JPS61169871A - Image forming method - Google Patents

Abstract

PURPOSE:To execute development of various hues and to make possible the long-period safe preservation of an image by processing a recording material formed with a specifically constituted recording layer on a conductive substrate with a heat pattern and developing the same in an electrolyte contg. a coloring material. CONSTITUTION:The recording layer 2 consisting of a polymer complex composed of a basic polymer such as N-pyrolidone and acidic polymer such as citric acid is formed on the conductive substrate 1 consisting of a metallic plate of gold, platinum, copper, etc. and an insulating layer 3 is deposited on the other surface. Such material 10 is processed with the heat pattern to form a latent image 5 in the recording layer 2. The material in such a state is immersed into the electrolyte 6 incorporated therein with the coloring material and electricity is conducted thereto to develop the image. The development of various hues is thus made possible and the easy production and recording are executed without exercising special care for the photosensitivity. The long- period stable preservation of the image is thus made possible.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method of recording various information and forming a visible image by thermal pattern processing.
A recording layer made of a polymer complex with a specific configuration is formed on a conductive substrate, a latent image is formed in the recording layer by thermal patterning, and the latent image is developed by electrical means to easily form a visible image. The purpose is to provide a method that can be used.

(Prior Art) Conventionally, there are many known methods for recording various types of information through thermal pattern processing. By providing recording layers with varying degrees of change and applying a thermal pattern to these recording layers, a visible change in the recording layer or a recorded image readable by other reading means is formed. For forming the recording layer,
Heat-sensitive materials are often used, many of which are various polymers, pigments, or mixtures thereof.

(Problems to be Solved by the Invention) Heat-sensitive polymers and dyes are often used to form the recording layer of the recording material used in the conventional recording method using thermal pattern processing as described above. When forming a recording layer from these materials, there is a problem in that sufficient care must be taken in handling these materials.

That is, in order to form recording layers from heat-sensitive materials, those materials must be rendered heat-insensitive before use, and for similar reasons, preservation of the recording material after formation requires even more adequate protection. If care is not taken, there is the problem that it loses its heat sensitivity before use, rendering it unusable.

In addition, even with such various precautions, recording materials using conventional thermal pattern processing still have problems with the storage stability of recorded materials after recording, and are not fully reliable in terms of long-term storage life. It wasn't something to give.

Therefore, there is a need for a recording material and a recording method that do not require special precautions during production, can easily form a recording layer, can easily record information, and can stably store recorded information for a long period of time. The reality is that there is still a strong demand for it.

In order to meet the demands of the prior art as described above, the present inventors
As a result of extensive research, we have found that when a conductive substrate is used as the supporting base of the recording material and a polymer material with a specific composition is used as the material constituting the recording layer, various information can be easily recorded by thermal pattern processing. The present invention was completed based on the finding that a recorded image with excellent storage stability can be obtained by converting the latent image of recorded information into a visible image using specific electrochemical means. be.

(Means for Solving the Problems) That is, one aspect of the present invention is a recording medium comprising a conductive substrate and a recording layer provided on the conductive substrate, the recording layer comprising a polymer complex of a basic polymer and an acidic polymer. Image formation consisting of thermally patterning a material to form a latent image, then immersing the recording material as one electrode in an electrolytic solution containing a coloring material and applying electricity to develop the latent image portion. It's a method.

To explain the present invention in detail, 1. The main features of the present invention are as follows:
The first feature is that a conductive substrate is used as the substrate for the recording material used. The second feature is that a specific polymer complex is used to form the recording layer. The feature is that the recording material thus formed is thermally patterned using a conventional method, and electrochemical means are used to develop the resulting latent image.

Therefore, the present invention will be further described in detail focusing on these main features.

The conductive substrate used as the substrate of the recording material in the present invention may be any material as long as it is conductive.For example, metal plates such as gold, platinum, silver, nickel, copper, etc., or tin oxide, Any conductive oxide such as indium oxide, indium-tin oxide, or other conductive material deposited on any substrate, such as a glass plate, various resin films, or sheets, can be used.

Furthermore, the polymer complex used to form the recording layer on the substrate is composed of a basic polymer and an acidic polymer, and is, for example, disclosed in Japanese Patent Publication No. 55-427.
The basic polymer itself is already known in Japanese Patent No. 44, and includes, for example, the following.

N-vinylpyrrolidone, N-vinyl-3-methylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-3,3,5-trimethylpyrrolidone, N-vinyl-3
-Benzylpyrrolidone, N-vinylpiperidone, N-vinyl-4-methylpiperidone, N-vinyl-caprolactam, N-vinylcapryllactam, N-vinyl-3-
Morpholine, N-vinylthiopyrrolidone, N-vinyl-
Homopolymers such as 2-pyridone or random copolymers, block copolymers, graft copolymers, etc. with other common monomers: N-vinyl-2-oxacylidone, N-vinyl-5-methyl-2 -Oxazolidone, N-vinyl-5-ethyl-
2-oxacylidone, N-vinyl-4-methyl-2-oxacylidone, N-vinyl-2-thioxazolidone,
Homopolymers such as N-vinyl-2-mercaptobenzothiazole or random copolymers, block copolymers, graft copolymers, etc. with other common heptadol; N-vinylimidazole, N-vinyl- Homopolymers such as 2-methylimidazole and N-vinyl-4-methylimidazole, or random copolymers, block copolymers, graft copolymers, etc. with other common monopolymers; 2- or 4- Homopolymers such as vinyl pyridine, random copolymers, block copolymers, graft copolymers, etc. with other common monomers are mentioned, and other copolymerizable monomers that may be used in the above include: methacrylate, acrylate.

acrylamide, acrylonitrile, vinyl ether,
Vinyl acetate, vinylimidazole, ethylene, styrene and other common monomers, among which are particularly useful in the present invention are N-vinylpyrrolidone, N-
Vinylpiperidone, N-vinylcaprolactam, N-
Vinylmorpholine.

These include homopolymers and copolymers of N-vinyl-2-oxacylidone and N-vinyl-5-methyl-2-oxazolidone. In the case of copolymers, nitrogen-containing polymers such as those mentioned above are used.
is preferably included in an amount of 50 mol% or more.

Further, examples of acidic polymers that can form a polymer complex with the above basic polymer include the following.

Polyesters with terminal carboxyl groups obtained by reacting polycarboxylic acids such as citric acid, tartaric acid, and phthalic acid with polyhydric alcohols such as ethylene glycol, 1.4-butanediol, and diethylene glycol in excess of acid: Various polycarboxylic acids Acidic cellulose derivative modified with (
Homopolymers such as vinyl ether ester monomers of polyvalent carboxylic acids, random copolymers, block copolymers, graft copolymers, etc. with other common monomers (see Japanese Patent Publication No. 35-5093); 35-8495
Homopolymers of monomers such as niacrylic acid or methacrylic acid, or random copolymers with other common heptamers,
Block copolymers, graft copolymers, etc.: Random copolymers and block copolymers with anhydrous α, β-unsaturated vinyl monomers such as leic acid and itaconic acid, or other common monomers. Coalescence, graft copolymers, etc.: Other homopolymers of monomers containing sulfonic acid or phenol groups, or random copolymers, block copolymers, graft copolymers, etc. with other common monomers: Other carboxyl groups or acidic modified products of various polymers with sulfonic acid group- or phenol group-containing compounds: Any of the above acidic polymers can be used, but particularly preferred in the present invention are α,β-unsaturated monopolymers. These include polymers, random copolymers, block copolymers, and graft copolymers, and particularly preferred is a copolymer of alkyl vinyl ether and maleic anhydride.

The inventor of the tree had been conducting various research on mixtures of basic polymers and acidic polymers as described above.
By mixing these polymers in a solution, both polymers interact in some way to form a polymer complex that is different from either polymer,
If both polymers are mixed in a relatively good solvent, a polymer complex will precipitate, and if mixed in a relatively good solvent, a significant increase in viscosity will occur, resulting in properties different from those of a simple mixture of both polymers used. This is what we have discovered.

Therefore, the polymer complex used in the present invention means a polymer complex consisting of the above-mentioned polymers. In the present invention, it is preferable to use both polymers in such a manner that their basicity and acidity are approximately the same. The mixing ratio can be determined by calculating the basicity and acidity of both polymers and determining the mixing ratio of both polymers accordingly. Furthermore, a polymer complex formed by mixing in an appropriate ratio becomes a polymer complex that cannot be strongly dyed by either acidic dyes or basic dyes. Therefore, the mixing ratio of both polymers can also be determined using these facts.

The polymer complexes thus obtained are generally not soluble in relatively good solvents such as water, alcohols, esters, hydrocarbons, and the like.

The polymer complex used in the present invention can be isolated by dissolving both polymers in these poor solvents and mixing the internal solutions. Also,
If mixed in a relatively good solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, etc.,
A solution of the polymer complex can be obtained. Therefore, when forming a recording layer on a conductive substrate as described above using a polymer complex as described above, (1) Prepare solutions of both polymers,
A method of applying one of the solutions onto a substrate and then applying a predetermined amount of the other polymer solution thereon to form a polymer complex on the substrate; (2) using a relatively good solvent as described above; A method of preparing a solution of a polymer complex and applying it onto a substrate can be used.

The recording material used in the present invention is formed using the above-mentioned materials, but in the present invention, in addition to the above-mentioned materials, for example, thermoplastic polymers other than those mentioned above may be used in combination with the above-mentioned polymer complex. They may enhance their film-forming ability, or they may include small amounts of colorants to give their films a light color.

Next, the present invention will be described in more detail with reference to the accompanying drawings that schematically illustrate the structure of the recording material used in the present invention. FIG. 1 diagrammatically shows the structure of the recording material 10 of the present invention with its cross-sectional shape, where 1 represents the conductive substrate as described above, 2 represents the recording layer made of a polymer complex, and 2 represents the recording layer made of a polymer complex. Figure 2 is a schematic cross-sectional view of a recording material of another example, and Figure 3 is a general polymer of any thickness that does not have electrical conductivity, such as polyolefin resin, vinyl resin, polyester resin, polyamide resin, etc. It is an insulating film.

As shown in FIGS. 1 and 2, the recording material lO used in the present invention
The recording layer 2 made of the above polymer complex is formed on at least one surface of the conductive substrate 1. As shown in FIG. 1, if the recording layer 2 is formed on both sides of the conductive substrate 1, the recording material 10 will have recording layers on both sides. It is preferable to apply an insulating coating H3 of arbitrary thickness to the surface.However, when the conductive substrate itself is a single-sided conductive substrate such as ITO vapor-deposited glass or aluminum vapor-deposited film, this is not necessary. do not have.

The conductive substrate l used can technically have any thickness and any shape, but generally has a thickness of about 0.0
It is preferably in the form of a plate, sheet, or film with a thickness of 3 to 3 m.The shape may be any shape, such as a tape shape, depending on the purpose of use of the recording material obtained.The recording layer 2 is as described above. It may be formed by a one-liquid method or a two-liquid method, but the thickness is generally about 0.1 to 2.
Approximately 1 pot (m) is suitable.

The inventors have found that the recording material formed as described above becomes a poor conductor as a whole and loses good conductivity, even though its substrate is conductive. This was naturally predictable since the two types of polymers that make up the polymer complex forming the recording layer are mutually neutralized, but further detailed research by the present inventor revealed that found that when these recording layers are treated with a thermal pattern that has more energy than the surrounding atmosphere, only that portion of the recording layer becomes conductive again, that is, a latent image consisting of conductive areas is formed. This is what I did. Moreover, such latent images retained their electrical conductivity for several minutes to several days after the application of the thermal pattern treatment was discontinued, and then returned to their original insulating properties.

As for the method of recording information and forming a latent image by exposing the recording material to a thermal pattern as described above, any conventionally known method can be used.For example, as shown schematically in FIG. , a thermal stylus, a thermal type, a mechanical method in which the heat-sensitive layer of the recording material is heated locally and selectively by scanning thermal energy such as a thermal printing head or a laser beam, and a radiation-absorbing method. Any other method may be used, such as a radiant heating method in which a document having a character pattern (not shown) and a recording material are placed one on top of the other in a heat conduction position, and intense radiation is applied using an incandescent tungsten lamp or the like.

As described below, a desired latent image 5 is formed in the recording layer of the recording material used in the present invention, but the recording material of the present invention can be developed into a visible image as follows. , such a developing method is also an important feature of the present invention.

A method for developing the latent image formed as described above will be specifically explained with reference to the accompanying drawings. FIG. 4 schematically shows a method for developing the latent image 5 formed on the recording material used in the present invention, and FIG. 5 schematically shows a cross section of the developed recording material IO. This is what is shown.

As shown in FIGS. 4 and 5, one preferred method for developing is to soak the recording material 10 on which these latent images have been formed in an electrolytic solution 6.
In this method, the colored material in the electrolytic solution is electrophoresed by being immersed in the electrolytic solution as an anode or a cathode and energized once, so that it is adsorbed or attached only to the conductive latent image area 5.

As method 1, a dye having an acidic group (for example, a sulfonic acid group, a phenolic hydroxyl group, or a carboxylic acid group) is dissolved or dispersed in an electrolytic solution, and a current is applied using the recording material 10 having a latent image as an anode. For example, the latent image 5 can be turned into the visible image 7 very easily, and the same effect can be obtained by using the recording material as the cathode and using the basic dye as the coloring agent. Coloring materials used in such methods include pigments that have ionic groups such as acidic or basic groups, such as conventionally known acid dyes, direct dyes, reactive dyes, and basic dyes, or those that develop color by redox. Any dye that can be used can be used.

Another preferred method is to add an electrolytically polymerizable material to the electrolytic solution and conduct electrolytic polymerization using the recording material as an anode.

The electrolytic polymerization method preferably used in the present invention includes, for example, “Oyoi Jisho, Vol. 52, No. 11 (1983) P.
97 L to 974, which is known per se, but according to detailed research by the present inventor, such an electrolytic polymerization method is suitable for developing the above-mentioned treated recording material in the present invention. This is what I discovered to be a method.

That is, when the recording material treated above is used as an anode and electricity is applied in an electrolytic solution containing a monomer for electrolytic polymerization, electrolytic polymerization occurs only in the conductive area of the recording material that is the anode, that is, the latent image area. As a result, a colored electropolymerized film is formed only in that area, and excellent development is achieved.

Examples of the seven polymers used in such electrolytic polymerization include seven polymers such as virol, thiophene, furan, selenophene, tellurophene, indole, azulene, aniline, chenothiophene, pyrrolopyrrole, and diacetylene. of monomer in the electrolyte is about 0.
It is preferable to use it at a concentration of about 001 to IM.

In addition, as the cathode which is the opposite electrode to the above anode, gold, platinum,
Any electrode material such as nickel may be used, and these cathodes may have any shape.

As the electrolytic solution, any conventionally known electrolytic solution such as water, acetonitrile, ethanol, dimethylformamide, dioxane, dichloroethane, tetrahydrofuran, etc. can be used, and Kc 1. Na
Br, KI, Li Cl o4, Li B F4. Any electrolyte can be used such as tetra-n-butylammonium perchlorate, tetra-n-butylammonium perfluoroborate, tetramethylammonium chloride, NaJS 04, etc., and these electrolytes have a
It is preferable to dissolve it at a concentration of about 1 to IM.

Electrolytic polymerization conditions vary depending on the type of monomer used, the type and shape of the electrode, the type and concentration of the electrolytic solution and electrolyte, and the size of the recording surface of the recording material used in the present invention, but generally Approximately 0.1 to 10 g is deposited on the latent image of the anode in several seconds to several minutes by applying a DC voltage of 1 to IOV.
An electropolymerized film with a film thickness of
If the coloring is strongly black, but the degree of coloring is small, the coloring can be reduced by dissolving an appropriate amount of dyes such as dyes with anionic groups such as acid dyes and direct dyes in the electrolyte. You can change the hue or increase the density.

As explained in detail above, the image forming method of the present invention uses a recording layer formed on a conductive substrate using a specific heat-sensitive polymer complex, and the formed recording layer is It does not lose any of its heat sensitivity even if it is left in an atmosphere, and there is no need to take special precautions when forming the recording layer in a normal atmosphere, making it industrially advantageous to manufacture. Moreover, the formed latent image can be developed not only to black but also to various hues by selecting the coloring material. After development, that is, after that part becomes a visible image,
Over time, the area where the latent image was and the other areas return to the same state as the stable polymer complex before recording, and as a whole, it does not change, either in whole or in part, depending on the ambient conditions. , the storage stability of recorded information is extremely excellent.

Next, the present invention will be explained in more detail by giving examples.
Note that "%" or "%" in the middle of the sentence is based on weight.

Example 1 Polyvinylpyrrolidone (K = 90) 5 parts Methyl vinyl ether/maleic anhydride-monobutyl nistyl copolymer (Gantretz ES-425, 50% ethanol solution, manufactured by GAF) 10 parts Ethanol 100 parts Dimethylformamide 100 parts The above mixed solution was placed on an ITO glass substrate (resistance 200C layer, size 20 x 20 cm),
Apply it evenly using a Meyer's bar (#32) and
After drying at 00° C. for 5 minutes, a recording material having a recording layer with a thickness of 3 ILm was obtained.

Next, Argo 7L/
- laser (wavelength 514 nm, power 10 mW) at 1 pse
Bit recording was performed using C irradiation.

Next, connect this to the anode of a DC power supply, connect a nickel plate to the cathode, and connect 0.0, OLM's pyrrole and 0.0.
When constant voltage electrolysis (4V, 10 seconds) was performed in an electrolyte of IO'0 parts of distilled water containing 1M sodium P-)luenesulfonate, a positive pattern of green-brown color corresponding to the heat pattern used was generated. image was formed. The obtained images had high contrast and could be used as slides, and the storage stability of the obtained images was very good.
The adhesion of the film to the substrate was also sufficient.

Example 2 Using the polymer solution for the recording layer used in Example 1, an ITO glass substrate was coated in the same manner as in Example 1 to obtain a recording material having a recording layer with a thickness of 34 m. After carrying out a thermal pattern treatment in the same manner as in Example 1, this recording material was connected to the anode of a DC power source, a nickel plate was connected to the cathode, and 0.01M pyrrole and 0.0M copper phthalocyanine tetrasulfone were added. 100 containing acid soda
When constant voltage electrolysis (4V, 10 seconds) was performed in a water electrolyte, the heat pattern treated area was colored blue, and a transparent blue positive pattern with high contrast was obtained on a colorless and transparent background. .

[Brief explanation of the drawing]

1 and 2 schematically show the structure of the recording material used in the present invention, FIG. 3 schematically shows the thermal pattern treatment in the method of the present invention, and FIG. 4 shows the structure of the recording material used in the present invention. The method of development is shown diagrammatically, and FIG. 5 diagrammatically shows the developed recording material. 1... Conductive base material 2... Recording layer 3... Insulating layer 4... Thermal energy 5... Latent image 6...・・・・・・
Electrolyte 7...Image 8-......on the cathode'' Recording material patent applicant Canon Co., Ltd. agent Patent attorney Yoshi 1) Katsuhiro, l':L・,° :
1- Figure 1 Figure 4

Claims (1)

[Claims] A recording material consisting of a conductive substrate and a recording layer provided on the conductive substrate, where the recording layer is a polymer complex of a basic polymer and an acidic polymer, is treated with a thermal pattern to form a latent image, and then An image forming method comprising immersing the recording material as one electrode in an electrolytic solution containing a coloring material and applying electricity to develop a latent image portion.