JPS61143190A - Recording medium - Google Patents

Abstract

PURPOSE:To provide a high-density recording medium capable of a chemical or physical change on a molecular basis under an external cause, comprising a monomolecular film or a built-up film thereof of a metal chelate compound having a C=N bond capable of releasing or incorporating a metal ion or a metal atom through syn-anti isomerization when being irradiated with light, and a liquid phase. CONSTITUTION:The recording medium comprises a two-layer built-up film of anti-form chelate ligand molecules 2 on a glass base 7, which is immersed in a liquid phase 6 containing metal ions (or metal atoms) 3 and contained in a container having an upper surface consisting of a transparent glass plate 5. When the recording medium is irradiated with syn-form isomerizing light 4 consisting of light capable of supplying energy necessary for photo- isomerization, such as UV rays and visible rays, in a pattern, photo- isomerization in the direction of hnu' in formula (I) takes place at the irradiated part, whereby the metal ion 3 is incorporated into the molecule, and rearrangement into a syn-form chelate ligand molecule 1 is caused. Accordingly, a recording medium with information recorded therein can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a recording medium that performs recording using chemical or physical changes in a monomolecular film or a cumulative monomolecular layer of chelate ligand molecules. .

[Prior Art] Various types of recording media having recording layers made of organic compounds are known.

For example, regarding an optical recording medium that uses a thin film of an organic compound as a recording layer,
It is also disclosed in Japanese Patent Application Laid-Open No. 58-1252413. All of them relate to laser recording media in which recording layers are made of organic dyes and recording and reproduction are performed using laser beams. In particular, the medium disclosed in JP-A-58-12524F3 uses a thin film of a cyanine dye represented by the general formula (C) as a recording layer. A cyanine dye solution represented by the general formula (I) is coated onto a plastic substrate to a thickness of 100 OA or less, for example about 300 Å, using a spin coater or the like to form a thin film. If the molecular distribution and orientation within the film is random, light scattering occurs within the film upon light irradiation, and when viewed microscopically, the degree of chemical reaction that occurs each time the film is irradiated differs. Therefore, as a recording medium, it is desirable that the molecular distribution and orientation within the film be uniform, and the film thickness is required to be as thin as possible in order to achieve high density recording.

However, when using the coating method, the film thickness is 30
The limit is about 0A, and the fact that the molecular distribution and orientation within the film are random is difficult to solve.

A diacetylene compound cumulative film, which has been proposed as a resist material with high photon efficiency and excellent resolution, has been used not only as a resist material but also as a thin film electrical
It has been shown in JP-A-58-42229 and JP-A-58-43220 that it is also applied to optical devices, electro-acoustic devices, piezoelectric devices, etc. , Japanese Patent Application Laid-open No. 111029/1983 discloses an improvement in the method for producing a diacetylene compound cumulative film. The diacetylene compound cumulative film on the substrate produced according to this invention is polymerized by irradiating ultraviolet rays to form a diacetylene compound polymer film, or by masking and irradiating ultraviolet rays to partially polymerize, unpolymerized Portions are removed to create shapes and used as thin film optical devices or integrated H-path devices.

However, all of these are limited to diacetylene compounds, and there is no mention of the possibility of erasing once recorded data when used as a thin film optical device.

On the other hand, in order to solve the above-mentioned drawbacks, a monomolecular film or a monomolecular layer stack of one type of photopolymerizable monomer having a parent tree group, a hydrophobic group, and at least one unsaturated bond in the molecule is formed on a substrate. An optical recording medium which can be used repeatedly is disclosed in Japanese Patent Application No. 58-IH832, which is characterized in that a recording layer is formed by using the same method.

Whether it is a cumulative film of these diacetylene compounds, a monomolecular film or a monomolecular layer cumulative film of photopolymerizable olefin monomers, a parent group or a hydrophobic group is introduced into a photoreactive compound and the film is directly deposited on a substrate. Adopts a manufacturing method that allows it to be supported. Therefore, not only is it difficult to easily produce various functional films, but also there is a fear that photoreactivity may decrease due to the introduction of parent groups and hydrophobic groups. Furthermore, there is a problem in that an extremely complicated operation is required for controlling the molecular orientation within the film plane, which is important when performing extremely advanced high-density recording.

[Problems to be Solved by the Invention] The present invention solves the drawbacks of the conventional examples, and provides 1) a method for relatively easily producing various functional films; Even if the function becomes thinner,
3) A method for forming a film in such a way that the film is expressed without loss or deterioration; As a result of various studies on how to orient the material with an ordered structure, the present invention was completed. Furthermore, by using such a film forming method, it has become possible to easily provide a high-sensitivity, high-resolution recording medium with high quality.

An object of the present invention is to provide a high-density recording medium that undergoes chemical or physical changes in molecular units due to external factors.

Another object of the present invention is to provide a medium that is superior to conventional examples in terms of molecular orientation within the medium plane, which is an important factor when performing high-density recording on a molecular basis. Furthermore,
In manufacturing the above-mentioned recording medium, it is an object of the present invention to provide a medium having various properties through relatively simple operational changes.

[Means for Solving the Problems] and [Operation] The above objects of the present invention are achieved by the present invention as described below.

A recording medium comprising a monomolecular film of chelate ligand molecules having a C=N bond that undergoes syn-anti isomerization when exposed to light and desorbs metal ions or metal atoms, or its cumulative H and a liquid phase. It is.

In the present invention, desorption of metal ions or metal atoms refers to the uptake or release of metal ions or metal atoms,
And it means that both j± are not performed at the same time.

The substance constituting the recording layer of the present invention has a hydrophilic site in its molecule,
It consists of a molecule each possessing at least one hydrophobic site, at least one chelating ligand, and at least one site for syn-anti isomerization.

By forming a monomolecular film or a monomolecular cumulative film of such molecules on a phase, an uninvented recording medium is formed. Components that can form hydrophilic sites and hydrophobic sites include various types of parent groups and hydrophobic groups that are generally widely known. A chelate ligand is formed by introducing at least two or more groups such as a hydroxyl group, a carbonyl group, an ether group, a carboxyl group, an ester group, an amine group, a nitrile group, a thioalcohol group, an imino group, a sulfone group, a sulfinyl group, etc. be done.

The chelate ligand molecule is represented by the general formula (g) to un.

Incidentally, the substitution sites of the chelate ligand and the long-chain alkyl group are not limited to the positions shown in the formula. Further, in general formulas (g) to 11, R: long-chain alkyl group R", R": H, (H3, C2H5, OCH
3 is shown.

Table 1 (L (L (L L In other words, having a hydrophilic site and a hydrophobic site in the molecule) means, for example, in the above general formula, the hydrophobic site is an alkyl chain, and the hydrophilic site is a chelate moiety. It shows other moieties such as a position.When introducing a hydrophobic moiety, a long chain alkyl group having 5 to 30 carbon atoms is particularly preferable.

A specific example of a chelate ligand molecule in the present invention is the following formula! -! Examples include compounds represented by n.

H2 H2 C)12 B/CH2 The compounds listed above are known compounds in themselves, except for the fact that a hydrophobic moiety is introduced into the chelate ligand molecule, and
It is also known that chelating ligand molecules that are not modified with long-chain alkyl groups form chelate complexes with various metal ions.

As metal ions that can form chelate complexes with these chelate ligand molecules, those that can form a coordination bond with the chelate ligand molecules are generally desirable, such as Ag", Cu'""
, Hg"'+Rb", K+, etc.

Examples of methods for creating a monomolecular film or a monomolecular cumulative film of compounds such as chelate ligand molecules include 1. Lan
The Langmuir-Prodgett method (LB method) developed by Gmuir et al. is used. In the LB method, for example, in a molecule with a structure that has a parent wood group and a hydrophobic group, when the balance between the two (amphiphilic balance '7.) is maintained appropriately, the molecule is This is a method of creating a monomolecular film or a cumulative film of monomolecular layers by using the fact that the group is oriented downward to form a monomolecular layer. A monolayer on the water surface has the characteristics of a two-dimensional system. When the molecules are sparsely dispersed, the two-dimensional ideal gas equation, nA=kT, holds between the area per molecule A and the surface pressure ■, resulting in a gas film. Here, k is Portzmann's constant, and T is the absolute temperature.If A is made small enough, the intermolecular interaction becomes strong, resulting in a two-dimensional solid "condensed film (or solid film)."Condensed films can be made of various materials such as glass substrates, The method can be used to transfer layer by layer onto the surface of a shaped carrier.A specific method for producing a monomolecular film of chelate ligand molecules or a cumulative film of chelate ligand molecules of the present invention using this method is as follows: For example, the following methods can be mentioned.

First, the vertical immersion method will be explained using a film forming apparatus.

As shown in FIGS. 4(a) and (b), a frame 12 made of, for example, polypropylene acid is hung horizontally inside a shallow and wide rectangular water tank 11 containing pure water. 20
is in charge of Inside the frame 12, a float 13 made of, for example, polypropylene acid is floating. Float 1
3 is a rectangular parallelepiped whose width is slightly shorter than the inner width of the frame 12, and is capable of two-dimensional piston movement in the horizontal direction in the figure. A weight 14 is tied to the float 13 via a pulley 15 for pulling the float 13 to the right in the figure. Further, there are provided a magnet 18 fixed on the float 13 and a pair of magnets 17 which are movable from side to side in the figure above the float 13 and repel each other when approaching the magnet 1B. It is possible to move left and right in the figure as well as stop. Such a weight 14 or a set of magnets 16°17
Instead, use a rotary motor or pulley to directly move the float 1.
Some move 3.

Suction nozzles 19 connected to a suction pump (not shown) via suction pipes 18 are arranged on both sides of the frame 12 . This suction nozzle 18 quickly removes unnecessary monomolecular films from the previous process on the liquid surface 20 in order to prevent impurities from being mixed into the monomolecular film or monomolecular cumulative film. It is used for. Note that 21 is a carrier that is attached to the upper and lower carrier arms 22 and is vertically moved up and down.

Using the above-described film forming apparatus, metal ions are first dissolved in an aqueous phase, and target chelate ligand molecules are dissolved in a solvent. A chelate ligand molecule solution is developed on an aqueous phase to precipitate chelate ligand molecules.

Next, to prevent this precipitate from freely diffusing on the aqueous phase and spreading too much, a partition plate (or float) is installed to limit the area of development and control the state of aggregation of the membrane material, and Obtain surface pressure ■. 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. By gently moving the clean carrier up and down vertically while maintaining this surface pressure, the chelate ligand molecule film is transferred onto the carrier. A chelate ligand molecule layer film is produced as described above, and a chelate ligand molecule layer cumulative film having a desired degree of accumulation can be formed by repeating the above operations.

In order to transfer the chelate ligand molecule layer onto the carrier, in addition to the above-mentioned vertical immersion method, methods such as the horizontal deposition method and the rotating cylinder method can be used. The horizontal adhesion method is a method in which the carrier is transferred by bringing it into horizontal contact with the water surface, and the rotating cylinder method is a method in which a cylindrical carrier is rotated on the water surface to transfer the chelate ligand molecule layer onto the surface of the carrier. In the vertical immersion method described above, when a carrier with a hydrophilic surface is lifted out of water in a direction across the water surface, a layer of chelate ligand molecules is formed on the carrier with the parent groups of the chelate ligand molecules facing the carrier. be done. When the carrier is moved up and down as described above, one chelate ligand molecule layer is stacked on top of the other with each step. Since the direction of the film-forming molecules is reversed between the pulling process and the dipping process, according to this method, between each layer, the hydrophilic group of the chelate ligand molecule and the hydrophilic group, and the hydrophobic group of the chelate ligand molecule and the hydrophobic group are opposite to each other. A mold film is formed. On the other hand, the horizontal attachment method is a method in which the carrier is brought into horizontal contact with the water surface and transferred, and a layer of chelate ligand molecules with the hydrophobic groups of the chelate ligand molecules facing the carrier side is formed on the carrier. In this method, there is no change in the orientation of the film-forming molecules even when the films are accumulated, and an X-type film is formed in which the hydrophobic groups face the phase body in all layers. On the other hand, a cumulative film in which the parent tree groups in all layers face the carrier side is called an X-type film.

The rotating cylinder method is a method in which a cylindrical carrier is rotated on the water surface to transfer a monomolecular layer onto the carrier surface.

The method of transferring the monomolecular layer onto the carrier is not limited to these methods, and when a large-area carrier is used, a method of extruding the carrier from a carrier roll into an aqueous phase may also be used.

Furthermore, the orientation of the aforementioned parent wood group and hydrophobic group toward the carrier is a general rule, and can be changed by surface treatment of the carrier.

The chelate ligand molecule film and the chelate ligand molecule layer cumulative film formed on the carrier by the above-mentioned method have a high density and a high degree of order, and these films can constitute a recording layer. Accordingly, it is possible to obtain a recording medium having a high-density, high-resolution recording function capable of optical recording, thermal recording, electrical recording, magnetic recording, etc. depending on the function of the chelate ligand.

Next, a metal ion release/intake reaction by light-induced syn-anti isomerization of chelate ligand molecules in the recording medium according to the present invention will be described.

1 to 3 are longitudinal sectional views showing one embodiment of a recording medium according to the present invention. Note that each figure is a schematic diagram and does not specifically show the shape of the molecules. In Figure 1,
The recording medium according to the present invention is a container in which a two-layer accumulated chelate ligand molecule film consisting of anti-type chelate ligand molecules 2 is formed on a glass substrate 7, and the upper surface is formed of a transparent glass plate 5. It is formed by immersing it in a liquid phase 6 containing metal ions (or metal atoms) 3 contained therein. Now, when syn-isomerization light 4 consisting of light such as ultraviolet rays and visible light that can supply the energy necessary for photoisomerization is irradiated according to a certain pattern, at the irradiated site, as shown in formula (I) and formula (1), A photoisomerization reaction occurs in the direction of hυ', the metal ion 3 is taken up, and rearranged into a syn-type chelate ligand molecule. In this way, a recording medium on which information is recorded can be obtained. Next, as shown in FIG. 2, the recording can be reproduced by irradiating the recording medium with monitor light 8 and reading the change in absorption of light from transmitted light 9.9'.

Furthermore, after reproducing the recording, if necessary, if anti-isomer light 10 is irradiated as shown in FIG. Rearrangement of the chelating ligand molecules occurs, releasing metal ions, and the record can be erased.

The information recorded as described above is read by, for example, irradiation with light of a wavelength that does not involve photoisomerization. That is, since the absorption wavelength of the chelate ligand and the absorption wavelength of the chelate ligand molecule are different, information is reproduced by reading changes in the absorption spectrum. Since the difference in absorption wavelength is very large, the S/N ratio when reproducing information is excellent.

Since this photoisomerization reaction can be reversibly controlled by light irradiation, metal ions can be desorbed as desired. That is, it is possible to use the recording and reproduction repeatedly. Furthermore, since the film has high density and high orderliness, it has excellent resolution.

[Example] EXAMPLES The present invention will be explained in more detail by showing examples below.

Formula 1u-! The compounds shown in Table 2 were used.

Example 1 An imine derivative of formula 1 as a chelating ligand molecule was dissolved in chloroform at a concentration of 5×10″3M, and then at pH 5,
2. Developed on an aqueous phase with a copper ion concentration of 4×10′IM. After the solvent chloroform was removed by evaporation, the surface pressure was increased to 30 dyne/cm while irradiating 313 nm light to precipitate the chelate ligand in the form of a film.

After this, while keeping the surface pressure constant, move the glass substrate whose surface is sufficiently clean and hydrophilic at a vertical speed of 3.5 cm/w.
The chelate ligand molecular film was transferred onto the substrate by gently moving it up and down in the direction across the water surface, and the chelate coordination accumulated in the chelate ligand monomolecular film and the 5, 11, 15, 21, 25 layers was removed. An optical recording medium having a molecular film as a recording layer was manufactured. During this cumulative process, each time the substrate was lifted from the aqueous phase, it was left for 30 minutes or more to evaporate and remove the water adhering to the substrate. The film forming equipment is manufactured by JOYCE in the UK.
A Langmuir-Trough manufactured by Co., Ltd. was used. The prepared optical recording medium was immersed in an aqueous solution and irradiated with 450 nm light according to a pattern to perform an anti-syn isomerization reaction and record information. High-density recording on the molecular order was possible.

Reproduction of recording was performed by reading the change in absorption at 530 nm. Next, when 313 nm light was irradiated for 3 minutes, thin-anti isomerization occurred and the record was erased. Furthermore, the recording-reproducing-erasing operation was repeated 35 times, and it was confirmed that repeated use was possible. No decrease in S/N ratio was observed.

Examples 2 to 11 Compounds of formulas 1u to U as chelate ligand molecules were dissolved in chloroform at a concentration of 5 x 10'H, respectively, followed by cupricin, silver nitrate or molybdenum thioglycolate salt 4 x 1 (at a concentration of 1'H). Developed on the aqueous phase. After removing the solvent chloroform by evaporation,
The surface pressure was increased to 3.0 nm while irradiating light with an appropriate wavelength between 0 nm.
The concentration was increased to 0 dyne/cm to precipitate the Kir-1 ligand molecules in a film form.

After this, while keeping the surface pressure constant, move the glass substrate whose surface is sufficiently clean and hydrophilic at a vertical speed of 3.5 cm/w.
The chelate ligand and molecular film are transferred onto the substrate by gently moving the chelate ligand up and down in the direction across the water surface. An optical recording medium having a molecular film as a recording layer was manufactured. During this cumulative process, each time the substrate was lifted from the aqueous phase, it was allowed to stand for 30 minutes or more to evaporate and remove moisture adhering to the substrate. The film forming apparatus used was a Langmuir-Trough manufactured by JOYCE, UK. The created optical recording medium is immersed in an aqueous solution and heated from 400nrrr to 850nr according to the pattern.
An anti-syn isomerization reaction was carried out by irradiating light with an appropriate wavelength of m, and information was recorded. High-density recording on the molecular order was possible. Record playback is 500-85
This was done by reading the absorption change at an appropriate wavelength of 0 nm. Next, when light of an appropriate wavelength of 300 nm to 500 nm was irradiated for 3 minutes, thin-anti isomerization occurred and the record was erased.

Furthermore, the recording-reproducing-erasing operation was repeated 25 to 40 times, and it was confirmed that repeated use was possible.

No decrease in S/N ratio was observed.

[Effect of the invention] The effects of the present invention are listed below.

1. Since a monomolecular film or a monomolecular layer stack having high density and high orderliness can be easily produced using the Langmuir-Prodgett method, high-density recording with an excellent S/N ratio is possible.

2. The isomerization of the chelate ligand molecules is almost quantitative, resulting in excellent recording stability.

3. Since a chelate ligand molecule that causes efficient syn-anti isomerization and anti-syn isomerization reactions is used, repeated use is possible.

4. Since it uses a reversible photoisomerization reaction, it can be applied as a recording medium with both negative and positive functions.

[Brief explanation of drawings]

1 to 3 are longitudinal sectional views showing one embodiment of a recording medium according to the present invention, in which FIG. 1 shows a recording process, FIG. 2 shows a reproduction process, and FIG. 3 shows an erasing process. Figure 4 (a), (b)
) is an explanatory diagram showing an example of a conventional film forming apparatus. 1... Syn-type chelate ligand molecule 2... Anti-type chelate ligand molecule 3... Metal ion (or metal atom) 4... Syn-type isomerization light 5... Glass plate 6. ... Liquid phase 7 ... Glass substrate 8 ... Monitor light 9.9° ... Transmitted light 10 ... Anti-isomerization light 11 ... Water tank 12 ... Frame 13 ... Float 14 ... Weight 15 ... Pulley 18 ... Magnet 17 ... Pair magnet 18 ... Suction pipe 19 ... Suction nozzle 20 ... Liquid level 21 ... Carrier 22 ... Upper and lower arms of carrier

Claims (1)

[Claims] A recording medium comprising a monomolecular film of chelate ligand molecules having a C=N bond that isomerizes when exposed to light and desorbs metal ions or metal atoms, or a cumulative film thereof, and a liquid phase.