JPH0726093B2 - Organic electrochromic material - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improved organic electrochromic material that reversibly develops and decolors by an oxidation-reduction reaction by applying a voltage.

<Prior Art> In recent years, as the living environment has become more electronic, interest in display elements for human vision is rapidly increasing. Among them, electrochromic elements known as non-emissive elements are familiar to the eyes like ordinary printed materials under normal ambient light and do not become hard to see by external light like light emitting diodes, that is, they have been conventionally used. Compared with liquid crystal, it has a bright color display with no dependence on the viewing angle, it has a low driving voltage of 0.5 to 5 V, it can be driven directly from a unit battery, and it has good compatibility with MOS-IC. However, it has many excellent features such as that it is generally simple and does not require precise control of the inter-electrode distance like a liquid crystal display, it is easy to make a large screen, and the operating temperature range is wide. Is attracting attention.

Typical electrochromic materials that have been proposed in the past include organic compounds such as low molecular weight viologen derivatives (4,4′-bipyridine derivatives) and inorganic compounds such as tungsten oxide (WO ₃ ).

Among these, organic compounds such as low-molecular-weight viologen derivatives have brighter color display than inorganic compounds,
Moreover, there is a feature that various colors can be selected by selecting the derivative.

However, the display using the low molecular weight viologen derivative solution has a short repeated display life, an insufficient response speed, and since it has absorption in the visible light region, ground coloration occurs even in a non-coloring state. The current situation is that it has not reached the level of practical application.

<Problems to be Solved by the Invention> The present invention has been made in view of the above problems, and it is an object of the present invention to provide an improved organic electrochromic material that is durable, has a fast response speed, and is free from background coloration. To aim.

<Means for Solving Problems> The present invention provides a general formula (In the formula, A represents a substituted or unsubstituted heterocyclic group, R ₁ and R ₂ may be the same or different, and are hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen-substituted alkyl group, Represents a hydroxyalkyl group, an alkoxy-substituted alkyl group, a cyanoalkyl group, an aralkyl group, and R ₁
And R ₂ may combine with each other to form a heterocycle containing nitrogen. R ₃ represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or halogen. The present invention provides an organic electrochromic material comprising a compound represented by the formula (1) (see JP-A-56-4148 for the method for producing the compound in the present invention).

Typical examples of the compounds that can be used in the present invention are listed below.

Compound No. (1) 1,1-bis (4-N, N-diethylaminophenyl) -2-pyridylmethane (2) 1,1-bis (4-N, N-diethylamino-2-methylphenyl) -2 -Pyridylmethane (3) 1,1-bis (4-N, N-diethylaminophenyl) -3-pyridylmethane (4) 1,1-bis (4-N, N-diethylaminophenyl) -4-pyridylmethane ( 5) 1,1-bis (4-N, N-diethylaminophenyl) -2-furylmethane (6) 1,1-bis (4-N, N-diethylaminophenyl) -2-thienylmethane (7) 1, 1-bis (4-N, N-diethylaminophenyl) -3-indolylmethane (8) 1,1-bis (4-N, N-diethylaminophenyl) -2-pyrrolylmethane (9) 1,1-bis ( 4-N, N-diethylaminophenyl) -4-quinolylmethane (10) 1,1-bis (4-N, N -Diethylamino-2-methylphenyl) -4-pyridylmethane (11) 1,1-bis (4-N, N-diethylamino-2-methylphenyl) -2-furylmethane (12) 1,1-bis (4 -N, N-diethylamino-2-methylphenyl) -2-thienylmethane (13) 1,1-bis (4-N, N-diethylamino-2-methylphenyl) -3-pyridylmethane (14) 1,1 -Bis (4-N, N-diethylamino-3-methylphenyl) -2-furylmethane (15) 1,1-bis (4-N, N-dimethylamino-3-ethylphenyl) -2-pyridylmethane ( 16) 1,1-bis (4-N, N-dimethylamino-3-ethylphenyl) -3-indolylmethane (17) 1,1-bis (4-N, N-di-n-butylaminophenyl) ) -3-Pyridylmethane (18) 1,1-bis (4-N, N-di-n-butylaminophenyl) ) -4-Quinolylmethane (19) 1,1-bis (4-N-chloroethyl-N-ethylaminophenyl) -2-furylmethane (20) 1,1-bis (4-N-chloroethyl-N-ethylamino) Phenyl) -2-pyrrolylmethane (21) 1,1-bis (4-N-hydroxyethyl-N-ethylaminophenyl) -2-pyridylmethane (22) 1,1-bis (4-N-ethyl-N- Hydroxyethylaminophenyl) -2-furylmethane (23) 1,1-bis (4-N-methyl-N-benzylaminophenyl) -2-thienylmethane (24) 1,1-bis (4-N-methyl) -N-benzylaminophenyl) -2-pyridylmethane (25) 1,1-bis (4-morpholinophenyl) -4-quinolylmethane (26) 1,1-bis (4-morpholinophenyl) -2-furyl Methane (27) 1,1-bis (4-N, N- Methylamino-2-methoxyphenyl) -4-pyridylmethane (28) 1,1-bis (4-N, N-dimethylamino-2-methoxyphenyl) -3-indolylmethane (29) 1,1-bis (4-N, N-Dimethylamino-2-methoxyphenyl) -2-pyrylmethane (30) 1,1-bis (4-N, N-dimethylamino-2-chlorophenyl) -2-pyridylmethane (31) 1,1-bis (4-N, N-dimethylamino-3-chlorophenyl) -2-thienylmethane (32) 1,1-bis (4-N, N-diethylaminophenyl)
-5-isoquinolylmethane (33) 4- (1,1-bis (4-N, N-diethylaminophenyl) methylfluorenone (34) 4- (1,1-bis (4-N, N-diethylaminophenyl) ) Methylcarbazole (35) 1,1-bis (4-N, N-diethylamino-2-methoxyphenyl) -5-isoquinolylmethane (36) 1,1-bis (4-N, N-diethylamino-2) -Chlorophenyl) -5-isoquinolylmethane (37) 4- (1,1-bis (4-N, N-diethylamino-2)
-Methoxyphenyl) methylfluorenone (38) 4- (1,1-bis (4-N, N-diethylamino-2)
-Chlorophenyl) methylfluorenone (39) 4- (1,1-bis (4-N, N-diethylamino-2)
-Methoxyphenyl) methylcarbazole (40) 4- (1,1-bis (4-N, N-diethylamino-2)
-Chlorophenyl) methylcarbazole Each of the above compounds of the present invention is applied to a display device after being prepared into an electrochromic liquid using, for example, a solvent and a supporting electrolyte.

The organic electrochromic material of the present invention is a compound exemplified above, but a polymer compound containing structures of these compounds as pendant groups and a polymer compound containing these structures in a structure are also electrochromic materials. It is expected to have a function as.

Hereinafter, examples of the present invention will be described in detail.

<Example> FIG. 1 shows the structure of a display device to which the organic electrochromic material according to the present invention is applied. For example, a transparent substrate 2 having a transparent or semitransparent display electrode 1 and a counter electrode (back electrode). The electrochromic liquid 6 according to the present invention is enclosed between the support 4 provided with 3 and the insulating spacer 5 such as Mylar or Teflon and sealed with the seal 7. The display electrode is made of a transparent electrode material such as indium oxide, tin oxide or indium tin oxide, and the counter electrode is made of the same material as the above transparent electrode material or a metal such as platinum, gold or aluminum. The support is made of a material such as glass or plastic.

As the electrochromic liquid 6, the N exemplified above is used.
1000 ml of 1 mmol of the compound of o. (1) and 0.1 mol of cetyltrimethylammonium bromide (CTAB) as a supporting electrolyte
A solution prepared by dissolving it in acetonitrile was prepared and filled in the device. After that, the display electrode 1 and the counter electrode 3
When a DC voltage of 2 to 5 V was applied between the two, red color was observed on the display electrode 1. By removing the applied voltage or applying a reverse polarity voltage of about 1 V, this color development disappeared promptly.

The application of the organic electrochromic material shown in the present invention is not limited to the so-called solution type cell as in the examples. As described above, even if the compound shown in the present invention is introduced into a polymer as a pendant group of a polymer compound, it exhibits electrochromism, and this means can be applied to a solid-state cell. It is also possible to control the migration of the coloring species generated on the electrode surface by binding the compound of the present invention with a compound having an appropriate size and increasing the molecular weight.

<Effects of the Invention> The present invention is composed of the above-mentioned compounds, and since this compound has a good reversibility between a cation / radical that is presumed to be a color-forming species and a neutral molecule corresponding thereto, it is possible to reduce The number of reactions that change into the compound of (3) is reduced, and the repeated property of coloring / decoloring to a specific color, that is, stable durability is obtained, and conventionally known organic electrochromic materials such as porphyrin compounds or viologen compounds are obtained. Originally has absorption in the visible light region, and the display is made by changing the color, whereas the compound shown in the present invention does not absorb in the visible region in the non-coloring state and electrochemically causes a coloring species. Since it develops color only when it is exposed, it has the excellent feature that there is no so-called background color.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of the electrochromic display element of the present invention. 1 ... Display electrode, 2 ... Transparent substrate, 3 ... Counter electrode, 4
…… Support, 5 …… Insulating spacer, 6 …… Electrochromic liquid, 7 …… Seal.

Claims (1)

[Claims] 1. A general formula (In the formula, A represents a substituted or unsubstituted heterocyclic group, R ₁ and R ₂ may be the same or different, and are hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen-substituted alkyl group, Represents a hydroxyalkyl group, an alkoxy-substituted alkyl group, a cyanoalkyl group, an aralkyl group, and R ₁
And R ₂ may combine with each other to form a heterocycle containing nitrogen. R ₃ represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or halogen. ) An organic electrochromic material comprising a compound represented by: