JPS6353096A - Optical recording method - Google Patents

Abstract

PURPOSE:To enable recording at high speed with high density and high sensitivity, by irradiating an optical recording medium having a recording layer comprising a polydiacetylene derivative compound and a specified cyanine dye with light to form pits constituted of recessed parts. CONSTITUTION:A combination of at least one cyanine dye of either of formulas I-III with a polydiacetylene derivative compound is used to provide a recording layer of an optical recording medium. In the formulas, each of R<1> and R<2> is hydrogen, a substd. or unsubstd. alkyl, cycloalkyl, allyl, substd. or unsubstd. aralkyl or substd. or unsubstd. aryl, each of R<3> and R<4> is hydrogen or a halogen, each of Z1 and Z2 is an atomic group necessary for completing a substd. or unsubstd. nitrogen-containing heterocyclic ring, each of A1 and A2 is a bivalent hydrocarbon group for forming a substd. or unsubstd. 5- or 6-membered ring, M<+> is a cation, and X<-> is an anion.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical recording method using an optical recording medium, and in particular, to a high-density, high-sensitivity, high-speed pit recording even when using a low-output semiconductor laser. The present invention relates to an optical recording method that is possible and 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 record and store a large amount of documents, documents, etc. on a single disc, so they can be used to organize documents, etc. in the office.
It has the advantage of being more efficient in management.

The recording layer used in such optical disc technology can store high-density information by forming optically detectable small dots (eg, about 11) 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 pits due to evaporation or melting at that location. In another beat mode recording method, absorption of the applied 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 no dots are 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. In the case of pit recording, the output of the photodetector is reduced in areas where pits are not formed, whereas in areas where bits are formed, the laser beam is sufficiently reflected by the reflective surface of the underlying layer and the output of the photodetector 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 vapor-deposited films, bismuth thin films, tellurium oxide thin films, and chalconitic amorphous glass films. However, products using organic materials are attracting attention due to their cost and ease of manufacture.

As organic materials used for optical recording media, Japanese Patent Application Laid-Open No. 58-1
Cyanine dyes are disclosed in No. 18650 and Japanese Unexamined Patent Publication No. 58-224354, and cyanine dyes containing these dyes are
It is known that so-called heat moat recording, in which pits are formed using laser energy, can be performed because the organic film absorbs radiation in the semiconductor laser radiation wavelength range and generates heat.

(Problems to be Solved by the Invention) However, although the conventional pit recording method has the advantage of clear recording, that is, good contrast, it is not as good as the recording method that forms dots through discoloration. ii i,:y = requires more energy and has the disadvantage of slow recording speed.Furthermore, since physical pits are formed on the surface of the recording medium,
As long as the initial recording medium surface is sufficiently smooth and
? Also in &, sufficient precautions are required to prevent scratches on the surface of the recording medium, and it is difficult to perform high-density, high-sensitivity recording.

For example, when the recording n layer of an optical recording medium is formed using the above cyanine dye, the cyanine dye is exposed to the semiconductor laser beam (
It absorbs infrared rays and generates heat, and as a result of the heat generation, it self-melts, so this property can be used to form bits on optical recording media. However, it requires a large amount of energy to form a bit, has low sensitivity, and requires a relatively long constant exposure (light irradiation) time. Therefore, it was not possible to shorten the exposure time and recording at higher speeds was not possible.

The present invention has been made in order to solve the problems of the prior art, and the present inventors have discovered that a recording layer of an optical recording medium is formed by combining a cyanine dye and a diacetylene derivative compound. The present invention was completed based on the discovery that the bit formation speed under light irradiation is significantly accelerated even when a high output semiconductor laser is used.

An 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.

Another object of the present invention is to provide an optical recording method capable of recording at high density and high 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 comprises a polydiacetylene derivative compound and the following general formula [I], [II] or [
irradiating an optical recording medium having a recording layer containing one or more of the compounds represented by [III] with light in accordance with the expression jH+'iN to form a bit consisting of a concave portion in the recording layer. It is characterized by

General formula [■ko. ~ ■ General formula E
, represents a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, and R3 and R4 represent a hydrogen atom or a halogen atom.

Z and z2 represent an atomic group necessary to complete a substituted or unsubstituted nitrogen-containing heterocycle, and A2 and A2 are divalent hydrocarbon groups forming a substituted or unsubstituted 5- or 6-membered ring. , M represents a cation, and × represents an anion.

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 % (wherein R and R' are polar groups; an alkyl group, a saturated aliphatic hydrogen group such as cyclohexylph2 (which may be substituted with a polar group,
An olefinic hydrocarbon group such as a vinyl group or a propenyl group, or an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, or an alkylphenyl group, which may be substituted with a polar group; is, for example, 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, a guanidine group, and a dorazine group. , phosphoric acid group, silicic acid group, aluminate group, nitrile group, thioalcohol group, nitro group and halogen atom. ) and their polymers.

Furthermore, as will be described later, in the case where the recording layer is formed from a monomolecular film or a monomolecular cumulative film, the DA compound has a 1°4-addition between c=c-c=c-c functional groups in adjacent molecules. A compound capable of polymerization reaction, typically the following general formula (%) (wherein, X is a hydrophilic group forming a hydrophilic site,
m and n represent integers. ) is included.

In this case, the hydrophilic group X includes, for example, a carboxyl group, an amine group, a hydroxy group, a nitrile group, a thioalcohol group, an imino group, a sulfonic acid group, a sulfinyl group, or a metal or amine salt thereof.Hydrophobic site The alkyl group represented by +1((:112)l- forming the formula is preferably a long-chain alkyl group having 1 to 30 carbon atoms. Also, n+m is 1 to 30 carbon atoms.
An integer of is preferred.

On the other hand, the compound represented by the general formula [I], [II] or [m] used in the present invention (hereinafter abbreviated as cyanine dye) has an absorption peak in a wavelength range of 750 nm or more, and has an absorption peak in the wavelength range of 750 nm or more. It is a compound that generates heat when exposed to external light.

To explain this cyanine dye more specifically, in the general formulas [I], [II] and [III], R
1 and R2 are alkyl groups (e.g., methyl group, ethyl group, n-propyl group, 1so-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- and droxyethyl groups, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group) group, carboxymethyl group, 2-carboxyethyl group, 3-carboxydipropyl 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, etc.), cyclic alkyl group (e.g.
cyclohexyl group, etc.), allyl group ((:R2-C1l
-CH2-), aralkyl groups (e.g., hensyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.), substituted aralkyl groups (e.g., carboxyhensyl group, sulfobenzyl group, hydroxyhensyl group, etc.) ), an aryl group (eg, phenyl group, etc.) or a substituted aryl group (eg, carboxyphenyl group, sulfophenyl group, hydroxyphenyl group, etc.). In particular, in the present invention, among these organic residues, hydrophobic ones are preferred.

R3 and R4 represent a hydrogen atom or a halogen atom (for example, a chlorine atom, a bromine atom, an iodine atom, etc.).

Zl and l are substituted or unsubstituted heterocycles, for example, 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-dimethylhenzothiazole, 5
-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5゜6-cymethoxyhenzothiazole, 5,6-diokidimethylenebenzothiazole, 5-hydroxybenzothiazole, 6- hydroxybenzothiazole, 4.5.6.7-titrahydroxybenzothiazole, etc.), naphthothiazole series nuclei (e.g. naphtho(2,1-d)thiazole, naphtho(1,2-d)thiazole, 5-methoxynaphtho (1,2-d]thiazole, 5-ethoxynaphtho(1,2-d)thiazole, 8
-methoxynaphtho(2,1-d]thiazole, 7-methoxynaphtho(2,1-d)thiazole, etc.), 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-hydroxybenzothiazole, 6-hydroxybenzothiazole, 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.), penzoselenal series nuclei (e.g. benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole, 5,6-dimethylbenzoselenazole, 5 -methylbenzoselenazole, 5-methyl-6-methylbenzoselenazole, 5,6-siiximethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4°5,6.7-titrahydroxybenzoselenazole, etc.) , naphthoselenazole series nuclei (e.g. naphtho(2,1,d) 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 Nuclei of the series (e.g. isoquinoline, 3,4-dihydroxyisoquinoline), nuclei of the 3-isoquinoline series (e.g. 3-inquinoline), nuclei of the 3,3-dialkylindolenine series (e.g. 3,3-dimethylindolenine, , 3-dimethyl-5-chloroindolenine, 3.3.5- ) dimethylindolenine, 3,
3゜7-drimethylintorenine), pyridine series nuclei (e.g. pyridine, 5-methylpyridine), benzimidazole series nuclei (e.g. 1-ethyl-5,6-cyclohenzimidazole, 1-hydroxyethyl-5 ,6
-cyclohenzimidazole, l-ethyl-5-chlorobenzimidazole, 1-ethyl-5,6-cyanohenzimidazole, 1-ethyl-5-phenylhenzimidazole, 1-ethyl-5-fluorohenzimidazole, 1- Ethyl-5-cyanobenzimidazole, 1
-(β-acetoxyethyl)-5-cyanohenzimidazole, 1-ethyl-5-chloro-6-diatzhenzimidazole, 1-ethyl-5-fluoro-6-cyanohenzimidazole, 1-ethyl-5-acetyl Henzimitazole, 1-ethyl-5-carboxyhenzimidazole, 1-ethyl-5-ethoxysulfonylhenzimidazole, 1-ethyl-5-sulfamylbenzimidazole, 1-ethyl-5-N-ethylsul familhencyimidazole, 1-ethyl-5,6-cyfluoropenzimidazole, 1-ethyl-5,6-cyanohencyimidazole, l-ethyl-5-ethylsulfonylhenzimidazole, 1-ethyl-5-methylsulfonylbenzo Imidazole, 1-ethyl-5-trifluoromethylbenzimidazole, 1-ethyl-5-trifluoromethylsulfonylbenzimidazole, 1-ethyl-5-
Represents a group of nonmetallic atoms necessary to complete a compound (such as trifluoromethylsulfinylbenzimidazole).

A and A2 represent only two hydrocarbon groups (for example, H3CH3 -CH2-CH2-, etc.) forming a substituted or unsubstituted 5- or 6-membered ring, and these 5- or 6-membered rings are It may be fused with a ring, naphthalene ring, etc.

θ X is a chloride ion, bromide ion, iodide ion,
A chlorate ion, Hensensulfonate ion, p-
toluene sulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion, etc.), P represents R and/or R2 itself is an anionic group, e.g. -5o34 oso34-coo'p
59No-, -5o2Q-co-1-so2Q-so2
- does not exist. P represents a cation such as a hydrogen cation, a sodium cation, an ammonium cation, a potassium cation, or a pyridium cation.

Next, representative examples of the cyanine dyes used in the present invention are listed below, or for convenience, are expressed in the form of a betaine structure of general formula [I] or [m]. However, in the preparation of these dyes, mixtures of dyes in betaine or salt form are obtained and are therefore used as mixtures.

Specific examples of general formulas [I] and [11] are (1) to (33
) or (34) to (4) as specific examples of general formula [I11]
7) are listed.

(8) oe(13)
o” (16)
oOshi! C1
(21) (+e(24)
. e(2B)
o” (27) OeshiH31ji2H5 I C)
IC7H1I C2) 15 1 θ IC2
Hc, I
C2HSl Br
IeC2H5 The cyanine dyes (1) to (47) above can be used alone or in combination of two or more.

A typical configuration of the optical recording medium used in the present invention is shown in FIG. In this example, a recording layer 2 containing the DA compound and cyanine dye is provided on a substrate 1.

The recording layer 2 of the optical recording medium used in the present invention is the OA
Typically, a coating liquid is prepared by mixing a fine crystalline powder of a DA compound and a cyanine dye in an appropriate volatile solvent, and this coating liquid is applied onto a substrate. Alternatively, it can be obtained by a method such as forming a mixed monomolecular film or a mixed monomolecular cumulative film of compound D and cyanine dye on a substrate.

As the substrate 1 of the optical recording medium used in the present invention, glass,
Various support 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 can be used. Use something that allows the lines to pass through.

A coating prepared by mixing the D^ compound and cyanine dye in a suitable volatile solvent is applied onto the substrate 1! When forming the recording layer 2 by a method of applying 5 liquids, the coating liquid includes the substrate 1
In order to improve the adhesion between the two, a binder made of natural or synthetic polymer may be added as appropriate. Furthermore, various additives may be added to improve the stability and quality of the recording layer 2.

The solvent used for coating is appropriately selected depending on the type of binder used and the type of OA compound and cyanine dye, but in general, alcohols such as methanol, ethanol, and impropatol; acetone, methyl ethyl ketone, and cyclohexanone are generally used. Ketones, r'r, N
- Ketones such as dimethylformamide and KN-dimethylacetamide Sulfoxides such as dimethyl sulfoxide: Ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether: Methyl acetate,
Esters such as ethyl acetate and butyl acetate: Aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene: Aromatic carbonization such as benzene, toluene, xylene, monochlorobenzene, dichlorohenzene, etc. Examples include hydrogens.

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

In this case, the thickness of the recording layer 2 is 500 to 2μ.
A range of 1000 to 5000 A is particularly preferred. The blending ratio of the D compound and the cyanine dye in the recording layer 2 is preferably about 1715 to 1071, and optimally about 1710 to 5/1.

On the other hand, a typical structure of an optical recording medium used in the method of the present invention in which the recording layer 2 is formed from a monomolecular film or a monomolecular cumulative film is illustrated in FIGS. 4 and 5. In the example shown in FIG. 4, a recording layer 2 consisting of molecules 11Q in a mixture of the DA compound 7 and the cyanine dye 6 is formed on a substrate 1, and in FIG. It is something.

In order to form the recording layer 2 made of such a monomolecular film or a monomolecular cumulative film on the substrate 1, for example, 1. Langm
The Langmuir-Prodgett method (hereinafter abbreviated as LB method) developed by Uir et al. is used. In the LB method, when a molecule has a parent wood group and a hydrophobic group in its molecule, and the balance between the two (amphipathic balance) is maintained appropriately, this molecule lowers the parent wood group on the water surface. This is a method of creating a monomolecular film or a film made up of monomolecular layers by taking advantage of the fact that the monomolecular layer becomes a layer directed toward the molecule. 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 true between the area per molecule A and the surface pressure ■, 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 both 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.

Using this method, a mixed monomolecular film or a mixed monomolecular cumulative film of a DA compound and cyanine dye constituting the recording layer of the present invention is produced, for example, as follows. First, a DA compound and a cyanine 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 into a film. Next, to prevent this developed layer from spreading freely on the aqueous phase and spreading too much, use a partition plate or float.
is provided to limit the area of the developed layer and control the state of aggregation of these compounds, thereby obtaining a surface pressure (1) proportional to the state of aggregation.

By moving this partition plate, the developed area can be reduced to control the state of aggregation of the film material, and the surface pressure can be gradually increased to set the surface pressure (2) suitable for producing a cumulative film. By gently moving the clean substrate vertically up and down while maintaining this surface pressure, a mixed monomolecular film of the OA compound and cyanine 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 consistency 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 is formed on the substrate with the parent group of the D-formula compound facing the substrate in the -th layer. be done.

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 contact with the water surface horizontally and transferred, and a monomolecular layer of the D-type compound with the hydrophobic group facing the substrate is formed on the substrate. In this method, even if accumulated, the orientation of the molecules of the D-type compound does not change, and an X-type film is formed in which the hydrophobic groups face the substrate side 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, it is possible to achieve high density optical recording and thermal recording according to the functions obtained by the combination of the DA compound and the cyanine dye.
A high resolution recording medium can be obtained.

The film thickness of the recording layer in this case (cumulative number of monomolecular films) is 5
-400 is suitable, with a range of 20-170 being particularly preferred. The mixing ratio of the DA compound and cyanine dye in the recording layer is the same as in the case of the coating method described above.

Note that various protective layers may be provided on the recording layer configured in this way, if necessary.

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

In this optical recording medium, by applying light to the D-type 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 light and not by the application of other physical energy such as heat. As a result of this polymerization, it has a maximum absorption wavelength in the range of 620 to 660 nm, and its color changes from blue to dark. This change in hue due to polymerization is an irreversible change, and -
The recording layer that has changed to a blue or dark color does not return to a colorless transparent film.

Furthermore, when a semiconductor laser is irradiated onto the recording layer containing the polydiacetylene derivative compound and the cyanine dye, which has changed to a blue or dark color, the cyanine dye absorbs the light and generates heat, and the heat causes the light-irradiated area of the recording layer to change. melt. The energy required for melting at this time is significantly smaller than when the recording layer is formed using cyanine dye alone.

The optical recording method of the present invention performs recording by utilizing the characteristics obtained by the combination of compound A and cyanine 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 nI.

When carrying out the optical recording method of the present invention, when using an optical recording medium having an optical recording layer containing a D-type compound (excluding a polymer) and a cyanine dye, first, the recording layer is Irradiates the entire area with ultraviolet light. By this irradiation with ultraviolet rays, the OA compound (
(excluding polymers) polymerizes and converts into polydiacetylene and conductive compounds, and the recording layer changes color to a blue or dark film.

(Of course, this operation is not required for those having a recording layer using a polydiacetylene derivative compound directly 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, is placed on, for example, an optical recording medium mounting means, and is imaged at a predetermined position on a synchronously rotating disc-shaped optical recording medium, as shown in FIG. The imaging position is the recording layer 2 of the optical recording medium.

The cyanine dye present at the imaging point (site) 3 absorbs this laser beam 4 and generates heat. Due to the heat generated by the cyanine dye, the recording layer 2 at the imaging point 3 is melted, and a bit consisting of a concave portion 5 is formed as shown in FIG. In this case, since the recording layer 2 of the recording medium used in the present invention is constituted by a combination of a cyanine dye and a polydiacetylene derivative compound as described above, in other words, the presence of the polydiacetylene derivative compound allows the recording layer 2 to be formed by the cyanine dye. The pit formation described above is greatly promoted. In other words, compared to pit formation in a recording layer composed of cyanine dye alone, it is highly sensitive to semiconductor lasers, and when a semiconductor laser with the same output is used, the exposure time with the laser beam is shorter. Finish.

In this way, optical recording is performed by forming bits on the recording layer according to manual information.

In the above example, the optical recording medium is a disc-shaped disk (
Although an optical disk (optical disk) was used, it is of course possible to use an optical tape, an optical card, etc. depending on the type of substrate supporting the recording layer containing the D^ compound and cyanine dye.

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

(1) Since the recording layer contains a combination of a cyanine dye and a polydiacetylene derivative compound, high-sensitivity and high-speed recording can be performed even using a small and lightweight semiconductor laser.

(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. Furthermore, when the recording layer is formed of a mixed monomolecular film of a DA compound and a cyanine dye or a cumulative film thereof, the recording layer has a higher density and a higher degree of iron B property, and therefore A higher density and more homogeneous composition is possible.

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

[Actual hh example]

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

Example 1 General formula C, 2H7, -c=c-c=c-c8H,, -c
1 part by weight of fine crystal powder of a diacetylene derivative compound represented by ooH and 1 part by weight of 15 parts by weight of a cyanine dye represented by the dye shown above JJEL1 were added to 20 parts by weight of methylene chloride and thoroughly stirred to prepare a coating solution. did. Next, a glass disk substrate (thickness 1.5 mm, diameter 20 mm
■〉 attached to a spinner coater, drop a small amount of the coating liquid onto the center of the disk substrate, rotate the spinner at a predetermined number of rotations for a predetermined time, dry at room temperature, and after drying on the substrate. The thickness of the coating film is 500, 1000 and 2.
000 people each created an optical recording medium.

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, each optical recording medium containing this blue-colored recording layer was irradiated with a laser beam for 400 hours per pit.
Optical recording was performed under the following recording conditions, except for various changes between ns and 5 μs.

Semiconductor laser wavelength: 830 nm Laser beam diameter: 1 question Laser output = 8111 N After completing the recording under the above conditions, observe the recording results on each optical recording medium using a microscope, and check whether there is a clear concave area in the laser beam irradiation area. The laser beam irradiation time required to form the bit was investigated. The results are shown in Table 1.

Next, we comprehensively evaluated the resolution and the contrast ratio between pit and non-bit areas for the optical recording media recorded with an irradiation time of 1000 ns/1 bit. Items that could not be completed or were defective were marked with an X. The results are shown in Table 1.

Example 2 A mixed solution containing 1 part by weight of diacetylene derivative compound, 10 parts by weight of cyanine dye, and 20 parts by weight of methylene chloride was used as a coating liquid, and the same method as in Example 1 was carried out. An optical recording medium was created.

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 A mixed solution containing 1 part of diacetylene derivative compound, 5 parts by weight of cyanine dye, and 12 parts by weight of methylene chloride was used as a coating liquid, and was coated with light in the same manner as in Example 1. Created a recording medium.

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

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4nL11 of ultraviolet light 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 5 A mixed solution containing 5 parts by weight of diacetylene derivative compound, 1 part by weight of cyanine dye, and 12 parts by weight of methylene chloride was used as a coating liquid, and the same method as in Example 1 was carried out. An optical recording medium was created.

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 6 A mixed solution containing 10 parts by weight of the diacetylene derivative compound, 1 part by weight of the cyanine dye, and 20 parts by weight of methylene chloride was used as a coating liquid, and the same method as in Example 1 was carried out. An optical recording medium was created.

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 A mixed solution containing 15 parts by weight of a diacetylene derivative compound, 1 part by weight of cyanine dye I, and 30 parts by weight of methylene chloride was used as a coating liquid, and the same method as in Example 1 was carried out. An optical recording medium was created.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4r++n 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.

Comparative Example 1 An optical recording medium was prepared in the same manner as in Example 1, using as a coating liquid a solution in which 1 part by weight of a diacetylene derivative compound was added to 2 parts by weight of methylene chloride without using a cyanine dye. Each of the optical recording media thus obtained was first uniformly and sufficiently irradiated with 254 nm ultraviolet rays to make the recording layer a blue film, and then optical recording was performed in the same manner as in Example 1, and this was evaluated. did. Table 1 shows the evaluation of the recorded results.

Comparative Example 2 An optical recording medium was prepared in the same manner as in Example 1, without using a diacetylene derivative compound, but using a solution prepared by dissolving 1 part by weight of cyanine dye in 2ffi parts of methylene chloride as a coating liquid.

Each of the optical recording media thus obtained was directly irradiated with a semiconductor laser beam under the same conditions as in Example 1 according to the input information, without performing ultraviolet irradiation, to perform recording. Table 1 shows the evaluation of the recording results.

Table 1 Example 8 The amount of diacetylene derivative compound 1 is 1 part by weight, the amount of cyanine dye is 1 part by weight, the amount of methylene chloride (■) is 4 parts by weight,
Furthermore, a mixed solution containing 2 parts by weight of nitrocellulose as a binder was used as a coating liquid, and an optical recording medium with a recording layer of J7 size 3000 was prepared in the same manner as in Example 1.

This optical recording medium was uniformly and sufficiently irradiated with 254 nm ultraviolet rays to make the recording layer a blue film, and then recording was performed under the following recording conditions according to input information. In addition, the laser beam irradiation time per pit is 400ns~5
Various changes were made between μs.

Semiconductor laser wavelength: 840 nm Laser beam diameter: 1 laser output = 81 Comparative Example 3 Without using a diacetylene derivative compound, 2 parts of cyanine dye and 2 parts by weight of nitrocellulose were dissolved in 4 ffl parts of methylene chloride. Using the solution as a coating liquid, an optical recording medium with a recording layer thickness of 3000 was prepared in the same manner as in Example 1.

This optical recording medium was directly irradiated with a semiconductor laser beam according to the input information under the same conditions as in Example 8, without performing ultraviolet irradiation, to perform recording.

Regarding the optical recording medium of Example 8, as a result of microscopic observation, good recording was possible when the irradiation time was 900 ns/1 pit or more, but for the optical recording medium of Comparative Example 3, 180 to clearly form two pits
An irradiation time of 0 ns/1 pit or more was required.

Example 9 General formula c, 2H, 5-C=C-CmiC-C3H, 6-G
In place of the diacetylene derivative compound represented by
An optical recording medium was prepared in the same manner as in Example 3 except that the compound represented by I was used.

First, 254r+I1
After uniformly and sufficiently irradiating the ultraviolet rays of Example 1 to turn the recording layer into a blue film, recording was performed under the same recording conditions as in Example 1, and the light irradiation time and resolution necessary for forming clear pits and the pit area were determined. and the contrast ratio of non-pit areas were evaluated. The results are shown in Table 2.

Examples 1O to 13 The same method as in Example 9 was carried out except that the cyanine dyes represented by dyes A1 and 7.20.31.43 were used in place of the cyanine dyes represented by dye AI. 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.

Table 2 Example 14 General formula C,2H25-C=c-Cmic-c8H,6-c
A solution prepared by dissolving 1 part by weight of a diacetylene derivative compound represented by O-ko and 1 part by weight of a cyanine dye represented by Kanki dye A3 in chloroform at a concentration of 1XIO-3 mol/1 was prepared with p++ of 6.5. When the cadmium chloride concentration is 1
Developed on an aqueous phase of xl0-3 mol/l. 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.
A mixed monomolecular film of compound A and cyanine dye was transferred onto a substrate, and the mixed monomolecular film, 21st layer, 41st layer and 8th layer
An optical recording medium was prepared in which a mixed monomolecular film accumulated in one layer was formed on a substrate.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4r++n ultraviolet rays to form a W color film, optical recording was carried out in the same manner as in Example 7i6 and this was evaluated. Table 3 shows the evaluation of the recorded results.

Example 15 An optical recording medium was prepared in the same manner as in Example 14, except that 1 part by weight of a diacetylene derivative compound was contained with respect to 10 parts by weight of the cyanine dye.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4r+m ultraviolet rays to make the recording layer a blue film, optical recording was performed in the same manner as in Example 1,
This was evaluated. Table 3 shows the evaluation of the recorded results.

Example 16 An optical recording medium was prepared in the same manner as in Example 14, except that 1 part by weight of a diacetylene derivative compound was contained per 51 parts of cyanine dye.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4nI11 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 3 shows the evaluation of the recorded results.

Example 17 Example 1 except that 1fflffi part of diacetylene derivative compound was contained per 1 part by weight of cyanine dye.
An optical recording medium was prepared in the same manner as in Example 4.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4r+m ultraviolet rays to make the recording layer a blue film, optical recording was performed in the same manner as in Example 1,
This was evaluated. Table 3 shows the evaluation of the recorded results.

Comparative Example 4 An optical recording medium was produced in the same manner as in Example 14, except that only a diacetylene derivative compound was used without using cyanine dye.

Each of the optical recording media obtained in this way was first given 25
After uniformly and sufficiently irradiating the recording layer with 4r+m ultraviolet rays to make the recording layer a blue film, optical recording was performed in the same manner as in Example 1,
This was evaluated. The evaluation of the recording results is shown in Table 3.

Table 3

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view illustrating one aspect of the structure of an optical recording medium used in the method of the present invention, FIGS. 2 and 3 are schematic cross-sectional views of the optical recording medium illustrating the optical recording process of the present invention, FIG. 4 is a schematic cross-sectional view illustrating one embodiment of the structure of an optical recording medium used in the method of the present invention in which the recording layer is formed of a monomolecular film;
The figure is a schematic cross-sectional view illustrating one aspect of the structure of an optical recording medium in which a recording layer is formed of a monolayer cumulative film. 2: Recording layer 3: Light irradiation (recording) region 4: Laser beam 5 bits 6: Cyanine dye 7, diacetylene derivative compound

Claims (1)

[Scope of Claims] 1) A polydiacetylene derivative compound and the following general formula [
Forming pits consisting of concave portions in the recording layer by irradiating an optical recording medium with a recording layer containing one or more of the compounds represented by [I], [II], or [III] with light according to recorded information. An optical recording method comprising the step of: General formula [I] ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ General formula [II] ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ General formula [III] ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ ▲Mathematical formulas, chemical formulas, There are tables, etc. ▼ (In the above formula, R^1 and R^2 are hydrogen atoms, substituted or unsubstituted alkyl groups, cyclic alkyl groups, allyl groups, substituted or unsubstituted aralkyl groups, or substituted or unsubstituted aralkyl groups. represents an aryl group, R^3 and R^4 represent a hydrogen atom or a halogen atom. Z_1 and Z_2 represent an atomic group necessary to complete a substituted or unsubstituted nitrogen-containing heterocycle, and A_1 and A_2 represents a substituted or unsubstituted divalent hydrocarbon group forming a 5- or 6-membered ring, M^■ represents a cation, and X^
■ indicates an anion. )