JPS62151384A - Optical recording medium - Google Patents

Abstract

PURPOSE:To enable high-density and high-sensitivity recording at a high speed by optical writing with small-sized light wt. semiconductor laser, by providing a recording layer composed of a monomolecular film mixture of a diacetylene derivative compound having at least both of a hydrophilic area and a hydrophobic area and a chloconic methine dye or a built-up film thereof. CONSTITUTION:A diacetylene derivative compound (DA compound) is a poly merizable compound and represented by formula H(CH2)m-CidenticalC-Cidentical(CH2)n-X and, as a hydrophilic group X, a carboxyl group, an amino group, a hydroxyl group, a nitrile group, a thioalcohol group, an imino group, a sulfonic acid group, a sulfinyl group or a metal or amine salt thereof are designated. As the alkyl group represented by H(CH2)m- forming a hydrophobic area, a 1-30C long chain alkyl group is pref. In order to form a recording layer 2 composed of a monomolecular film mixture of the DA compound 3 and a chloconic methine dye 4 on a substrate 1, for example, a Langmuir-Blodgett's method is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical recording medium, and particularly to an optical recording medium suitable for optical writing using an infrared laser.

[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 elements have been studied 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 elements. Focusing on the thermochromic properties of these compounds, a recording technique for use as a laser recording element was disclosed in Japanese Patent Laid-Open No. 5FT-147807. There is. However, this specification does not mention what kind of laser was used or should be used, and merely states that recording was performed using a laser.

The present inventors investigated the laser recording of this diacetylene derivative compound using various lasers, and found that although thermochromic recording is possible using a large, high-power laser such as an argon laser, It has been confirmed that laser recording cannot be performed when a relatively low output semiconductor laser (wavelength: 800 to 850 mm) 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-58-
No. 80443 discloses croconic methine dyes, and it was discovered that organic films containing these dyes absorb radiation in the wavelength range of semiconductor lasers and generate heat, making it possible to perform so-called heat mode recording in which bits are formed using laser energy. Disclosed. However, when recording is performed by forming physical pits on the surface of a recording medium, the surface of the initial recording layer must be sufficiently smooth and at the same time the surface of the recording medium will not be damaged even after recording. In addition, it is relatively difficult to perform high-density, high-speed recording.

Furthermore, the recording layer of these recording media is made up of microcrystals of diacetylene derivative compounds or croconic methine dyes dispersed in a binder, and the orientation of these compounds within the recording layer is random. This method was not necessarily suitable for high-density recording because the absorption rate and reflectance of light differed depending on the location, and the degree of chemical reaction varied depending on the location.

[Problem that the invention seeks to solve]

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide an optical recording medium that can be optically written with a small and lightweight semiconductor laser.

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

Still another object of the present invention is to provide an optical recording medium with excellent stability and high quality.

゛ [Means for solving the problem] That is, the optical recording medium of the present invention comprises a mixed monomolecular film of a diacetylene derivative compound having at least a hydrophilic site and a hydrophobic site and a croconic methine dye, or a mixed monomolecular film thereof. It is characterized by having a recording layer having a cumulative film.

The diacetylene jaw conductor compound (hereinafter abbreviated as r3A compound) that has both a hydrophilic site and a hydrophobic site used in the present invention is a compound that has both a hydrophilic site and a hydrophobic site. , 4-It is a compound capable of addition polymerization reaction, and is typically represented by the following general formula % formula %) (wherein, X is a hydrophilic group forming a hydrophilic site,
m and n represent integers. ) Compounds represented by:

Examples of the hydrophilic group X in the above DA compound include a carboxyl group, an amide group, a hydroxy group, a nitrile group,
Examples thereof include a 1,000-alcohol group, an imino group, a sulfonic acid group, a sulfinyl group, or a metal or amine salt thereof.

@ Forms an aqueous region. The alkyl group represented by (co,)m- is preferably a long-chain alkyl group having 1 to 30 carbon atoms. Further, m+n is preferably an integer of 1 to 30.

On the other hand, a compound (including an inner salt) having a substituent containing a croconic methine dye complex used in the present invention,
It is a compound that has an absorption peak in the ~850n layer and generates heat by infrared light of this wavelength. The Crocony and Dametin dyes are typically expressed by the following general formulas [1] to [■]
The dyes shown are exemplified.

General formula [I] Hatake general formula [II] 0Xe General formula [I [1] General formula [TV] fη , 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, -octyl group, etc.), substituted alkyl group (e.g. 2-hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxypropyl group, etc.) -Hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carpoxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group, 4-sulfobutyl group, 3
-sulfatepropyl group, 4-sulfatephthyl group, X-(methylsulfonyl)-carbamylmethyl group,
3-(acetylsulfamyl)propyl group, 4-(
(acetylsulfamyl) butyl group, etc.), cyclic alkyl group (e.g., cyclohexyl group, etc.), allyl group (OH
2=OH-CH2-), aralkyl group (e.g., benzyl group, phenethyl group, α-naphthylmethyl group, β-
naphthylmethyl group), 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, 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, 6-methylbenzothiazole, 5.
8-dimethylbenzothiazole, 5-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 8-methoxybenzothiazole, 5
, 6-Simethoxybenzothiazole, 5.8-Dioxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 4,5,
8.7-titrahydropenzothiazole), 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-d]thiazole, 8-methoxynaphtho[2,1-dl thiazole, 7-methoxynaphtho (2,1-dl thiazole, etc.), thionaphthene [7
,6-d] thiazole series nuclei (e.g. 7-medoxythionaphthene[7,13-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-chloropendioquinazole, 5-methylbenzoxazole, 5-phenylbenzooxazole, C-methylbenzoxazole, 5.8- dimethylbenzoxazole, 5-methoxybenzoxazole,
6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), naphthoxazole series nuclei (e.g. nut [2
, 1-dl oxazole, naphtho[1,2-dl oxazole, etc.), selenazole series nuclei (e.g. 4-dl oxazole, etc.),
methylselenazole, 4-phenylselenazole, etc.)
, benzoselenazole series nuclei (N: benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole, 5,8-dimethylbenzoselenazole, 5-methoxybenzoselenazole, 5-methyl-8-
methoxybenzoselenazole, 5,8-dioxymethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4.5,8,7-titrahydrobenzoselenazole, etc.), naphthoselenazole series nuclei (e.g. naph)
[2,1-dl selenazole, nut [l,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,
8-methylquinoline, B-chloroquinoline, 6-medoxyquinoline, 6-nitoxyquinoline, 6-hydroxyquinoline), 4-quinoline series nuclei (e.g. quinoline, 6-hydroxyquinoline),
-methoxyquinoline, 7-methylquinoline, 8-methylquinoline), 1-inquinoline series nuclei (e.g. isoquinoline, 3,4-dihydroisoquinoline), 3-isoquinoline series nuclei (e.g. isoquinoline), 3.3-
Nuclei of the dialkylindolenine series (e.g. 3,3-dimethylindolenine, 3,3-dimethyl-5-chloroindolenine, 3,3,5-trimethylindolenine, 3,
3,7-trimethylindolenine), pyridine series nuclei (e.g. pyridine, 5-methylpyridine), or benzimidazole series nuclei (e.g. 1-ethyl-5,6-dichlorobenzimidazole, l-hydroxyethyl-5
,6-dichlorobenzimidazole,! -Ethyl 5-
Chlorobenzimidazole, 1-ethyl-5,6-dipL1mobenzimidazole, 1-ethyl-5-phenylbenzimidazole, 1-ethyl-5-fluorobenzimidazole,! -Ethyl-5-cyanobenzimidazole,! -(β-acetoxyethyl)-5-cyanobenzimidazole, 1-ethyl-5-chloro-6-cyanobenzimidazole, 1-ethyl-5-fluoro-6-
Cyanobenzimidazole, l-ethyl-5-acetylbenzimidazole, l-ethyl-5-carboxybenzimidazole, l-ethyl-5-ethoxycarbonylbenzimidazole, l-ethyl-5-sulfamylbenzimidazole, 1-ethyl -5-N-ethylsulfamylbenzimidazole, l-ethyl-5,6-difluorobenzimidazole, l-ethyl-5,8-dicyanobenzimidazole, l-ethyl-5-ethylsulfonylbenzimidazole, 1-ethyl -5-methylsulfonylbenzimidazole, l-ethyl-5-trifluoromethylbenzimidazole, 1-ethyl-5-trifluoromethylsulfonylbenzimidazole, l-
ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.) R3 and R4 represent methyl, ethyl, propyl,
It represents an alkyl group such as butyl, and R3 and R4 can also form a ring such as morpholino, piperidinyl, pyrrolidino, etc. with the nitrogen atom. R5, H&, R
7 and P are hydrogen atoms, alkyl groups (methyl, ethyl,
(propyl, butyl, etc.), an alkoxy group (methoxy, ethoxy, 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 R6 to form a benzene ring.
8 can be combined with each other to form a benzene ring.

X is chloride ion, bromide ion, iodide ion, perchlorate ion, benzenesulfonate ion, P
-toluenesulfonate ion, methylsulfate ion,
represents an anion such as ethyl sulfate ion or propyl sulfate ion;
θ e-5O:+, 09O3, -CO
O, SO2NH-, -0O2-N-GO-1-502-
Contains N-3o, , - and is not present.

(2) represents a cation such as a hydrogen cation, sodium cation, ammonium cation, potassium cation, or pyridium cation. n and m are 0 or 1
It is.

Next, representative examples of the croconic methine dye used in the present invention are listed below, but for convenience, general formula [I] or [I
II] is represented by the betaine structure. However, in the preparation of these dyes, a mixture of dyes in betaine form or salt form is obtained, and therefore they are generally used as a mixture.

Typical example of general formula [+1, [IT] 0゜(11) o○(17)
ga→(18)
. (U(19) 0θ (20) Oθ(23)
. θ(24)
. e(25) O(E+(
26). θ(27)
. eUU Representative example of general formula [I[11, [■] (35) eO (3B) eO (37)e.

(38) e.

(39) e.

(4o) e.

The crocony-cumetine dyes (1) to (42) above are:
They can be used alone or in combination of two or more.

A typical configuration of the optical recording medium of the present invention is shown in FIGS. 1 and 2.
An example is shown in the figure. In the example shown in FIG. 1, a recording layer 2 consisting of a mixed monomolecular film of the OA compound 3 and the croconic methine dye 4 is formed on a substrate 1, and in FIG. It was established. Note that a protective layer (not shown) may be provided on the recording layer 2 if necessary.

As the substrate 1 of the optical recording medium of the present invention, various supporting materials such as glass, a plastic plate such as acrylic resin, a plastic film such as polyester, paper, and metal can be used. When performing recording, a material that transmits recording radiation of a specific wavelength is used.

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, Langmuir (1
The Langmuir e-prodget method (hereinafter abbreviated as LB method) developed by et al. In the LB method, when a molecule has a structure in which a parent wood group and a hydrophobic group are exposed, and the balance between the two (balance of amphiphilicity) is maintained appropriately, this molecule will expose the parent wood group on the water surface. This is a method of creating a monomolecular film or an accumulated film of monomolecular layers by utilizing the fact that the monomolecular layer is directed downward. When the monomolecular layer on the water surface has the characteristics of a two-dimensional system and zero molecules are sparsely dispersed, the two-dimensional ideal gas equation, nA=kT, is established between the area per molecule A and the surface pressure ■. , resulting in a "gas film", where k is Portzmann's constant and T is the absolute temperature. If A is made sufficiently small, the intermolecular interaction becomes strong and a two-dimensional solid "condensed film (or solid M)" is formed. 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 layer cumulative film has both a hydrophilic site and a hydrophobic site, and not all compounds are necessarily hydrophilic. A monomolecular layer is formed on the water surface, and as long as the amphipathic balance is maintained in at least one compound, a monomolecular layer is formed on the water surface, and other compounds are not required to have a hydrophobic group. The compound is sandwiched between amphiphilic compounds, and a monomolecular layer with molecular order is formed as a whole.

Using this method, a mixed monomolecular film or a mixed monomolecular cumulative film of a DA compound and croconic methine dye constituting the recording layer of the present invention is produced, for example, as follows.

First, an OA compound and a croconic methine dye are dissolved in a solvent such as chloroform, and this is developed on an aqueous phase to form a developed layer in which these compounds are developed into a film. A partition plate (or float) is installed to limit the area of the developed layer to prevent it from spreading too much and controlling the state of aggregation of these compounds, thereby obtaining a surface pressure n 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 up and down vertically while maintaining this surface pressure, a mixed monomolecular film of DA compound and croconic methine dye is transferred onto the substrate. A mixed monomolecular layer film is produced in this manner, and a mixed monomolecular layer cumulative film having a desired degree of accumulation is formed by repeating the above-mentioned operations.

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

When the substrate is moved up and down, the mixed monomolecular film is laminated one layer at each step.The direction of the film-forming molecules is reversed between the pulling step and the dipping step, so according to this method, the space between each layer is A Y-shaped film is formed in which the parent wood group and the hydrophobic group face each other.

On the other hand, the horizontal deposition method is a method in which the substrate is brought into horizontal contact with the water surface and transferred, and a monomolecular layer with the hydrophobic group of the OA compound facing the substrate is formed on the substrate. In this method, there is no change in the orientation of the IIA compound molecules even if they are accumulated, and an X-type film is formed in which the hydrophobic groups face the substrate in all layers.On the contrary, in all layers the parent groups are The cumulative film facing the substrate side is called a Z-type film.

The rotating cylinder method is a method in which a cylindrical substrate is rotated at the water surface to transfer a monomolecular layer onto the substrate surface.

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 accumulation formed on the substrate have a high density and a high degree of order, so the variation in light absorption depending on the location is extremely small. By configuring the recording layer with a film, a recording medium having a high-density, high-resolution recording function capable of optical recording and thermal recording can be obtained depending on the functions of the DA compound and the croconic methine dye.

The optical recording medium of the present invention allows various types of optical recording to be performed; however, by applying light or heat, the absorption wavelength of the recording layer changes and the apparent color changes. The recording mechanism using a semiconductor laser will be briefly explained below.

The OA compound is initially almost colorless and transparent, but when the recording layer is irradiated with ultraviolet rays, it polymerizes and changes into a polyacetylene derivative compound. This polymerization is caused by irradiation with ultraviolet rays, etc., and is not caused by simply applying thermal energy. As a result of this polymerization, the recording layer has a maximum absorption wavelength of 620 to 8BOr++s, and its color changes from blue to dark. . 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 polyacetylene derivative compound that has changed from blue to dark color is heated to about 50°C or higher, it now has a maximum absorption wavelength at about 54 degrees hazy.
Changes to a red film. This change is also an irreversible change.

Therefore, optical recording using the recording medium of the present invention is performed by the following mechanism.

First, when the entire recording layer of the recording medium of the present invention is irradiated with ultraviolet rays, the DA compound 3 in the recording layer undergoes seven combinations and changes into a polyacetylene derivative compound, thereby changing the recording layer 2 into a blue to dark-colored film. As shown in the third leap,
When a predetermined position of this recording medium is irradiated with a semiconductor laser beam 6 with a wavelength of 800 to 850 nn+ that blinks in response to an information signal, the polyacetylene derivative compound does not absorb this laser beam 6, but the croconic methine dye in the recording layer 4 absorbs this laser beam 6 and generates heat.

The heat generated by this croconic methine dye 4 is transmitted to the adjacent polyacetylene derivative compound, changing the color to red. In this way, optical recording is performed by changing the color of the recording region 5 on the recording layer in accordance with the input information.

〔Effect of the invention〕

The effects of the recording medium of the present invention are listed below.

(1) Since the recording layer is formed of a mixed monomolecular film of an OA compound and a croconic methine dye or a cumulative film thereof, it has high density and a high degree of order, and therefore high density and homogeneous recording is possible. It is possible.

(2) Since the recording layer contains a croconic methine dye that absorbs light with a wavelength of 800 to 850 nm and generates heat, recording using a small and lightweight semiconductor laser is possible.

(3) Since it is possible to record using changes in the hue of the recording layer due to light irradiation, high-speed, high-sensitivity, and high-density optical recording can be performed.

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

Example 1 General formula C, 2n25-c=c-cmiC-C8Hl b-
1 part by weight of a diacetylene derivative compound represented by C0OH and 1 part by weight of the croconic methine dye represented by dye (1) above were mixed in chloroform with lXl0-3 mol/l.
! The solution was developed on an aqueous phase with a pH of 6.5 and a cadmium chloride concentration of 1X10-3 mol/l.

After removing the solvent chloroform, the surface pressure was reduced to 20 dyn.
While raising the temperature to e/c■ and keeping it constant, the glass substrate, which has been thoroughly cleaned and whose surface is hydrophilic, is gently moved up and down in the direction across the water surface at a vertical speed of 1.0 cs/min to remove the OA compound and the crocodile. A mixed monomolecular film with a nickmethine dye was transferred onto a substrate, and an optical recording medium was prepared in which a mixed monomolecular film and mixed monomolecular film grafts accumulated in 5R121 layer and 41 layer were formed on the substrate.

Example 2 An optical recording medium was prepared in the same manner as in Example 1, except that 2 parts by weight of the diacetylene derivative compound was used for 1 part by weight of the croconic methine dye.

Example 3 An optical recording medium was prepared in the same manner as in Example 1, except that the diacetylene derivative compound was used in an amount of 10 parts by weight per 1 part by weight of the croconic methine dye.

Example 4 An optical recording medium was prepared in the same manner as in Example 1, except that 15 parts by weight of the diacetylene derivative compound was used for 1 part by weight of the croconic methine dye.

Comparative Example 1 An optical recording medium was produced in the same manner as in Example 1, except that only a diacetylene derivative compound was used without using a croconic methine dye.

Comparative Example 2 A film with a thickness of 1500 mm was formed on a glass substrate by sputtering.
A radiation absorption layer made of Gd·τb@Fe of A was provided. Using this substrate, an optical recording medium was prepared in which a monomolecular film or a monomolecular cumulative film of a diacetylene derivative compound was formed on the radiation absorbing layer in the same manner as in Comparative Example 1.

Recording Test 1 The optical recording media prepared in Examples 1 to 4 and Comparative Example 1.2 were uniformly and sufficiently irradiated with 254 nm ultraviolet rays, and the recording layer was made into a blue film, 0th order output 3IIW, wavelength 830 nm,
A semiconductor laser beam with a beam diameter of 1 μs was irradiated at a predetermined position on the surface of each optical recording medium according to manual information (irradiation time 200 ns/1 bit) to form a red recorded image on the blue recording layer.

The evaluation of the recording results is shown in Table 1. The evaluation was based on the quality of the recording sensitivity, image resolution and image tC, with 0 being particularly good, O being good, and X being unable to record or being poor.

Comparative Example 3 The same procedure as in Example 1 was carried out using a solution prepared by dissolving 3 parts by weight of croconic methine dye and 1 part by weight of nitrocellulose in 11 parts by weight of methylene chloride without using a diacetylene derivative compound. The thickness of the recording layer is 200 mm depending on the method.
An optical recording medium for 0 was created.

Recording Test 2 Recording Test 1 was repeated except that the irradiation time of the semiconductor laser beam was variously changed (irradiation time 100 to 800 ns/1 bit) to the optical recording medium having the 21-layer mixed monomolecular cumulative film prepared in Example 2. Recording was performed using the same procedure as above. Regarding the optical recording medium of Comparative Example 3, a semiconductor laser beam was directly applied to the surface of the recording layer at a predetermined position on the surface of the optical recording medium with the same output according to the input information, and the irradiation time was changed in various ways without performing ultraviolet irradiation. Irradiation to crab (irradiation time 500ns
~5 S/l bits) and recording was performed by forming pits.

For the optical recording medium of Example 2, the irradiation time was 200
Particularly good recording was achieved when the irradiation time was ns or more, but as a result of microscopic observation of the optical recording medium prepared in Comparative Example 2, it was found that an irradiation time of 2 gs or more was required to clearly form one bit. It turned out that it was necessary.

Example 5 General formula C1□H2s-(:= c-c= C-Cs H
+ 6- Instead of the diacetylene derivative compound represented by C0OH, the general formula C5H17-C=C-C=C-C2
An optical recording medium was prepared in the same manner as in Example 1 except that H4-COOH was used.

Examples 6 to 14 Dye N6 (12), (23), (28) in place of the croconic methine dye represented by Dye N6 (+)
, (31), (3B).

(37), (39), (40) and (42)
Optical recording media were prepared in the same manner as in Example 1, except that croconic methine dyes represented by the following were used.

Recording Test 3 A recording test was conducted in the same manner as Recording Test 2 using the optical recording media prepared in Examples 5 to 14. The evaluation of this recording result is shown in Table 2.

Table 2

[Brief explanation of drawings]

1 and 2 are schematic cross-sectional views illustrating the configuration of a first optical recording medium of the present invention, and FIG. 3 schematically shows an optical recording method using the first optical recording medium of the present invention. It is a schematic cross-sectional view. 1: Substrate 2: Recording layer 3 Nidiacetylene derivative compound 4: Croconic methine dye 5: Recording site 6: Laser beam patent development

Claims (1)

[Claims] 1) An optical recording medium characterized by having a recording layer comprising a mixed monomolecular film of a diacetylene derivative compound having at least a hydrophilic site and a hydrophobic site and a croconic methine dye, or a cumulative film thereof. .