JPS6163489A - Photo-recording element - Google Patents

Abstract

PURPOSE:To obtain a photo-recording element capable of highly reliable high- density recording by a method in which at least one of A-layer, B-layer and a light absorptive layer is made up of the monomolecular film or its laminate film of constituent substances and a reflection film is further provided. CONSTITUTION:A laminate consisting of A-layer 2 of a leuco dye, B-layer 4 of a phenolic compound and a light absorptive layer 3 of a light absorptive substance which is provided between the A- and B-layers 2 and 4 is provided through the B-layer 4 on a reflection layer 30 formed on a substrate 1. In such a constitution, at least one of the A- and B-layers and the layer 2, 4 and 3 is made up of the monomolecular film or its laminate film of constituent substances and the other layer is formed of deposit films. The leuco dye of the A-layer is contacted with the phenolic compound of the B-layer by irradiation of infrared rays and a chromogenic reaction proceeds to form color points at given positions. Information can thus be recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical recording element using an organic material, and in particular to an optical recording device capable of highly reliable and high-density recording using a highly molecularly oriented organic thin film. This relates to elements.

[Background Art] Recently, optical disks have been attracting attention as a central player in office automation (OA).

The reason for this is that a single optical disc can record (or store) a large amount of documents, literature, etc. Therefore, introducing an information storage device using this optical disc will revolutionize the organization and management of documents and literature in offices. It is something that brings. In addition, the recording element for the optical disk is inexpensive;
2. Description of the Related Art Elements made of organic materials that have features such as ease of manufacture and high-density recording are attracting attention.

Among the conventional techniques using such organic recording materials, a two-component optical recording element that utilizes a coloring reaction caused by contact between a coloring agent and a periodizing agent has been reported (Nikkei Sangyo Shimbun, 1972).
(October 18, 2017).

An example of the optical recording element will be described based on the drawings.
As shown in FIG. 3(a), a color former layer 7 and a preservative layer 5 are laminated on a substrate 1, separated by a light absorbing layer 8.

The coloring agent (leuco body) and the stabilizing agent are colorless or light-colored when each exists alone.

When recording on the recording element, a laser beam 8 is irradiated onto a desired position of the light absorption layer 6 as shown in FIG. 2(b).
The portion of the light-absorbing layer that is irradiated with the laser beam absorbs the laser beam, melts, and rips, leaving a small hole.

As a result, as shown in FIG. 2(C), the coloring agent and the time-setting agent, which were separated by the light absorption layer 6, mix through the small holes and develop a color. Information is recorded or stored in the form of coloring points 9, and reading is performed by scanning the recording element with another light source and detecting changes in reflectance, transmittance, etc. due to the coloring points.

[Problems to be Solved by the Invention] In the above-mentioned optical recording element, in order to achieve high recording density, it is desirable that the light absorption layer 6 be as thin as possible, flat, and without unevenness in film thickness. However, in the conventional Genferi R element, the light absorption layer is coated on the substrate by, for example, a vacuum evaporation method or a spin coating method, so the thickness is reduced to 20%.
If an attempt is made to reduce the thickness to 0 to 500 angstroms or less, pinholes tend to occur frequently, and the two components, the coloring agent and the periodizing agent, come into contact at these pinholes and develop color, resulting in a drawback of lack of reliability. Furthermore, since the molecular distribution and orientation within the film of each layer formed by the above-mentioned conventional coating method is random, light scattering occurs within the film with light irradiation, and when viewed microscopically, each light irradiation The degree of chemical reaction that occurs differs each time. Furthermore, the above-mentioned coating method has drawbacks such as unevenness in film thickness and unevenness in recording quality when the substrate of an optical disk has a large area.

Therefore, as an optical recording element, it is desirable that the molecular distribution and orientation within the film be uniform, that there are no pinholes, and that the film thickness is uniform, and that the film thickness be as thin as possible to achieve high recording density and high reliability. The present invention has been made in view of these demands, and an object of the present invention is to provide an optical recording element capable of highly reliable and high-density recording. Another object of the present invention is to provide an optical recording element that is easy to manufacture and inexpensive.

Still another object of the present invention is to provide a large area optical recording element.

[Means for Solving the Problems] and [Operation] That is, the present invention is directed to A, which is composed of a leuco form of a normally colorless or light-colored dye.
A layer, a B layer made of a phenolic compound that develops color when in contact with the leuco form of the dye, a light absorption layer made of a light absorbing substance, and a reflective layer, and the A layer, the B layer, and the light absorption layer. The optical recording element is characterized in that at least one of the layers is composed of a monomolecular film of a constituent material or a cumulative film thereof.

The present invention will be explained in detail below.

What is the optical recording element related to the present invention? It utilizes a color-forming reaction of a component system, and more specifically, it utilizes a color-forming reaction between a leuco form of a dye and a phenolic compound that develops a color when it comes into contact with the leuco form of the dye.

Therefore, the optical recording element according to the present invention is usually colorless.
A basic device is formed of a layer A consisting of a leuco form of a light-colored dye, a Bfi consisting of a phenolic compound that develops color when it comes into contact with the leuco form of the dye, a light absorption layer made of a light absorbing substance, and a reflective layer. The leuco type of the usually colorless to light-colored dye of the A layer used in the present invention includes, for example, triphenylmethane type, fluoran type, phenothiazine type, auramine type, spiropyran type, etc. The details of specific compounds contained in are shown in Table 1.

Next, as for the phenolic compound of the B layer that develops color when it comes into contact with the leuco form of the dye.

For example, pt-butylphenol, α-naphthol, β
- Naphthol, phenolphthalein, bisphenol A, 4-hydroxydiphenoxide, 4-hydroxyacetophenone, 3,5-xylenol, thymol, hydroquinone, 4-tert-butylphenol, 4-hydroxyphenoxide, methyl-4-hydroxy Benzoate, catechol, 4-hydroxyacetophenone, resorcinol, 4-tertiary-octylcatechol, 4,4'-secondary-butylidene diphenol,
2.2'-dihydroxydiphenyl, 2.2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-bis(4'-oxydiphenyl)propane, 4.4'-isopropylidenebis( 2-tert-butylphenol), 4.4'-secondary
Examples include butylidene diphenol, pyrogallol, phloroglucin, phloroglucin carboxylic acid, and the like.

Next, the light-absorbing material used in the formation of the light-absorbing layer in the present invention may be any light-absorbing dye that absorbs infrared rays, such as a melting light-absorbing dye that melts by absorbing infrared rays, or Sublimable light-absorbing dyes that absorb infrared rays and sublimate, non-melting dyes, non-sublimating dyes, etc. can be used.

Examples of such light-absorbing dyes include metal phthalocyanines such as copper phthalocyanine and vanadium phthalocyanine, metal-containing azo dyes, acidic azo dyes, and xanthine dyes such as fluorescein.

One feature of the optical recording element according to the present invention is that at least one layer among the A layer, the B layer, and the light absorption layer is composed of a monomolecular film of each constituent material or a cumulative film thereof. Therefore, when Afi, B5, or the light absorption layer forms a monomolecular film or a cumulative film thereof, the leuco form of the dye, the phenolic compound, or the light absorption substance all have affinity for appropriate sites within the molecule. It is necessary to use a derivative having larger wood groups, hydrophobic groups, or both groups.

Any commonly used hydrophobic group and parent tree group can be used, but particularly preferred hydrophobic groups include long-chain alkyl groups having 5 to 30 carbon atoms;
As the parent group, carboxyl groups and metal salts thereof (eg, cadmium salts) are desirable.

On the other hand, if the A layer, the B layer, or the light absorption layer does not form a monomolecular film or a cumulative film thereof, any film can be used as each layer as long as it is formed by a conventional coating method. Among them, a layer consisting of a deposited film such as a vapor deposited film, a coating film, a dipping film, or a laminate is preferred.

In addition, the film thickness of the A layer and the B layer is 2.
The range is preferably from 00 people to 1 OJL, preferably 1.0
The range is from 00 people to 1=.

On the other hand, when using a monomolecular film or a cumulative film thereof, the thickness of the light absorption layer is preferably in the range of 30A to t, ooo A, preferably in the range of 50A to 200A, and
When using a deposited film, a range of 90A to 1.000A is desirable, preferably a range of 140A to 400A.

In the present invention, the reflective layer may be any material as long as it reflects light, such as a metal reflective layer such as aluminum, a dielectric mirror, and the like.

In addition, among the reflective layers, the thickness of the metal reflective layer is particularly 1.00.
0 to 2,000 people is suitable.

In addition, the materials used for the substrate in the present invention include:
Semiconductor materials such as silicon, metal materials such as aluminum, preferably tempered glass, more preferably acrylic (PMMA), polycarbonate (PC), polypropylene, polyvinyl chloride (PV(:)), plastic materials such as polystyrene, ceramics The material is preferably 1).

As mentioned above, in the optical recording element according to the present invention, at least one of the layer A consisting of a leuco dye, the layer B consisting of a phenolic compound, and the light absorbing layer consisting of a light absorbing substance is a monomolecular film or a layer consisting of a constituent material. One of its characteristics is that it is composed of a cumulative film thereof.

As a method for producing a monomolecular film or a cumulative film thereof having such high orderliness and orientation of molecules, for example, 1. La
The Langmuir-Prodgett method (LB method) developed by Ngmuir et al. is used. The Langmuir-Prodgett method is based on the Langmuir-Prodgett method. For example, when a molecule has a parent tree group and a hydrophobic group in its molecule, and the balance between the two (balance of amphiphilicity) is maintained appropriately, the molecule will react to the parent tree on the water surface. This is a method of creating a monomolecular film or a monomolecular cumulative film by using the fact that the monomolecular layer is formed with the group facing downward. 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 A per molecule and the surface pressure n, resulting in a 'gas film', where k is Portsmann's The constant, T, is the absolute temperature.If A is made sufficiently small, the intermolecular interaction will become stronger, resulting in a two-dimensional solid "condensed film (or solid film)."Condensed films can be formed on various materials such as plastic substrates and glass substrates. It can be transferred layer by layer to the surface of a carrier having a shape of

Next, the method for forming a monomolecular film or a cumulative film thereof of an organic molecule having a leuco form of a dye used in the present invention, a phenolic compound, or a parent wood group or a hydrophobic group that is a light-absorbing substance will be described in further detail. .

First, the organic molecule is dissolved in a volatile solvent such as benzene, chloroform, etc., and spread on the aqueous phase 11 in the water tank 10 of the monomolecular cumulative film forming apparatus schematically shown in FIG. 3 using a cylinder or the like.

As the solvent evaporates, the organic molecules develop on the water phase 11 with the parent tree groups 12 facing the water phase and the hydrophobic groups 13 facing the gas phase.

Next, in order to prevent the precipitates (organic molecules) from freely diffusing on the aqueous phase 11 and spreading too much, a partition plate (or float) 14 is provided to limit the spread area and control the aggregation state of the membrane substance.
Obtain a surface pressure (■) proportional to the aggregate state. This partition plate 1
4, 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 the surface pressure (2) suitable for producing a cumulative film. By gently vertically moving the clean substrate 14 up and down while maintaining this surface pressure, the monomolecular film 16 is transferred onto the substrate. Monolayer ■
6 is manufactured in the above manner, and the monomolecular layer cumulative film 17 is formed by repeating the above-mentioned operations to form a desired cumulative number of monomolecular layer cumulative films.

For example, when the substrate 15 whose surface is woody is pulled out of water in a direction across the water surface, the woody groups of the organic molecules are removed from the substrate 15.
A side facing monolayer 1B is formed on the substrate 15. When the substrate 15 is moved up and down as described above.

The monomolecular layer 18 is stacked one by one in each process.The direction of the molecules formed in the film is reversed between the pulling process and the dipping process. , a so-called Y-type film is formed in which the hydrophobic groups of the organic molecules face each other (FIG. 4(a)).

The Y-type film is strong because the hydrophilic groups and hydrophobic groups of the organic molecules face each other.

In contrast, only when lowering the substrate 15 into the water,
There is also a method of transferring the organic molecules onto the substrate surface.

In this method, there is no change in the direction of the film-forming molecules even if the films are accumulated, and an X-type film is formed in which the hydrophobic groups face the substrate 15 in all layers (FIG. 4(b)). On the other hand, a cumulative film in which parent wood groups in all layers face the substrate 15 side is called an X-type film (FIG. 4(C)).

The X-type film is obtained by transferring organic molecules to the substrate surface only when the substrate 15 is lifted out of the water.

The monomolecular film and monomolecular layer cumulative film formed on the substrate by the above method have high density and a high degree of order and orientation, and by configuring the recording layer with these films, photothermal Accordingly, it is possible to obtain a recording element having a high-density and high-resolution recording function capable of performing digital recording. Further, as can be seen from the principles thereof, these film forming methods are very simple methods, and a recording element having the above-mentioned excellent recording function can be provided at low cost. 1
The substrate on which the monomolecular film or monomolecular cumulative film in the present invention is formed as described above is not particularly limited, but as long as a surfactant is attached to the surface of the substrate.

When the monomolecular layer is transferred from the water surface, the monomolecular film is disturbed and a good monomolecular film or monomolecular layer accumulation film cannot be formed, so it is necessary to use a substrate with a clean surface.

The monomolecular film or monomolecular layer film ms on the substrate is sufficiently strongly fixed and hardly peels off or peels off from the substrate. An adhesive layer can also be provided between the layer stacks. Furthermore, the adhesion force can be strengthened by selecting the monomolecular layer formation conditions, such as the hydrogen ion concentration of the aqueous phase, the ion species, the water temperature, the rate of raising and lowering the carrier, or the surface pressure.

Next, the method for forming the deposited film of layer A, layer B, or light absorption layer is to use a ball mill or the like to prepare a water mixture in which a binder and water are added to the leuco form of the dye, phenolic compound, or light absorption substance. After pulverizing and mixing, it is applied onto a substrate etc. using a conventional method.

The binder used in the present invention includes gelatin,
Natural polymers such as starch, cellulose nitrate, cellulose derivatives such as carboxymethyl cellulose, chlorinated rubber,
Semi-synthetic polymers such as natural rubber plastics such as cyclized rubber, polyisobutylene, polystyrene, terpene resins,
Polyacrylic acid, polyacrylic ester, polymethacrylic ester, polyacrylonitrile, polyacrylamide, polyvinyl acetate, polyvinyl alcohol, polyvinylpyrrolidone, polyacetal resin, polyvinyl chloride, polyvinylpyridine, polyvinylcarbazole tyrene-butadiene, butyl rubber, Polymerizable synthetic polymers such as polyoxymethylene, polyethyleneimine, polyethyleneimine hydrochloride, poly(2-acryloxyethyldimethylsulfonium chloride), phenolic resin, amino resin, toluene resin, alkyd resin, unsaturated polyester resin, allyl resin, polycarbonate, polyamide resin, polyether resin,
Examples include condensation polymerization type synthetic polymers such as silicone resins, furan resins, and thiocol rubbers, and addition polymerization type resins such as polyurethane, polyurea, and epoxy resins.

As a method for forming the reflective layer in the present invention, conventional methods that have been conventionally used can be used, and among these, vacuum evaporation, sputtering, etc. are preferable.

The optical recording element according to the present invention can be easily manufactured by sequentially combining the methods for forming each layer described above according to the intended structure.

Next, embodiments of the structure of the optical recording element according to the present invention will be shown below.

(1) FIG. 1(a) shows an example of an embodiment, in which the A layer 2 is made of a leuco dye, and the A layer 2 is made of a phenolic compound.
A laminate consisting of a layer 4 and a light-absorbing layer 3 made of a light-absorbing material interposed between the A layer and the B layer is supported on a reflective layer 30 provided on a substrate l via the B layer 4. , substrate/reflection layer/B layer/previous and subsequent recording layer/AM are laminated in this order.

Furthermore, as another example, the A layer of the laminate is supported on a reflective layer provided on a substrate, and substrate/reflective layer/A layer/previous and subsequent collecting layer/
The B layer may be laminated in this order, or two of the A-layer bodies may be stacked one on top of the other, and the lowest layer A5 or B layer may be supported on a reflective layer provided on the substrate.

In the above structure, at least one of the A layer, B layer, and light absorption layer of the laminate is made of a monomolecular film of each constituent material or a cumulative film thereof, and the other layers are formed of deposited films or the like.

Specific examples thereof are as follows.

(1) The A layer, the B layer, and the light absorption layer are all monomolecular films or their cumulative films (hereinafter referred to as "rLB film"). (2) The A layer, the light absorption layer are LB films, and the B layer is a deposited film (rLB film). 3) Light absorption layer, B layer is LB
Film, A layer is a deposited film (4) A layer, B layer is an LB film, light absorption layer is a deposited VK film (5) A layer is an LB film, B layer, light absorption layer is a deposited film (6) Light absorption layer is the LB film, and the A and B layers are deposited films (7
) The B layer is an LB film, the A layer is a deposited film, and the light absorption layer is a deposited film.The optical recording element according to the present invention having the structure described in (1) above is constructed by separating the A layer and the B layer by a light absorption layer. Therefore, by melting or sublimating the light-absorbing layer by infrared irradiation and creating holes at desired positions, the leuco form of the dye in layer A and the phenolic compound of Bfi come into contact and a coloring reaction progresses. Information can be recorded by forming colored points.

(n) Figure 1(b) shows a layer A 2 made of a leuco dye and eight layers 4 made of a phenolic compound, and a light absorption layer 3 is provided roughly on the layer B 4. The 81-layer structure is supported on a reflective layer 30 provided on a substrate 1 via the light absorption layer 3, and is laminated in the order of substrate/reflective layer/front/rear collecting layer/B layer/A layer. . In this case, the A-layer 2 and the 8-layer 4 may be reversed and laminated in the order of substrate/reflection layer/pre-rear collection layer/A-layer/B-layer.

Furthermore, to show another example, as shown in FIG. 1(C),
Layer 2 and 8 layers 4 are laminated, and a light absorption layer 3 is further provided on the A layer 2 to form a laminate, and 8 layers 4 are supported on a reflective layer 30 provided on the substrate 1, Substrate/Reflection F/B 17F
77/ A layer/light absorbing layer is laminated in this order. In this case, similarly to the above, the A layer 2 and the 8-layer 4 may be reversed and laminated in the order of substrate/reflective layer/A layer/B layer/light absorption layer.

Furthermore, in any of the configurations shown in FIGS. 1(b) and 1(c) above, two of the above-mentioned laminates may be stacked and supported on a reflective layer provided on a substrate.

In the configuration (II) above, at least one layer among the A layer, B layer, and light absorption layer of the laminate is formed of a monomolecular film of each constituent material or a cumulative film thereof, and the other layers are formed of deposited films. Ru.

Specific examples include (1) to (1) of embodiment (I) above.
As stated in 7).

The optical recording element having the structure (■) above is constructed by closely adhering the A layer made of a leuco dye and the B layer made of a phenolic compound. Conventionally, the A layer and the B layer were in contact with each other. Then, since a coloring reaction takes place, the A layer and B layer are separated from the beginning.
It was impossible to realize an optical recording element having a structure in which the layers were in contact with each other.

However, in the optical recording element according to the present invention,
Since the A layer and/or the B layer are composed of single molecules with a high degree of molecular order and orientation and their cumulative film, reactive sites can interact with each other through non-reactive sites within the molecules. This made it possible to use the above configuration.

That is, color development occurs when the reactive site of the phenolic compound molecule and the reactive site of the leuco dye molecule come into contact, but when the reactive site of the molecule and the non-reactive site of the molecule (e.g. alkyl chain) come into contact, color development occurs. No color reaction occurs upon contact with.

Therefore, a monomolecular film or a cumulative film thereof may be constructed such that the contact surface is composed of non-reactive portions of molecules.

The non-reactive sites constituting the contact surface may be those of molecules of phenolic compounds or leuco molecules of dyes - for example, hydrophobic sites (alkyl chains). A monomolecular film or a cumulative film thereof may be formed as a contact surface.

In addition, since the optical recording element according to the present invention having the above structure (TI) is constructed by laminating the A layer and the B layer in close contact with each other and further providing a light absorption layer on the outside, it is possible to absorb light by infrared irradiation. When the absorption layer is heated, the leuco form of the dye in layer A and the phenolic compound in layer B come into contact with each other under heat due to the heat conduction, and a coloring reaction progresses, forming coloring points at predetermined positions and recording information. I can do it. In this case, non-melting dyes and non-sublimating dyes are suitable as the light-absorbing substance.

In embodiments (I) and (II) above, the reflective layer is provided on the substrate, but in particular when using a transparent or semi-transparent substrate, the reflective layer is not provided on the substrate. The laminate is laminated on the laminate, and a reflective layer is provided on the laminate, for example, substrate (transparent or translucent)/B layer/light forward layer/
It is also possible to form a layer A/reflection layer/substrate and to irradiate light by passing through the transparent or semi-transparent substrate.

Therefore, the optical recording element according to the present invention can be mainly used as an optical disc. FIG. 5 shows an example of an information storage device having an optical pickup optical system for writing or reading information from the optical disc.

The information storage device is composed of a writing means consisting of a control circuit 27 and an optical pickup optical system, an optical recording element according to the present invention, and a reading means consisting of an output circuit 28 and an optical peak-up optical system.

Writing is performed as follows. The control circuit 27 controls the oscillation of the semiconductor laser 26. Therefore, the input information is converted into an optical signal by the control circuit 27 and the semiconductor laser 26. The optical signal 23 passes through the optical pickup optical system shown in FIG. 5, forms an image on the recording layer of the synchronously rotating optical disc 1B, and is recorded in color by the coloring mechanism described above.

Reading is performed as follows, using low-power continuous wave light emitted from the semiconductor laser 26 as the reading light. This is because, since the output is low, color recording is not performed during reading. Alternatively, another visible light source may be used as the reading light source.

The reading light beam forms an image on the substrate surface of the optical disk 18 and is reflected, but since the reflectance differs between the coloring point and the non-coloring point, this reflected light is applied to the light receiving surface of the photodiode 25 through the optical pickup optical system. This converts the signal into an electrical signal and reproduces and reads it.

Also, A! A protective layer may be provided on the surface of the outermost layer to protect the i, BN, light absorption layer, etc. Materials for such a protective layer include dielectrics such as 5i02, plastic resins,
Other polymerizable LB films and the like are suitable.

[Example] Hereinafter, the present invention will be explained in more detail by showing examples. In the following, unless otherwise specified, "1 part" means "part by weight" and "%" means "% by weight."

Synthesis example 1 (synthesis example of light-absorbing substance) Vanadium phthalocyanine! - After mixing and dissolving 10 parts of nourea and 1 part of 10-15% phosphoric acid aqueous solution, add 2 parts of phthalic anhydride and VOCfLz (
10 parts of henadyl salt) and 8 parts of a phthalic anhydride derivative represented by formula (1) were added, and 100 parts of
It was heated at ℃ for 5 hours. After cooling, 100 parts of a 2% dilute NaOH aqueous solution was added, hydrolyzed, and separated by chromatography to obtain the formula (H) ゛ 0 C-0-C2H.

0.1 part of a target substance (vanadium phthalocyanine derivative) represented by 0H ((J2), CH 2) was obtained.

Synthesis example 2 (synthesis example of leuco dye) Example 1 of two crystal violet and Trafton units (
III) 1 part of the m-ami7benzoic acid derivative represented by the formula (IV
) 1 part of Michler's hydrol represented by H 2 was added with 1 part of acid) and refluxed for 8 hours.

Formula (V) NCH Yo (CH2), □CH3 A triphenylmethane derivative represented by was produced.

Next, the triphenylmethane derivative of the product was converted into lead dioxide (
After heating in sulfuric acid for 3 hours in the presence of 1 part), a crystal bioleft lactone derivative represented by the formula (Vl) (CH2), 7CH3 was obtained.

Next, by adding an aqueous solution of caustic soda to this and cyclizing it, a crystal violet lactone derivative represented by the formula (■) (C:H2)77CH 0.
Got 2 copies.

Synthesis Example 3 (Synthesis Example of Phenolic Compound) One part of an ortho-xylene derivative represented by the formula (■) (CHZ) t 7 CH3 was heated with hot air (400 ℃−5
00°C), a phthalic anhydride derivative represented by the formula (IX) (OH2)770H30 was obtained.

Next, 2 parts of phenol and an appropriate amount of H2So4 were added to this and heated at 130°C.

0.1 part of a phenolphthalein derivative represented by formula (X) was obtained.

replacement Example 1 (1) Method of forming reflective layer An aluminum reflective layer was formed by vacuum evaporation.

A sufficiently cleaned glass (disk) substrate with a thickness of 10 mm and a diameter of 18 hm was placed in a vacuum chamber of a vacuum evaporation apparatus, and the degree of vacuum was 2 x 1O-.
After evacuation to 6 Torr, no substrate heating, evaporation rate 20 people/sea, vacuum degree at that time 2 x 10'5
Vacuum deposition was performed under conditions of Torr to obtain each sample in which an aluminum reflective layer with a thickness of 2,000 mm was formed on a glass substrate.

(2) Method for Forming Layer B Next, on the reflective layer formed on the glass substrate of each sample in (1) above, a VK film made of phenolphthalein, which is a phenolic compound, was formed.

The formation method is to mix 77 parts of phenolphthalein, 1 part of polyvinyl alcohol as a binder, and 40 parts of water, then grind and mix for several hours using a ball mill, spin coat on the reflective layer of the substrate, and mix in a binder. A deposited film (thickness 1 l) of phenolphthalein was obtained.

(3) Method for forming a light-absorbing layer Next, on the B layer formed on the glass substrate of each sample obtained in (2) above, a light-absorbing material such as vanadium A monomolecular cumulative film of phthalocyanine derivatives was formed.

A monomolecular cumulative film of a vanadium phthalocyanine derivative was formed as follows.

After submerging the substrate in water so that the substrate on which layer B was formed is perpendicular to the water surface, a vanadium phthalocyanine derivative is made into a chloroform solution with a concentration of 2×10'o1/i and dropped onto the water surface to form a monomolecular film on the water surface. Expand on top. The surface pressure was set at 30 dyne/Cm, and the substrate was moved up and down at a speed of 2 am/win to form a monomolecular cumulative film (Y-type [)] on each sample, which was accumulated in each layer shown in Table 2.

(4) Method of Forming Layer A Next, a deposited film of crystal violet lactone, which is a leuco dye, was formed on the light absorption layer formed on the glass substrate of each sample in (3) above.

The formation method is to mix 7 parts of crystal violet lactone, 1 part of polyvinyl alcohol as a binder, and 100 parts of water, then grind and mix for several hours using a ball mill, and then spin-coat it on the light absorption layer of the substrate and disperse it in the binder. Deposited film of crystal violet lactone (15!
J! (for Xi) was obtained.

(5) Performance test Jz An optical recording element according to the present invention manufactured by the method described above and a conventional similar structure as a comparative example (all constructed without using a reflective layer and a monomolecular film or a cumulative film thereof) After recording on an optical disk using the information storage device shown in FIG. 5 under the following recording conditions, the performance of the two was compared by reading and reproducing the information.

Recording conditions> Semiconductor laser wavelength: 830 mm Laser output: 6 to 91 Recording frequency: 5 MHz Optical disk rotation speed: 1.80 Orpm or more, reading was performed with a laser output of 1 mW, and the signal/noise ratio was determined. Table 2 shows the results. show.

Notes to Table 2: This book shows comparative examples, and each layer was formed by a four-roll coating method.

From the results in Table 2, when comparing Sample No. 1 and Sample No. 6, it is recognized that No. I has a significantly higher signal/fl sound ratio. I? Even though the two thickness conditions are almost the same, this difference in sex and night occurs.

1) No.1 has significantly fewer defects such as pinholes.

2) Contrast was improved L7 by providing a reflective film.

etc.

Comparing samples No. 2 to No. 5 and No. 8, N
It is recognized that the signal/noise ratio is significantly higher for No. o, 2 to No. 5. The reason why such a difference in performance occurs even though the film thickness conditions are almost the same is the same as the above-mentioned reason.

[Effects of the Invention] As explained above, the optical recording element according to the present invention has layers A and B.
Since at least one of the layers and the light-absorbing layer is composed of a monomolecular film of a constituent material or a layer consisting of a cumulative film thereof, and a reflective layer is further provided, there are excellent effects as shown below.

(1) Compared to optical recording elements that do not use conventional monomolecular films or their cumulative films, the signal/noise ratio is higher, and the reliability of recording can be improved.

(2) Physical defects such as pinholes in optical recording elements can be significantly reduced.

(3) Higher density recording is possible than with conventional optical recording elements.

(4) It is possible to increase the area of the optical recording element.

(5) When the light absorption layer is not interposed between the A layer and the B layer, color development efficiency and fidelity are improved.

(6) By adopting a configuration in which the light absorption layer is not interposed between layer A and B5, the recording layer can be made thinner, and higher density recording is possible.

(7) Chemically changes (synthesizes) materials that have good coloring efficiency and are excellent as coloring agents, etc., but are difficult to form a monomolecular film or a cumulative film thereof, or derivatives that are difficult to form a monomolecular film or a cumulative film thereof. There is an advantage that materials which are difficult to manufacture due to cost can be used for the deposited film.

(8) Since a deposited film is used in a part of the laminate, sensitivity is improved, there is a wide range of material selection during manufacturing, and manufacturing is easy, and the difference between contrast and non-contrast during reading is improved. It has effects on optical properties such as clearness.

(9) Since the reflective layer is provided, the contrast of the reproduced signal can be increased during reproduction readout, and the image quality etc. can be improved.

[Brief explanation of drawings]

FIGS. 1(a) to 1(c) are schematic cross-sectional views showing embodiments of the optical recording element according to the present invention, and FIG. 2(a) is
- Fig. 2(C) is an explanatory diagram showing the recording process of a conventional optical recording element, Fig. 3 is a schematic cross-sectional view of a monomolecular cumulative film forming apparatus, and Fig. 4(a) to Fig. 4(c). 5 is a manufacturing process diagram of a monomolecular cumulative film, and FIG. 5 is a block diagram of an information storage device. l, 15...Substrate 2...A layer 3.6...
・Light absorption layer 4...8 layer 5...auxiliary color layer
7... Color former layer 8... Laser light 9.
... Colored light lO ... Water tank 11 ... Water phase I2 ... Mother tree group 13 ... Hydrophobic group 14
...Partition plate 16...Monolayer film I7...
・Single molecule cumulative film I8...Optical disc 19...
Objective lens 20...1/4 wavelength plate 21...
Anti-1t [22...Collimating lens 23...Polarizing beam splitter 24...Cylindrical lens 25...Photodiode 26...Semiconductor laser 27...Control circuit (signal control means) 2 days... Output circuit 29... optical signal 30...
・Reflection layer

Claims (1)

[Claims] (1) A usually consists of a leuco form of a colorless or light-colored dye
A layer, a B layer made of a phenolic compound that develops color when in contact with the leuco form of the dye, a light absorption layer made of a light absorbing substance, and a reflective layer, and the A layer, the B layer, and the light absorption layer. An optical recording element characterized in that at least one of the layers is composed of a monomolecular film of a constituent material or a cumulative film thereof.