JPS62174191A - Optical recording method - Google Patents

Abstract

PURPOSE:To enable three-value recording, to achieve miniaturization and wt. reduction and to perform optical writing by semiconductive laser of low output, by irradiating an optical recording medium having a specific recording layer with beam of which the light exposure is controlled corresponding to recording information and discoloring an exposed part of light exposure Q1 and forming a pit comprising a recessed part to an exposed part of light exposure Q2. CONSTITUTION:An optical recording medium has an optical recording layer 2 containing a polydiacetylene derivative and a chroconic methine dye and recording information is converted to an optical signal by semiconductive laser through a control circuit. Said optical signal is formed into an image at the predetermined position of the optical recording medium. Light exposure at image forming points 3a, 3b are respectively controlled to quantity Q1 heating the polydiacetylene derivative for discoloration recording to about 50 deg.C or more and sufficient to set temp. not melting the recording layer 2 and quantity Q2 sufficient to melt the recording layer 2 for pit recording (Q1<Q2). The image forming point 3a changes to red to become a dot 5a and the image forming point 3b is melted to become a pit being a recessed part 5b.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical recording method using an optical recording medium, and particularly to a method that enables a combination of color change recording and bit recording, that is, ternary recording, on one optical disk. The present invention relates to an optical recording method that enables high-density, high-sensitivity optical recording even when using a low-output semiconductor laser, and is advantageous in terms of energy saving.

[Conventional technology]

Recently, optical recording media such as optical disks, optical tapes, and optical cards (hereinafter collectively referred to as optical disks) have been attracting attention as central players in office automation. For example, optical discs can store a large amount of documents and literature on a single disc, so they can be used to organize documents in offices, etc.
It has the advantage that management can be carried out efficiently.

The recording layer used in such optical disc technology can store high density information using optically detectable small (eg 1 micron) dots in the form of spiral or circular tracks.

A typical disk used in this optical disk technology is one in which a recording layer made of a material sensitive to laser is provided on a substrate. To write information on this disc, a laser beam focused on the laser sensitive layer (recording layer) is scanned, dots are formed only on the surface irradiated with the laser beam, and the dots are shaped into a spiral or circular shape depending on the recorded information. Form in the form of a track. That is, the laser sensitive layer is capable of absorbing laser energy to form optically detectable dots. For example, in the heat mode recording method, the laser-sensitive layer absorbs thermal energy and can form dots consisting of small recesses (pits) at that location by evaporation or melting. In another heat mode recording method, the absorption of irradiated laser energy can form a dot of optically detectable discoloration at that location.

Information recorded on this optical disk is detected by scanning a laser along a track and reading optical changes in areas where dots are formed and areas where dots are not formed. For example, when using a disk with a recording layer provided on the reflective surface of a substrate, a laser is scanned along a track and the energy reflected by the disk is monitored by a photodetector. At this time, in the case of pit recording, the output of the photodetector decreases in areas where pits are not formed, while in areas where pits are formed, the laser beam is sufficiently reflected by the underlying reflective surface and the photodetector output is reduced. output becomes larger.

Various types of recording layers for such optical discs have been studied, including those mainly using inorganic materials such as metal thin films such as aluminum evaporated films, bismuth thin films, tellurium oxide thin films, and chalcogenide amorphous glass films. However, recently, organic materials have been attracting attention due to their cost and ease of manufacture.

On the other hand, since the conventional heat mode method performs binary recording of whether dots are formed or not, there is a limit to the ability to perform higher density recording.

[Problem that the invention seeks to solve]

The present invention was made to solve the problems of the prior art, and by forming the recording layer of an optical recording medium by combining a croconic methine dye and a diacetylene derivative compound, a single optical disc can be produced. Color change recording and pit recording are possible, that is, 3 types of dots with 2 types are possible.
It was developed based on the discovery that it is possible to record values, and even when using a low-output semiconductor laser, color change recording and pit recording can be performed at comparable high speeds.

An object of the present invention is to provide an optical recording method that enables three-value recording using two types of dots on one disc.

Another object of the present invention is to provide an optical recording method that enables optical writing using a small, lightweight, and low-output semiconductor laser and also enables high-speed recording.

Still another object of the present invention is to provide an optical recording method that allows recording at higher density and higher sensitivity.

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 irradiates an optical recording medium having a recording layer containing a polydiacetylene derivative compound and a croconic methine dye with light whose exposure amount is controlled according to recorded information, The method is characterized in that it includes a step of discoloring the exposed area with the exposure amount Q1 and forming a pit consisting of a concave part in the exposed area with the exposure amount Q2 (however, Qt < 02).

The diacetylene derivative compound (hereinafter abbreviated as DA compound) contained in the optical recording medium used in the method of the present invention has the following general formula % (where 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, and a guanidine group. group, hydrazine group, phosphoric acid group, silicic acid group, aluminate group, nitrile group, thioalcohol group, nitro group and halogen atom. ) and their polymers.

On the other hand, the croconic methine dye used in the present invention is a compound (including an inner salt) having the following basic structure; And (80
It is a compound that has an absorption peak in the range 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 [1] to [I
V] is exemplified.

General formula [I] ^ General formula [II] General formula [I11] General formula [IV] a) e In general formula (I) (II), R1 and R2 are alkyl groups (for example, methyl group, ethyl group, n-propyl group, igo-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 groups (e.g. 2-hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-7cetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group,
4-sulfobutyl group, 3-sulfatepropyl group, 4
-Sulfate butyl group, t(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 (e.g., carboxyphenyl group, sulfophenyl group, etc.) hydroxyphenyl group, etc.). In particular, in the present invention, among these organic residues, hydrophobic ones are preferred.

Substituted or unsubstituted heterocycle 1 For example, a thiazole series nucleus (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, 8-methylbenzothiazole, 5,
8-dimethylbenzothiazole, 5-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 6-medoxybenzothiazole, 5
, 6-simethoxybenzothiazole, 5,6-cyoxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 4,5,8
．． 7-titrahydrobenzothiazole, etc.), naphthothiazole series nuclei (e.g. naph) [2,1-d]thiazole, naph) [1,2-dl thiazole, 5-methoxynaphtho[1,2-dl thiazole, 5 -ethoxynaphtho [1,2-dl thiazole, 8-methoxynaphtho [2,1-dl thiazole, 7-medoxynaf]
[2,1-dlthiazole, etc.), thionaphthene [7,
El-dl thiazole series nuclei (e.g. 7-medoxythionaphthene[7,8-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. naph) [2
, 1-dl oxazole, nuts (1,2-dl oxazole, etc.), selenazole series nuclei (e.g. 4-methylselenazole, 4-phenylselenazole, etc.),
Nuclei of the benzoselenazole series (e.g. benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole, 5,6-dimethylhenzoselenazole,
5-methoxybenzoselenazole, 5-methyl-6-methoxybenzoselenazole, 5,6-cyoxymethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4.5.1(,?-tetrahydrobenzoselenazole, etc.) ), nuclei of the naphthoselenazole series (e.g. naphthor2, l-dl selenazole, naphtho[1,2-
dl 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-hydroxyquinoline),
-Medoxyquinoline, 7-methylquinoline, 8-methylquinoline), 1-isoquinoline series nuclei (e.g. inquinoline, 3,4-dihydroisoquinoline), 3-inquinoline series nuclei (e.g. inquinoline), 3. 3-
Nuclei of the dialkylindolenine series (e.g. 3,3-dimethylindolenine, 3,3-dimethyl-5-chloroindolenine, 3,3,5-trimethylindolenine, 3,
3.7-) dimethylindolenine), pyridine series nuclei (e.g. pyridine, 5-methylpyridine), benzimidazole series nuclei (e.g. 1-ethyl-5,6-dichlorobenzimidazole, !-hydroxyethyl-5.
6-dichlorobenzimidazole, 1-ethyl-5-chlorobenzimidazole, 1-ethyl-5,6-dibromobenzimidazole, 1-ethyl-5-phenylbenzimidazole, 1-ethyl-5-fluorobenzimidazole, 1- Ethyl-5-cyanobenzimidazole, 1-(β-acetoxyethyl)-5-cyanobenzimidazole, 1-ethyl-5-chloro-6-cyanobenzimidazole, 1-ethyl-5-fluoro-8-cyanobenzimidazole , 1-ethyl-5-acetylbenzimidazole, 1-ethyl-5-carboxybenzimidazole, 1-ethyl-5-ethoxycarbonylbenzimidazole, 1-ethyl-5-sulfamylbenzimidazole, 1-ethyl-3- N-ethylsulfamylbenziimiguzole, 1-ethyl-5,8-difluorobenzimidazole, 1-ethyl-5,6-dichlorobenzimidazole, 1-ethyl-5-ethylsulfonylbenzimidazole, 1-ethyl-5 -Methylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylbenzimidazole, 1-ethyl-5-trifluoromethylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.) to complete e. X represents a necessary non-metallic atomic group, chloride ion, bromide ion, iodide ion, perchlorate ion,
Benzene sulfonate ion, p-)luene sulfonate ion, methyl sulfate ion, ethyl sulfate ion,
represents an anion such as propyl sulfate ion θ ion, and X represents R1 and/or
e e θ -C00,5O2NH-, -902-N-CO-1-9
When O2-N-9o2- is included, the genus does not exist. X represents a cation such as a hydrogen cation, sodium cation, ammonium cation, potassium cation, or pyridium cation. n and m are O or 1.

In general formula (m) (IV), R3 and R4 are methyl,
Indicates an alkyl group such as 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 represent a hydrogen atom, an alkyl group (methyl, ethyl, propyl, butyl, etc.), an alkoxy group (methoxy, nidoxy, propoxy, butoxy, etc.), or a 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, representative examples of the croconic methine dye used in the present invention are listed below, but for convenience, general formula [I] or [
Expressed in the form of betaine structure in ml. However, in the preparation of these dyes, mixtures of dyes in betaine or salt form are obtained and are therefore used as mixtures.

-Representative example (21) of general formula [11, [11]. e(23)
. θ (24). e 2'8 Representative example (35) of general formula [ml], [IV] e.

(3B) e.

(39) e'0 (40)
e 0 The croconic methine dyes (1) to (42) above are.

It can be used alone or in combination of two or more.

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 a DA compound and croconic methine dye, and the two-layer separated system refers to
[A multi-layer laminated system refers to a system in which a layer containing an 1A compound and a layer containing a croconic methine dye are laminated separately. Each refers to a structure that does not include the above-mentioned two-layer separation system in which one or more layers are laminated in a predetermined number and order.

A typical configuration of the optical recording medium used in the present invention is shown in Figure 1 (A
) and shown in FIG. 1(B). Figure 1 (A) is.

A recording layer 2 of a single-layer mixed type is provided on a substrate 1, and FIG.
A recording layer 2 consisting of a first layer 2a containing a compound and a layer 2b containing a croconic methine dye is provided on a substrate l.

To form the recording layer 2, typically, in the case of a single-layer mixed system, a coating liquid is prepared by mixing a fine crystal powder of an OA 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 OA compound and the coating solution containing the croconic methine dye are separately separated. 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 [lA compound and croconic methine dye, but in general, methanol, ethanol, impropatol, etc. alcohols; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ketones such as N,N-dimethylformamide and KN-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, and ethylene glycol methyl 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, dichlor Examples include aromatic hydrocarbons such as benzene.

In addition, when the croconic methine dye is in an amorphous state, suitable solvents for the coating solution used to form a two-layer separation system or a multilayer laminated system include methanol, ethanol, inorganic Alcohols such as propatool; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether Ethers such as methyl acetate, ethyl acetate, etc., aromatics such as benzene, toluene, xylene, ligroin, etc., and when croconic methine is in the form of particles, dichloromethane, chloroform, carbon tetrachloride, etc. , 1,1-dichloromethane, 1,2-dichloromethane, 1.1.2-)dichloromethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene, and other halogenated hydrocarbons.

A suitable dispersion medium for OA compounds is n-hex. However, since OA compounds are highly crystalline compounds, even if they are dissolved in a solvent and this solution is applied onto a substrate, it recrystallizes during the drying process. progresses and grains are obtained. therefore,
Not only a dispersion but also a solution of the DA compound 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 a natural or synthetic polymer may be appropriately added to each coating liquid in order to improve the adhesion to the substrate 1 or to 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 l can be carried out 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, its film thickness is 400A.
~23111 is suitable, especially 1000~500
A range of 0 people is preferred. Further, in the case of a two-layer separation system, the thickness of each layer is suitably about 200A to IIL11, and particularly preferably in the range of 200 to 5000A. Furthermore, in the case of a multilayer laminated system, it is suitable that both the total thickness of the layers containing the individual DA compounds and the total thickness of the layers containing the individual croconic methine dyes are approximately 100A-tg. A range of 200 to 5000 A is preferred.

The blending ratio of the IIA compound and croconic methine dye in the recording layer 2 is preferably about 1715 to 15/1,
The optimum range is 1/10 to 1011.

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

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 (excluding the polymer), the absorption wavelength of the recording layer changes and the apparent color changes. That is, the DA compound (excluding the polymer) 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 rays, and not by the application of other physical energy such as heat. As a result of this polymerization, the color has a maximum absorption wavelength of 820 to 820 eEl Onm and changes to a blue or 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.

Further, the recording layer containing the polydiacetylene derivative compound and the croconic methine dye, which has changed its color from blue to dark, generates heat at a temperature corresponding to the exposure amount of the irradiated light. At that time, if the recording layer 2 is not melted and the polydiacetylene derivative compound is heated to about 50°C or higher,
The exposed portion of the recording layer has a maximum absorption wavelength at about 540 nm and turns into a red film. Note that this change to a red film is also an irreversible change.

Further, when the exposure amount is increased and the exposure amount exceeds a certain limit, the exposed portion of the recording layer melts.

The optical recording method of the present invention performs recording by utilizing the characteristics obtained by the combination of compound A and croconic methine dye.

This recording method will be explained in detail below.

As the semiconductor laser used in the method of the present invention, it is particularly suitable to use a GaAs junction laser with an output wavelength of 800 to 850 nm.

When carrying out the optical recording method of the present invention, if an optical recording medium having an optical recording layer composed of a DA compound (excluding polymers) and a croconic methine dye is used, first, recording is performed. The entire layer is irradiated with ultraviolet light. By this irradiation with ultraviolet rays, the OA compound (excluding the polymer) in the recording layer is polymerized and changed into a polydiacetylene derivative compound, and the recording layer changes color into a blue or dark film. (Of course, this operation is not required for those having a recording layer using a polydiacetylene derivative compound as a DA compound.) On the other hand, the recorded information is converted into an optical signal by a semiconductor laser via a 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). The imaging position is recording R2 on the optical recording medium.

The exposure amount at imaging points (parts) 3a and 3b is approximately 50°C for polydiacetylene derivative compound for color change recording.
It is heated to a temperature higher than 100% (Q1) and is controlled to a sufficient amount (Q1) to keep the recording layer 2 at a temperature that does not melt, and an amount (Q2) sufficient to melt the recording layer 2 for pit recording (
However, Q+ < Q2).

In order to change the exposure amount at the imaging point in this way, it is possible to use a method such as changing the intensity of the semiconductor laser, changing the laser irradiation time by X, or using these in combination. Note that when performing irradiation with two types of exposure doses, the above control may be performed using one semiconductor laser, or multiple semiconductor lasers that can obtain different exposure doses may be used. .

The croconic methine dye present at the imaging points (sites) 3a and 3b absorbs this laser beam 4 and generates heat.

Here, the image forming point 3a that received the exposure amount of Ql mentioned above is
As the polydiacetylene derivative compound is heated by the heat generated by the croconic methine dye, it changes to red color, and as shown in FIG. becomes. In addition, in an optical recording medium having a recording layer consisting only of [lA compound], since the polydiacetylene derivative compound does not have sensitivity to a laser with a wavelength of 800 to 850 nm, when a semiconductor laser with this wavelength is used, optical recording was impossible due to discoloration.

On the other hand, the image forming point 3b that received the above-mentioned exposure amount of Q2 melts due to the heat generated by the croconic methine dye.
As shown in FIG. 2(B), a pit consisting of a recess 5b is formed.

In this case, since the recording layer 2 of the optical recording medium used in the present invention is constituted by a combination of a croconic methine dye and a polydiacetylene derivative compound as described above, that is, due to the presence of a polydiacetylene derivative compound, The energy required for melting the recording layer can be significantly reduced, and pit formation by the croconic methine dye is greatly promoted.

In this way, the discolored portion 5a is formed on the recording layer 2 according to the input information.
(b) Optical recording using two different types of dots 5b, that is, ternary recording is performed. Moreover, since the optical recording medium used in the present invention has high sensitivity to both color change recording and pit recording, such ternary recording can be performed at high speed.

The case where an optical recording medium having a single mixed recording layer is used has been described above, but when a two-layer separation system as shown in FIG. 1(B) is used, the imaging points 3a and 3b are , 3rd
As shown in Figure (A), the layer 2b contains a croconic methine dye. When the laser 4 is irradiated in this way,
Exposure amount Q1, Q2 of image forming points 3a, 3b according to recorded information
The croconic methine dye generates heat in response to the
), dots 5a consisting of discolored portions or pits 5b consisting of concave portions are formed.

The two types of dots recorded in the above manner can be read both at once or only one of them, as desired.

Note that as the optical recording medium, a disk-shaped disk (optical disk) was used in the above example, but of course it depends on the type of substrate that supports the recording layer containing the DA compound and the 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 a combination of croconic methine dye and polydiacetylene derivative compound is used in the recording layer, desired discoloration recording and pit recording can be performed on one recording medium using a small and lightweight semiconductor laser. You can do it accordingly. That is, high-density recording by ternary recording is possible with one recording medium. Moreover, the recording layer has high sensitivity in both color change recording and pit recording, and high-speed recording is possible.

(2) Since the recording layer is formed uniformly and with good surface properties, it is possible to perform optical recording with excellent stability and high quality.

(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-C=C-C* C-C8Hl
1 part by weight of fine crystalline powder of a diacetylene derivative compound represented by 6-C0OH and 15 parts by weight of the croconic methine dye represented by dye N625 were mixed with 3 parts by weight of methylene chloride.
A coating liquid was prepared by adding 0 parts by weight and thoroughly stirring the mixture.

Next, a glass disk substrate (thickness 1.5cm, diameter 2
00mM) is attached to a spinner coater, and a small amount of the coating liquid is dropped onto the center of the disk substrate.The spinner is rotated at a predetermined number of revolutions for a predetermined time to coat, and then dried at room temperature. The thickness of the subsequent coating film is 500A, 1000A
Optical recording media of A and 2000A were respectively produced.

Each of the optical recording media obtained in this way was first given 25
The recording layer was uniformly and sufficiently irradiated with 4 nm ultraviolet rays to turn the recording layer into a blue film.

Next, a semiconductor laser with a wavelength of 830 nm whose laser output can be varied (maximum weight: 1 hW, laser beam diameter: 1 u, irradiation time: 200 ns/1) is applied to each optical recording medium having this blue film recording layer. A dot) was irradiated according to the input information, and the optical recording of the present invention was carried out. In addition, when pit recording command is issued, the laser output is set to 8■W.
and when the color change recording command is issued, the laser output is set to 4■W.
And so.

The evaluation of the recording results is shown in Table 1. The evaluation is based on a comprehensive evaluation of the sensitivity, resolution, and contrast ratio between recorded and non-recorded areas for recording both pits and discoloration, with 0 being particularly good, 0 being good, and not being able to record. Or a defective one was marked as X.

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.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4 nm ultraviolet rays to turn the recording layer into a blue film, optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 1 shows the evaluation of the recorded results.

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 made up of parts by weight was used as a coating liquid.
An optical recording medium was prepared in the same manner as described above.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4 nw of ultraviolet rays to turn the recording layer into a blue film, optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 1 shows the evaluation of the recorded results.

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.

for each of the optical recording media thus obtained.

First, the recording layer was uniformly and sufficiently irradiated with ultraviolet rays of 254 nm to form a blue film, and then optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 1 shows the evaluation of the recorded results.

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.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating with 4r+m ultraviolet rays to form a blue recording layer, optical recording was performed in the same manner as in Example 1,
This was evaluated. Table 1 shows the evaluation of the recorded results.

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.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4 nm ultraviolet rays to turn the recording layer into a blue film, optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 1 shows the evaluation of the recorded results.

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.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4 nm ultraviolet rays to turn the recording layer into a blue film, optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 1 shows the evaluation of the recorded results.

Example 8 General formula C12H2s-C41i C-C"= C-C3
Instead of the diacetylene derivative compound represented by H16-Cool, the general formula C3H1, -CEC-1jc-C2H
An optical recording medium was prepared in the same manner as in Example 4 except that a compound represented by a-COOH was used.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4 nm ultraviolet rays to turn the recording layer into a blue film, optical recording was carried out in the same manner as in Example 1, and this was evaluated. Table 2 shows the evaluation of the recorded results.

Examples 9 to 12 The same method as in Example 8 except that the croconic methine dye represented by Dye Sui 25 was replaced with the croconic methine dye represented by Dye Sui 2.29.371.42. An optical recording medium was created. Each of these optical recording media was first uniformly and sufficiently irradiated with 254 nm ultraviolet rays to form a blue film in the recording layer, and then optical recording was performed in the same manner as in Example 1 and evaluated. Table 2 shows the evaluation of the recorded results.

Example 13 1 part by weight of a croconic methine dye represented by Dye Seishin 25 was dissolved in 10 parts by weight of dichloroethylene to prepare a coating liquid A.

Apart from this, C1□H2s-CEC-CEC-C3H□
1 part by weight of fine crystal powder of a diacetylene derivative compound represented by 6-C0OH was added to 10 parts by weight of Bencef and thoroughly stirred to prepare a coating liquid B.

Next, a glass disk substrate (thickness 1.5 mm, diameter 2
00 +ua) on a spinner coater, first drop a small amount of the coating liquid A onto the center of the disk substrate, and then rotate the spinner at a predetermined number of rotations for a predetermined time to apply the coating solution.
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.
It was dried at room temperature, and a layer containing an OA compound was laminated on the layer containing the croconic methine dye to form a recording layer.

Note that the film thicknesses of the layer containing the croconic methine dye and the layer containing the DA compound were varied as shown in Table 3, and samples were prepared. , 13-1-13-25 were obtained.

Each of the optical recording media obtained in this way was first given 25
The recording layer was uniformly and sufficiently irradiated with 4 nm ultraviolet rays to turn the recording layer into a blue film.

Next, optical recording was performed on each optical recording medium having the blue recording layer in the same manner as in Example 1, and the results were evaluated. Table 4 shows the evaluation of the recorded results.

Example 14 Coating liquid B has the general formula Cl2H25C3C-C=C-Cs
In place of the diacetylene derivative compound represented by H16-C0OH, the general formula c, )(,, -Ci C-C:
Samples J, 14-1 to 14-2 as shown in Table 5 were prepared in the same manner as in Example 13 except that a diacetylene derivative compound represented by C-C2H4-C0OH was used.
5, 25 types of optical recording media were created.

Each of the optical recording media obtained in this way was first given 25
The recording layer was uniformly and sufficiently irradiated with 4 nm ultraviolet rays to turn the recording layer into a blue film.

Next, optical recording was performed on each optical recording medium having the blue recording layer in the same manner as in Example 1, and the results were evaluated. Table 6 shows the evaluation of the recorded results.

Example 15 The methods shown in Table 7 were prepared in the same manner as in Example 14, except that a croconic methine dye represented by dye 6 was used in coating solution A instead of a croconic methine dye represented by dye M625. Samples like 15-1 to 15-25
25 types of optical recording media were created.

Each of the optical recording media obtained in this way was first given 25
The recording layer was uniformly and sufficiently irradiated with 4 nm ultraviolet rays to turn the recording layer into a blue film.

Next, optical recording was performed on each optical recording medium having the blue recording layer in the same manner as in Example 1, and the results were evaluated. Table 8 shows the evaluation of the recorded results.

Example 16 The dyes shown in Table 9 were prepared in the same manner as in Example 14, except that the dye represented by Dye Sui 14 was used in place of the croconic methine dye represented by Dye Sho 25 in coating solution A. Twenty-five types of optical recording media, samples #6.1B-1 to 1ft-25, were created.

Each of the optical recording media obtained in this way was first given 25
The recording layer was uniformly and sufficiently irradiated with 4 nm ultraviolet rays to turn the recording layer into a blue film.

Next, optical recording was performed on each optical recording medium having this blue film recording layer in the same manner as in Example 1, and the results were evaluated. Table 10 shows the evaluation of the recording results.

[Brief explanation of drawings]

FIG. 1(A) 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.
Figure (A) and Figure 2 (B) and Figure 3 (A) and Figure 3
Figure (B) is a schematic cross-sectional view of an optical recording medium showing the optical recording process of the present invention. Substrate 2: Recording layer 2a: Layer containing OA compound 2b: Layer containing croconic methine dye 3a, 3b = Exposure section 4: Laser beam 5a: Discoloration section 5b Two pits

Claims (1)

[Claims] 1) An optical recording medium having a recording layer containing a polydiacetylene derivative compound and a croconic methine dye is irradiated with light whose exposure amount is controlled according to recorded information, and the exposed area of the exposure amount Q_1 is discolored. and forming a pit consisting of a concave portion in the exposed area of the exposure amount Q_2 (however, the step of forming a pit consisting of a concave part
<Q_2) An optical recording method characterized by having <Q_2).