JPS6350831A - Optical recording method - Google Patents

Abstract

PURPOSE:To enable optical writing using a semiconductor laser having a small size and a light weight, and a rapid recording by incorporating a squarylium dyestuff and a diacetylene derivative compd. with a specific combination thereof to a recording layer. CONSTITUTION:A latent image is formed by radiating IR rays having 800-900nm wave-length according to the recording information to the optical recording medium having the recording layer contg. a mono-molecular film or its built-up film composed of the diacetylene derivative compd. contg. jointly with a hydrophilic group and a hydrophobic group, and the squarylium dyestuff. The latent image is developed by radiating UV rays to the optical recording medium formed by the latent image. The diacetylene derivative compd. is composed of a compd. capable of effecting 1,4-addition polymerization at a functional group of CidenticalC-CidenticalC-C contg. in adjacent molecule. Thus, the optical writing makes possible by the semiconductor laser having small size and light weight, and the recording information is developed optionally and read.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an optical recording method on an optical recording medium containing a diacetylene derivative compound, and in particular to an optical recording method using an 800-900 nm infrared laser as an optical writing means. Regarding recording methods.

[Conventional technology]

Recently, optical discs have been attracting attention as a central player in office automation. Optical discs can store large amounts of documents, literature, etc. on a single disc, so
Organize and manage documents, etc. in the office efficiently. Various types of recording media are being considered for this optical disc, but those using organic materials are attracting attention because of their cost and ease of manufacture.

Diacetylene derivative compounds are known as organic materials for such recording media, and a recording technology for use as a laser recording medium was disclosed in Japanese Patent Application Laid-Open No. 147807/1983, focusing on the thermochromic properties of these compounds. ing. but,
This specification does not mention what kind of laser was used or should be used, and merely states that recording was performed using a laser.

The present inventors investigated laser recording of this diacetylene derivative compound using various lasers, and found that although thermochromic recording is possible using a large, high-output laser such as an argon laser, a small and relatively It has been confirmed that laser recording cannot be performed when a low-output semiconductor laser (wavelength: 800 to 900 nm) is used. However, for practical recording media such as optical discs, it is required that optical writing be possible using a small, low-output semiconductor laser.

Furthermore, since the conventional recording layer made of a diacetylene derivative compound as described above is formed using microcrystalline powder of the diacetylene derivative compound, the distribution of diacetylene derivative compound molecules within the recording layer is It is random, and therefore has disadvantages such as the transmittance and reflectivity of light differing depending on the location, and the degree of chemical reaction differing, so it is not necessarily suitable for high-quality, high-density recording.

On the other hand, JP-A-58-181052 and JP-A-59-
Publication No. 60443 discloses various square aryllium dyes, and organic coatings containing these dyes absorb radiation in the radiation wavelength range of semiconductor lasers and generate heat, so that so-called heat mode recording in which pits are formed by laser energy is possible. Discloses what can be done. However, when recording by forming physical pits on the surface of a recording medium, a relatively large amount of energy is required.
In particular, it has been relatively difficult to perform high-density, high-sensitivity, and high-speed recording.

[Problem that the invention seeks to solve]

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to enable optical writing using a small and lightweight semiconductor laser, and to first record recorded information on a recording medium as a latent image. The object of the present invention is to provide an optical recording method in which the recorded information can then be visualized and read as desired.

Another object of the present invention is to provide an optical recording method capable of high-density, high-sensitivity, and high-speed recording.

Still another object of the present invention is to provide an optical recording method that has excellent stability and can obtain high-quality optically recorded images.

[Means for solving problems]

That is, the optical recording method of the present invention provides an optical recording medium having a recording layer containing a monomolecular film of a diacetylene derivative compound having at least a hydrophilic site and a hydrophobic site, or a cumulative film thereof, and a square aryllium dye. , 800
A step of irradiating infrared rays of ~900 nm according to recorded information to form a latent image; and a step of irradiating an optical recording medium on which the latent image is formed with ultraviolet rays to make the latent image visible. It is characterized by

The diacetylene derivative compound having both a hydrophilic site and a hydrophobic site (hereinafter abbreviated as DA compound) used in the present invention is defined as 1, A compound capable of 4-addition polymerization reaction, typically represented by the following general formula 1 (%) (wherein, X is a hydrophilic group forming a hydrophilic site,
m and n represent integers. ) Compounds represented by:

Examples of the hydrophilic group X in the above DA compound include a carboxyl group, an amino group, a hydroxy group, a nitrile group,
Examples include a thioalcohol group, an imino group, a sulfonic acid group, a sulfinyl group, or a metal or amine salt thereof.

The alkyl group represented by +(CH2)11- which forms a hydrophobic site is preferably a long-chain alkyl group having 1 to 30 carbon atoms. Further, n+m is preferably an integer of 1 to 30.

On the other hand, the squarelylium dye used in the present invention is a compound (including inner salts) having the following basic structure; ) and 800
It is a compound that has an absorption peak at ~900r+n+ and generates heat when exposed to infrared light at this wavelength. This squarerium dye typically has the following general formulas [1] to [TV].
The dyes shown are exemplified.

-Kayusuhi [■Koroθ Ichiosumon [+1Koshi0θM89Xθ General formula [m] General formula [rV] In the general formula (I) (11), R1 and R2 are alkyl groups (e.g., methyl group , ethyl group, n-propyl group, 1
so-propyl group, n-butyl group, 5ec-butyl group,
1so-butyl group, t-butyl group, n-amyl group, t-
amyl group, n-hexyl group, n-octyl group, t-octyl group, etc.), substituted alkyl group (e.g. 2- and droxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxy Methyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group, 4-
Sulfobutyl group, 3-sulfatepropyl group, 4-sulfatebutyl group, N-(methylsulfonyl)-carbamylmethyl group, 3-(acetylsulfamyl)propyl group, 4-(acetylsulfamyl)butyl group ), cyclic alkyl groups (e.g., cyclohexyl group, etc.)
, allyl group, aralkyl group (e.g., benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.), substituted aralkyl group (e.g., carboxybenzyl group, sulfobenzyl group, bitroxybenzyl group, etc.), It represents an aryl group (eg, phenyl group, etc.) or a substituted aryl group (eg, carboxyphenyl group, sulfophenyl group, hydroxyphenyl group, etc.). especially,
In the present invention, among these organic residues, hydrophobic ones are preferred.

Substituted or unsubstituted heterocycles, e.g. thiazole series nuclei (e.g. thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4.5-dimethylthiazole, 4.5-
diphenylthiazole, 4-(2-chenyl)-thiazole, etc.), benzothiazole series nuclei (e.g. benzothiazole, 5-chlorobenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5.
6-dimethylbenzothiazole, 5-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5
．． 6-dimethoxydibenzothiazole, 5.6-cyoxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 4,5,5
．． 7-titrahydropenzothiazole, etc.), naphthothiazole series nuclei (e.g. naphtho[2,1-d]thiazole, naphtho[1,2-d]thiazole, 5-methoxynaphtho[1,2-dlthiazole, 5 -ethoxynaphtho[1,2-d]thiazole, 8-methoxynaphtho[2,
1-d]thiazole, 7-methoxynaphtho[2,1-d
] thiazole), thionaphthene [7,6-dl thiazole series nuclei (e.g. 7-medoxythionaphthene [7
, 6-d]thiazole), oxazole series nuclei (e.g. 4-methyloxazole, 5-methyloxazole,
4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole), benzoxazole series nuclei (e.g. benzoxazole, 5-chlorobenzoxazole, 5-methylbenzo Oxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylpenzoxazole, 5-methoxybenzoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole,
6-hydroxybenzoxazole, etc.), naphthoxazole series nuclei (e.g. naphtho[2,1-d]oxazole, naphtho[1,2-d]oxazole, etc.), selenazole series nuclei (e.g. 4-methylselenazole,
4-phenylselenazole, etc.), benzoselenazole series nuclei (e.g. benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole, 5.
6-dimethylbenzoselenazole, 5-methoxybenzoselenazole, 5-methyl-6-methoxybenzoselenazole, 5,6-cyoxymethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4.5,6. 7
-titrahydropenzoselenazole, etc.), naphthoselenazole series nuclei (e.g. naphtho(2,1-d coselenazole, naphtho[1,2-d]selenazole), thiazoline series nuclei (e.g. thiazoline, 4-methylthiazoline). , 4-hydroxymethyl-4-methylthiazoline, 4
．． 4-bis-hydroxymethylthiazoline, etc.), oxazoline series nuclei (e.g. oxazoline), selenazoline series nuclei (e.g. selenazoline), 2-quinoline series nuclei (e.g. quinoline, 6-methylquinoline, 6-chloroquinoline, 6- medoxyquinoline, 6-nitoxyquinoline, 6-hydroxyquinoline), 4-quinoline series nuclei (e.g. quinoline, °6-medoxyquinoline, 7-methylquinoline, 8-methylquinoline), 1-isoquinoline series nuclei (e.g. isoquinoline, 3.4-dihydroisoquinoline), 3-isoquinoline series nuclei (e.g. inquinoline), 3.3-dialkylindolenine series nuclei (e.g. 3.3-dimethylindolenine, 3.3-dimethyl-5- chloroindolenine, 3,3.5-trimethylindolenine, 3,3.7-trimethylindolenine), lysine series nuclei (e.g. pyridine, 5-methylpyridine), benzimidazole series nuclei (e.g. l-ethyl -5,6-dichlorobenzimidazole, 1-hydroxyethyl-5,6-dichlorobenzimidazole,
l-ethyl-5-chlorobenzimidazole, l-ethyl-5,6-dibromobenzimidazole, 1-ethyl-5-phenylbenzimidazole, 1-ethyl-5-
Fluorobenzimidazole, l-ethyl-5-cyanobenzimidazole, i-(β-acetoxyethyl)-
5-cyanobenzimidazole, ■-ethyl-5-chloro-6-diatubenzimidazole, l-ethyl-5-
Fluoro-6-cyanobenzimidazole, ■-ethyl-5-acetylbenzimidazole, 1-ethyl-5-
Carboxybenzimidazole, 1-ethyl-5-ethoxycarbonylbenzimidazole, l-ethyl-5-
Sulfamylbenzimidazole, 1-ethyl-5-N
-ethylsulfamylbenzimidazole, l-ethyl-5,6-difluorobenzimidazole, 1-ethyl-5,6-dichlorobenzimidazole, l-ethyl-
5-ethylsulfonylbenzimidazole, l-ethyl-5-methylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylbenzimidazole, 1-
ethyl-5-trifluoromethylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.). X is a chloride ion, bromide ion, iodide ion, perchlorate ion,
Benzene sulfonate ion, p-toluene sulfonate ion, methyl sulfate ion, ethyl sulfate ion,
represents an anion such as propyl sulfate ion;
3,eeee -600,5o2NH-, -502-N-(:0-1-
502-N-5O,-, does not exist when Φ is included. M represents a cation such as a hydrogen cation, a sodium cation, an ammonium cation, a potassium cation, or a pyridium cation. n and m are 0 or 1.

In the general formula (I[I) (rV), R3 and R4 are
Indicates an alkyl group such as methyl, ethyl, propyl, butyl. Further, R3 and R4 can also form a ring such as morpholino, piperidinyl, or pyrrolidino together with the nitrogen atom. R5, R6, R7 and R8 are hydrogen atoms, alkyl groups (methyl, ethyl, propyl, butyl, etc.),
Indicates an alkoxy group (methoxy, ethoxy, propoxy, butoxy, etc.) or hydroxy group. Furthermore, R5 and R6 can be combined to form a benzene ring, and R5 and R6 can be combined with R7 and R8, respectively, to form a benzene ring.

Next, typical examples of the square aryllium dye used in the present invention are listed below, but for convenience, general formula [I] or [I
II] in the form of a betaine structure. However, in the preparation of these dyes, mixtures of dyes in betaine or salt form are obtained and are therefore used as mixtures.

Representative examples of general formulas [1] and [II] (2)　　　　　　　　　.

Shooting (3)　　　　　　　　　.

(4)　　　　　　　.

■ (7)　　　　　　　　.

(8).

(9)　　　　　　　　　.

(10)　　　　　　　　　.

(11)　　　　　　　　.

(13)　　　　　　　　　.

(14)　　　　　　　　　.

(+5) 　 　 　 0 (16)　　　　　　　　　.

genus (17)　　　　　　　　.

what 0”8).

(19)　　　　　　　.

(20).

C) I CHH2CH2 (23) O(25
) Q (2B)
.

(2?) 0 (28)
Q general formula [ml, [[V]
Representative example (35) O (3B) 0 (37) O (38).

The squarelillium dyes (1) to (42) above can be used alone or in combination of two or more.

The optical recording medium used in the present invention comprises a monomolecular film or a monomolecular cumulative film of Kenhoku-Aido and the square lyllium dye, and has a structure of any one of a -layer mixed system, a two-layer separation system, and a multilayer laminated system. But it's okay.

Here, the -layer mixed system refers to a system consisting of a mixed layer of a DA compound and square aryllium dye, and the two-layer g system refers to a system consisting of a mixed layer of a DA compound and square aryllium dye.
A multi-layer laminated system is one in which a layer containing A compound and a layer containing squareylium dye are laminated separately.
It refers to a structure that does not include the two-layer separation system, in which one or more layers containing a compound and one or more layers containing a square aryllium dye are laminated on a substrate in a predetermined number and order.

A typical configuration of an optical recording medium used in the present invention is shown in FIGS. 1 and 2.

In FIG. 1, a recording layer 2 of a -layer mixed system is provided on a substrate 1, and in FIG. 1(A), a DA
The configuration in which a mixed monomolecular film of Compound 8 and Squarelylium Dye 7 is formed, FIG. 1(B) shows DA Compound 8.
The structure is such that a mixed monomolecular cumulative film of and square lyllium dye 7 is formed.

On the other hand, in FIG. 2, a two-layer separation system recording layer 2 is provided on the substrate 1, and in FIG. A structure in which layer 2a consisting of a monomolecular film of compound 8 is laminated, the second
Figure (B) shows that D
It has a structure in which a layer 2a made of a monomolecular cumulative film of A compound 8 is formed.

The layer 2b containing the square aryllium dye may be formed as a monomolecular film or a cumulative film thereof by a method described later.

As the substrate 1 of the optical recording medium used in the present invention, glass,
Various supporting materials such as plastic plates such as acrylic resin, plastic films such as polyester, paper, and metal can be used, but when recording by irradiating radiation from the substrate side, recording radiation of a specific wavelength is used. Use something that allows the lines to pass through.

DA previously formed on the substrate 1 or on the substrate 1
On top of the layer containing the compound or squarelillium dye,
In order to form a monomolecular film or a monomolecular cumulative film as described above, for example, 1. The Langmuir-Prodgett method (hereinafter abbreviated as LB method) developed by Langmuir et al. is used. In the LB method, when a molecule has a structure that has a parent wood group and a hydrophobic group in the molecule, and the balance between the two (amphiphilic balance) is maintained appropriately, this molecule is placed above the water surface with the hydrophilic group facing down. This is a method of creating a monomolecular film or a film made up of monomolecular layers by utilizing the fact that the monomolecular layer is oriented. 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." Here, k is Boltzmann's constant and T is 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)". The condensed film can be transferred layer by layer to the surface of a substrate such as glass.

In addition, a so-called mixed monomolecular film or mixed monomolecular cumulative film composed of two or more compounds can also be obtained by the same method as described above. At this time, it is sufficient that at least one of the two or more compounds constituting the mixed monomolecular film or the mixed monomolecular cumulative film has both a hydrophilic site and a hydrophobic site,
Not all compounds are necessarily required to have a hydrophilic site and a hydrophobic site. In other words, if the amphipathic balance of at least one compound is maintained, a monomolecular layer will be formed on the water surface, and the other compounds will be sandwiched between the amphipathic compounds, resulting in a well-ordered molecular layer as a whole. A monolayer is formed.

A typical method for forming the recording layer 2 will be described below.

The one-layer mixed recording layer 2 shown in FIG.
It can be obtained by forming a mixed monomolecular film or a cumulative film of the A compound and the square aryllium dye.

That is, first, a DA compound and a square lylium dye are dissolved in a solvent such as chloroform, and this is spread on an aqueous phase to form a spread layer in which these compounds are spread in the form of a film. Next, to prevent this spread layer from spreading freely on the water phase and spreading too much, a partition plate (or float) is provided to limit the area of the spread layer and control the aggregation state of these compounds. Obtain a proportional surface pressure n. Move this partition plate,
By reducing the spread area and controlling the aggregation state of the film material, the surface pressure can be gradually increased to set a surface pressure n suitable for producing a cumulative film. By gently moving the clean substrate vertically up and down while maintaining this surface pressure, a mixed monomolecular film of the DA compound and the square aryllium dye is transferred onto the substrate.

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

In addition to the above-mentioned vertical dipping method, methods such as a horizontal deposition method and a rotating cylinder method can be used to transfer the monomolecular film onto a substrate. The horizontal deposition method is a method in which the substrate is brought into horizontal contact with the water surface and transferred, and the rotating cylinder method is a method in which a cylindrical substrate is rotated on the water surface to transfer a monomolecular layer onto the surface of the substrate. In the vertical immersion method described above, when a substrate with a hydrophilic surface is lifted out of water in a direction transverse to the water surface, a monomolecular layer with the hydrophilic groups of the OA compound facing the substrate is formed on the -th layer. .

As the substrate is moved up and down, one layer of mixed monomolecular film is deposited 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, a Y-shaped film is formed between each layer in which parent wood groups and parent wood groups, and hydrophobic groups face each other.

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 the hydrophobic group of the OA compound facing the substrate is formed on the substrate. In this method, there is no change in the orientation of the DA compound molecules even if they are accumulated, and an X-type film is formed in which the hydrophobic groups face the substrate in all layers. On the other hand, a cumulative film in which all the layers have parent groups facing the substrate is called a Z-type film.

The rotating cylinder method is a method in which a cylindrical substrate is rotated on the water surface to transfer a monomolecular layer 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 an aqueous phase 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.

Details of these monomolecular film transfer operations are already known and are described, for example, in "New Experimental Chemistry Course 18 Interfaces and Colloids", pages 498-507, published by Maruzen.

In this way, the mixed monomolecular film and its cumulative film formed on the substrate have a high density and a high degree of order, so variations in light absorption depending on location are extremely small. Therefore, by configuring the recording layer with such a film, a high-density, high-resolution recording medium capable of optical recording and thermal recording according to the functions obtained by the combination of the DA compound and the square aryllium dye can be obtained. It will be done.

In addition, when forming the recording layer 2 of a two-layer separation system or a multilayer stack system, one or more of the layers 2a consisting of a monomolecular film of a DA compound or a cumulative film thereof and one or more of the layers 2b containing squareylium dye. may be laminated on the substrate 1 in a predetermined number of layers and in a predetermined order.

Layer 2a consisting of a monomolecular film of a DA compound or a cumulative film thereof
can be formed on substrate 1 or on other layers already formed on substrate 1 by preparing a developing solution containing a DA compound (without squareylium dye) by the LB method described above.

The layer 2b containing the square lyllium dye is formed by applying a coating solution prepared by dissolving or dispersing the square lyllium dye in a suitable volatile solution onto the substrate 1 or on other layers already formed on the substrate 1. The film can be formed by coating the film to a dry film thickness of 100 mL and then drying it. Alternatively, the above-mentioned LB method can be applied to the squareylium dye by using an organic polymer with an appropriate amphipathic balance, such as a polymeric fatty acid such as stearic acid or araxic acid, as a carrier molecule in an arbitrary ratio. , it can also be formed as a monomolecular film or a cumulative film thereof. Furthermore, if a long-chain alkyl group or the like is introduced into the square aryllium dye, a monomolecular film or a monomolecular cumulative film thereof can be formed with good film formability.

When the layer 2b containing the square allylium dye is formed by a coating method, when the square allylium dye is in an amorphous state, alcohols such as methanol, ethanol, and impropatul can be used as the solvent for forming the coating solution. Ketones such as acetone, methyl ethyl ketone, and cyclohexanone; Amides such as N,N-dimethylformamide, ff, and N-dimethylacetamide; Sulfoxides such as dimethyl sulfoxide; Ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether;
Examples include esters such as methyl acetate and ethyl acetate, aromatics such as benzene, toluene, xylene, and ligroin, and when squarelylium is in the form of particles, dichloromethane, chloroform, carbon tetrachloride, and 1,1-dichloromethane. , 1,2-dichloromethane, 1,1,2-trichloromethane, chlorobenzene, bromobenzene, 1,
Examples include halogenated hydrocarbons such as 2-dichlorobenzene.

In addition, in order to improve the adhesion with the substrate 1 or with other layers, a binder made of a natural or synthetic polymer may be appropriately added to the coating liquid.

Application of such a coating liquid to the substrate 1 can be performed by a spinner rotation coating method, a dip coating method, a spray coating method,
Peed coating method, wire bar coating method,
Techniques such as a blade coating method, a roller coating method, and a curtain coating method are used.

When the recording layer 2 is a single-layer mixed type, the film thickness is suitably in the range of 200 to 2-2, and particularly preferably in the range of 400 to 5,000. In addition, the film thickness of each layer in the case of a two-layer separation system is
Approximately 100 people to 1 scale is suitable, especially 200 to 50 people.
A range of 00 people is preferred. Furthermore, in the case of a multilayer laminated system, both the sum of the film thicknesses of the layers containing the individual DA compounds and the sum of the film thicknesses of the layers containing the individual square lylium dyes are
Approximately 100 people to 1 bar is suitable, especially 200 to 500 people.
A range of 0 people is preferred.

The mixing ratio of the DA compound and the square aryllium dye in the recording layer 2 is preferably about 1/I5 to 15/l, and optimally 1/lO to 10/1.

Note that various protective layers may be provided on the recording layer 2 configured as described above, if necessary. Furthermore, the present invention can be carried out regardless of the order in which the layers are stacked in the case of a two-layer separation system or a multilayer laminate system.

Furthermore, when forming the recording layer 2, its stability,
Various additives may be added to this to improve quality.

The optical recording method of the present invention can be carried out using an optical recording medium configured in this manner.

In this optical recording medium, by adding ultraviolet rays to the DA compound, the absorption wavelength of the recording layer changes and the apparent color changes. That is, the DA compound is initially almost colorless and transparent, but upon irradiation with ultraviolet rays, it polymerizes and changes into a polydiacetylene derivative compound. This polymerization occurs only by irradiation with ultraviolet light and not by the application of other physical energy such as heat. As a result of this polymerization, 620
~660 nmk: It has a maximum absorption wavelength and changes from blue to dark color. This change in hue due to polymerization is an irreversible change, and the recording layer that has changed from blue to dark does not return to a colorless transparent film.

In addition, when this polydiacetylene derivative compound that has changed to blue or dark color is heated to about 50°C or higher, it becomes about 54°C.
It has a maximum absorption wavelength at 0 nm and changes to a red film. This change is also an irreversible change.

On the other hand, the present inventors conducted various studies on the recording layer having the above-mentioned structure, and found that HA is a process in which it is heated at an appropriate temperature that does not destroy or deform its shape to bring it into a -degree molten state. It has been found that even if the recording layer is irradiated with ultraviolet rays as described above, the color of the recording layer does not change to blue or dark.

In other words, this means that the change to a blue or dark film as a result of the polymerization of the DA compound due to this ultraviolet irradiation is mainly caused by O.
This is obtained by the highly ordered molecular conformation of the A compound, and when the orientation order of the DA compound within the layer is disturbed by heating the recording layer to melt the layer containing the DA compound as described above. This is thought to be because the number of molecules of the DA compound in a reactive positional relationship at the molecular arrangement level is significantly reduced.

The optical recording method of the present invention performs recording by utilizing the characteristics of this compound and the function obtained by combining it with a squareylium dye.

An example of this recording method will be described in detail below.

First, recorded information is converted into an optical signal by a semiconductor laser via a suitable control circuit. This optical signal passes through an optical system and is placed, for example, on an optical recording medium mounting means, and is placed at a predetermined position on a synchronously rotating disc-shaped optical recording medium having a single-layer mixed recording layer (see FIG. 2). The image is formed as shown in A),
Optical writing of recording information is performed using a semiconductor laser.

The semiconductor laser used at this time has an output wavelength of 80
Particular preference is given to using a 0-900 nm GaAs bonding laser.

At this time, there is no apparent change such as discoloration at the imaging point (light irradiation area) 3, but the square lyllium dye in this area absorbs the light and generates heat, and this heat generation causes the light irradiation area 3 to The recording layer melts, and the highly ordered orientation of the constituent molecules in this region is disturbed. As a result, the highly ordered orientation of the DA compound at the light irradiation site 3 is disturbed, and the light irradiation site 3
This is a portion that will not change color in the later visualization process.

Note that the irradiation conditions of the laser beam 4 during this writing may be appropriately selected depending on the configuration of the optical recording medium used, but at least the temperature of the light irradiation area 3 melts the recording layer and changes the orientation of the constituent molecules. It is necessary to maintain a temperature that is sufficient to disrupt the order and not destroy the recording layer or deform its shape.

In this way, the light irradiation caused by the difference in the state of the molecular orientation level in the recording layer, that is, the light irradiation formed in the portion 5b where the highly ordered orientation of the DA compound that was not irradiated with light is maintained. A latent image consisting of a portion 5a in which the highly ordered orientation of the DA compound is disturbed is formed, and recording information is written.

Incidentally, the DA compound is sensitive to the above-mentioned semiconductor laser, and such optical writing was not possible with conventional optical recording media made only of the DA compound.

Here, as described above, since no recorded information is recorded in the recording layer 2 as an optically detectable image, the written recorded information cannot be read at this stage.

Therefore, if it is desired to read recorded information, it is necessary to visualize the latent image formed on the recording layer 2.

This latent image is visualized by uniformly irradiating the optical recording medium with ultraviolet light.

By this irradiation with ultraviolet rays, the DA compound that maintains the highly ordered orientation in the recording layer, that is, the portion 5b that was not irradiated with light during the previous writing, polymerizes and changes into a polydiacetylene derivative compound, thereby recording This portion of the layer changes color to a blue to dark colored film 6b having a maximum absorption wavelength between 620 and 660 nm, as shown in FIG. 3(C).

On the other hand, in the part 5a that was irradiated with infrared rays during the previous optical writing, the highly ordered orientation of the D^ compound is disturbed, so the polymerization reaction of the DA compound is difficult to occur, and in this part, the non- Discoloration to a blue or dark film as in the irradiated portion 5b does not occur. Therefore, the latent image portion 5a formed during the previous writing remains in the film 6b, which has become blue or darkened by this ultraviolet irradiation treatment, with the color of the original recording layer which is almost colorless and transparent.
It is visualized as a white part 6a that can be optically distinguished from b.

Note that after the treatment by ultraviolet irradiation is completed, if the recording layer 2 is heated to about 50° C. or higher as necessary,
Since the polydiacetylene derivative compound in the blue or dark-colored film 6b changes color to red as described above, the recorded information written on the recording layer 2 as a latent image is transferred to the white part 6 in the red film.
It can be visualized as a.

For this heating treatment of the recording layer, a heating means such as a heater may be used, or the recording layer may be irradiated with radiation such as infrared rays since the recording layer contains square lyllium dye that absorbs radiation and generates heat. You can actually do tJ'sa by doing this.

The optical recording method of the present invention in the case of using an optical recording medium having a recording layer of a -layer mixed system has been described above, but the optical recording method with a recording layer of a two-layer separation system as shown in FIG. When using a medium, the imaging point 3 of the laser beam is the fourth
Layer 2 containing square lyllium dye as shown in Figure (A)
b. When the laser beam 4 is irradiated in this manner, the square aryllium dye contained in the layer 2b absorbs the laser beam 4 and generates heat, and this heat generation causes the portion of the layer 2a containing the DA compound above the imaging point 3 to It is melted and a latent image 5a is formed according to the process described above as shown in FIG. 4(B). This latent image is formed by the above-mentioned ultraviolet irradiation treatment and by further heat treatment as required, as shown in Fig. 4 (C
) Blue to dark color or red film 6b as shown in
This can be visualized as an optically distinguishable white part 6a.

In the above example, a disk-shaped disk (optical disk) was used as the optical recording medium, but of course, optical tape, optical Cards can also be used.

〔Effect of the invention〕

The effects of the optical recording method of the present invention are listed below.

(+) Since the recording layer uses a combination of square aryllium dye and diacetylene derivative compound, optical writing is possible using a small and lightweight semiconductor laser, and high-speed recording is possible. Moreover, the recorded information is recorded as a latent image on the recording medium, and then the recorded information can be visualized and read as desired.

輯) At least because the diacetylene derivative compound constitutes the recording layer as a monomolecular film or a cumulative film thereof,
The constituent components of the recording layer have a high density and a high degree of order, and the recording layer is formed homogeneously and with good surface properties. As a result, high-quality optical recording with excellent stability at high density and high sensitivity can be performed.

(3) Optical recording using an inexpensive recording medium having a highly homogeneous, large-area recording layer becomes possible.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on examples.

Example 1 General formula c12H25-CEC-C-C8H,6-(:
1 part by weight of a diacetylene derivative compound represented by OOH and 15 parts by weight of a squareylium dye represented by dye/a28 were added to chloroform at 3xlO'mol/).
The solution was developed on an aqueous phase having a pH of 6.5 and a cadmium chloride concentration of 1×1 O −3 mol/1.

After removing the solvent chloroform, while keeping the surface pressure constant, the glass substrate whose surface had been thoroughly cleaned was gently moved up and down in the direction across the water surface at a vertical speed of 1.0 cm/min to remove the DA compound. A mixed monomolecular film of 5 layers, 21 layers, 41 layers, 101 layers, and 201 layers was formed on the substrate by transferring a mixed monomolecular film of 5 layers, 21 layers, 41 layers, 101 layers, and 201 layers onto the substrate. An optical recording medium was created.

Using the optical recording medium thus obtained, the optical recording method of the present invention was carried out as follows.

First, each of the above optical recording media was irradiated with a semiconductor laser having a wavelength of 830 nm (laser beam diameter: 1 scale, irradiation time: 200 ns/1 dot, output 3 mW) according to the recorded information to form a latent image. .

At that time, no apparent change was observed in the light irradiated portion of each optical recording medium.

Next, after writing by this semiconductor laser was completed, each optical recording medium was uniformly and sufficiently irradiated with ultraviolet rays having a wavelength of 254 nm. Then, the area other than the area irradiated with the semiconductor laser during writing at the end of the recording layer of each optical recording medium changes color to blue, and the latent image formed earlier, that is, the negative where the area irradiated with the semiconductor laser is white, becomes blue. The image was made visible.

The evaluation of the recorded results is shown in Table 1A. The evaluation was based on a comprehensive evaluation of the sensitivity, image resolution, and contrast between the white area and the surrounding area. Particularly good results were evaluated as ◎, and cases in which O1 recording was not possible or poor were evaluated as ×.

Example 2 An optical recording medium was produced in the same manner as in Example 1, except that the amount of the diacetylene derivative compound was 1 part by weight and the amount of squarelylium dye was 10 parts by weight.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with 54 nm ultraviolet rays, and this was evaluated. The results are shown in Table 1A.

Example 3 Example 1 except that the amount of diacetylene derivative compound was 1 part by weight and the amount of square lylium dye was 5 parts by weight.
An optical recording medium was prepared in the same manner as described above.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with ultraviolet rays of 54 r+m, and was evaluated. The results are shown in Table 1A.

Example 4 Example 1 except that the amount of diacetylene derivative compound was 1 part by weight, and the amount of square lylium dye was 1 part by weight.
An optical recording medium was prepared in the same manner as described above.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with 54 nm ultraviolet rays, and this was evaluated. The results are shown in Table 1A.

Example 5 Example 1 except that the amount of diacetylene derivative compound was 5 parts by weight and the amount of square lylium dye was 1 part by weight.
An optical recording medium was prepared in the same manner as described above.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with ultraviolet rays of 54°C, and was evaluated. The results are shown in Table 1B.

Example 6 An optical recording medium was prepared in the same manner as in Example 1, except that the amount of the diacetylene derivative compound was 10 parts by weight and the amount of squarelylium dye was 1 part by weight.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with 54 nm ultraviolet rays, and this was evaluated. The results are shown in Table 1B.

Example 7 An optical recording medium was prepared in the same manner as in Example 1, except that the amount of the diacetylene derivative compound was 15 parts by weight and the amount of square lylium dye was 1 part by weight.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with 54 nm ultraviolet rays, and this was evaluated. The results are shown in Table 1B.

Table 1A Table 1B Examples 8 to 14 After optical recording and development of negative images were carried out in the same manner as in Examples 1 to 7, each optical recording medium was heated to about 80°C and the background A negative image was obtained in which the blue color of the image was changed to red.

The results of evaluating this negative image using the same criteria as in Example 1 are shown in Tables 2A and 2B.

Table 2A Table 2B Example 15 General formula CI2 H2S-CEC-CEC-C3) 11&
In place of the diacetylene derivative compound represented by -COOH, the general formula CoH17-C=C-C=C-C2H4-C
An optical recording medium was prepared in the same manner as in Example 4 except that a compound represented by OOH was used.

After performing optical recording on each of the thus obtained optical recording media in the same manner as in Example 1, each optical recording medium was uniformly and sufficiently irradiated with 254 nm ultraviolet rays to develop a negative image. The results were shown in Table 3A.

Examples 16-19 By the same method as in Example 15, except that the square lyllium dye represented by dye A11L6.18.24.28 was used individually instead of the square lyllium dye represented by dye J/L28. An optical recording medium was created.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, each optical recording medium was uniformly and sufficiently irradiated with 254 nm ultraviolet rays to visualize a negative image, and this was evaluated. The results are shown in Tables 3A and 3B.

Table 3A Table 3B Example 20 A coating solution was prepared by dissolving 10 parts by weight of a square aryllium dye represented by dye A29 in 20 parts by weight of methylene chloride.

Next, a glass disk substrate (thickness 1, 5+++ m
, diameter 200 mm) was attached to a spinner coating machine, and a small amount of the above coating liquid was dropped onto the center of the disk substrate, and then
The coating was applied by rotating a spinner at a predetermined rotation speed for a predetermined time, and dried at room temperature to form a layer containing the square lyllium dye on the substrate.

After forming a layer containing square aryllium dye in this way, Cl2H2S-CmiC-CE C-C81 (1
A solution of a DA compound represented by 6-C0OH dissolved in chloroform at a concentration of 3 x 10-3 mol/1 was prepared at a pH of 6.5 and a cadmium chloride concentration of 1 x 10-3 mol/1.
was developed on the aqueous phase. After removing the solvent chloroform, while keeping the surface pressure constant, the glass substrate on which the layer containing the squareylium dye, whose surface had been sufficiently washed, was formed, was moved in a vertical direction of 1 in the direction across the water surface. ．．
Gently move up and down at 0 cm/min to transfer the monomolecular film of the DA compound onto the surface of the layer containing squareylium dye.
An optical recording medium was prepared in which a monomolecular film of a compound or a monomolecular cumulative film obtained by accumulating a predetermined number of such monomolecular films was formed on a layer containing squareylium dye.

The thickness of the layer containing the square aryllium dye and the cumulative number of monolayers were varied as shown in Table 4A, and 25 types of optical recording media, samples MFL20-1 to MFL20-25, were obtained. Ta.

Example 1 was applied to each of the optical recording media thus obtained.
After performing optical recording in the same manner as above, two
The negative image was visualized by uniformly and sufficiently irradiating it with 54 nm ultraviolet rays, and this was evaluated. The results are shown in Table 4B.

[Brief explanation of drawings]

FIG. 1(A), FIG. 1(B), FIG. 2(A) and FIG. 2(B) are schematic cross-sectional views illustrating one aspect of the structure of the optical recording medium used in the method of the present invention, respectively. , Figure 3(A) ~ 3rd
FIG. 4(C) and FIGS. 4(A) to 4(C) are schematic cross-sectional views of an optical recording medium showing the optical recording process of the present invention. 1: Substrate 2: Recording layer 2a: Layer containing DA compound 2b: Layer containing square aryllium dye 3: Light irradiation area 4: Laser beam 5a: Latent image 5b: Non-irradiation area 6a: White area 6b = Discoloration area 7 : Square Lilium dye 8: DA compound

Claims (1)

[Scope of Claims] 1) An optical recording medium having a recording layer containing a monomolecular film of a diacetylene derivative compound having at least a hydrophilic site and a hydrophobic site or a cumulative film thereof and a squareryllium dye. A step of irradiating infrared rays of ~900 nm according to recorded information to form a latent image; and a step of irradiating an optical recording medium on which the latent image is formed with ultraviolet rays to make the latent image visible. An optical recording method characterized by: 2) The optical recording method according to claim 1, further comprising a step of heating the optical recording medium after the step of irradiating the optical recording medium with ultraviolet rays.