can be exemplified. In addition, thermosetting resins such as (meth)acrylic-based resins, urethane-based resins, (meth)acrylic urethane-based resins, epoxy-based resins, and silicone-based resins, or ultraviolet-curable resins can be exemplified. Further, vitreous polymers such as silicone-based polymers can be exemplified.

[0167] The application method can use any suitable method. As specific examples, roll coating, spin coating, wire bar coating, dip coating, die coating, curtain coating, spray coating, and blade coating (notched wheel coating, etc.) can be exemplified. In addition, a barrel coater can be used to form the coating film. In this case, the film-forming roll (drying roll) of the barrel coater can function as the substrate. The film-forming roll (drying roll) is formed of, for example, metals such as nickel, chromium, copper, iron, and stainless steel. The temperature of the emulsion at the time of application can be, for example, 10°C to 60°C. The thickness of the applied film can be adjusted so that the thickness of the obtained upconversion film is within the desired range (for example, 5 μm to 200 μm) described in item B above. The thickness of the applied film can be, for example, 100 μm to 1000 μm.

[0168] Next, the coating film is dried. The drying is performed by any suitable means such as an oven. The drying temperature can be, for example, 60°C to 90°C, and the drying time can be, for example, 20 minutes to 60 minutes. By the drying, a dried coating film having substantially the same thickness as the obtained upconversion film can be obtained. The dried coating film can be typically naturally cooled to room temperature (23°C).

[0169] By the above method, an upconversion film is prepared. The upconversion film can be peeled from the substrate, or can be used as a laminate with the substrate without being peeled therefrom.

[0170] I. Uses of the Photonic Upconversion Film

[0171] The upconversion film described in items A to H above can be used for any suitable industrial product. As the industrial product, for example, laminates and energy conversion devices can be exemplified. Therefore, one embodiment of the present application also includes laminates and energy conversion devices using such an upconversion film.

[0172] The laminate has the upconversion film described in items A to H above, and any suitable film (layer) laminated to the upconversion film.

[0173] The energy conversion device can have at least the upconversion film described in items A to H above, and can further have any suitable configuration in addition to the upconversion film.

[0174] I-1. Stack

[0175] The first protective layer and the second protective layer can be provided in the stack, respectively on the light incident surface and the light exit surface of the upconversion film. Each of the first protective layer and the second protective layer can be omitted as desired. In addition, any suitable optical member can be provided between the upconversion film and the first protective layer, and / or between the upconversion film and the second protective layer, as long as the effects of the present application can be obtained.

[0176] In one embodiment, the stack has a configuration in which the first protective layer to the second protective layer are integrated. Here, the "first protective layer to the second protective layer are integrated" means that each member constituting the stack from the first protective layer to the second protective layer is integrally connected as a whole. The integration can be performed, for example, by adhering adjacent members to each other via an adhesive layer, a bonding agent layer, or the like. In addition, a layer having a different function such as an overcoat layer can be directly applied to the photonic upconversion film. It is preferable that the first protective layer, the upconversion film, the second protective layer, and any protective layer be integrated via an adhesive layer.

[0177] The overcoat layer is composed of any suitable material. As the material of the overcoat layer, for example, an acrylic resin, an epoxy resin, or the like can be listed.

[0178] In another embodiment, the stack has a configuration in which the first protective layer and the second protective layer are not integrated. Here, the "first protective layer and the second protective layer are not integrated" means a state in which at least one member constituting the stack from the first protective layer to the second protective layer is simply stacked on one or both of the adjacent members. The stack in this embodiment can have, for example, a configuration in which the first protective layer, the upconversion film, and the second protective layer are sequentially provided without passing through an adhesive layer. In addition, for example, the stack in this embodiment can have a configuration in which the first protective layer and the upconversion film are integrated via an adhesive layer, and the second protective layer is provided on the light exit side of the integrated stack without passing through an adhesive layer. In addition, for example, the stack in this embodiment can have a configuration in which the upconversion film and the second protective layer are integrated via an adhesive layer, and the first protective layer is provided on the light incident side of the integrated stack without passing through an adhesive layer.

[0179] I-2. Protective layer

[0180] The first protective layer and the second protective layer are each formed of any suitable film that can be used as a protective layer for the upconversion film. As specific examples of materials that are principal components of the film, mention can be made of: cellulose-based resins such as triacetyl cellulose (TAC), or transparent resins such as polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based, acetate-based, and the like. In addition, mention can also be made of: thermosetting resins or ultraviolet-curable resins such as (meth)acrylic-based, urethane-based, (meth)acrylic urethane-based, epoxy-based, silicone-based, and the like, inorganic materials such as glass or silica, and the like. Furthermore, mention can also be made of glassy polymers such as silicone-based polymers, and the like. In addition, a polymer film described in Japanese Patent Laid-Open No. 2001-343529 (WO 01 / 37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imino group in a side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in a side chain can be used, for example, mention can be made of: a resin composition containing an alternating copolymer formed of isobutylene and N-methyl maleimide, and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extrusion molded product of the above-described resin composition.

[0181] J. Photon upconversion body

[0182] In the above Items A to H, the upconversion film is described in detail. However, the film shape is not limited, as long as the upconversion can be performed in a solid state.

[0183] The photon upconversion body has a solid state at normal temperature (23°C) and normal pressure (0.1 MPa). As the shape of the photon upconversion body, mention can be made of, for example: a crystal or a powder, a gel shape, and the like.

[0184] With regard to the photon upconversion body, the same description as the upconversion film is given, except for the solution state. Therefore, the description of the photon upconversion body is omitted.

[0185] Example

[0186] Hereinafter, the present application will be specifically described by way of examples, but the present application is not limited by these examples. Furthermore, unless otherwise specified, "parts" and "%" in the examples are based on weight.

[0187] Example 1

[0188] 1. Preparation of DMP solution of sensitizing component and light-emitting component

[0189] In a glove box, platinum octaethylporphyrin (PtOEP: the following chemical formula) as a sensitizing component and 9,10-diphenylanthracene (DPA: the following chemical formula) as a light emitting component were dissolved in dimethyl phthalate (DMP) to prepare a DMP solution of the sensitizing component and the light emitting component. In the solution, the concentration of the sensitizing component was 2.39 x 10 -7 M, and the concentration of the light emitting component was 4.78 x 10 -5 M. That is, the molar ratio of the sensitizing component to the light emitting component was 1:200. The prepared solution was sealed in a vial and stored before the emulsification step.

[0190] < Sensitizing Component >

[0191] [Chemical Formula 15]

[0192]

[0193] < Light Emitting Component >

[0194] [Chemical Formula 16]

[0195]

[0196] 2. Preparation of Emulsion

[0197] To an aqueous solution of polyvinyl alcohol (PVA) (9 mass%) 5 g, the above obtained solution 0.4 ml was added. While injecting the solution with a tube having an inner diameter of 0.75 mm, stirring was performed by a homogenizer (17500 rpm) until the whole was emulsified. To the obtained emulsion, argon gas was blown for about 2 minutes, and using a stirrer (THINKY), stirring was performed for 5 minutes in a mixing mode (2000 rpm) and for 5 minutes in a defoaming mode (2200 rpm). In this way, an emulsion was prepared. Further, the PVA used was PVA having a polymerization degree of 1700 and a saponification degree of 99%.

[0198] 3. Formation of Upconversion Film

[0199] Using an applicator, the above obtained emulsion was applied to a polyimide film (substrate) at a coating thickness of 700 μm. The laminate of the coated film / polyimide film was dried by a constant temperature bath. The drying temperature was 80°C, and the drying time was 30 minutes. After drying, the laminate was naturally cooled to room temperature (23°C). Finally, the dried coated film was peeled from the polyimide film to obtain an upconversion film (thickness 63 μm). Further, the steps after the preparation of the emulsion were performed in air, in the dark (under an environment where only light for a dark room is used).

[0200] < Example 2 >

[0201] The DMP solution of the sensitizing component and the light-emitting component was changed to a liquid crystal solution of the sensitizing component and the light-emitting component prepared in the following manner, and otherwise, an up-conversion film was obtained in the same manner as in Example 1.

[0202] A liquid crystal solvent was prepared by adding tetrahydrofuran (THF) 100 parts by mass to 5CB (4-cyano-4'-pentylbiphenyl) 100 parts by mass, and stirring and mixing at room temperature (23°C). Next, PtOEP as the sensitizing component and DPA as the light-emitting component were dissolved in the liquid crystal solvent, thereby preparing a liquid crystal solution of the sensitizing component and the light-emitting component.

[0203] <Example 3>

[0204] 5CB was changed to 7CB (4-cyano-4'-heptylbiphenyl), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0205] <Example 4>

[0206] The DMP solution of the sensitizing component and the light-emitting component was changed to a liquid crystal solution of the sensitizing component and the light-emitting component prepared in the following manner, and otherwise, an up-conversion film was obtained in the same manner as in Example 1.

[0207] A liquid crystal solvent was prepared by heating 5OCB (4-cyano-4'-pentoxybiphenyl) 100 parts by mass to 60°C to be in a liquid crystal state, adding tetrahydrofuran 100 parts by mass, and stirring and mixing with a hot water bath. Next, PtOEP as the sensitizing component and DPA as the light-emitting component were dissolved in the liquid crystal solvent, thereby preparing a liquid crystal solution of the sensitizing component and the light-emitting component.

[0208] <Example 5>

[0209] The PVA aqueous solution was changed to a polyethylene oxide (PEO) aqueous solution (molecular weight 200,000) (9 mass%), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0210] <Example 6>

[0211] The sensitizing component was changed to meso-tetraphenyl-tetraanthracyclopalladium (PdTPTAP: the following chemical formula), and the light-emitting component was changed to rubrene (the following chemical formula), and otherwise, an up-conversion film was obtained in the same manner as in Example 2. The PdTPTAP concentration in the solution was set to 0.554 mM, and the rubrene concentration was set to 20 mM. That is, the molar ratio of the sensitizing component: light-emitting component was set to 1:36.

[0212] <Sensitizing Component>

[0213] [Chemical Formula 17]

[0214]

[0215]

[0216] [Chemical Formula 18]

[0217]

[0218] <Example 7>

[0219] A liquid crystal solvent was prepared by adding, to 5CB (4-cyano-4'-pentylbiphenyl) 100 parts by mass, as a sensitizing component, PtOEP, as a luminescent component, DPA, tetrahydrofuran (THF) 100 parts by mass, and MCT oil 5 parts by mass, and stirring and mixing at room temperature (23°C). To 1 mL of an aqueous solution of CTAB (surfactant aqueous solution) 1 mass%, the above liquid crystal solution was added, and stirring was performed with an ultrasonic homogenizer, whereby an emulsion solution was prepared. To an aqueous solution of polyvinyl alcohol (PVA) (9 mass%) 5 g, the above obtained solution 1.8 mL was added. The subsequent procedure was the same as in Example 1, and an upconversion film was obtained.

[0220] <Example 8>

[0221] 5CB was changed to PCH5CN (4-cyano-4'-pentylphenylcyclohexane), and otherwise, an upconversion film was obtained in the same manner as in Example 7.

[0222] <Example 9>

[0223] 5CB was changed to 5OCB (4-cyano-4'-pentyloxybiphenyl), and otherwise, an upconversion film was obtained in the same manner as in Example 7.

[0224] <Example 10>

[0225] MCT oil 5 parts by mass was changed to hexadecane 5 parts by mass, and otherwise, an upconversion film was obtained in the same manner as in Example 7.

[0226] <Example 11>

[0227] MCT oil 5 parts by mass was changed to liquid paraffin 5 parts by mass, and otherwise, an upconversion film was obtained in the same manner as in Example 7.

[0228] <Example 12>

[0229] The sensitizing component was changed to meso-tetraphenyl-tetraanthracyclopalladium (PdTPTAP: the above chemical formula), and the luminescent component was changed to rubrene (the above chemical formula), and otherwise, an upconversion film was obtained in the same manner as in Example 7. The respective concentrations were the same as in Example 6. ​

[0230] Example 13

[0231] 5CB was changed to ZLI1052 (a mixed liquid crystal of PE105 (4-methoxybenzoic acid 4-pentylphenyl ester) and PE605 (4-hexyloxybenzoic acid 4-pentylphenyl ester)), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0232] Example 14

[0233] 5CB was changed to ZLI1132 (a mixed liquid crystal of PCH-3CN (4-cyano-4'-propylphenylcyclohexane), PCH-5CN (4-cyano-4'-pentylphenylcyclohexane), PCH-7CN (4-cyano-4'-phenylcyclohexane), and BCH-5CN (4-cyano-4'-pentylbiphenylcyclohexane)), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0234] Example 15

[0235] 5CB was changed to ZLI1083 (a mixed liquid crystal of PCH-3CN (4-cyano-4'-propylphenylcyclohexane), PCH-5CN (4-cyano-4'-pentylphenylcyclohexane), and PCH-7CN (4-cyano-4'-phenylcyclohexane)), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0236] Example 16

[0237] 5CB was changed to E7 (a mixed liquid crystal of 5CB (4-cyano-4'-pentylbiphenyl), 7CB (4-cyano-4'-heptylbiphenyl), 80CB (4-cyano-4'-n-octyloxybiphenyl), and 5CT (4-cyano-4'-pentyl-p-terphenyl)), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0238] Example 17

[0239] 5CB was changed to E8 (a mixed liquid crystal of 5CB (4-cyano-4'-pentylbiphenyl), 7CB (4-cyano-4'-heptylbiphenyl), 50CB (4-cyano-4'-pentyloxybiphenyl), 80CB (4-cyano-4'-n-octyloxybiphenyl), and 5CT (4-cyano-4'-pentyl-p-terphenyl)), and otherwise, an up-conversion film was obtained in the same manner as in Example 2.

[0240] Example 18

[0241] DMP was changed to tricaprin, and otherwise, an up-conversion film was obtained in the same manner as in Example 1.

[0242] Example 19

[0243] A liquid crystal solvent was prepared in the same order as in Example 4. In addition, a glass was set on a hot plate heated to 80°C, the liquid crystal solvent was disposed on the glass, and THF was volatilized. Thereby, an upconversion body in a crystalline shape was obtained.

[0244] Comparative Example 1

[0245] An upconversion film (thickness: 60 μm) was obtained in the same manner as in Example 1, except that DMP was changed to toluene.

[0246] Comparative Example 2

[0247] An upconversion film was obtained in the same manner as in Example 6, except that the crystalline solvent was changed to toluene.

[0248] Measurement of Relaxation Time by Time Domain Nuclear Magnetic Resonance Method (TD-NMR)

[0249] The upconversion film or upconversion body obtained in the above-described examples was cut into a long strip shape to make a sample. The dimension of the short side of the sample was 1.5 cm, and the dimension of the long side of the sample was 7 to 12 cm. Two to four samples were inserted into a sample tube.

[0250] Next, using a TD-NMR (pulsed NMR), the sample in the sample tube was measured at 298 K by a spin echo method. From the obtained free induction decay curve of the spin-spin relaxation of the 1H nucleus, analysis was performed by a non-linear least squares method, and the T2 relaxation time was calculated. The results are shown in Tables 1 to 3.

[0251] As to the measurement conditions, the repetition time was 10 s, the number of accumulations was 8, and the number of measurement points was 50. When the signal intensity of the first point of the chart was normalized to 1, the relative signal intensity of the final chart became 0.1 or less, and the relaxation time was analyzed.

[0252] In addition, using an analysis software "TDNMR-A Version 6.9 Rev 2.0" manufactured by BRUKER, Inc., fitting was performed in an exponential function type with a Weibull coefficient of 1, in accordance with the product manual. In the case where some samples were not suitable for a Weibull coefficient of 1, the best value was used in the range of 1 to 2.

[0253] Hereinafter, the measurement conditions are described.

[0254] Apparatus: TD-NMR (minispec mq20) manufactured by Bruker

[0255] Detected nucleus: 1 H

[0256] Measurement temperature: 298 K

[0257] Measurement method: Spin-echo method

[0258] Analysis method: Nonlinear least squares method

[0259] Scans: 8

[0260] Recycle delay: 10 sec

[0261] First 90-180 pulse separation: 0.0082

[0262] Final 90-180 pulse separation: adjusted to the conditions described above

[0263] Number of data points for fitting: 50

[0264] In the case where two or more components are detected in the obtained relaxation time, the obtained relaxation time is multiplied by the proton ratio, the average value is calculated from the relaxation time calculated by the sum of all components, and this average value is taken as the relaxation time.

[0265] < Absolute quantum yield measurement >

[0266] The upconversion luminescence absolute quantum yield (100% conversion) of the upconversion film or upconversion body (hereinafter, as a sample) obtained in the above examples and comparative examples was measured by an absolute quantum yield measurement system Quantaurus-QY Plus C11347-02 (manufactured by Hamamatsu Photonics, detection wavelength: 400 to 1100 nm).

[0267] In the absolute quantum yield measurement, a diode laser (808 nm, 200 mW, 532 nm, 75 mW, 460 nm, 500 mW, RGB Photonics) was used as an excitation source by adjusting the light intensity using a laser output and an ND (Neutral density) film. The light amount was adjusted so that the sample was irradiated with 27000 mW / cm 2 with 808 nm, 31000 mW / cm 2 with 532 nm, and 31000 mW / cm 2 with 460 nm, and measurement was performed.

[0268] The measured absolute quantum yields are shown in Tables 1 to 3.

[0269] <Transmittance Measurement>

[0270] The transmittance of the upconversion film or upconversion body obtained in the above examples and comparative examples was measured by a UV-VIS-NIR spectrometer UH4150 (manufactured by Hitachi High-Tech Corporation). In the transmittance measurement, the sample was directly set in front of an integrating sphere, and the total light transmittance was measured at a wavelength ranging from 400 nm to 800 nm at an interval of 1 nm. At this time, the average value of the transmittance obtained at 400 nm to 800 nm was used as the average transmittance.

[0271] The measured average transmittance is shown in Tables 1 to 3.

[0272] [Table 1]

[0273]

[0274] [Table 2]

[0275]

[0276] [Table 3]

[0277]

[0278] [Evaluation]

[0279] As is clear from Tables 1 to 3, the T2 relaxation time measured by the spin echo method of TD-NMR at 298 K of less than 210 ms can improve the absolute quantum yield, and can improve the upconversion luminescence efficiency.

[0280] [Industrial Applicability]

[0281] The photonic upconversion film and photonic upconversion body of the embodiments of the present application can be suitably used for solar cells or solar power generation, photocatalysts, biological imaging, optical devices, laminates, energy conversion devices, and the like.

Claims

1. A photon upconversion film comprising a colorimetric region and a matrix, The color-developing part includes at least Sensitizing components capable of absorbing light within the first wavelength range λ1; and The luminescent component capable of emitting light within a second wavelength range λ2, which is shorter than the first wavelength range λ1. The chromogenic component is dispersed in the matrix as a dispersed phase. The color-developing part contains a single-molecule liquid crystal compound. The matrix contains a water-soluble resin. For the photonic upconversion film, the relaxation time measured by the spin echo method using pulsed NMR at 298K is less than 210ms.

2. The photon upconversion film as described in claim 1, wherein, The water-soluble resin comprises polyethylene oxide and / or polyvinyl alcohol-based resins.

3. The photon upconversion film as described in claim 1, wherein, The colorimetric part contains a solvent with a boiling point of 80°C or higher.

4. The photon upconversion film as described in claim 1, wherein, The colorimetric part contains a solvent with a viscosity of 0.6 mPa•s or higher at 23°C.

5. The photon upconversion film as described in claim 1, wherein, Relative to 1g of the water-soluble resin, it contains 7.00 × 10 - 9 mol~5.00×10 -6 The sensitizing component of mol and 5.00 × 10 -6 mol~7.00×10 -5 The luminescent component is mol.

6. A method for manufacturing a photonic upconversion film, which is the method for manufacturing the photonic upconversion film according to any one of claims 1 to 5, comprising the following steps: The process of preparing an emulsion from a medium in which the sensitizing component and the luminescent component are dispersed and / or dissolved, and an aqueous solution containing a water-soluble resin; The process of applying the emulsion to a substrate to form a coating film; and The process of drying the coating film.

7. A laminate comprising the photon upconversion film according to any one of claims 1 to 5.

8. An energy conversion device comprising the photon upconversion membrane according to any one of claims 1 to 5.

9. A photon upconverter comprising a colorimetric part and a matrix, wherein the colorimetric part comprises at least... Sensitizing components capable of absorbing light within the first wavelength range λ1; and The luminescent component capable of emitting light within a second wavelength range λ2, which is shorter than the first wavelength range λ1. The chromogenic component is dispersed in the matrix as a dispersed phase. The color-developing part contains a single-molecule liquid crystal compound. The matrix contains a water-soluble resin. For the photon upconverter, the relaxation time measured by the spin echo method using pulsed NMR at 298K is less than 210ms.

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