JPS62174750A - Optical recording method - Google Patents

Abstract

PURPOSE:To permit optical writing with a small-sized and lightweight semiconductor laser by irradiating IR rays of a specific waveform on an optical recording medium contg. a diacetylene deriv. compd. film and chroconic methine dye to form a latent image and irradiating UV rays thereon to develop the latent image to a sensible image. CONSTITUTION:The chroconic methine dye is the compd. expressed by the formula and has an absorption peak at 800-900nm. Said compd. generates heat when irradiated with the IR light of said wavelength. Recording information is imaged to the prescribed position of the optical recording medium through a control circuit, semiconductor laser and optical system. The compd. of the formula existing at the imaging point absorbs the light and generates heat. The crystal body of the diacetylene deriv. compd contained in the part irradiated with the light is then melted and made amorphous to form the part which does not discolor in the development process to be executed afterward. A GaAs junction laser having 800-900nm wavelength is adequate as the semiconductor laser to be used. The development of the latent image is executed by uniformly irradiating UV rays on the optical recording medium.

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 have been considered for this optical disk, 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. Focusing on the thermochromic properties of these compounds, a recording technology for use as laser recording media was disclosed in Japanese Patent Application Laid-Open No. 147807/1983. There is. However, this specification does not mention what kind of laser was used or should be used, and only states that recording was performed using a laser in No. 11.

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 laser such as an argon laser and Riki Takada, 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.

On the other hand, JP-A-58-181052 and JP-A-59-
No. 60443 discloses various croconic methine 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. but,
When performing recording by forming physical bits on the surface of a recording medium, the initial surface of the recording medium must be sufficiently smooth and at the same time be sufficiently smooth to prevent scratches on the surface of the recording medium after recording. In addition to requiring special care, it was relatively difficult to perform high-density, high-sensitivity, and high-speed recording.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the problems of the prior art. An object of the present invention is to provide an optical recording method capable of recording information as a latent image on a recording medium and then optionally visualizing and reading the recorded information as needed.

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, in the optical recording method of the present invention, an optical recording medium having a recording layer containing a diacetylene derivative compound and a croconic methine dye is irradiated with infrared rays of 800 to 900 nm according to recorded information to perform a latent recording. The process of forming an image:
The method is characterized by comprising the step of irradiating the optical recording medium on which the latent image is formed with ultraviolet rays to make the latent image visible.

The diacetylene derivative compound (hereinafter abbreviated as OA compound) contained in the optical recording medium used in the method of the present invention has the following general formula % (wherein R and R' are polar groups; Saturated aliphatic hydrogen groups such as alkyl groups and cyclohexyl groups, which may be substituted with; vinyl groups, which may be substituted with polar groups;
an olefinic hydrocarbon group such as a propenyl group; or a phenyl group, a naphthyl group, which may be substituted with a polar group;
An aromatic hydrocarbon group such as an alkylphenyl group,
Examples of the polar group here include a carboxyl group or a metal or amine salt thereof, a sulfonic acid group or a metal or amine salt thereof, a sulfamide group, an amide group, an amino group, an imino group, a hydroxy group, an oxyamino group, a diazonium group, Examples thereof include a guanidine group, a hydrazine group, a phosphoric acid group, a silicic acid group, an aluminate group, a nitrile group, a thioalcohol group, a nitro group, and a halogen atom. ) is a compound represented by

On the other hand, the croconic methine dye used in the present invention is a compound (including an inner salt) having the following basic structural formula: (M: described below, A1, A2, substituent containing aromatic ring and/or heterocycle) And (80
It is a compound that has an absorption peak at a wavelength of 0 to 900 nm and generates heat when exposed to infrared light at this wavelength. The croconic methine dyes typically have the following general formulas [I] to [
IV] is exemplified.

General formula [1] General formula [■ General formula [III] General formula [IV] In the general formulas (I) and (II), R' and R2Gt, an alkyl group (for example, a methyl group, an ethyl group, a Propyl group, 1so-propyl group, n-butyl group, 5ec-butyl group, 1so-butyl group, shi-butyl group, n-amyl group,
Shi-amyl group, rhohexyl group, n-octyl group, t-
octyl group, etc.), substituted alkyl groups (e.g. 2- and droxyethyl groups, 3-hydroxypropyl groups, 4-hydroxybutyl groups, 2-acetoxyethyl groups, carboxymethyl groups, 2-carboxyethyl groups, 3-carboxypropyl groups, 2-sulfoethyl group, 3-sulfopropyl group,
4-sulfobutyl group, 3-sulfatepropyl group, 4
-sulfate butyl group, N-(methylsulfonyl)
-Carbamylmethyl group, 3-(acetylsulfamyl)
propyl group, 4-(acetylsulfamyl)butyl group, etc.), cyclic alkyl group (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, hydroxybenzyl group, etc.), aryl group (e.g., phenyl group, etc.), or substituted aryl group (For example, carboxyphenyl group, sulfophenyl group, hydroxyphenyl group, etc.). In particular, 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-dimethoxyhenzothiazole, 5,6-cyoxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 4,5,6
．． 7-tetrahydropenzothiazole), naphthothiazole series nuclei (e.g. naphtho[2,1-d]thiazole, naphtho[1,2-dlthiazole, 5-methoxynaphtho[1,2-dlthiazole, 5-ethoxy naphtho[1,2-dlthiazole, 8-methoxynaphtho[2,
1-dl thiazole, 7-methoxynaphtho[2,1-d
1thiazole), thionaphthene[7,6-d]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- Methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 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
-tetrahydropenzoselenazole, etc.), naphthoselenazole series nuclei (e.g. naphtho(2,1-dl selenazole, 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. quinoline, 3.4-dihydroisoquinoline), 3-inquinoline series nuclei (e.g. isoquinoline), 3.3-dialkylindolenine series nuclei (e.g. 3.3-dimethylindolenine, 3.3-dimethyl-5- chloroindolenine, 3,3.5-trimethylindolenine, 3,3.7-4-limethylindolenine), pyridine series nuclei (e.g. pyridine, 5-methylpyridine), benzimidazole series nuclei (e.g. l-
Ethyl-5,6-dichlorobenzimidazole,! - and droxyethyl-5,6-dichlorobenzimidazole, l-ethyl-5-chlorobenzimidazole, l-ethyl-5,6-dibromobenzimidazole, 1-ethyl-5-phenylbenzimidazole, ■-ethyl-5
-fluorobenzimidazole, l-ethyl-5-cyanobenzimidazole, 1-(β-acetoxyethyl)
-5-cyanobenzimidazole, 1-ethyl-5-chloro-6-cyanobenzimidazole, l-ethyl-5
-fluoro-6-cyanobenzimidazole, -ethyl-5-acetylbenzimidazole, l-ethyl-5
-carboxybenzimidazole, l-ethyl-5-ethoxycarbonylbenzimidazole, 1-ethyl-5
-Sulfamylbenzimidazole, l-ethyl-5-
N-ethylsulfamylbenzimidazole, l-ethyl-5,6-difluorobenzimidazole, [-ethyl-5,6-dichlorobenzimidazole, 1-ethyl-5-ethylsulfonylbenzimidazole, l-ethyl-5- Methylsulfonylbenzimidazole, ■-Ethyl-5-trifluoromethylbenzimidazole, l
-ethyl-5-trifluoromethylsulfonylbenzimidazole, l-ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.) × means chloride ion, bromide ion, iodide ion, perchlorate ion, benzenesulfonate ion, p-toluenesulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion, etc. represents an anion; × represents an anion group in which R1 and/or R2 itself is an anion group, such as -503, -0SO
3.■ Does not exist when it is included. M does not represent a cation such as a hydrogen cation, sodium cation, ammonium cation, potassium cation, or pyridium cation. n and m are 0 or 1.

In general formula (III) (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 R [1 is a hydrogen atom,
Alkyl groups (methyl, ethyl, propyl, butyl, etc.)
, represents an alkoxy group (methoxy, ethoxy, propoxy, butoxy, etc.) or a hydroxy group. Also, R5 and R
6 can be combined to form a benzene ring, and R5 and R6 can be combined with R7 and RO, respectively, to form a benzene ring.

Next, representative examples of the croconic methine dye used in the present invention are listed below, but for convenience, general formula [I] or [
m] 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 [I] and [II] (7) 0e(8)0°(11) Oe(Hjlsite (21) oθ(24)
. e(25)
. θ(2B). θ(27
). θ general formula (ml, [I
Representative example (35) e.

(36) e.

(37) ’90 (38) e.

(39) eO (40) e.

The croconic methine dyes (+) to (42) above are 1
A species or a combination of two or more species can be used.

The optical recording medium used in the present invention contains the DA compound and the croconic methine dye, and may have a one-layer mixed system, a two-layer separated system, or a multilayer laminated system.

Here, the one-layer mixed system refers to one consisting of a mixed layer of the D-formula compound and croconic methine dye, and the two-layer separated system refers to
A system in which a layer containing the Formula D compound and a layer containing a croconic methine dye are separately laminated is further referred to as a multilayer laminated system.
For example, one or more layers containing a DA compound and one or more layers containing a croconic methine dye are laminated on a substrate in a predetermined number and order of layers, which does not include the two-layer separation system described above.

A typical structure of the optical recording medium used in the present invention is shown in FIG. 1(8) and FIG. 1(B). In FIG. 1 (8), a single-layer mixed recording layer 2 is provided on a substrate l,
In FIG. 1(B), a recording layer 2 of a two-layer separation system, that is, a recording layer 2 consisting of a layer 2a containing a DA compound and a layer 2b containing a croconic methine dye, is provided on a substrate 1.

To form the recording layer 2, typically, in the case of a single-layer mixed system, a coating solution is prepared by mixing a fine crystal powder of a prefecture compound and a croconic methine dye in a suitable volatile solvent; This coating solution is coated on the substrate l, and in the case of a two-layer separation system or a multilayer laminated system, the coating solution containing the crystalline fine powder of the DA compound and the coating solution containing the croconic methine dye are separately applied. They may be prepared and applied to the substrate 1 in a predetermined order.

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.

The solvent of the coating liquid used to form the single-layer mixed recording layer is selected depending on the type of binder used and the type of DA compound and croconic methine dye, but in general, methanol, ethanol, isopropanol, etc. Alcohols; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ketones such as N,N-dimethylformamide and N,N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether esters such as methyl acetate, ethyl acetate, butyl acetate; aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichloroethylene; benzene, toluene, xylene, monochlorobenzene, Examples include aromatic hydrocarbons such as chlorobenzene.

In addition, when the croconic methine dye is in an amorphous state, methanol, ethanol, isopropanol, Alcohols such as Patul; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; and amides such as N-dimethylformamide and N,N-dimethylacetamide;
Examples include sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; aromatics such as benzene, toluene, xylene, and ligroin; When methine is in the form of particles, dichloromethane, chloroform,
Examples include halogenated hydrocarbons such as carbon tetrachloride, 1.1-dichloromethane, 1.2-dichloromethane, 1.1.2-trichloromethane, chlorobenzene, bromobenzene, and 1.2-dichlorobenzene.

Further, suitable dispersion media for the DA compound include aliphatic hydrocarbons such as n-hexane, n-hebutane, 0-octane, and cyclohexane. However, since the DA compound is a compound with strong crystallinity, even if it is once dissolved in a solvent and this solution is applied onto a substrate, recrystallization proceeds during the drying process and dhalein is obtained.

Therefore, not only a dispersion but also a solution of the compound of formula D may be used. As the solvent in this case, the same solvents as those mentioned above for the croconic methine dye can be used.

Note that a binder made of natural or synthetic polymer may be added to each coating liquid as appropriate in order to improve the adhesion with the substrate 1 or with other layers. Furthermore, various additives may be added to improve the stability and quality of the recording layer 2.

Coating of such a coating liquid onto the substrate 1 can be performed by a spinner rotation coating method, a T'f1m coating method, a spray coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coach ink method, or a curtain coating method. The following methods are used.

When the recording layer 2 is a single-layer mixed type, the film thickness is suitably in the range of 300 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 1JJJ1 is suitable, especially 200 people.
A range of 5,000 to 5,000 people is preferred. Furthermore, in the case of a multilayer laminated system, it is suitable that the total thickness of the layers containing the individual D compounds and the total thickness of the layers containing the individual croconic methine dyes are approximately 100 to Ip. , especially 200
A range of 5,000 to 5,000 people is preferred.

The mixing ratio of the DA compound and the croconic methine dye in the recording layer 2 is preferably about 1/15 to 1571, and optimally about 1710 to/I.

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.

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 applying light to the OA compound, the absorption wavelength of the recording layer changes and the apparent color changes. That is, the OA 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, 620-6
It has a maximum absorption wavelength of 60 nm and changes from blue to dark color. This change in hue due to polymerization is an irreversible change, and once the recording layer changes from blue to dark, it 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.
The maximum absorption wavelength is at 0 nm, and the film changes to a red color. This change is also an irreversible change.

On the other hand, the inventors of the present invention have conducted various studies on the recording layer having the above-mentioned structure, and found that it is possible to heat the recording layer at an appropriate temperature that does not destroy it or change its shape, and then heat it to a molten state. It has been found that even if the recording layer is irradiated with ultraviolet rays as described above, the recording layer does not change in color from blue to dark.

In other words, this is because the change to a bright blue to dark film as a result of polymerization of the D compound due to ultraviolet irradiation is mainly due to the polymerization of the eye compound molecules in the DA compound crystals contained in the recording layer 2. It is obtained by ordered molecular conformation, and by heating the recording layer as described above to melt the layer containing the D-type compound, and melting the DA compound crystal contained in that part, this When DA is made into an amorphous state and the orientation order of the compound molecules is disturbed toward D in that part, the number of DA (arsenic compound molecules) that is in a positional relationship that allows reaction at the molecular arrangement level will be greatly reduced. it is conceivable that.

The optical recording method of the present invention performs recording by utilizing the characteristics of such an ascending compound crystal and the function obtained by combining it with a croconic methine dye.

An example of the optical recording method of the present invention will be described 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 ball, and is delivered to a predetermined position of 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 8),
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 0-850 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 croconic methine dye in this area absorbs light and generates heat, and this heat generation causes the light irradiation area to The finely powdered OA compound crystal contained in 3 is melted, and this portion becomes an amorphous state, and the highly ordered orientation of the DA compound molecules is disturbed. As a result, the light irradiation area 3 is
This is the part that will not change color in the later visualization process.

The laser beam irradiation conditions for this writing are as follows:
It may be selected as appropriate depending on the configuration of the optical recording medium used, but at least the temperature of the light irradiation site 3 is sufficient to melt the DA compound crystal fine powder and disturb the orientation order of the DA compound molecules, and It is necessary to maintain a temperature that does not destroy the recording layer or deform its shape.

In this way, the recording layer has a D
A region 5a in which the highly ordered orientation of the DA compound molecules is disturbed (irradiated with light) formed in a region 5b where the highly ordered orientation of the compound molecules is maintained (not irradiated with light)
A latent image is formed as shown in FIG. 2 (13), and recording information is written.

Note that the DA compound has no sensitivity to the above-mentioned semiconductor laser, and such optical writing is not possible with conventional optical recording media made only of OA compounds.

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 compound polymerizes to D in the portion 5b that was not irradiated with light during the previous writing of the recording layer 2, and to D where the highly ordered orientation in the compound crystal is maintained, resulting in polydiacetylene. It changes to a derivative compound, and this part of the recording layer has 620-6 as shown in FIG.
The color changes to a blue or dark-colored film 6b having a maximum absorption wavelength at 60r+m. 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 OA compound is disturbed, so the polymerization reaction of the D^ 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.
White portion 6 that is optically distinguishable from the blue or dark color film 6b
It is visualized as a.

Note that if the recording layer 2 is heated to a temperature of about 50'C or above after this ultraviolet irradiation treatment is completed, the polydiacetylene derivative compound in the blue or dark film 6b becomes red as described above. Since the color changes to , the recorded information written in the recording layer 2 as a latent image can be visualized as a white part 6a in the red film.

For this heating treatment of the recording layer, a heating means such as a heater may be used, or radiation such as infrared rays may be applied to the recording layer since the recording layer contains a croconic methine dye that absorbs radiation and generates heat. This can be carried out by irradiation, etc.

The optical recording method of the present invention using a recording medium having a single mixed recording layer has been described above.
When using a recording medium having a two-layer separated recording layer as shown in [I], the focal point 3 of the laser beam is
As shown in FIG. 3(A), a layer 2b containing croconic methine dye is obtained.

When the laser beam 4 is irradiated in this way, the croconic methine dye contained in the layer 2b absorbs the laser beam 4 and generates heat, and this heat generation causes the DA compound-containing layer 2a to appear on the imaging point 3. The portion is melted, and a latent image 5a is formed as shown in FIG. 3 ([1)] according to the process described above. This latent image can be optically distinguished from the blue, dark-colored, or red film 6b as shown in FIG. This can be visualized as a white white part 6a.

In the above example, a disk-shaped disk (optical disk) was used as the optical recording medium, but of course, depending on the type of substrate that supports the recording layer containing the D^ compound and croconic methine dye, optical tape , optical cards, etc. can also be used.

〔Effect of the invention〕

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

(1) Since the recording layer uses a combination of croconic methine dye and diacetylene derivative compound, optical writing is possible using a small and lightweight semiconductor laser, allowing high-speed recording with high density and high sensitivity. is possible. In addition, the recorded information is recorded on the recording medium as a latent image, and after it has been erased, the recorded information can be visualized and read as desired.

(2) Since the recording layer is formed homogeneously and with good surface properties, stable and high-quality optical recording 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 C, 2H25-C=C-CmiC-CoH, 6-C
1 part by weight of fine crystal powder of a diacetylene derivative compound represented by 0OH and 15 parts by weight of the croconic methine dye represented by dye A11125 are added to 30 parts by weight of methylene chloride, and the mixture is sufficiently stirred to prepare a coating solution. did.

Next, a glass disk substrate (thickness: 5 mm, diameter: 200 mm) was mounted on a spinner coater, and a small amount of the coating solution was dropped onto the center of the disk substrate. The thickness of the coating film after drying on the substrate was 509 and 100.
Optical recording media with 0 and 2000 people were created respectively. □ Using the optical recording medium thus obtained, the optical recording method of the present invention was carried out as follows.

First, a semiconductor laser with a wavelength of 830 nm (laser beam diameter: 1μ face,
Irradiation time: 200 ns 71 dots, output 5 mW-)
was irradiated according to manual information to form a latent image. At that time, no apparent change was observed in the light irradiated portion of each optical recording medium. .

[Yo9, o0 operation is completed, yo, □-ka9] After the completion of the process, 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 recording results is shown in Table 1. 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 The amount of diacetylene derivative compound was 1 part by weight, the amount of croconic methine dye was 10 parts by weight, and the amount of methylene chloride was 2 parts by weight.
An optical recording medium was prepared in the same manner as in Example 1 using a mixed solution containing 0 parts by weight as a coating liquid.

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 1.

Example 3 The amount of diacetylene derivative compound was 1 part by weight, the amount of croconic methine dye was 5 parts by weight, and the amount of methylene chloride was 12 parts by weight.
Example 1 A mixed solution expressed as parts by weight was used as a coating liquid.
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 1.

Example 4 A mixed solution containing 1 part by weight of the diacetylene derivative compound, 1 part by weight of the croconic methine dye, and 4 parts by weight of methylene chloride was used as the coating liquid, and the same procedure as in Example 1 was carried out. An optical recording medium was prepared by the method.

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 1.

Example 5 The amount of diacetylene derivative compound was 5 parts by weight, the amount of croconic methine dye was 1 part by weight, and the amount of methylene chloride was 12 parts by weight.
Example 1 A mixed solution expressed as parts by weight was used as a coating liquid.
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 1.

Example 6 The amount of diacetylene derivative compound was 10 parts by weight, the amount of croconic methine dye was 1 part by weight, and the amount of methylene chloride was 2 parts by weight.
An optical recording medium was prepared in the same manner as in Example 1 using a mixed solution containing 0 parts by weight as a coating liquid.

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 1.

Example 7 The amount of diacetylene derivative compound was 15 parts by weight, the amount of croconic methine dye was 1 part by weight, and the amount of methylene chloride was 3 parts by weight.
An optical recording medium was prepared in the same manner as in Example 1 using a mixed solution containing 0 parts by weight as a coating liquid.

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 1.

Table 1 Examples 8 to 14 After optical recording and visualization 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 to remove the blue background. A negative image changed to red was obtained.

Table 2 shows the results of evaluating this negative image using the same criteria as in Example 1.

Table 2 Example 15 General formula G, 2H25-CEC-CEC-C8H; 6-G
Instead of the diacetylene derivative compound represented by OON,
General formula c,,H,-cmic-cmi(nee C2)14-C
An optical recording medium was prepared in the same manner as in Example 4 except that a compound represented by OOH was used.

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 3.

Examples 16 to 19 Same as Example 15 except that instead of the croconic methine dye represented by Dye A 25, the croconic methine dye represented by Dye/L2.29.37.42 was used individually. An optical recording medium was prepared by the method.

Each optical recording medium obtained in this way is fruitful.
After optical recording was performed in the same manner as in Example 1, each optical recording medium was uniformly and sufficiently irradiated with 254 nm ultraviolet rays to visualize a negative image, which was then evaluated. The results are shown in Table 3.

Table 3 Example 20 1 part by weight of croconic methine dye represented by Dye/L25 was dissolved in 10 parts by weight of acetonitrile to prepare coating liquid A.

Apart from this, C, 2H25-C=C-C=C-C3H1
1 part by weight of a fine crystalline powder of a diacetylene derivative compound represented by 6-(0) was added to 10 parts by weight of benzene and thoroughly stirred to prepare a coating liquid B.

Next, a glass disk substrate (thickness 1.5 mm, diameter 200 mm) was mounted on a spinner coater, and after first dropping a small amount of the coating liquid A onto the center of the disk substrate, it was heated at a predetermined number of rotations. Apply by rotating the spinner for an amount of time.
It was dried at room temperature to form a layer containing croconic methine dye on the substrate. Next, the substrate on which the layer containing the croconic methine dye has been formed is mounted on the spinner coating machine again, and a small amount of the coating liquid B is applied to the center of the surface of the layer containing the croconic methine dye on the disk substrate formed previously. After dropping, apply by rotating a spinner at a predetermined number of rotations for a predetermined time.
Dry at room temperature and apply O on the layer containing croconic methine dye.
Layers containing compound A were laminated to form a recording layer.

The thicknesses of the layer containing the croconic methine dye and the layer containing the OA compound were varied as shown in Table 4A, and 25 types of optical recording media, Samples A 20-1 to 20-25, were prepared. Obtained.

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.

Example 21 General formula G12H2S-C Mi c-c Mi C-C3 in coating liquid B
In place of the diacetylene derivative compound represented by H16-C00II, general formula C3)1. , -C=C-C=C-
Samples A/L21-1 to 21 as shown in Table 5A were prepared in the same manner as in Example 20, except that a diacetylene derivative compound represented by 00)1 was used for C,, H4-.
-25 types of optical recording media were created.

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 5B.

Example 22 The samples shown in Table 6A were prepared in the same manner as in Example 21 except that a croconic methine dye represented by dye A6 was used in coating solution A instead of a croconic methine dye represented by dye A/lL25. Sample A11L22'- as shown
25 types of optical recording media, numbered 1 to 22-25, were created.

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 6B.

Example 23 The samples shown in Table 7A were prepared in the same manner as in Example 21, except that the croconic methine dye represented by Dye/L39 was used in coating solution A instead of the croconic methine dye represented by Dye 25. Samples as shown, 7i2:1-1~
A 25WA optical recording medium of 23-25 was prepared.

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 7B.

[Brief explanation of drawings]

FIG. 1(8) and FIG. 1(B) are schematic cross-sectional views illustrating one aspect of the configuration of an optical recording medium used in the method of the present invention, and FIG.
Figures (A) to 2 (C) and Figures 3 (A) to 3 (
G) is a schematic cross-sectional view of an optical recording medium showing the optical recording process of the present invention. 1: Substrate 2: Recording layer 2a: Layer containing compound to D 2b: Layer containing croconic methine dye 3: Light irradiation area 4: Laser beam 5a: Latent image 5b: Non-irradiation area 6a: White area 6b = discoloration Department

Claims (1)

[Scope of Claims] 1) An optical recording medium having a recording layer containing a diacetylene derivative compound and a croconic methine dye;
A step of irradiating infrared rays of 00 to 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 comprising: 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.