JPS61175084A - Image forming element - Google Patents

Abstract

PURPOSE:To enable an image forming element to be used in simple displayers, recorders, and memories, which is capable of giving high-contrast images, by providing a heating element to give heat energy to an image forming layer composed of a phase transitionary organic compound having hydrophilic and hydrophobic portions and also having no unsaturated bonds in its molecular skeleton and a functional molecule having hydrophilic and hydrophobic portions. CONSTITUTION:A functional molecule used has an image forming function (displaying, recording, and storing functions) and information conversion function (arithmetic function) other than image conversion and exhibits its functions by light, electric energy, etc. A heating element used is an infrared rays absorptive layer preferably. The functional molecule making up a film with a phase transitionary organic compound is selected from materials capable of exhibiting functions in the softened state where it is chemically changeable. When the film is heated to a temperature higher than the phase transition temperature by the heating element to keep the organic compound in softened state, the functional molecule quickly responds to input energy (functional manifestation).

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 light energy, and in particular is constructed of an organic functional film and can also be used as a recording element or a display element. The invention relates to an image forming element.

[Conventional technology]

Photochromic molecules are functional molecules that change color when exposed to light at wavelength 1 and return to their original state when exposed to light in the dark, heat, or wavelength 2 (for example, in fiber polymer materials). Institute Research Report No. 141 1984-3)
.

However, despite being a functional molecule that reversibly changes color, it has not been used in optical devices such as display devices, recording devices, and memory devices, 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, one 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 two-legged object is solved by the following invention.

That is, the present invention provides an image consisting of an organic compound molecule having at least a hydrophilic site and a hydrophobic site and having no unsaturated bond in the molecular skeleton, and a functional molecule having at least a lignophilic site and a hydrophobic site. This is an image forming element characterized by having a forming layer and a heat generating element for applying thermal energy to the image forming layer.

[Effect]

In the present invention, phase transition refers to a case where a substance changes from an immobile solid state to a dynamic state due to heat. Therefore, it is impossible to change from a solid state to a fluid or flexible state, from a static state to a dynamic state, from a crystalline phase to a liquid crystalline phase, from a solid to a liquid, from one type of liquid crystalline phase to another, etc. It's all a phase transition.

Functional molecules refer to image forming functions (display functions, recording functions, memory functions) and information conversion functions other than image conversion (arithmetic functions), and also include substance or energy transport functions, as well as light and electrical energy transport functions. It is not limited to cases in which functions are expressed by the application of heat, magnetism, pressure, substances, etc., but also includes functions expressed by the application of heat, magnetism, pressure, substances, etc. Preferably, the heat generating element is an infrared absorbing layer.

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 the changes occur extremely 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.

By heating the mixed film thus ar&ed to a temperature above the phase transition temperature using the heating element, the organic compound is maintained in a highly flexible state. Since the functional molecules existing in such a state are in a state where they are easily chemically changed, they respond rapidly to the application of input energy (
The object of the present invention is achieved by the configuration described above.

In short, the present invention has the following points: 1. A solid medium is desired because a liquid medium has limited uses and is unstable.

2. However, the function cannot be fully expressed in a solid medium.These two problems were solved by mixing a phase-transitionable organic compound.

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

FIG. 1 is a sectional view of the image forming element of the present invention, and FIG.
A) shows a transmission type image forming element, and FIG. 1(B) shows a reflection type image forming element. 1 is a substrate, 2 is a heating element, 3 is an image forming layer composed of a mixed film of a thermal phase changeable organic compound and a functional molecule that exhibits a function by light, and 4 is a protective substrate. The image forming principle of the transmission type image forming element shown in FIG. 1(A) is as follows.

For image formation, the heating element 2 is heated as a bias, and a phase transition change is caused in the phase-transitionable organic compound, which is a component of the image forming layer 3, on the heated heating element 2. As a result, light 6 (infrared, infrared,
The image forming layer 3 is irradiated with visible light, ultraviolet rays, or
It causes the photochemical changes described below in the functional molecules that are the constituent components of. 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 7 is incident from the protective substrate 4 side, contrary to the transmission type, and the reflective film 11 is provided on the substrate l side from the mixed film 3. The image forming layer 3 of the image forming element of the present invention captures and displays or reads the intensity, etc. of the reflected light 8 reflected in the photochemical change area 5 and areas other than the photochemical change area.
The following are examples of phase transition organic compounds that do not have unsaturated bonds in their molecular skeletons.

(1) Saturated higher fatty acids CH3(CH2), 2 C00H CH3(CH2)14COOH CH3(CH2), 6COOH CH3(CH2)18COOH CH3(CH2), oCOOH (2) Long chain dialkyl salt o Long chain dialkyl ammonium salt (m is an integer from 10 to 30) Long chain dialkyl sulfur ionate Long chain dialkyl phosphateNext, 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:

(3) Spiropyran and analogues (ion dissociation) 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.

(4) Cis-trans isomerization (example based on isomerization of unsaturated double bonds such as =C, C=N, N=N), thioindigo (5) G mutagenesis with hydrogen transfer, keto-enol Isomerization/aci-nitroisomerization Ph2CMN, NN=CH◎ h, PiC<;su.・Self, 2□ (6) Photo-ring closure reaction Self-cis-stilbene fulgide (7) Valence isomerization containing a heterocycle Reaction Nitrone-oxacillinsine system (8) 1-phenoxyanthraquinones (91) Photodimerization reaction (Io) Photodimerization reaction to aromatic polycyclic compounds (11) Photoredox reaction Thiazine dye system Creating a mixed film using viologen As a method, there is the Langmuir-Prodgett method (monomolecular cumulative film formation 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, and can also form a film of a liquid organic compound on a solid surface.
It also has features such as a wide range of materials to choose from.

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 two-dimensional ideal gas equation, rlA=k, is expressed between the area A per molecule and the surface area n.
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 stronger, resulting in a two-dimensional solid "condensation film (or solid film)". "become.

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

First, an organic compound (including mixed systems) is dissolved in a solvent, and this is spread on the water surface to precipitate the organic compound in a film form.Next, this precipitate should be free to diffuse on the water surface and prevent it from spreading too much. A partition plate (or float) is provided to limit the development area and control the state of collection of the membrane material, thereby obtaining a surface pressure n proportional to the state of collection. By moving this partition plate, the developed area can be reduced to control the aggregation state of the film material, and the surface pressure can be gradually increased to set a surface pressure n suitable for producing a cumulative film. 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 by gently moving the clean substrate up and down vertically. 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.

r&film-forming molecules are selected from one or more of the above-mentioned organic compounds.

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

In order to transfer the monomolecular layer onto the substrate, in addition to the above-mentioned vertical dipping method, methods such as the horizontal deposition method and the one-turn cylinder method are used. 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 YJ where wood base and parent wood base, hydrophobic group and hydrophobic group face each other! ! II
I is formed. A schematic diagram of the monomolecular layer cumulative film prepared in this way is shown in Fig. 2. In Fig. 0, 10-1 is the parent tree group;
1O-2 is a hydrophobic group, 11%/I is a phase changeable organic molecule, 1
2 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 molecules even if they are accumulated, and an X-shaped film is formed in which the hydrophobic groups face the substrate in all the layers.On the contrary, in all the layers, the hydrophilic groups face the substrate. A cumulative film oriented toward is called an X-type film.

The rotating cylinder method is a method in which a cylindrical substrate is rotated above the water surface and a monomolecular layer is transferred onto the surface of the substrate. The method of transferring the monomolecular layer onto the substrate is not limited to these methods, and when using a large-area substrate, a method of extruding the substrate from a substrate roll into a water bath 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 the functional molecule in the present invention, a long-chain alkyl group having 5 to 3 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. Although it is preferable in order to improve the properties, the protective substrate may or may not be provided depending on the selection of the film-forming molecules.

Examples of the heat generating element 2 include those that utilize heating by infrared irradiation (Fig. 1); representative examples include various inorganic or organic materials, such as Gd*Tb@Fe;
and inorganic pigments such as carbon black. Examples of organic materials include organic dyes such as nigrosine.

Examples of such light-absorbing dyes include metal phthalocyanines such as copper phthalocyanine and vanadium phthalocyanine;
Examples include metal-containing azo dyes, acidic azo dyes, and xanthine dyes such as fluorescein. However, the film thickness of the heating element 2, which itself does not melt under a certain amount of heat, affects energy transfer efficiency and resolution.

From these points of view, the preferred film thickness of the heat generating element 2 is 1000 mm.
~2000 people. When the image forming element is of a transmissive type, the heat generating element 1 is required to be a film that is transparent to visible light (for example, 5i02). However, even if the heating element 2 is not specially provided, the substrate 1 can also serve as a heating element by selecting a substrate material having the above characteristics.

As the reflective film 9, a metal film, dielectric mirror, etc. is formed on the substrate 1 using a metal material or a metal compound material with a high melting point by a sputtering method, a vapor deposition method, etc. Similarly to the heat generating element 2, the reflective film 9 is formed using the material of the substrate 1. By selecting a material that can reflect light, the substrate can also serve as the substrate l.

The temperature at which the phase transition occurs, ie, the phase transition temperature (Tc), is unique depending on the substance. The preferred Tc is 4O-100°C. For example, the Tc of palmitic acid is 60-6.
At 3°C, Tc of dialkyl ammonium salt is 20-60
It is ℃. Generally, Tc increases with alkyl chain length.

FIG. 3 schematically shows the phase transition phenomenon in the case of a dialkyl ammonium salt mixed with the functional molecule 12.

The ratio of functional molecule (B) to (A) is 1/10-10
/l is desirable. Image formation may be performed in a state where the mixed film is heated in advance, or image formation and heating may be performed simultaneously.

In the case of infrared heating (FIG. 1), the configuration of the apparatus can be simplified by using a polychromatic light source 15 that includes infrared rays 13 and a light beam of a specific wavelength necessary for photochemical reaction (hereinafter referred to as signal light beam 14). , the production cost is also low. Furthermore, since it is only necessary to heat a predetermined location corresponding to the input signal, there is an advantage that energy can be saved.

FIGS. 4(A) and 4(B) are schematic diagrams in which image formation is performed using a polychromatic light source 15 that emits infrared rays 13 and signal light beams 14 at the same time. A xenon lamp is a multicolor light source that emits from ultraviolet to infrared light.

There are halogen lamps, etc. Of course, the infrared light source and the signal light source may be provided separately.

The spot diameter of the beam on the image forming layer is suitably 0.5 to loOgm, as required. however,
It is not necessary that the spot diameters of the infrared rays and the signal light beams (wavelengths differ depending on each functional molecule) completely match on the mixed film; the spot diameter of the infrared rays 13 is slightly larger than that of the signal light beam 14. I don't mind the 4th
(Fig. 4 (A)), on the other hand, it is acceptable even if it is slightly smaller (Fig. 4 (B)), because for the reason mentioned above, an image is formed only in the area irradiated with both the infrared ray and the signal beam. be. Therefore, the size of the image point is determined by the spot diameter of the smaller of the rays (Fig. 4 (
A) (B)) When simultaneously irradiating the image forming element with the infrared ray 13 and the signal beam 14, it is possible to irradiate the infrared ray 13 and the signal beam 14 on a pattern corresponding to a predetermined image, or the infrared ray 13 can be irradiated as a beam. Although it is possible to simultaneously irradiate a large number of beams in dots and holes, it is also possible to use a method in which one beam or one line beam is scanned over the infrared absorbing layer 16. In this case, the infrared beam may be scanned in advance of the signal beam.Although the method of forming the detection element by infrared heating has been described above, in the present invention, the infrared absorbing layer 16 in FIG. 4 will be described later. Instead of a heat transfer layer made of a metal or the like (not shown), a heat generating element (not shown) may be brought close to or in contact with the heat transfer layer to heat the mixed film by conduction.

In the present invention, in order to further enhance the discrimination effect of the formed image, the visible light reflecting film 9 may be separately interposed between the infrared absorbing layer 16 and the image forming layer as described above. The reflective film 9 needs to be formed of a high melting point metal material or metal compound material that does not melt itself during heat conduction.

In order to explain the present invention more specifically, Examples are given below.

Example 1 The image forming element of the present invention was manufactured as follows.

A 5i02 layer having a thickness of 1500 layers was deposited on the surface of a 50 mm square glass substrate by sputtering to form an infrared absorbing WJ2.

Next, 1 part of a large propyran compound represented by (i) and (I
Myristicin expressed by I)! ! Part 1 (I)
Me Me 18H37 (II) CH3(CH2) A solution of each 12COOH dissolved in chloroform to a concentration of 2.5X10-3 mol/JL was adjusted to pH with sodium bicarbonate in distilled water containing cadmium chloride at a concentration of IXIO-3 mol/i.
The mixture was dropped onto the water surface of a 20°C aqueous phase adjusted to 6.3.

After the solvent chloroform was removed by evaporation, 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 dyne/cm.Then, the surface pressure was kept constant. At the same time, the glass substrate was
The monomolecular film was transferred onto the glass surface to which the 5i02 film was attached by gently moving it up and down at a speed of i n to obtain a colorless imaging layer 2. Furthermore, a glass substrate was placed on top of this. By this method, the calendar number of each monolayer is 2.
Five types of imaging elements were prepared with colorless imaging layers of 1, 51, 101, 201, 301.

Infrared (850mm) and ultraviolet (
When two lights were irradiated simultaneously using a polychromatic light source that emitted 356 mm, a clear blue image was obtained at the irradiated area.

Example 2 The imaging element of the present invention was manufactured as follows.

Gd, Tb, Fe (gadolinium,
A layer of terbium (iron) was deposited to form an infrared absorbing layer 2. In order to prevent this Gd·Tb5Fe layer from being oxidized, an S+02 protective film was coated thereon.

Next, using 1 part of a cis-trans photoisomerizable compound represented by (Ul) and 1 part of palmitic acid represented by (rV), (rV) CH3(CH2) 14COOH was produced under the same conditions and method as in Example 1. A yellow imaging element was produced.

When this image forming element was irradiated with infrared rays spread over the image information under direct sunlight, a red image was obtained.

Example 3 The imaging element of the present invention was manufactured as follows.

An infrared absorbing layer 2 was formed by depositing a 5i02 layer with a thickness of 1500 mm on the surface of a 50 mm square glass substrate by sputtering.

Next, 1 part of the imidazole compound represented by (V) and (
(V) OH (■) CH3(CH2) 16e00H A white image forming element was produced in the same manner and under the same conditions as in Example 1 using 1 part of stearic acid represented by VI).

When this image forming element was irradiated with infrared rays according to image information under direct sunlight, a deep purple image was obtained.

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 element is relatively simple, its productivity is excellent, and the element has high durability and reliability.

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

(6) Since a monomolecular film or a monomolecular layer accumulation film can be created using the Langmuir-Prodgett 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) Mixed J1g In the case of utilizing phase transition (of a monomolecular or monomolecular layer stack), depending on the structure of the constituent molecules of the mixed film (monolayer film), some may maintain the phase-transformed state for a long time. 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).

(10) Imaging can be quickly obtained.

(11) Image erasure/reproduction is also possible.

(12) Since it approximates the function of biological lipids, it is compatible with single-molecule devices and bioelectronics.

(13) Since a radiation absorption layer is used, thermal efficiency is good.

[Brief explanation of drawings]

FIG. 1(A) is a sectional view of a transmission type image forming element of the present invention;
FIG. 1(B) is a cross-sectional view of the reflective image forming element of the present invention,
FIG. 2 is a schematic diagram of a monomolecular cumulative film according to the present invention, FIG. 3 is a schematic diagram showing a phase transition phenomenon according to the present invention, and 4r17:1
(A) (B) C is a cross-sectional view of an image forming element when forming an image using a polychromatic light source. l Substrate 2 Radiation absorption layer 3 Image forming layer 4 Protective substrate 6 Light 7, 8 Illumination light 9 Reflective film 10-1 Parent wood group 10-2 17iIi water group 11 Phase changeable organic compound molecule 12 Functional molecule 13 Infrared rays 14 Signal light beam 15 Multicolor light source 16 Infrared absorption layer patent applicant Canon Corporation Figure 1 (A) (j3)

Claims (2)

[Claims] (1) An image consisting of a phase-transitionable organic compound molecule that has at least a hydrophilic site and a hydrophobic site and has no unsaturated bonds in its molecular skeleton, and a functional molecule that has at least a hydrophilic site and a hydrophobic site. An image forming element comprising a forming layer and a heat generating element for applying thermal energy to the image forming layer. (2) The image forming element according to claim 1, wherein the heat generating element is a radiation absorbing layer.