JPS61176929A - Image forming element - Google Patents

Abstract

PURPOSE:To enable an image high in resolution by forming an image forming layer composed of a phase-transitive org. compd. having both of hydrophilic and hydrophobic sites and an unsatd. bond in the molecular structure and a functional compd., and a resistance heating layer for giving heat energy to the image forming layer. CONSTITUTION:The image forming layer 3 composed of a phase-transitive org. compd. A having both of hydrophilic and hydrophobic sites and an unsatd. bond in the molecular structure and a functional compd. B, and a resistance heating layer 2 for giving heat energy to the image forming layer 3 are formed, and the layer 2 is heated as bias for forming an image to cause phase transition of the compd. A of the overlying layer 3, resulting in converting the layer 3 into a fluid state. The layer 3 is exposed to light 6 in accordance with a pattern for forming an image or input information, at a prescribed position 5 to cause optical change of the molecule B. The displayed image can be seen or read by illuminating the layer 3 e.g., from the reverse side with illumination light 7, thus permitting an image high in compactness and resolution to be formed, and this image forming element to be used also for recording and memory devices.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel image forming element that utilizes thermal energy, and in particular to an image forming element that is constructed of an organic functional film and that can also be used as a recording element or a display element. Regarding elements.

[Conventional technology]

The color changes depending on the light of wavelength λ1, and when exposed to light in the dark, heat or wavelength 2
Photochromic molecules have long been known as functional molecules that return to their original state when exposed to light (for example, MTA Polymer Materials Research Institute Research Report No. 141 1984-3).
.

However, despite being a functional molecule that reversibly changes color, it has not been used in optical elements such as display elements, recording elements, and memory elements, except in a very limited range. This is because photoresponsiveness does not occur or is insufficient in the solid state.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to solve problems that could not be solved by the conventional techniques in this technical field.

That is, an object of the present invention is to provide an image forming element that has high contrast and is used in simple display devices, recording devices, storage devices, and the like.

Another object of the present invention is to provide a display element for use in color display devices, color recording devices, and the like.

[Means for solving problems]

The above object is solved by the present invention as follows.

That is, the present invention provides a phase-transitionable organic compound molecule having at least a hydrophilic site and a hydrophobic site and an unsaturated bond in the molecular skeleton, and a functional molecule having at least a lignophilic site and a hydrophobic site. 4. having an image forming layer and a heat generating element for applying thermal energy to the image forming layer; This is an image forming element with a +F characteristic.

[Effect]

Phase transition as used in the present invention refers to when a substance changes from an immobile solid state to a dynamic state due to heat. Therefore, from a solid state to a fluid or flexible state, from a static state to a dynamic state. A change in state, from a crystalline phase to a liquid crystalline phase, from a solid to a liquid, from one kind of liquid crystalline phase to another, etc. are all phase transitions.

Functional molecules have an image-forming function (display function).

Recording function, memory function) and information change other than image conversion M! ! Refers to functions (arithmetic functions), and also includes functions for transporting matter or energy. Furthermore, it is not limited to the case where a function is expressed by the application of light or electric energy, but also includes the case where a function is expressed by the application of heat, magnetism, pressure, substance, etc.

Next, the basic driving principle of the element of the present invention will be explained.

When energy is applied to certain functional molecules, chemical changes occur rapidly in liquids or fluids, but chemical changes do not occur or occur very slowly in solid solids.

The organic compound molecules that undergo a phase transition and the functional molecules that make up the mixed film are molecules such as those mentioned above, that is, molecules that do not change chemically in a rigid state, or that do not express their functions because it is difficult to do so, or that are flexible but are difficult to change. Since it is easy to undergo chemical changes under certain conditions, materials that can perform functions are selected.

The organic compound molecules are maintained in a highly flexible state by heating the thus configured mixed film to a temperature higher than the phase transition temperature using the heating element. Since the functional molecules existing in such a state are in a state where they are susceptible to chemical changes, the object of the present invention can be achieved by the above-described configuration that responds (functions) quickly to the application of input energy. It is something that will be done.

In short, the present invention solves the following two problems: 1. A solid medium is desired because a liquid medium has limited uses and is unstable; 2. However, a solid medium cannot fully express its functions. This problem was solved by mixing organic compounds.

Furthermore, examples of the image forming element of the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of an image forming element according to the present invention, and the first
FIG. 1A shows a transmission type image forming element, and FIG. 1B shows a reflection type image forming element. l is the substrate,
2 is a heat-generating resistor layer that generates heat by Joule heat; 3 is an image forming layer composed of a mixed film of phase-transition organic compound molecules and functional molecules that exhibit functions when exposed to light; and 4 is a protective substrate. The image forming principle of the transmission type image forming element shown in tJS1 (A) is as follows.

For image formation, the heat generating resistor layer 2 is heated as a bias, causing a phase transition change in the phase transition organic compound molecules, which are the constituent components of the image forming layer 3, on the heated heat generating resistor layer 2. As a result, light 6 (6) is applied to a desired position of the image forming layer 3, for example, position 5, according to a pattern or input information for forming an image on the image forming layer 3, which is kept in a fluid or flexible state.
The image forming layer 3 is irradiated with infrared rays, visible light, ultraviolet rays, or X-rays to cause a photochemical change, which will be described later, in the functional molecules constituting the image forming layer 3. In this way, this photochemically changed pattern or information (photochemically changed area 5) is directly or indirectly captured and displayed or read while illuminating the illumination light 7 from the back side of the element.

In the reflective image forming element shown in FIG. 1(B), the illumination light beam enters from the protective substrate 4 side, contrary to the transmission type, and the reflective film 9 is provided on the substrate 1 side from the mixed film 3. The intensity, etc. of the reflected light 8 reflected by the photochemical change area 5 and areas other than the photochemical change area are captured and displayed or read. Note that an insulating layer 1O is provided between the reflective layer 9 and the heat-generating resistive layer 2 if necessary. Examples of compound molecules include the following.

(1) Unsaturated higher fatty acid CH2=CH(CH2)8COOH CH2= CH(CH2),, C00HCH2=CH(
CH2)2oCOOH CH3(CH2),7CCOOH CH2 CH3(CH2)8C=C-C=C(CH2)8COO
HCH3(CH2)3CH=CHCH=CHCH=CH
(CH2)7COOHCH3(CH2)7CH=CH(
CH2), C00HCH3(CH2)7CH=CHCO
OHCH3= CH(CH2)8COOH CH3(CH2). C=C-C=C(CH2), C0
0HCH3(CH2)1. C=C-C=C(CH2)8
COOHCH3(CH2), 3CmiC-C=C(CH2
), C00H(2) 7-anine dye Specific examples of the cyanine dye are illustrated below.

(3) Azo dye (R2 is CIo, 30 alkyl group) (4)
Phospholipid lecithin kephalin sphingomyelin plus irodan Next, examples of functional molecules that respond to light include compounds that change color depending on light, that is, photochromic compounds. Examples of such things include the following:

(5) Spiropyran and analogs (ion solution #) wavelength input 1
The ions are dissociated by light, changing to the structure on the right, which returns to the structure on the left either thermally in the dark or by light at another wavelength of 2.

(6) Cis-trans isomerization Based on isomerization of unsaturated double bonds such as C=C1C=N, N=N (Example: Thioindigo (7) Tautomerization with hydrogen transfer/keto-enol isomerization -aci-nitroisomerization QCONHN=C)IQ Ph,c,N(H-Ph.・ξ2h (8) Photoclosing term reaction/cis-stilbene fulgide (9) Valence isomerization reaction involving heterocycle Nitrone-oxacillinsine (1G) 1-phenoxyanthraquinones (11)
Photodimerization reaction (12) Photodimerization reaction to aromatic polycyclic compound (13) Photoredox reaction Thiazine dye-based viologen A method for creating a mixed film by mixing the above-mentioned phase-transition organic compound molecules and the above-mentioned functional molecules is , Langmuir-Prodgett method (41 molecule cumulative implantation method (LB method)).

According to the LB method, it not only has excellent quality and efficiency in image formation, but also has the advantage of obtaining high resolution or ultra-high resolution. It also has features such as significantly expanding the range of material selection.

The case of forming a film using the LB method will be described below.

In the LB method, when a molecule has a parent wood group and a hydrophobic group in its molecule, and the balance between the two (amphiphilic balance) is maintained appropriately, the molecule is placed on the water surface with the parent wood group facing down. This method creates a monomolecular film or a cumulative film of monomolecular layers. The monomolecular layer on the water surface has the characteristics of a two-dimensional system.When the molecules are sparsely dispersed, the area per molecule is a A
and the surface an, the two-dimensional ideal gas equation, nA=k
T holds true, resulting in a "gas film". Here, k is Portzmann's constant and T is the absolute temperature. If A is made sufficiently small, the intermolecular interaction becomes strong, resulting in a two-dimensional solid "condensed film (or solid film)". Become °゛.

When the heating resistor layer 3 is formed on the surface of a substrate such as glass, the condensed film can be transferred layer by layer to the surface reflective film 9 of the substrate. Using this method, a monomolecular film or a monomolecular layer stack is produced, for example, as follows.

First, organic compound molecules (including mixed systems) are dissolved in a solvent,
This is spread out on the water surface and the organic compound is precipitated in the form of a film.Next, to prevent this precipitate from spreading freely on the water surface and spreading too much, a partition plate (or float) is provided to limit the spread area. The aggregation state of the membrane material is controlled by the method, and a surface pressure n proportional to the aggregation state is obtained. By moving this partition plate, the developed area can be reduced to control the state of aggregation of the film material, and the surface pressure can be gradually increased to set the surface pressure (2) suitable for producing a cumulative film. By gently vertically moving a clean substrate up and down while maintaining this surface pressure, a monomolecular film or a mixed monomolecular film of two or more types of molecules is transferred onto the substrate.

A monomolecular layer film is produced as described above, and a monomolecular layer cumulative film having a desired degree of accumulation is formed by repeating the above-mentioned operations.

The film-forming molecules are selected from one or more of the organic compound molecules described above.

The thickness of the monomolecular film or monomolecular layer stack is suitably 30 to 300 ILm, particularly 3000 to 30 ILm.

In addition to the above-mentioned vertical dipping method, methods such as horizontal deposition method and rotating cylinder method can be used to transfer the monomolecular layer onto the substrate. The horizontal deposition method is a method in which substrates are brought into horizontal contact and transferred, and the rotating cylinder method is a method in which a cylindrical substrate is rotated above the water surface to transfer a monomolecular layer onto the surface of the substrate. In the above-mentioned vertical immersion method, when the substrate is raised in a direction across the water surface, a monomolecular layer is formed on the substrate with the parent wood groups facing the substrate in the first layer. As mentioned above, when the substrate is moved up and down, the monomolecular layers in each step are overlapped one by one.The direction of the film-forming molecules is reversed in the pulling step and the dipping step, so according to this method, each layer is A Y-shaped film is formed in which wood bases and parent wood bases, and hydrophobic groups face each other. The middle molecular layer Wt fl created in this way
! A schematic diagram of J is shown in FIG.
3 is a functional molecule.

On the other hand, the horizontal deposition method is a method in which the substrate is brought into horizontal contact with the water surface and transferred, and a monomolecular layer with hydrophobic groups facing the substrate is formed on the substrate.

In this method, there is no change in the direction of the film-forming molecules even if they are accumulated, and an X-type film is formed in which the hydrophobic groups face the substrate in all layers. A side-facing cumulative film is called a Z-type film.

The rotating cylinder υ is a method in which a cylindrical substrate is rotated above the water surface to transfer a monomolecular layer onto the substrate surface. Methods for transferring a monolayer onto a substrate are not limited to these methods,
When using a large-area substrate, a method such as extruding the substrate from a substrate roll into a water tank may also be used. Furthermore, the orientation of the aforementioned parent wood group and hydrophobic group toward the substrate is a general rule, and can be changed by surface treatment of the substrate, etc.

When introducing a hydrophobic moiety into a functional molecule in the present invention, a long-chain alkyl group having 5 to 30 carbon atoms is particularly preferred.

Examples of materials that can be used as the substrate 1 include glass, metals such as aluminum, plastics, ceramics, and paper.

In the case of the transmission type shown in FIG. 1(A), it is preferable to use pressure-resistant and transparent glass or plastic, especially colorless or light-colored ones.

As the protective substrate 4, pressure-resistant, translucent glass or plastic is suitable as much as possible, and colorless or light-colored ones are particularly preferable.Providing the protective substrate 4 increases the durability and stability of the mixed film. In order to improve the properties, it is desirable that the i! ! Depending on the interpretation, the protective substrate may or may not be provided.

However, as the resistance heating layer 2, materials that do not melt by themselves under a predetermined heat, such as metal compounds such as boride/unium or tantalum nitride, or alloys such as nichrome, are suitable. The thickness of the heating resistor layer 2 affects energy transfer efficiency and resolution. From these points of view, the preferred thickness of one heating resistor layer 2 is iooo~2000. When the image forming element is a transmission type, 1 heating element 2 is transparent to visible light (
For example, the film must be an indium tin oxide film.

As the reflective film 9, a metal film, dielectric mirror, or the like is formed on the substrate 1 side by sputtering, vapor deposition, etc. using a metal material or a metal compound material with a high melting point. If the reflective film 9 is a conductor such as a metal, it can also serve as a reflective film 9 and a heating resistor! f! 2 and S t
Insulating layer 10 made of dielectric material such as O2, TiO2, etc.
It is desirable to provide

The temperature at which the phase transition occurs, ie, the phase transition temperature (Tc), is unique depending on the substance. The Tc is preferably 40 to 100°C. For example, the Tc of elaidic acid is 44 to 45.
℃, Tc of eleostearic acid is 71-72℃.

Generally, Tc increases with alkyl chain length.

Mixing ratio of the mixed film, i.e. phase transition organic compound molecules (A)
The ratio of the functional molecule (B) to the functional molecule (B) is preferably 1/10 to 10/1.The image may be formed in a state where the mixed film is heated in advance, or the image formation and heating may be performed simultaneously.

Such heating resistor layers include a linear heating resistor layer (Fig. 1) corresponding to a signal light beam (or erasing light beam) or a plurality of scanning lines, and a grid-like heating resistor layer (Fig. 1).
(all of which are not shown) are suitable. When using a linear heat generating resistor layer or a lattice heat generating resistor layer, the irradiation of the signal beam 6 onto the image forming layer 3° and the heating of the image forming layer 3 by the heat generating resistor layer may be synchronized or the irradiation may be performed in response to the heating. It is preferable to slightly delay . In the case of a linear heating resistance layer, a scanning circuit (not shown) performs line-sequential scanning to sequentially
cause fever.

Note that when a linear or lattice-shaped heating resistor layer is provided, it is possible to generate heat only at a location corresponding to an input signal and perform image formation using light as a bias. - Examples are given below to further specifically explain the present invention.

Example 1 Production of image formation On the surface of a sufficiently clean glass substrate 11 shown in FIG.
100mm thick indium tin oxide (IT
O) A film was formed by a snobbing method, and then a photoresist was applied to the film-formed surface, a striped heating resistor pattern of 16 lines/mm was baked, and an etching step was provided.

Next, an image forming layer was attached to the surface of this heating resistor layer 3 using the LB method described above.

First, 1 part of the imidazole compound represented by (1) and (
II) 1 part of lylunic acid (1) O
H tTi) CIJq (CHqCH= (H”
)* (CH2)7COOH in chloroform for 2.
Distilled water containing cadmium chloride at a concentration of IXIO-3 mol/l was adjusted to pH 6.3 with sodium hydrogen carbonate.
It was dropped and developed on the surface of the aqueous phase at 0°C.

After the solvent chloroform was removed with heat, the partition plate was moved to reduce the spread area of the mixed monomolecular film left on the water surface, and the surface pressure was increased to 20 dyn/Cm.8Then, the surface pressure was kept constant. while holding the substrate at l Omm/m i
By gently moving the monomolecular film up and down at a speed of n, the monomolecular film was transferred from the surface heating resistor layer side of the substrate to obtain a white image forming layer. Furthermore, a glass substrate was placed on top of this.

By this method, the calendar number of the monolayer is 21°51.1, respectively.
Five types of imaging elements having white imaging layers of Nos. 01, 201, and 301 were manufactured.

・Display implementation A display test was carried out on an image forming element with a monomolecular film calendar number of 51.
An external electrode was connected to each terminal of -3-1-- and heated with electricity, and the output was 3 mw and the wavelength was 633 mm.

1, □ He-Ne laser beam with a spot diameter of 40 μm
Wow, 3, 9, ah! ! -, Yo 7kiya L! -3
, ---1, and similar heating and irradiation were performed.

As a result, a deep red image corresponding to the information signal was obtained.

This confirmed that only the irradiated area under heating changed color.

When the device was then placed in a dark place, the image disappeared and the original white color returned. Similar display tests were conducted on four other types of display elements with different monomolecular film numbers, and similar results were obtained.

Example 2 The same method as in Example 1 was used, except that a solution of 1 part of the compound represented by (IV) and 1 part of the diazo compound represented by (IV) dissolved in chloroform at a concentration of 2.5 x 10-3 mol/l was used. Depending on the conditions, each monolayer has a calendar number of 21°51.101.
Five types of imaging elements having a yellow imaging layer 2 of 201, 301 were manufactured.

- Display test A display test was conducted on an image forming element having 21 monomolecular film layers. Linear heating resistance layer 15-1.15-2.15-
3. --- Connect external electrodes to each terminal of the
0) Output 3 mw, wavelength 633 during heating with electricity for seconds
A He-Ne laser beam with a spot diameter of 4 to 0 gm is used to sequentially scan the second and third lines perpendicular to the linear heating resistor layer, and generate heat in a predetermined combination according to the information signal synchronized therewith. The resistance layer was electrically heated.

As a result, a red image corresponding to the information signal was obtained. Similar display tests were conducted on other four types of display elements with different monomolecular film numbers, and similar results were obtained.

This confirmed that only the irradiated area under heating changed color.

Example 3: (V) Me Me 18H37 (Vl) CH3(CH2) 7CH= (CH2
) 7 COOH chloroform each/? 2.5X 10-
3mol/! 5, each having a colorless image forming layer 2 with a calendar number of 21°51.101, 201, and 301 in the monomolecular film by the same method and conditions as in Example 1 except that a solution dissolved at a concentration of L was used. Different types of imaging elements were manufactured.

Display test was carried out on an image forming element having 101 monomolecular film layers. Linear heating resistance layer 15-1.15-2.15
-3. An external electrode is connected to each terminal of −−−−, and a predetermined combination of heating resistor layers corresponding to the information signal is connected to τ (τ
≦10) During energization heating for seconds, the output is 3 mw and the wavelength is 3.
The first line perpendicular to the linear heating resistor layer was scanned with an ultraviolet beam having a diameter of 56 mm and a spot diameter of 40 gm.

The second and third rows were sequentially scanned with the laser beam, and a predetermined combination of heating resistor layers was heated by energization in accordance with an information signal synchronized therewith.

As a result, a clear blue image corresponding to the information signal was obtained.

Similar display tests were conducted on other four types of display elements having different numbers of monomolecular H layers, and similar results were obtained. This confirmed that only the irradiated area under heating changed color.

The main effects of the present invention are summarized as follows.

(1) Since it is possible to arrange one of the irradiation parts or heating parts of a minute monomolecular film or a monomolecular layer stack as a unit of element in a high density, high-resolution images can be formed.

(2) Still images or moving images including slow motion can be easily displayed by adjusting or selecting functional molecules.

(3) Color display can be easily implemented by adjusting and selecting functional molecules.

(4) Since the structure of the device is relatively simple, productivity is excellent, and the device has high durability and reliability.

(5) Applicable to a wide range of drive systems.

(6) Since a monomolecular film or a monomolecular layer cumulative film can be created using the Langmuir-Blodgett method, it is extremely easy to increase the area.

(7) Since no liquid such as liquid crystal is used, manufacturing is easy and safe.

(8) Since the phase transition temperature is not so high, less power is required for the image forming element, etc., and the power supply section, i.e.,
The image forming device can be downsized.

(9) When utilizing a phase transition of a mixed film (of a monomolecular or monomolecular layer stack), some molecules may maintain a phase-transitioned state for a long time depending on the structure of the constituent molecules of the mixed film (monolayer film). In such a case, the image forming element according to the present invention can also be used as a recording device (material) or a storage device (material).

(lO) Imaging can be obtained quickly.

(11) Image erasure/reproduction is also possible.

(12) Since it approximates the function of biological lipids, it is compatible with molecular devices, bioelectronics, etc.

[Brief explanation of drawings]

FIG. 1 shows a sectional view of an image forming element of the present invention, (A) is a sectional view of a transmission type image forming element, (B) is a sectional view of a reflective type image forming element, and FIG. 2 is a sectional view of the image forming element of the invention. FIG. 3 is a schematic diagram of such a monomolecular cumulative film, and FIG. 3 is a plan view showing another embodiment of the present invention. 1 Substrate 2 Heat generating resistor layer 3 Image forming layer 5 Protective substrate 6 Lights 7 and 8 Illumination light 11-2 Hydrophobic portion 12 Phase changeable organic compound molecule 13 Functional molecule 14 Glass substrate 15 Heat generating resistor layer

Claims (1)

[Claims] A phase-transitionable organic compound molecule having at least a hydrophilic site and a hydrophobic site and having an unsaturated bond in the molecular skeleton;
An image forming element comprising an image forming layer made of a functional molecule having at least a hydrophilic site and a hydrophobic site, and a heat generating resistive layer for applying thermal energy to the image forming layer.