JPH0313379A - Display element - Google Patents

Abstract

PURPOSE:To impart a good color change and a response speed sufficiently subjected to practical use to a display element by providing a thermal color changeable material layer on a film-like heating body generating heat by the supply of a current. CONSTITUTION:A thermal color changeable material layer is provided on a film-like heating body generating heat by the supply of a current. As the thermal color changeable material, a heat-sensitive dye or a cholesteric liquid crystal is designated. As the heat-sensitive dye, a compound selected from an electron donating color developable org. compound (a), a compound (b) selected from a compound having a phenolic hydroxyl group and a metal salt thereof, aromatic carboxylic acid, 2-5C aliphatic carboxylic acid, metal carboxylate, acidic phosphoric ester and a metal salt thereof and 1, 2, 3-triazole and a derivative thereof and a compound (c) selected from alcohols, esters, ketones, ethers, acid amides, 6 or more C aliphatic carboxylic acid, thiols, sulfides, disulfides, sulfoxides and sulfonic acids is used as an essential component.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display element. Specifically, the present invention relates to a display element such as a film-like heating element that generates heat by passing electricity through a layer of thermosensitive color-changing material.

[Conventional technology and problems]

2. Description of the Related Art Currently, thermosensitive color-changing materials that are widely used are mostly inks, paints, and stickers made by printing these on base materials. However, with these methods of using thermochromic materials, when the heat capacity of the printed or pasted material is large, it takes time for the temperature to change and it is difficult to change color quickly. When small, it was difficult to control the color change.

Furthermore, although it is known that a display can be produced by combining a heating element and the thermochromic material described above, a combination with a heating element that can be put to practical use has not been known at all.

[Means to solve the problem]

Therefore, the present inventors conducted intensive studies to put into practical use a display element using a thermochromic material, and as a result, they formed a thermochromic dye material layer on a film-like heating element that generates heat when energized. The present invention was achieved by discovering that display elements have good color change and response speed that can be used in practical use. A display element is characterized in that it has a color-changing material layer.

Since the display element of the present invention uses a film-like heating element with a small heat capacity, it exhibits extremely good responsiveness and color change with a small amount of electric power, and also has better resolution and sharpness of a single image, which are important for display elements, than those of conventional display elements. It's better than anything else.

In the present invention, thermosensitive color-changing materials include thermosensitive dyes, cholesteric liquid crystals, and the like. As heat-sensitive dyes, (a) electron-donating color-forming organic compounds, (b) compounds having phenolic hydroxyl groups and their metal salts, aromatic carbodiic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, and power/L. / Metal phonic acid salts, acidic phosphoric acid esters and metal salts thereof, 1. Ko,,y-)! Compounds selected from J azoles and their derivatives, and () alcohols, esters, ketones, ethers, acid amides, aliphatic carboxylic acids having 6 or more carbon atoms, thiols, sulfides, disulfides, Heat-sensitive dyes containing compounds (a) to (nori) selected from sulfoxides and sulfonic acids as essential components are used.
-gtis'i, Tokukai Akira/-311, g2, Tokukai Akira!
r2-14IO'ltJ, JP-A-59-7-〇'192
, JP-A-4343-1O7j and other known heat-sensitive dyes can be used. Specific electron-donating color-forming organic compounds include diaryl phthalides, polyarylcarbinols, leucouramines, acylouramines, arylauramines, and rhodamine B-lactams.

These include indolines, spiropyrans, fluorans, etc.

Examples of these compounds are shown below.

Crystal violet lactone, malachite green lactone, Michler hitrol, crystal violet carpinol, malachite green carpinol, N
-(2,3-dichlorophenylnoleukoolamine, N
-benzoyluramine, rhodamine B-lactam, N-
7 Cetyluramine, N-phenyluramine, -1 (
phenyliminoethanedylidene) -J,J-dimethylindoline, N-3,3-1-limethylindolinobenzos biropyran g/-methoxy-N-3,3-)limethylindolinobenzospiropyran, J -diethylamino-6-methyl-7-chlorofluorane, J-diethylamine-7-medoxyfluorane, J-diethylamine-6-penzyloxyfluorane/, 8-1benz-6-
Diethylaminofluorane, 3,6-p-)leucine, s-dimethylfluoran-phenylhydrazide-γ-lactam, J-amino-termethylfluoran, co-methyl-J-amino-6-methyl-71 methylfluoran , 3-butylene-6-c n -7”
thylaminofluorane, J-diethylamino-7-anilinofluorane, J-diethylamino-7-(halatoluidino)-fluoran, 7-acetamino-J-diethylaminofluorane/, coprom-6-cyclohexylaminofluorane, - 17-dichloro-3-methyl-6
-n-butylaminofluora 7 and the like.

Compounds having a phenolic hydroxyl group include monophenols to polyphenols, and substituents thereof include alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, and halokenes. Examples of these compounds are shown below.

tertiarybutylphenol, α-naphthol, β-naphthol, hydroquinone Monomethyl ether, guaiacol, oi';'/'y p-chlorophenol, p-7'' lomophenol, o-chlorophenol, o
-7” lomophenol, 0-phenylphenol, p-
phenylphenol, p-(p-chlorophenylin-phenol, o-(o-chlorophenynoly-7phenol,
Methyl p-oxybenzoate, ethyl p-oxybenzoate, propyl p-oxybenzoate, butyl p-oxybenzoate, octyl p-oxybenzoate, dodecyl p-oxybenzoate, 3-isoprobyl Tecor J&, p
-tershak-butylcatechol, +4'-methylenediphenol, Hiroshi, 9'-thio-bis-(6-ter-
Sha! J-7” Chiru J-ifruphenol).

Hel-bis-(couhydroxyphenyl)-cyclohexane, y,! -butylidene bis(6-p--/
Yarybutyl-bisphenol A, bisphenol S, /, 2-dioxynaphthalene, λ,3-dioxynaphthalene, chlorcatechol, bromocatechol.

, 2-dihydroxybenzophenone, phenolphthalein, 0-cresol phthalein, protocatechu-
Methyl acid, ethyl protocatechuate, propyl protocatechuate, octyl protocatechuate, dodecyl protocatechuate, co*'lr4) lyoxymethylbenzene, r,3,y-trioxyethylbenzene, methyl gallate, ethyl gallate , propyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, 2,3,! - Trioxynaphthalene, tannic acid, phenolic resin, etc.

As a metal salt of a compound having a phenolic hydroxyl group,
sodium of the compound having a phenolic hydroxyl group;
Potassium, lithium, cal-/”mu% zinc hy
luconium, aluminum.

Magnesium, nickel, cobalt, tin, copper.

There are metal salts of metals such as iron, vanadium, titanium, lead, and molybdenum.

Carboxylic acids include monocarboxylic acids, polycarboxylic acids, and derivatives thereof. Examples of these compounds are shown below.

Acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid,
Capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, crotonic acid, oleic acid, elaidic acid, linoleic acid, linoleic acid, monochloroacetic acid, motupromacetic acid, monofluoracetic acid, glycolic acid, hydroxypropion Acid, hydroxybutyric acid, ricinoleic acid, /,2-hydroxystearic acid, lactic acid, pyruvic acid, oxalic acid, malonic acid, succinic acid, adipic acid, cepatic acid, malic acid, tartaric acid, xosocholic acid, maleic acid, fumaric acid, naphthenic acid, benzoic acid, toluic acid, phenylacetic acid, p-tarjarifthylbenzoic acid, cinnamic acid, chlorobenzoic acid, bromobenzoic acid,
Ethoxybenzoic acid, mandelic acid, protocatechuic acid,
Vanillic acid, resorcinic acid, dioxybenzoic acid, dioxychlorobenzoic acid, dicarboxylic acid, naphthoic acid, hydroxynaphthoic acid, phthalic acid, phthalic acid monoethyl ester.

Examples include naphthalene dicarboxylic acid, naphthalene dicarboxylic acid monomethyl ester, trimellitic acid, and hyromellisotonic acid.

Examples of carboxylic acid metal salts include sodium, potassium, lithium, calcium, zinc, zirconium, and aluminum such as the above-mentioned carboxylic acids.

There are metal salts of metals such as magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

Alcohols include monohydric alcohols, polyhydric alcohols, and derivatives thereof. Examples of these compounds are shown below.

n-octyl alcohol, n-nonyl alcohol, n-
Decyl alcohol, n7'7! J alcohol h n (resteel alcohol, n-heptyl alcohol, n-stearyl alcohol, n-7 icosyl alcohol, n-tocosyl alcohol, n-mericyl alcohol, incetyl alcohol, instearyl alcohol, intoko Syl alcohol, oleyl alcohol, cyclohexanol, cyclopentanol, benzyl alcohol, cinnamyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol.

Propylene glycol, phtylene glycol.

Hexylene glycol, cyclohexane/. Z-diol, trimethylolpropane, /. Examples include 2.6-hexandriol, pentaerythritol, nruvit, and mannitol.

Examples of compounds as esters are shown below.

Amyl acetate, octyl acetate, butyl propionate, octyl propionate, phenyl propionate, ethyl caproate, amyl caproate, ethyl caprylate, amyl caprylate, ethyl caprate, amyl caprate, octyl caprate, methyl laurate , ethyl laurate, butyl laurate, hexyl laurate, octyl laurate, dodecyl laurate, myristyl laurate, cetyl laurate, stearyl laurate, methyl myristate, ethyl myristate, butyl myristate, hexyl myristate, myristin Octyl myristate, lauryl myristate, myristyl myristate, cetyl myristate, stearyl myristate, methyl rumitate, ethyl valmitate, phthyl palmitate,
Hexyl valmitate, octyl valmitate, lauryl valmitate, myristyl calcitate, cetyl palmitate.

Stearyl valmitate, methyl stearate, ethyl stearate, butyl stearate, hexyl stearate, octyl stearate, lauryl stearate,
Myristyl stearate, cetyl stearate, stearyl stearate, methyl behenate, ethyl behenate, propyl behenate, butyl behenate, ethyl benzoate, butyl benzoate, amyl benzoate 5 phenyl benzoate, ethyl acetoacetate, oleic acid Methyl, butyl oleate, butyl acrylate, diethyl oxalate, diptyl oxalate, diethyl malonate, dibutyl malonate, dibutyl tartrate, dibutyl sepatate, dimethyl sepatate, dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, phthalate Diotyl acid, diethyl maleate, dibutyl maleate, triethyl citrate, muco-hydroxystearic acid triglyceride, castor oil, dioxystearic acid methyl ester/co-hydroxystearic acid methyl ester, and the like.

The following compounds are exemplified as ketones.

Diethyl ketone, ethyl butyl ketone, methylhexyl ketone, mesityl oxide, cyclohexanone, methylcyclohexanone, acetophenone, propiophenone, benzophenone, -, goupentanedione, acetonyl acetone.

Examples include diacetone alcohol and ketone wax.

The following compounds are exemplified as ethers.

Butyl ether, hexyl ether, diimpropyl benzyl ether, diphenyl ether, dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol diethyl ether, ethylene glycol monophenyl ether, etc. Ru.

Examples of cholestic liquid crystal compounds include JP-A-67-
Known substances such as J/4'gda can be used, and specifically, aspartic acid, glutamic acid, oxyglutamic acid and ester derivatives thereof are used.

Other thermosensitive color-changing materials include:
It causes a change in color tone, fading, or change in color in the visible light range. ;, Tokukai Showyu j-/
-ri θ3.2. Substances shown in JP-A-52-1λ25, etc., specifically, caprylic acid, lauric acid, myristic acid, linoleic acid, linolenic acid, stearic acid, alagic acid, or mixtures thereof and brilliant. A combination of organic dyes such as fast scarlet dye, 7 talocyanine blue B2, red No. A aluminum lake dye, yellow No. aluminum lake dye, and blue No. C aluminum lake dye.

Combinations of fatty acids such as alginic acid, caprylic acid, caproic acid, mixtures thereof, metal salts, etc., and basic dyes such as Rhodamine B stearate, Sudan ■, Quinoline ID-8S, Sudan Blue 66. AgzHgL%
Combinations of metal complex salts such as Cu28gIn and phenolic compounds, spiropyran derivatives, anthrone derivatives, polydiacetylene derivatives, etc. can be used in summer. In the display element of the present invention, it is preferable to use a heat-sensitive dye from the viewpoint of display stability.

A method for forming a thermochromic material layer on a heating element using the thermochromic material described above is to dissolve the thermochromic material in a solvent or to form the thermochromic material layer by a generally known microencapsulation method. A method of encapsulating a heat-generating material in microcapsules, dispersing it in a vehicle, etc., making it into a paint or ink, and applying it directly onto a heat-generating body, or using a known coating or printing method, or on a heat-generating body or a heat-generating body. A method in which it is applied directly to an insulating layer or protective layer such as paper or resin provided above.
Any method may be used in which a layer of thermochromic material is separately formed and laminated onto the heating element.

On the other hand, the heating element may be anything in the form of a film, and any material such as metal or resin may be used as long as it generates resistance heat when an electric current is passed through it. However, it is preferable to use a material that has moderate flexibility and can be freely deformed like paper when formed into a film. Particularly desirable is a material that can be adjusted to any desired resistance value by adding a conductive carbon blank or metal powder to the resin, and that can be easily formed into a film.

As the resin, any of thermoplastic resins such as polyethylene, polypropylene, polystyrene, polyester, polyamide, polycarbonate, polyurethane, and polyvinyl chloride, and thermosetting resins such as epoxy, polyurethane, and polyimide can be used. In particular, in the present invention, compatibility with the thermochromic material layer in the film state, responsiveness (
It is preferable to select a resin such as polycarbonate, polyamide, polyimide, etc. from the viewpoint of contrast, etc. during display and erasing), and polycarbonate is particularly recommended.

On the other hand, as the conductive substance, carbon black, graphite, conductive metal powder such as iron, copper, aluminum, nickel, etc., carbon fiber, etc. can be used. However, from the viewpoint of display uniformity, carbon black, graphite, etc. are preferred, and among carbon blanks, conductive carbon blanks are particularly recommended.

Methods for making these resins exhibit conductivity include melting and kneading the above-mentioned conductive substances together with the resin using a generally known method and forming a film by melt extrusion, and dissolving the resin in a solvent. After that, a method of dispersing a conductive substance to form a film and evaporating the solvent to form a film, a method of adding these conductive substances to a resin monomer or oligomer, polymerizing it, and then forming it into a film; Any method in which a conductive substance is added to a monomer or oligomer, formed into a film, and then polymerized can be applied. These film forming methods are not particularly limited.

The film-shaped heating element formed in this way is cut into a certain size, and the heat-sensitive color-changing material is dissolved in a solvent, or it is microencapsulated and made into paint, ink, etc., and is then used in offset printing, letterpress printing, intaglio printing, etc. By applying this ink to a pen and applying it by hand, etc., to a film-like heating element, or by covering the surface with a transparent or translucent protective layer. An object can be used as a display element. In addition, it is possible to attach an insulating layer such as paper or plastic to the surface of this film-like heating element, and to coat or print ink using a thermosensitive color-changing material on this insulating layer, and to display the entire heat generation of the conductive film through the insulating layer. Alternatively, a protective layer may be laminated on the surface of the thermochromic material layer. At this time, if the thickness of the insulating layer attached to the surface is too thick, the responsiveness of the conductive film to heat generation will be slow, which is undesirable. Furthermore, if the thickness of the protective layer is too thick, the heat capacity of the display element will be large and the responsiveness will be poor, so the protective layer should be as thin as possible, and it is desirable to use a material that allows the color change of the thermochromic material to be sufficiently seen through. Furthermore, the conductive film is exposed only in the area that can be used as a terminal on one side, and an insulating layer is provided on the remaining part to create a thermosensitive color-changing material. It is also possible to coat or print the ink used on both sides or one side, and to display the entire heat generated by the conductive film through the insulating layer. Furthermore, this display element is fixed on the base,
For use, a heat insulating layer, an insulating layer, an adhesive layer, an adhesive layer, etc. may be laminated on one side of the element depending on the required VC.

In addition, when a heating element provided with a thermochromic material layer is grounded and electricity is applied to the heating element with a pen that is thinner than the surface of the heating element that is not insulated, the thermochromic material layer slides in the trajectory of the pen and discolors. In combination with a heat-sensitive color-changing material with hysteresis such as that described in 1972-/λ0 (192), it can also be applied as a recordable display element.

The thickness of the film-like heating element used in the display element of the present invention is 100 μm or less or suitable for use! -jOμm range is preferred. Further, the thickness of the thermochromic material layer is suitably 190 μm or less due to the relationship with the thickness of the film-like heating element, and 10-! ; A range of 0 μm is preferable. The most preferable film heating element is a combination of polycarbonate resin and carbon black, the composition of which is polycarbonate resin go-gs and carbon blank 15-50% by weight, preferably 10% by weight. ~q50-95% by weight. The molecular weight of the polycarbonate resin is 2 as the viscosity average molecular weight (Mv).
A carbon blank having a pore volume of 5 cC as determined by the mercury porosimeter method is particularly preferably used as a carbon blank.
7y or less, the maximum peak position of the pore distribution is 100 angstroms or more, and the DBP absorption amount is 20-
2. ! ;0Inl/1009. Furthermore, in order to improve the breaking strength of this film-like heating element and to obtain the display element of the present invention with improved flexibility and processability, it is recommended to mix a nidistomer into the polycarbonate resin. The blending amount is preferably O0/-3% by weight based on the polycarbonate resin. The nidistomer to be added has an elastic modulus (JIS, KbJol) of 7 to
100 MPa is preferred.

As mentioned above, the display element of the present invention can be made extremely thin and flexible than ever before, or if flexibility is a disadvantage for the purpose of the display element, it can be formed on a transparent or opaque substrate. Needless to say, it is at least suitable for that purpose.

〔Example〕

Hereinafter, the present invention will be explained in detail using examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example-7 Thermosensitive color-changing material is crystal violet rough tonk as an electron-donating color-forming organic compound. , 20t to bisphenol as a compound having a phenolic hydroxyl group,
Myristyl alcohol 100? (The material was homogenized by heating and melting and was used as a heat-sensitive color-changing material.

The heating element is made of polycarbonate resin (Mv"30.000
)/Co, Ko2 was added to a polymer solution of 1009 in methylene chloride, conductive carbon black s, gt'i1
(In addition, carbon black was uniformly dispersed using a ball mill. This dispersion was coated on a polyester film.
The solvent was evaporated. Thereafter, the carbon black-containing shiboricarbonate film was peeled off from the polyester film to obtain a film having a thickness of about 75 μm.

White paper was pasted on the obtained polycarbonate film containing carbon black of about is μm, and the above heat-sensitive color-changing material salted at 50°C was coated with &g's bar coater, and cooled in a refrigerator at 0°C. A blue thermosensitive color-changing material layer was formed.

The carbon black shibori carbonate film provided with this thermosensitive color-changing material layer has a width of 10 B and a length of ro ml.
It was then cut into a display element.

A conductor was connected to one end of this display element using a crocodile knob, and another conductor was connected in the same way to a point 10,111 meters away. In a room at 23℃, 10V, /jAy is applied to this conductor.
When an alternating current of ytA was applied, the blue color immediately faded.

Furthermore, when it was cooled with an iron ingot cooled to s°C, it turned blue again.

Example - 1 The heating element shown in Example 1 was cut into width/cIn-length 51Zm, white paper was pasted on the surface, and Daithermo DR-JO (orange color) manufactured by Dainichiseika Chemical Co., Ltd. was attached to the surface. was coated to form a thermochromic material layer, and a display element was prepared. In the same manner as in Example 1, the alligator clip interval was changed to θ and an alternating current of OV and /6/771A was conducted.

When electricity was applied, the orange color immediately faded.

Further, when it was left as it was and cooled, it turned orange again and its responsiveness was also very good.

Example-3 Low density polyethylene 650? Conductive carbon black J 3. The mixture was uniformly dispersed using an Otf coaxial melt-kneader, and a heating element having a thickness of approximately yo μm was molded using a T-die.

This heating element was cut into a width of 10H and a length of 5 oyrrs,
A display element similar to Example 1 was prepared, the alligator clip interval was set to 2011 II, and an alternating current of 1 θV,/g (ImA) was applied.

When electricity was applied, the orange color immediately faded.

Moreover, when it was left as it was and cooled, it turned orange again.

Example - Cut the carbon black shibori carbonate film used in Example/ into pieces of 1 cm width and g cm length, and apply Daithermo D3-30 (orange color) manufactured by Dainichiseika Chemical Co., Ltd. to one side. A piece of paper was pasted to form two display elements.

One end of this display element is grounded, and the tip of a 0.7mm diameter iron wire with an alternating current of 1OV applied to the polycarbonate surface is
When it was moved slowly, it was confirmed that the dye faded along the trajectory of the iron wire. It was also confirmed that when the movement speed is increased, the trajectory becomes thinner, and when the movement speed is increased, the trajectory becomes thicker. The faded area returned to its original orange color after several tens of seconds.

Furthermore, in the display element of this example, when a metal foil serving as an electrode was formed on the surface of the electrically heat-generating resin film on the side of the thermochromic material layer, the response speed of the display and the resolution and sharpness of the display were improved.

The metal foil is preferably formed by a method such as vapor deposition, and aluminum is suitable as the type of metal.

〔Effect of the invention〕

With the display element of the present invention, it is possible to electrically control the temperature of the heating element, change the color of the thermochromic material, and obtain a color change and response speed that can be used for f-fraction collection. became. For example, this method can be used for various display displays.
By using G, you can create panels that change pictures one after another under electrical control, battery checker card type current detectors, and display elements for checking the current status by incorporating them into circuits parallel to the load circuit. It is also possible to do so and is industrially useful.

Sender: Mitsubishi Kasei Corporation Representative: Patent Attorney Hase - 1 other person

Claims (2)

[Claims] (1) A display element characterized by having a thermosensitive color-changing material layer on a film-like heating element that generates heat when energized. (2) The display element according to claim 1, wherein the film-like heating element is an electrically heat-generating resin film.