JP2006071767A - Color rewritable display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color rewritable display device which is excellent in repetition responsiveness of coloring and is practicably used. <P>SOLUTION: The color rewritable display device is characterized by being constructed using an aromatic dicarboxylic acid ester derivative or an aromatic diacyl derivative as an electrochromic material and using a metallocene derivative as an electron donor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color rewritable display device using an aromatic dicarboxylic acid ester derivative such as a phthalic acid ester derivative or an aromatic diacyl derivative such as a diacetylbenzene derivative as an electrochromic material.

  In recent years, various studies have been actively conducted to develop a display device having excellent visibility different from that of liquid crystal or organic EL. Some of them use electrochromic materials.

  An electrochromic material is a material that reversibly undergoes oxidation or reduction reaction when a voltage is applied, and that is reversibly colored or decolored. For example, Advanced Materials, Vol. 13, p. 783 (2001) describes an example of an organic electrochromic material containing an inorganic material and a polymer (see Non-Patent Document 1).

  Furthermore, Japanese Patent Application Laid-Open No. 62-71934 discloses a display element using a phthalate derivative as an electrochromic material (see Patent Document 1). Furthermore, Japanese translations of PCT publication No. 2001-510590 describe a semiconductor metal oxide having a nanoporous structure, for example, a combination of a titanium dioxide film and an electrochromic material, and an example using ferrocene as an electron donor (patent) Reference 2).

On the other hand, there is a growing demand for color display with a rewritable display device, and it is desired that color display is possible with a rewritable display device using an electrochromic material. As a means for color display, a color filter using a technique already cultivated in a CRT or a liquid crystal display is generally used.
Advanced Materials, Vol. 13, p. 783 (2001) JP-A-62-71934 Special table 2001-510590 gazette

  In the case of a reflection type display using an electrochromic material, the color filter method cannot realize a sufficiently satisfactory color display. On the other hand, phthalic acid ester derivatives are suitable materials for developing color display, but it has been difficult to repeatedly color them at a practical level.

  Accordingly, an object of the present invention is to provide a color rewritable display device which has excellent repetitive characteristics and low power consumption in color display.

  The inventors of the present invention use a compound having a carbonyl group such as an aromatic dicarboxylic acid ester derivative such as a phthalic acid ester derivative or an aromatic diacyl derivative such as a diacetylbenzene derivative as an electrochromic material, and a metallocene derivative as an electron donor. When used, the present invention has been completed by finding that it is excellent in repeated color responsiveness in color display and at a practical level.

  That is, the present invention relates to a color rewritable display device using an aromatic dicarboxylic acid ester derivative or an aromatic diacyl derivative as an electrochromic material and a metallocene derivative as an electron donor.

The present invention also relates to the color rewritable display device in which the electrochromic material is represented by any one of the general formulas (I) to (III).

(In the formula, X _{1 to} X ₄ represent a hydrogen atom or a monovalent group, and may be the same or different. R ₁ and R ₂ represent a monovalent organic group, and are the same. Or different.)

(Wherein X _{11 to} X ₁₄ represent a hydrogen atom or a monovalent group, and may be the same or different. R ₁₁ and R ₁₂ represent a monovalent organic group, and each represents the same. Or different.)

(In the formula, X _{21 to} X ₂₈ each represent a hydrogen atom or a monovalent group, and may be the same or different. R ₂₁ and R ₂₂ represent a monovalent organic group, and each represents the same. Or different.)
The present invention also relates to the color rewritable display device in which an electrochromic material and / or an electron donor is adsorbed on a semiconductor metal oxide film having a nanoporous structure.

  The present invention uses an aromatic dicarboxylic acid ester derivative or an aromatic diacyl derivative as an electrochromic material, and uses a metallocene derivative as an electron donor, whereby phthalic acid having excellent repetitive characteristics and low applied voltage. A color rewritable display device using an ester derivative is obtained.

  In addition, the color rewritable display device obtained by the present invention is excellent in energy saving because of low power consumption, and is suitable as a rewritable paper that replaces paper.

  The color rewritable display device of the present invention uses an aromatic dicarboxylic acid ester derivative or an aromatic diacyl derivative as an electrochromic material, and uses a metallocene derivative as an electron donor.

  The electrochromic material used in the present invention is an aromatic dicarboxylic acid ester derivative or aromatic diacyl derivative, which has one aromatic ring and has a structure in which two carbonyl groups are bonded to one aromatic ring Or a compound having two or more conjugated aromatic rings and a structure in which two carbonyl groups are bonded to different aromatic rings.

  When the aromatic dicarboxylic acid ester derivative or the aromatic diacyl derivative has one aromatic ring, examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. When the aromatic dicarboxylic acid ester derivative has two or more aromatic rings to be conjugated, examples of the two or more aromatic rings to be conjugated include a biphenyl ring and a terphenyl ring.

Among these, preferred aromatic dicarboxylic acid ester derivatives or aromatic diacyl derivatives are those represented by the following general formulas (I) to (III).

X _{1 to} X ₄ , X _{11 to} X ₁₄ , and X _{21 to} X ₂₈ each represent a hydrogen atom or a monovalent group. Preferred examples of the monovalent group include F, Cl, Br, I, NO ₂ , NH ₂ , and alkyl groups such as a methyl group, an ethyl group, and a propyl group. By changing X, it is possible to change the absorption wavelength of the compounds represented by the general formulas (I) to (III). As the monovalent group in the present invention, a nitro group, an amino group and the like are preferable.

R ₁ , R ₂ , R ₁₁ , R ₁₂ , R ₂₁ , and R ₂₂ each represent a monovalent organic group. Examples of the monovalent organic group include alkyl groups such as a methyl group, ethyl group, and propyl group, aryl groups such as a phenyl group, and aralkyl groups such as a benzyl group.

  The general manufacturing method of the terephthalic acid ester derivative represented by the above general formula (I) of the present invention is a method of synthesis by reacting an acid chloride manufactured from terephthalic acid with various alcohols. Moreover, the general manufacturing method of the 1, 4- diacetylbenzene derivative represented by the said general formula (II) of this invention is a method of oxidizing alkyl acetophenone with potassium permanganate. Furthermore, the general production method of the 4,4′-biphenyldicarboxylic acid ester derivative represented by the above general formula (III) of the present invention is synthesized by reacting an acid chloride produced from biphenyldicarboxylic acid with various alcohols. It is a method to do.

  The metallocene derivative used in the present invention is not particularly limited as long as it is soluble in a solvent described later. In the present invention, it is preferable to use a ferrocene derivative as the metallocene derivative. Examples of the ferrocene derivative include ferrocene, methyl ferrocene, dimethyl ferrocene, ethyl ferrocene, propyl ferrocene, n-butyl ferrocene, t-butyl ferrocene, 1,1-dicarboxyferrocene, and the like. The metallocene derivatives can be used alone or in admixture of two or more.

  In the present invention, a general method when a dicarboxylic acid ester derivative or aromatic diacyl derivative that is an electrochromic material and a metallocene derivative that is an electron donor are used in a color rewritable display device will be described below.

  First, the electrochromic material is dissolved in a solvent to obtain a solution in which the electrochromic material is dissolved. The electrochromic materials can be used alone or in admixture of two or more. The concentration of the electrochromic material is generally 0.001 to 1M, preferably 0.005 to 0.5M, and more preferably 0.01 to 0.2M.

  Examples of the solvent to be used include dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, dimethylacetamide, acetonitrile, propylene carbonate, γ-butyrolactone, and polyethylene oxide. These solvents can be used alone or in admixture of two or more.

  Next, the electrolyte is dissolved in the solution. As the electrolyte, lithium perchlorate, tetrabutylammonium perchloric acid, hexafluorophosphate, tetraalkylammonium, dialkyl-1,3-imidazolium and the like can be used.

  Further, an electron donor is dissolved in the solution. The concentration of the electron donor is generally 0.001 to 1M, preferably 0.005 to 0.5M, and more preferably 0.01 to 0.2M.

  An electrochromic cell can be produced by facing a transparent conductive electrode, for example, an ITO electrode and another electrode, and bonding them together via a spacer having an arbitrary thickness. Another electrode may be an ITO electrode or an electrode other than the ITO electrode. As an electrode other than ITO, in addition to metal electrodes such as gold, silver, copper, and aluminum, an electrode formed by forming a conductive polymer such as PEDOT into a film may be used.

  Note that glass, plastic, or the like can be used for a substrate over which an electrode is provided.

  A solution (electrolytic solution) in which the electrochromic material, the electron donor, and the electrolyte are dissolved is injected into the cell prepared as described above, and finally the injection port is sealed. Thereafter, wiring or the like is performed to manufacture a color rewritable display device.

  In addition, a color rewritable display device in which an electrochromic material and / or an electron donor is adsorbed on a semiconductor metal oxide film having a nanoporous structure can also be produced.

First, a semiconductor metal oxide film having a nanoporous structure is formed on an FTO or ITO glass electrode. The semiconductor metal oxide to be used is not particularly limited. For example, titanium, zirconium, hafnium, chromium, molybdenum, tungsten, vanadium, niobium, tantalum, silver, zinc, strontium, iron (Fe ²⁺ or Fe ³⁺ ), nickel Or their perovskites. _{TiO 2, WO 3, MoO 3} , ZnO, and SnO ₂ are particularly preferred.

  The method for forming the semiconductor metal oxide is not particularly limited. In the present invention, for example, a method in which a semiconductor metal oxide paste is applied on, for example, an FTO or ITO glass electrode and sintered is used. As the semiconductor metal oxide paste, a paste containing 10 to 20% by weight of colloidal particles is preferably used, and a paste containing 10 to 20% by weight of colloidal anatase-type titanium oxide particles is more preferably used. The average particle diameter (primary particle diameter) of the titanium oxide particles contained in the paste is preferably about 9 to 13 nm, and when a paste having an average particle diameter of about 9 nm is used, a transparent film is used. When a paste having an average particle diameter of titanium oxide particles of about 13 nm is used, a white opaque film can be formed.

  Examples of commercially available products include SP-100 manufactured by Showa Denko KK, Ti-Nanoxide D, Ti-Nanoxide D / SP, Ti-Nanoxide T, Ti-Nanoxide T / SP, Ti-Nanoxide HT, manufactured by Solaronics, Inc. Ti-Nanoxide HT / SP etc. can be mentioned. The temperature at which the applied semiconductor metal oxide paste is sintered is usually preferably 400 to 500 ° C, more preferably 400 to 480 ° C, and particularly preferably 420 to 480 ° C.

  Moreover, it is also possible to use the paste which can be sintered at low temperature as a semiconductor metal oxide paste, and as a commercial item, for example, SP-200 manufactured by Showa Denko KK, Ti- manufactured by Solaronics, Inc. Nanoxide DL, Ti-Nanoxide TL, Ti-Nanoxide HT-L, etc. can be mentioned. The temperature for sintering such a semiconductor metal oxide paste is preferably 80 to 150 ° C, more preferably 100 to 150 ° C, and particularly preferably 100 to 120 ° C.

  The method for applying is not particularly limited, and a known method such as a spin coating method, a squeegee method, or a screen printing method can be used.

  When the sintering temperature is higher than the above range, the substrate tends to be deformed, and when lower than the above range, the solvent contained in the paste tends to remain in the film.

  The sintering time is preferably 5 to 120 minutes, more preferably 10 to 90 minutes, and particularly preferably 15 to 60 minutes. When the sintering time is shorter than the above range, the solvent contained in the paste remains in the film, so that the film tends not to be formed well. When the sintering time is longer than the above range, the substrate tends to be deformed.

  As a substrate used for providing the semiconductor oxide film, glass is generally used. However, when using the paste capable of low-temperature sintering described above, plastic can also be used.

  The thickness of the semiconductor metal oxide film thus obtained is preferably from 0.1 to 10 μm, more preferably from 0.5 to 8 μm, particularly preferably from 1 to 6 μm. When the thickness is less than 0.1 μm, the coloring density tends to be low, and when it exceeds 10 μm, the response speed tends to be slow.

  By immersing the electrode with the semiconductor metal oxide film having a nanoporous structure in the above-described solution containing the electrochromic material and / or electron donor in the dark state for 16 hours or more, the electrochromic material and / or electron The donor is adsorbed on the semiconductor metal oxide. Thereafter, the electrode is taken out and washed with a solution such as ethanol. Use it after it has been thoroughly dried. At this time, the concentration of the electrochromic material and the concentration of the electron donor are each preferably 0.001 to 10 mM, more preferably 0.01 to 10 mM, and particularly preferably 0.1 to 10 mM. . If the concentration is less than 0.001 mM, the adsorption tends to be insufficient.

  Next, the electrode on which the semiconductor oxide film is formed and another electrode are opposed to each other and bonded together via a spacer having an arbitrary thickness, thereby producing an electrochromic cell. Another electrode may be an ITO electrode or an electrode other than the ITO electrode. As an electrode other than ITO, in addition to metal electrodes such as gold, silver, copper, and aluminum, an electrode formed by forming a conductive polymer such as PEDOT into a film may be used.

  Arbitrary electrolyte solution is inject | poured into a cell later, and the injection hole is sealed finally. Solvents for the electrolyte include acetonitrile, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-methyloxazolidinone, dimethyl-tetrahydropyrimidinone, propylene carbonate, γ-butyrolactone, polyethylene oxide, and mixtures thereof. Can be used.

  As the electrolyte of the electrolytic solution, lithium perchlorate, tetrabutylammonium perchloric acid, hexafluorophosphate, tetraalkylammonium, dialkyl-1,3-imidazolium and the like can be used.

  When only one of the electrochromic material and the electron donor is adsorbed on the semiconductor metal oxide film described above, the remaining electrochromic material or electron donor is dissolved in an electrolytic solution and injected into the cell. In this case, the concentration of the electrochromic material and the concentration of the electron donor are generally 0.001 to 1M, preferably 0.005 to 0.5M, and preferably 0.01 to 0.2M. More preferred.

  In the electrochromic material, an oxidation-reduction reaction occurs when a voltage is applied, the light absorption energy state changes, and as a result, the color and optical reflectance change.

  Next, the color rewritable display device of the present invention will be described using examples, but the present invention is not limited to the following.

Example 1
Dimethyl terephthalate was dissolved in N-methylpyrrolidone so that the amount of dimethyl terephthalate was 0.05M, tetrabutylammonium perchloric acid was 0.05M, and ferrocene was 0.05M. On the other hand, ^two ITO electrodes having a sheet resistance of about 10 Ω / cm ² as a transparent conductive film were bonded to each other with a space of about 60 μm as a spacer through a heat welding film to form a cell. The display part (display part area 4cm < ² >) was produced by inject | pouring the solution created above from a filling port and sealing a filling port with an epoxy adhesive. Thereafter, wiring and the like were performed to produce a color rewritable display device.

(Example 2)
Biphenyldicarboxylic acid diethyl ester was dissolved in N-methylpyrrolidone so as to be 0.05M, tetrabutylammonium perchloric acid as 0.05M, and ferrocene as 0.05M. On the other hand, ^two ITO electrodes having a sheet resistance of about 10 Ω / cm ² as a transparent conductive film were bonded to each other with a space of about 60 μm as a spacer through a heat-welded film to form a cell. The display part (display part area 4cm < ² >) was produced by inject | pouring the solution created above from a filling port and sealing a filling port with an epoxy adhesive. Thereafter, wiring and the like were performed to produce a color rewritable display device.

(Example 3)
1,1-dicarboxyferrocene was dissolved in ethanol so as to be 0.001M. On the other hand, a titanium dioxide film having a nanoporous structure was formed on an ITO electrode having a sheet resistance of about 10 Ω / cm ² as a transparent conductive film using a titanium dioxide paste SP-200 manufactured by Showa Denko K.K. The coating was performed by spin coating, and dried at 100 ° C. for 20 minutes to form a film. The thickness of the formed titanium dioxide film was about 4 μm. The ITO electrode with the titanium dioxide film thus prepared was immersed in the above ethanol solution for 16 hours at room temperature. The electrode after immersion was washed with ethanol and dried before use. This electrode and another ITO electrode having another area resistance of about 10 Ω / cm ² were bonded to each other with a spacing of about 70 μm as a spacer through a double-sided adhesive film to form a cell. The display part (display part area 4 cm < ² >) was produced by inject | pouring electrolyte solution from a filling port and sealing a filling port with an epoxy adhesive. As the composition of this electrolytic solution, dimethyl terephthalic acid ester was used as an electrochromic material, N-methylpyrrolidone was used as a solvent, and tetrabutylammonium perchloric acid was used as an electrolyte. Thereafter, wiring and the like were performed to produce a color rewritable display device.

(Comparative Example 1)
Dimethyl terephthalic acid ester was dissolved in N-methylpyrrolidone so as to be 0.05M, and tetrabutylammonium perchloric acid so as to be 0.1M. On the other hand, ^two ITO electrodes having a sheet resistance of about 10 Ω / cm ² as a transparent conductive film were bonded to each other with a space of about 60 μm as a spacer through a heat-welded film to form a cell. The display part (display part area 4cm < ² >) was produced by inject | pouring the solution created above from a filling port and sealing a filling port with an epoxy adhesive. Thereafter, wiring and the like were performed to produce a color rewritable display device.

  A voltage was applied between the electrodes of the color rewritable display device manufactured by the above procedure to develop a color.

  In the case of Example 1, when a voltage of 2.4 V was applied between the electrodes, the display portion, which was initially transparent, turned red. When the voltage application was stopped and the voltage was changed to 0 V, the original transparent state gradually returned. Even when it was repeated 10,000 times or more, the characteristics did not change.

  In the case of Example 2, when a voltage of 2.4 V was applied between the electrodes, the display portion that was initially transparent turned yellow. When the voltage application was stopped and the voltage was changed to 0 V, the original transparent state gradually returned. Even when it was repeated 10,000 times or more, the characteristics did not change.

  In the case of Example 3, when an electrode with titanium dioxide was used as an anode and a voltage of 2.4 V was applied between the electrodes, there was no change in the display portion. When a voltage of 3.6 V was applied between the electrodes, the display portion that was initially transparent turned red. When the voltage application was stopped and the voltage was changed to 0 V, the original transparent state gradually returned. Even when it was repeated 10,000 times or more, the characteristics did not change.

  In the case of Comparative Example 1, when a voltage of 2.4 V was applied between the electrodes, there was no change in the display portion. When a voltage of 3.6 V was applied between the electrodes, the display portion that was initially transparent turned red. When the voltage application was stopped and the voltage was set to 0 V, the state gradually returned to the original transparent state. However, when it is repeated about 100 times, the coloring and decoloring characteristics are deteriorated and cannot be used.

  The color rewritable display device of the present invention is suitable as a rewritable paper that replaces paper because it has excellent repetitive characteristics and low power consumption and thus excellent energy saving.

It is sectional drawing of the display part of the color rewritable display apparatus which is one embodiment of this invention. It is sectional drawing of the display part of the color rewritable display apparatus which is one embodiment of this invention.

Explanation of symbols

1: Electrode (including substrate)
2: Electrolytic solution 3: Electrode (including substrate)
11: Electrode (including substrate)
12: Semiconductor metal oxide film 13: Electrolytic solution 14: Electrode (including substrate)

Claims (3)

  A color rewritable display device comprising an aromatic dicarboxylic acid ester derivative or an aromatic diacyl derivative as an electrochromic material and a metallocene derivative as an electron donor. The color rewritable display device according to claim 1, wherein the electrochromic material is represented by any one of the general formulas (I) to (III).

(In the formula, X _{1 to} X ₄ represent a hydrogen atom or a monovalent group, and may be the same or different. R ₁ and R ₂ represent a monovalent organic group, and are the same. Or different.)

(Wherein X _{11 to} X ₁₄ represent a hydrogen atom or a monovalent group, and may be the same or different. R ₁₁ and R ₁₂ represent a monovalent organic group, and each represents the same. Or different.)

(In the formula, X _{21 to} X ₂₈ each represent a hydrogen atom or a monovalent group, and may be the same or different. R ₂₁ and R ₂₂ represent a monovalent organic group, and each represents the same. Or different.)   The color rewritable display device according to claim 1, wherein the electrochromic material and / or the electron donor is adsorbed on the semiconductor metal oxide film having a nanoporous structure.

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