WO2006117982A1

WO2006117982A1 - Fluorescence conversion composition, and fluorescence conversion method and device using said composition

Info

Publication number: WO2006117982A1
Application number: PCT/JP2006/307649
Authority: WO
Inventors: Giseop Kwak; Michiya Fujiki; Chisato Okada
Original assignee: National University Corporation NARA Institute of Science and Technology
Priority date: 2005-04-28
Filing date: 2006-04-11
Publication date: 2006-11-09
Also published as: JPWO2006117982A1

Abstract

This invention provides a composition comprising a charge transfer coloring matter and a ferroelectric fluorine-containing polymer, wherein the charge transfer coloring matter is at least one coloring matter selected from the group consisting of DCM, DCM 2, Nile Red and Coumarin 6, and the ferroelectric fluorine-containing polymer is a copolymer of vinylidene fluoride with trifluoroethylene. A fluorescence conversion method using the composition and various device using them are also provided.

Description

Specification

Fluorescent color converting composition, fluorescent color converting method and device using the composition

Technical field

[0001] The present invention relates to a composition containing a charge transfer dye and a ferroelectric fluorine-containing polymer, and to a fluorescent color conversion method and device utilizing a novel function of the composition. Background art

[0002] Intramolecular charge transfer (ICT) dyes are used as light-emitting / photoelectric conversion materials for ELZPL devices, dye lasers, dye-sensitized solar cells, etc., and their photospecificity varies greatly depending on the polarity of the solvent. It has been known for a long time. For example, a dye laser is most often used as a wavelength tunable laser because a laser having an arbitrary wavelength can be obtained simply by changing the dye solution. However, when changing the oscillation wavelength, it was necessary to take out the dye solution, carefully wash it, and then circulate a new dye solution. In addition, since it is a solution, it has a drawback that it cannot be processed into an arbitrary shape.

[0003] There has been proposed a solid-state dye device that does not have such a defect (for example, Patent Document 1). There is no concept of changing the fluorescent color or emission intensity depending on the temperature difference.

[0004] It is to be noted that, using the vinylidene fluoride and trifluoroethylene copolymer used in the present invention, a layer containing the copolymer and a dye is laminated on a conductive support. An image record is disclosed (for example, Patent Document 2). However, the dye used in Patent Document 2 is different from the dye used in the present invention, and utilizes a function of light absorption and heat generation. In Patent Document 2, there is no concept of changing the fluorescent color or emission intensity depending on the temperature.

Patent Document 1: Japanese Patent Laid-Open No. 2004-346233

Patent Document 2: JP-A-3-296769

Disclosure of the invention

Problems to be solved by the invention [0005] As a result of examining the optical properties of ICT type dyes in various polymer matrices, the present invention uses a polymer matrix that exhibits a paraelectric-ferroelectric phase transition, and thereby the fluorescence intensity or wavelength of the ICT type dyes. Discovered a new function that reversibly changes.

[0006] An object of the present invention is to provide an intramolecular charge transfer type fluorescent dye-dispersed polymer, a fluorescent color conversion method using a novel function of the dispersed polymer, and various devices using them.

Means for solving the problem

[0007] The above object is achieved by a composition containing a charge transfer dye and a ferroelectric fluorine-containing polymer. More specifically, the charge transfer dye is at least one selected from the group force consisting of DCM, DCM2, Nile Red, and Coumarin6, and has a high molecular force of ferroelectric fluorine-containing vinylidene fluoride and trifluoro. It is a copolymer with ethylene.

The invention's effect

[0008] The fluorescent color of the composition of the present invention can be changed by a temperature change.

Brief Description of Drawings

[0009] FIG. 1 is a graph showing the relationship between the temperature and dielectric constant of a vinylidene fluoride trifluoroethylene copolymer.

[Fig. 2A] UV-vis absorption spectrum of DCM dispersion film.

[Figure 2B] UV-vis absorption spectrum of DCM dispersion film.

[FIG. 2C] Fluorescence spectrum of DCM dispersion film.

[Fig. 2D] Fluorescence spectrum of DCM dispersion film.

[Fig. 3A] UV-vis absorption spectrum of DCM2 dispersion film.

[Figure 3B] UV-vis absorption spectrum of DCM2 dispersion film.

[FIG. 3C] Fluorescence spectrum of DCM2 dispersion film.

[Fig. 3D] Fluorescence spectrum of DCM2 dispersion film.

[Figure 4A] UV-vis absorption spectrum of Nile Red dispersion film.

[Fig. 4B] UV-vis absorption spectrum of Nile Red dispersion film.

[Fig. 4C] Fluorescence spectrum of Nile Red dispersion film.

[Fig. 4D] Fluorescent spectrum of Nile Red dispersion film. [Fig. 5A] UV-vis absorption spectrum of Coumarin6 dispersion film.

[Fig. 5B] UV-vis absorption spectrum of Coumarin6 dispersion film.

[Fig. 5C] Fluorescence spectrum of Coumarin6 dispersion film.

[FIG. 5D] Fluorescence spectrum of Coumarin6 dispersion film.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Charge transfer dyes have a pi-conjugated structure with an electron donor and an acceptor, and their optical properties and nonlinear optical characteristics related to their charge transfer characteristics have been studied. As the charge transfer dyes that can be used in the present invention, conventionally known dyes can be used, and various commercially available dyes are commercially available from, for example, EXCITON, Aldrich, and Tokyo Chemical Industry. The charge transfer type dye used in this example is a dye having the structure and dye name described below. The dyes described below are intramolecular transfer charge type dyes, and have a dipole moment that is very large. Both the ground state and the excited state have 1 debye or more, and the viewpoint power that the difference is 0.1 debye or more is also selected. And When selecting a dye that can be used in the present invention from various known dyes, it is preferable to select a dye that can dissolve at least 0.1% in tetrahydrofuran (THF) from the viewpoint described on the left. This is because using a dye that does not dissolve in such a solvent makes it difficult to produce a film in which the dye is uniformly dispersed. The following dyes have such solubility.

[0011] [Chemical 1]

Coumarin6

As the ferroelectric fluorine-containing polymer used in the present invention, a polymer represented by the following general formula [I], which is a copolymer of vinylidene fluoride and trifluoroethylene, is used.

[0013] [Chemical 2]

[0014] In the above formula, X and y are copolymerization ratios. Figure 1 shows the temperature dependence of the dielectric constant of a vinylidene fluoride trifluoroethylene copolymer in which x: y is 52:48. As shown in FIG. 1, in the copolymer, the dielectric constant (ε) rapidly changes at a temperature of 50 to 70 ° C., and a paraelectric strong dielectric phase transition occurs. Paraelectric Ferroelectric phase transition is defined as a transition caused by a change in crystal structure between a paraelectric that does not have spontaneous polarization and a ferroelectric that has spontaneous polarization. Dielectric phase transition temperature is defined as the temperature at which spontaneous polarization disappears (Curie temperature). In the present invention, the ratio of x: y is not particularly limited as long as it is a copolymer that causes such a paraelectric ferroelectric phase transition. It is preferable to use a vinylidene fluoride-trifluoroethylene copolymer in which the paraelectric ferroelectric phase transition occurs more rapidly.

[0015] It should be noted that the dielectric constant was measured by dissolving 2 lOmg of vinylidene fluoride-trifluoroethylene copolymer having x: y of 52:48 in 2ml of organic solvent tetrahydrofuran (THF). Casting and drying were performed using a transparent film prepared.

[0016] The capacitance C [F] is proportional to the area A [m ² ] of the electrode plate and inversely proportional to the film thickness L (m) of the film.

C = (s -A) / L

In the above formula, the proportional constant ε is called the dielectric constant of the insulator, and its unit is [FZm]. ε depends on the material, and the dielectric constant of the vacuum is ε. Then ε = 8. 85 X 10 ^_12 [FZm], and ε = ε X ε

From the relation of r 0, the relative dielectric constant of the substance (ε

r) can be obtained. Capacitance is

, 100KHz, 20. Measured with C.

[0017] The ferroelectric fluorine-containing polymer used in the present invention is one that is soluble in tetrahydrofuran (THF) by 0.1% or more and can be used for film formation. A polymer having a dissolution amount lower than 0.1% by weight makes it difficult to produce a uniform film that is difficult to form. For example, in the above formula [I], a vinylidene fluoride homopolymer having y of 0 cannot be dissolved and a uniform film thickness that is difficult to form cannot be produced.

In the present invention, the above-described paraelectric ferroelectric phase transition as the polymer matrix is largely related to changing the fluorescent color emitted by the charge transfer dye by changing the temperature. It is believed that From such a viewpoint, the polymer matrix of the phosphor is not limited to the vinylidene fluoride-trifluoroethylene copolymer represented by the above general formula [I], and other matrices can be used. is expected.

[0019] The charge transfer dye may be used in an amount ranging from 1 PPM to 10% by weight with respect to the ferroelectric fluorine-containing polymer. Preferably, it is used in the range of 0.01 to less than 1% by weight. The charge transfer dye and the ferroelectric fluorine-containing polymer need to be dissolved in a solvent when a thin film to be described later is formed, and the present invention can be carried out as long as it dissolves. The amount of the charge transfer dye may be appropriately selected within the above range depending on the target fluorescent color, emission intensity, emission degradation rate, and the like.

[0020] The thin film is prepared by using a predetermined amount of the charge transfer dye and the ferroelectric fluorine-containing polymer in an appropriate solvent such as tetrahydrofuran, methyl ethyl ketone, acetone, black mouth form, Ν, Ν-dimethylformamide, dimethyl sulfoxide. This can be done by applying and drying a solution dissolved in a solution such as spin coating or solvent casting. The film thickness of the thin film is not particularly limited, but considering the film formability and mechanical strength, the film thickness after drying may be 1 to: LOO / zm.

The thin film obtained as described above can change the fluorescent color depending on the temperature. The temperature should be changed between the temperature range and the temperature range that is lower than the transition temperature and higher than the temperature range, taking into account the paraelectric and ferroelectric phase transition temperature of the ferroelectric fluorine-containing polymer used. To do.

[0022] The change in fluorescent color is caused by a change in fluorescence wavelength and a change in emission intensity. The fluorescent color can be changed in various colors depending on the combination of the phosphor and the fluorinated polymer. Hereinafter, the present invention will be described using examples.

Example

In the examples, “PVdF—co-TrFE” is vinylidene fluoride-3 fluorinated styrene copolymer (copolymer ratio 52:48) (hereinafter referred to as “1 ^ (1? -Co- TrFE ")).

52 48

The PVdF 2 -co-TrFE dissolves in 100% by weight or more in THF.

52 48

[0024] Example l (DCM)

PVdF-co- Good for both TrFE and DCM! A solution was prepared from THF, which shows solubility. A transparent film (film thickness 3 μm) was prepared in a triangular cell by the solvent casting method with a weight ratio of polymer to DCM of 500: 1. The obtained DCM dispersion film was heated from 0 ° C to 90 ° C in 10 ° C increments, and UV-vis absorption 'fluorescence spectrum measurement was performed while gradually cooling down to 90 ° C force 0 ° C in increments of 10 ° C. .

[0025] FIGS. 2A to 2D show UV-vis absorption and fluorescence spectra of the DCM dispersion film. The UV-vis absorption spectrum was blue-shifted from maxO ° C: 460 nm to 90 ° C: 455.5 nm by heating (Fig. 2A), and returned to its original wavelength by slow cooling (Fig. 2B). [0026] Fluorescence spectrum ranges from 0 ° C: 581 nm to 90 ° C: 583.5 nm, heating process (Fig. 2C) · Power that hardly shifts even in the slow cooling process (Fig. 2D). As a result, the strength decreased.

[0027] It was observed with the naked eye that the fluorescent color changed reversibly between yellow and dark colors by heating and slow cooling.

[0028] Example 2 (DCM2)

A DCM2 dispersion film was prepared in the same manner as in Example 1 except that DCM2 was used instead of DCM.

[0029] Figures 3A to 3D show the results of UV-vis absorption and fluorescence spectra. The UV-vis absorption spectrum was blue-shifted from 0 ° C: 500 nm force to 90 ° C: 492.5 nm by calo-heating (Figure 3A). Furthermore, by slow cooling, the original wavelength was restored from 90 ° C: 492.5 nm force to 0 ° C: 50.5 nm (Fig. 3B).

[0030] The fluorescence spectrum increases from 0 ° C: 584 nm to 90 ° C: 610 nm by heating (Fig. 3C), and from 90 ° C: 610 nm force by slow cooling to 0 ° C: 579.5 nm. Shifted (Figure 3D). It can be said that the polarization in the excited state is very large.

[0031] It was observed with the naked eye that the fluorescent color changed reversibly between orange and dark colors by heating and slow cooling.

[0032] Example 3 (Nile Red)

A Nile Red dispersion film was prepared in the same manner as in Example 1 except that Nile Red was used instead of DCM.

[0033] FIGS. 4A to 4D show the results of UV-vis absorption and fluorescence spectra. The UV-vis absorption spectrum was blue-shifted from 0 ° C: 545.5 nm force to 90 ° C: 531.5 nm by heating (Fig. 4A). Furthermore, by slow cooling, the original wavelength returned from 90 ° C: 531.5 nm to 0 ° C: 546 nm (Fig. 4B).

[0034] The fluorescence spectrum hardly shifted during the heating process (FIG. 4C) * the slow cooling process (FIG. 4D). In the emission intensity, the intensity increased by heating. The difference in strength between heating and gradual cooling can be attributed to thermal hysteresis.

[0035] The fluorescent color changes reversibly between dark purple and orange by heating and slow cooling. That was observed with the naked eye.

[0036] Example 4 (Coumarin6)

A Coumarin6 dispersion film was prepared in the same manner as in Example 1 except that Coumarin6 was used instead of DCM.

FIG. 5A to FIG. 5D show the results of UV-vis absorption / fluorescence spectrum of Coumarin 6 dispersion film. In the UV-vis absorption spectrum, the absorption around 390 nm increased and the absorption between 450 and 550 nm decreased during the heating process (Fig. 5A). Furthermore, the absorption was restored by slow cooling (Fig. 5B).

[0038] In the emission spectrum, the peak near 550 nm was lowered by heating (Fig. 5C). By further cooling, the peak at 490 nm decreased and the peak near 550 nm slightly increased (Fig. 5D). Simultaneously with these changes in spectrum, blue-green light emission by heating was also confirmed with the naked eye. However, the intensity of light emission did not return completely. After the measurement, the Co awakening arin6 dispersion film became colorless at the place where the excitation light hit, and the dye was decomposed by the excitation light.

[0039] It was observed with the naked eye that the fluorescent color reversibly changed between green and blue by heating and slow cooling.

Industrial applicability

[0040] By using the intramolecular charge transfer type fluorescent dye dispersion polymer of the present invention and the fluorescence expression method using the novel function, a temperature change display element, a new type of temperature surface emitting sensor (thermography), temperature · Polarized wavelength tunable plastic laser 1. It can be applied to stress sensors and bimorph type flat speakers that emit surface light.

[0041] As described above, at least the following inventions are provided.

1. A composition comprising a charge transfer dye and a ferroelectric fluorine-containing polymer, wherein the charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red and Coumarin6 A composition in which the dielectric fluorine-containing polymer is a copolymer of vinylidene fluoride and trifluoroethylene.

[0042] 2. The composition according to 1 above, wherein the charge transfer dye is contained in a range of 0.01 to less than 1% by weight based on the ferroelectric fluorine-containing polymer. [0043] 3. A fluorescent color-converting composition that contains a charge transfer dye and a ferroelectric fluorine-containing polymer, and whose fluorescence wavelength and Z or emission intensity change depending on temperature.

[0044] 4. A composition containing a charge transfer dye and a ferroelectric fluorine-containing polymer, wherein the charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red and Coumarin6 4. The composition according to 3 above, wherein the ferroelectric fluorine-containing polymer is a copolymer of vinylidene fluoride and trifluoroethylene.

[0045] 5. Using a thin film composed of a charge transfer dye and a ferroelectric fluorine-containing polymer, and changing the temperature applied to the thin film, thereby changing the fluorescent color emitted by the charge transfer dye. A fluorescent color conversion method characterized by the above.

[0046] 6. The fluorescent color conversion method according to 5 above, wherein the ferroelectric fluorine-containing polymer is a copolymer of vinylidene fluoride and trifluoroethylene.

[0047] 7. The fluorescent color conversion method according to 5 or 6 above, wherein the change in fluorescence color is due to a change in fluorescence spectrum wavelength.

[0048] 8. The fluorescence conversion method according to any one of 5 to 7 above, wherein the charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red and Coumarin6.

[0049] 9. A temperature change display element having a thin film containing the composition according to any one of 1 to 4 above.

[0050] 10. Temperature change display element using the fluorescent color conversion method according to any one of 5 to 7 above

Claims

The scope of the claims

[1] A composition containing a charge transfer dye and a ferroelectric fluorine-containing polymer, wherein the charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red, and Coumarin6 force, A composition in which the ferroelectric fluorine-containing polymer is a copolymer of vinylidene fluoride and trifluoroethylene.

[2] The composition according to claim 1, wherein the charge transfer dye is contained in an amount of 0.01 to less than 1% by weight based on the ferroelectric fluorine-containing polymer.

[3] A fluorescent color-converting composition that contains a charge transfer dye and a ferroelectric fluorine-containing polymer, and whose fluorescence wavelength, Z, or emission intensity varies with temperature.

[4] The charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red, and Coumarin6, and the ferroelectric fluorine-containing polymer is a co-polymer of vinylidene fluoride and trifluoroethylene. 4. The composition according to claim 3, which is a polymer.

[5] Using a thin film composed of a charge transfer dye and a ferroelectric fluorine-containing polymer, and changing the temperature applied to the thin film, the fluorescent color emitted from the charge transfer dye is changed. A fluorescent color conversion method.

6. The fluorescent color conversion method according to claim 5, wherein the ferroelectric fluorine-containing polymer is a copolymer of vinylidene fluoride and trifluoroethylene.

[7] The fluorescent color conversion method according to [5] or [6], wherein the change in fluorescence color is due to a change in fluorescence spectrum wavelength.

[8] The fluorescence conversion method according to any one of claims 5 to 7, wherein the charge transfer dye is at least one selected from the group consisting of DCM, DCM2, Nile Red and Coumarin6.

[9] A temperature change display element having a thin film containing the composition according to any one of claims 1 to 4.

[10] A temperature change display element using the fluorescent color conversion method according to any one of claims 5 to 7.