JPS6269245A - Photoresponsive photochromic display element - Google Patents

Abstract

PURPOSE:To form a photochromic display element having sufficient color developing property and high color developing rate by providing a photolytic layer which generates cations in the irradiating stage with light. CONSTITUTION:A photochromic element comprises an electrochromic layer consisting of a transition metal compd. and a layer from which cations are decomposed by the irradiation with light. For example, a display element 1 is composed of an electroconductive layer 3 formed on a substrate 2, a photochromic layer 4 comprising a transition metal compd., an electrolyte layer 5 adjacent to the layer 4 comprising a compd. generating cations by the irradiation with light and several media for supporting the compd., and if necessary, a transparent protecting substrate 6 which protects 4 and 5. The element develops color by the irradiation with light, and the degree of color development is controlled optionally depending on the intensity of light irradiation exhibiting higher density of developed color by the irradiation of more intense light.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a new color display element, and in particular to a new photoresponsive light color display in which writing is performed with light and the color life can be arbitrarily controlled by the light intensity during writing. Regarding elements.

[Technical background of the invention and its problems]

Transition metal compounds such as titanium oxide and tungsten oxide are known as materials that exhibit electrochromism (color development upon application of voltage), and electrochromic display elements that utilize this electrochromism have been developed. Such display elements are generally

It has a structure in which an electrochromic layer and an ion conductive layer or an electrolyte layer are sandwiched between opposing electrode substrates, at least one of which is transparent. Conventionally, the coloring mechanism of electrochromic elements, taking tungsten oxide (Cwos) as an example, produces color in the form of the following formula 〇 [Reference: RtStCrndall at
al Appl, Pluyss, Latt 2g,
(2) By applying an e voltage to the wO3 layer at 95°, cations H%<, are injected into the center of the perovskite crystal structure (hexagonal) of the transition metal oxide, and are produced in the near-infrared region called tungsten bronze. It becomes a crystal structure with strong absorption. As a result, red light, which is close to near-infrared rays, is absorbed and the opposite color, blue, is produced.

However, this method of repeating color development and decolorization by applying voltage cannot prevent excessive injection of cations due to overvoltage, especially for the purpose of improving contrast during color development, or injection of cations into deep electrochromia layers, and on the contrary, it is difficult to prevent color development. Overload of reversely applied voltage for erasing is also unavoidable, so essentially the reaction is irreversible, similar to the electrolytic principle of batteries, and electrode corrosion occurs, resulting in repeated discoloration and discoloration. There is a natural limit (≧10”) to the number of times (life), and this is the biggest bottleneck in practical use.Furthermore, the reaction mechanism described above is based on cations (H+) and Alternatively, since the electrolyte is a lithium cation (formula 2) in an organic solvent such as propylene carbonate, there is a limit to the electrolytic movement of cations in the bulk, and the problem remains that the response is slow.

In addition, when using the above solution-based electrolyte, its retention,
Spacers and sealants must be used for sealing,
The complexity of manufacturing the device is a major drawback. Furthermore, when a solution-based electrolyte is used, there are drawbacks such as solution leakage and element destruction due to gas generation accompanying electrolysis. In addition, all-solid-state electrochromic elements using solid electrolytes have been developed with the aim of improving the above-mentioned drawbacks of solution-based electrolytes, but there are problems with the movement of cations in the solid electrolyte and the reproducibility of color development and fading. However, there are still problems such as the fact that it is hardly put into practical use.

In view of these problems, we have already proposed a novel photoresponsive electroluminescent element that can be written with light and has excellent coloring properties, which solves the above problems. That is, since color writing is performed using light, the above-mentioned excessive injection of cations does not occur, and therefore erasing is extremely easy, and a practical display element with a long operating life and excellent response speed has been provided.

The coloring principle of the present invention is exactly the same as that of this new photoresponsive electrochromic element, and while the photoresponsive electrophoretic element mainly produces dynamic displays by coloring and fading, the present invention is capable of static display and printing using only light. , intended for printing, etc.

As such static display or printing, electrochemical printing includes an electrochemical coloring method using redox of a group of compounds called leuco dyes (Formula 3).

Since these series of leuco compounds essentially depend on electrochemical reactions as mentioned above, they have the same drawbacks as mentioned above, including their reversibility. Furthermore, as an example of applying light to static display or printing,
UV curable inks exist. UV ink is a composition in which a pigment or a light-fast dye is mixed into a photocurable resin such as an acrylic resin. Therefore, during UV curing, pigments absorb UV light and inhibit curing, resulting in the disadvantage that only an extremely thin coating film can be cured, and the disadvantage that coating properties are extremely poor due to increased viscosity due to the inclusion of pigments. ing.

[Purpose of the invention]

An object of the present invention is to provide a light-emitting color display element that has good color development properties with light and a fast color development rate, and is effective for use in static display, printing, printing, and the like.

[Summary of the invention]

The photoresponsive color display element of the present invention is a photoresponsive color display element consisting of an electrochromic layer of a transition metal compound and a layer that decomposes cations by light irradiation, and is, for example, an element as shown in FIG. is a conductive layer 3 formed on a substrate 2 and a photoelectrochromic layer 4 of a transition metal compound.
and an electrolyte layer 5 made of a compound that generates cations when irradiated with light and various media that support the compound, which are in contact with the layer 4, and a transparent protective substrate 6 for protecting the above 4 and 5 as necessary. Thus, it develops color by light irradiation, and the degree of color development (strong light irradiation→deep color density) can be arbitrarily controlled according to the intensity of light irradiation.

The coloring metal oxide layer used in the present invention is V2
O3+ Wow + Cu, 0. Nio, SnO,
pbo, CezO3eTie, Ga2O,Ag1l
e Hg5O* To, O,, Sin, Tag, F
eatO, 0, Au, 0. Mn09. Cry, C
d, 0. Ir, O,, Mn0.00. .

Cod, WO3t Uz05* Ga0g MnO3
,SnO,,Ir,O,,No1Osy00,,Ta
O2, CdO, Cr, 0. , NnO, , Ta, O, ,
Co, O,.

Bed, Au, 0. ,Sb,O,,Tie,,
CeO2, So, 0. , Age.

Fe12. This type of color-forming layer, in which transition metal oxides are particularly preferred, can be formed by vacuum heating vapor deposition.

It is generally formed on the conductive film 3 of the substrate 2 by a sputtering method, a sintering method, or the like.

The electrolyte layer that generates cations by light, which is the main material of the present invention, is 1 formula % formula % () (in the formula, R is a monovalent aromatic organic group, R1 is alkyl, cycloalkyl, and derivatives thereof). a monovalent aliphatic organic group selected from am is a polyvalent organic group selected from aliphatic groups and aromatic groups forming a heterocyclic structure or a clamp ring structure;
Or the element 1M selected from sulfur and selenium is various gold scraps,
a is an integer of O to 3, b is an integer of O to 2, C is an integer of 0 or 1, and the sum (a + b + c) is 3 or 2, which is the valence of X); in particular.

F-ku; Ward 5〉〉-Am〔spoken Σ〕ε], ASF, -
,ku;i5:〉-r-■SbF,-0oI+-0ocp
, o4−, (〉r−◇aPO,−”(■Is”−BF
,-,(CIrash-BF,-,((@;)S2s
nc4=(co,)t・S”−C1(,Cercat−o
F, -, ((g汲S1・F心、-＜gs+・CF、C凭S+・No、-、(qs size etc. salts such as sulfonium salts, iodonium salts, etc., and according to 2〇, the cation occurs.

Other useful photodegradable electrolytes include heteropolyacids, or onium salts of heteropolyacids, which have the linear formula: % formula % (where X represents a halogen atom, a nitrogen group atom, an oxygen group atom, R represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, Yne represents an anion of a heteropolyacid, m is an integer of 2 or 3, n is indicated by ), which represents an integer such as 3 or 4.5.

In the salt of formula (A), (Rm -x) represents an onium ion, where or as a halogen atom such as C1, I: a nitrogen group atom such as N, P: an oxygen such as O, S, Ss, etc. It is a group atom. Therefore, the onium salts corresponding to each of the above X are chromium salts.

Iodonium salts: ammonium salts, phosphonium salts: oxonium salts, sulfonium salts, selenonium salts, etc. R may be any of those listed above, and substituents to be introduced into R include halogen atoms such as C and F, ether groups, nitrile groups, nitro groups,
carbonyl group.

Examples include thioether groups.

Specific examples of substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, octadecyl group, and substituted or unsubstituted alkyl groups having 6 to 40 carbon atoms. Specific examples of the aryl group include phenyl group, 4-methylphenyl group, 4-methoxyphenyl group, 5-nitrophenyl group, 4-chlorophenyl group, 4-hebutylphenyl group, 4-dodecylphenyl group, 4- Trifluoromethylphenyl group, 3.5-
Dumeto-4-hydroxyphenyl group, tolyl group, 4
-Methylthiophenyl group, 2-benzochenyl group, naphthyl group, anthranyl group, etc.

Although the heteropolyacid Y is not particularly limited, for example, phosphotungstic acid, phosphomolybdic acid, tungsten germanic acid, silicotungstic acid, molybdenum silicic acid, borotungstic acid, etc. are preferable.

Specific examples of heteropolyacids include 1-rifylesulfonium phosphotungstate, tri(4-methoxyphenyl)sulfonium phosphotungstate, tritolylsulfonium phosphotungstate, tri(3,5
-dimethyl-4-hydroxyphenyl)sulfonium phosphotungstate, tri(4-methylthiophenyl)
Sulfonium phosphotungstate, diphenyliodonium phosphotungstate, di(5-nitrophenyl)iodonium phosphotungstate, dinaphthyliodonium phosphotungstate, di(4-trifluoromethylphenyl)iodonium phosphotungstate,
di(2-benzochenyl)iodonium phosphotungstate), di(3,5-dimethyl-4-hydroxyphenyl)iodonium phosphotungstate, tetratolylammonium phosphotungstate, tetraphenylphosphonium phosphotungstate, tetra(3,5
-dimethyl-4-hydroxyphenyl)phosphonium phosphotungstate, triphenylsulfonium silicotungstate, di(4-methylphenyl)iodonium silicotungstate, triphenylsulfonium phosphomolybdate, diphenyliodonium phosphomolybdate, di(4-dodecyl) Phenyl)iodonium phosphomolybdate, tetraphenylammonium phosphomolybdate, di(4-hebutylphenyl)iodonium tungstogermanate.

Examples include di(4-chlorophenyl)iodonium molybdosiliconate.

These may be any compound that decomposes when exposed to light and finally releases cations, preferably HΦ, Li'', etc., and the compound returns to its original photodegradable electrolyte salt by reverse applied voltage. preferable.

Furthermore, as a group of compounds having the role of retaining or acting as 8 of the photodegradable electrolyte salts, propylene carbonate, ethylene carbonate, acetonitrile, toluene, ethyl acetate, and ethyl cellosolve.

Solvents or solutions such as butyl cellosolve, cellosolve acetate, methanol, ethanol, butanol, water, methyl isobutyl ketone, xylene, n-hexane, etc., as well as essential materials for the solid or semi-solid element that is the gist of the present invention. Become. As a medium for solidification or semi-solidification,
Glycerin, wax, paraffin or various sol-like substances, or gel-like substances such as agar, gelatin, tofu, konnyaku, silica gel, etc., as well as epoxy resin, polyester resin, acrylic resin, polybutadiene resin, polyvinyl alcohol, polyvinyl chloride, polyvinyl formal , polyvinyl butyral, phenoxy resin 9, and various other resin compounds. Other substances forming the electrolyte layer include those with ionic conductivity such as acids, alkalis, salts, and water-containing substances.For example, H, SO, H
Cl, NaOH, KOH.

LiOH, NaCjl, LiCl, LiClO4, H
,0,Sin,Cr,0. .

Mid, etc. These compounds can be used alone, in combination, or in a mixture depending on the purpose and device configuration.

The wavelength of the light irradiated to the electrolyte during light irradiation can be varied depending on the type of composition, but is usually 180 to 7.
It is 00rv+. In particular, ultraviolet irradiation is effective. The light irradiation time depends on the composition of the composition, il! It varies depending on the type of solute, the intensity and type of light source, etc., but it usually takes a few microseconds.
It is several milliseconds. The light source at this time may be any conventional light irradiation device, such as a low-pressure mercury lamp, high-pressure mercury lamp, carbon arc lamp, metal halogen lamp, xenon-mercury lamp, or xenon lamp.

Hydrogen discharge tube, tungsten lamp, halogen lamp, sodium discharge tube, neon discharge tube, argon discharge tube, helium-neon laser, argon ion laser, nitrogen gas laser, cadmium ion laser, helium-cadmium laser, dye laser.

and one or more types of radiation such as various electron beams and X-rays.

[Embodiments of the invention]

Next, examples of the present invention will be described.

Example 1 An epoxy curing agent, 50 parts of hexahydrophthalic anhydride, and 50 parts of titanium oxide were added to an epoxy resin, Epikote 828 (Shell Chemical Industry Co., Ltd.), and on a tin plate 1 (also serving as a conductive layer 2), By roll coater application,
Form a thin film of 20 to 30μ and heat cure (180℃ x 2
time) to form a titanium oxide based (τ102) photo-electrochromic layer 4.

Next, epoxy resin, Celoxide 2021 (Dy%
After adding and kneading, it was evenly coated on T108 type photo-electrochromy single layer 4 with a film thickness of about 10μ, and then UV
Light (801/m, high pressure mercury lamp, 1 light, 153 height,
5 m/1zin line speed; manufactured by Toshiba),
) was formed on the photodegradable electrolyte layer. Photodegradable electrolyte layer 5
When the photoelectrochromic layer 4 was formed and solidified, the photoelectrochromic layer 4 developed a slight light blue color, but it disappeared after several hours.
Next, using a high-pressure mercury lamp 7 as a light source, parallel light collected by a condensing lens was irradiated. Upon irradiation, it develops a pale light blue color.

The color density increased as the irradiation time increased, and when irradiation was performed for 30 seconds or more, the color developed into bright light blue and did not fade even after irradiation. Figure 3 shows the relationship between the irradiation time (seconds), the coloring contrast, and the natural coloring time of the coloring layer (memory, one hour).
The reflectance ratio was measured using an e-No laser (632° 8 nm). ) Examples 2 to 4 Vo, Cr, 03. Each Ir1ss film was deposited to form a single electrochromic layer as shown in the table below. Using the electrolyte of the present invention used in Example 1 on each electrochromium layer obtained above, an electrolyte layer was formed in the same manner as in Example 1, and the structure shown in FIG. Then, under the same conditions as in Example 1,
When exposed to light, excellent contrast and response characteristics are shown in Table 1 below.

One hour of memory was gained. (1-Al 1 color) Table 1 Example 5 A single layer of vO and electrochromic as shown in Example 2 was provided on a transparent conductive polyester film (manufactured by Ondai), and then the same layer as shown in Example 1 was provided. A photodegradable electrolyte layer was provided to construct a device according to the present invention. Cover the above element with an ultraviolet photomask, light irradiation device, 1 80v/3 high pressure mercury lamp, 15cm
Height, line speed 5 m/win,
It came out with clear light blue letters printed on it.

Example 6 The device of Example 5 using a transparent conductive film was irradiated with ultraviolet parallel light shown in FIG. 2 under automatic control according to a certain program, and a certain figure was drawn on the film. A clear image was obtained.

Then, for the purpose of correcting the obtained image, Φ,
By applying a direct current of 1 V to the electric pen corresponding to the transparent conductive layer, erasing the unnecessary portion, and reversing the polarity, additional portions could be added.

(Effects of the Invention) According to the present invention, the simple structure provides good color development;
It is possible to obtain a photochromic display element with a fast coloring speed.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing one example of the element of the present invention, and FIG.
The figure is a layout diagram of an apparatus for recording and displaying using one element, and FIG. 3 is a diagram showing the characteristics of the element of the present invention. DESCRIPTION OF SYMBOLS 1... Element, 3... Conductive layer, 4... Photo-electrochromy single layer, 5... Electrolyte layer. Agent Patent Attorney Noriyuki Ken Yudo Takehana Kikuo No. 1 Figure // L/V Run Ahakus No. 2

Claims (4)

[Claims] (1) A photochromic display element comprising a transition metal compound layer as a photochromic material layer, which comprises a photodegradable layer that generates cations when irradiated with light. (2) The photochromic display element according to claim 1, wherein the transition metal compound layer is made of titanium oxide, tungsten oxide, or vanadium oxide. (3) The photochromic display element according to claim 1, wherein the transition metal compound layer is formed of titanium oxide, an epoxy compound, and an epoxy compound and a curing agent thereof. (4) The photochromic display element according to claim 1, wherein the photodegradable layer that generates cations contains a triallylsulfonium salt.