JPS6349489A - Optical recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical recording medium capable of high-speed high- density recording with high sensitivity, by providing a recording layer comprising a mixed monomolecular film, or a build-up film thereof, of a diacetylene derivative compound and a square arylium dye. CONSTITUTION:A recording layer 2 comprising a mixed monomolecular film, or a build-up film thereof, of a diacetylene derivative (DA) compound 3 and a square arylium dye 4 is provided on a base 1. The base 1 of this optical recording medium may be constituted of a glass, a plate of a plastic such as an acrylic resin, a film of a plastic such as a polyester, a paper, a metal or the like. When the recording medium is irradiated at predetermined positions with a semiconductor laser beam 6 of a wavelength of 800-900nm which is turned ON and OFF according to an information signal, the polyacetylene derivative compound does not absorbs the laser beam 6, but the square arylium dye 4 absorbs the laser beam 6 to generate heat. The heat is transmitted to the adjacent polyacetylene derivative compound, whereby a color change to red is brought about, resulting in optical recording through the color change at record parts 5 on the recording layer according to input information.

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 are being considered for future disks, 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 in laser recording elements was disclosed in Japanese Patent Laid-Open No. 56-147807. 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 laser recording of this diacetylene derivative compound using various lasers, and found that although thermochromic recording is possible using a large, high-output laser such as an argon laser, a small and relatively It has been confirmed that laser recording cannot be performed when a low-output semiconductor laser (wavelength: 800 to 900 nm) is used. However, for a practical recording medium such as an optical disk, optical writing is required to be possible using a small, low-output semiconductor laser.

On the other hand, JP-A-58-217558 and JP-A-58-
No. 220143 discloses square lyllium dyes, and it was discovered that organic films containing these dyes absorb radiation in the semiconductor laser radiation wavelength range and generate heat, making it possible to perform so-called heat mode recording in which bits are formed using laser energy. Disclosed. However, when performing recording by forming physical pits on the surface of a recording medium, a relatively large amount of energy is required, and it is relatively difficult to perform high-density and high-speed recording.

In addition, the recording layer of these recording media is made up of microcrystals of diacetylene derivative compounds or square lylium dyes dispersed in a binder, and the orientation of these compounds within the recording layer is random, so the locations vary. This led to phenomena such as differences in light absorption and reflectance, as well as differences in the degree of chemical reactions, and were not necessarily suitable for high-density recording.

[Problems to be Solved by the Invention] 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. It is about providing.

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 problems]

That is, the optical recording medium of the present invention has 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 square aryllium dye, or a cumulative film thereof. It is characterized by

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

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

The alkyl group represented by H(CI+2) forming the hydrophobic site 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, the squarelylium dye used in the present invention is a compound (including an inner salt) having a substituent containing the following basic structure heterocycle, and has 750
It is a compound that has an absorption peak in the nm range or below and generates heat when exposed to infrared light of this wavelength. As the square aryllium dyes, dyes represented by general formulas [I] to [IV] are typically exemplified.

-(lυ[,[1,) 艺(之代[+1 こし.eMe
For example, methyl group, ethyl group, n-propyl group, 1so
-propyl group, n-butyl group, 5ec-butyl group, 1s
o-butyl group, shi-butyl group, n-amyl group, shi-amyl group, n-hexyl group, n-octyl group, L-octyl group, etc.), substituted alkyl groups (e.g. 2-hydroxyethyl group, 3- Hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group,
2-carboxyethyl group, 3-carboxypropyl group,
2-sulfoethyl" group, 3-sulfopropyl group, 4-sulfobutyl group, 3-sulfatepropyl group, 4-sulfatebutyl group, N-(methylsulfonyl)-carbamylmethyl group, 3-(acetylsulfamyl) ) propyl group, 4-(acetylsulfamyl)butyl group, 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 represents a group (eg, phenyl group, etc.) or a substituted aryl group (eg, carboxyphenyl group, sulfophenyl group, hydroxyphenyl group, etc.). especially,
In the present invention, hydrophobic residues are preferred among these residues.

Substituted or unsubstituted heterocycles, e.g. thiazole series nuclei (e.g. thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-
diphenylthiazole, 4-(2-chenyl)-thiazole, etc.), benzothiazole series nuclei (e.g. benzothiazole, 5-chlorobenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5,
6-dimethylbenzothiazole, 5-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5
．． 6-Simethoxybenzothiazole, 5,6-cyoxymethylenehenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 4,5.6
．． 7-titrahydropenzothiazole, 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 [7,5-d]
Thiazole series nuclei (e.g. 7-medoxythionaphthene[7,6-d]thiazole), oxazole series nuclei (e.g. 7-medoxythionaphthene[7,6-d]thiazole),
For example, e-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-dimethylhendioxazole, 5-dimethoxybenzoxazole, 6-medoxybenzoxazole, 5-hydroxybenzoxazole , 6-hydroxybenzoxazole, etc.), naphthoxazole series nuclei (e.g. naphtho[2,1-d]oxazole, naphtho[1,2-d]oxazole, etc.)
, selenazole series nuclei (e.g. 4-methylselenazole, 4-phenylselenazole, etc.), benzoselenazole series nuclei (e.g. benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole,
5.6-dimethylbenzoselenazole, 5-methoxybenzoselenazole, 5-methyl-6-methoxybenzoselenazole, 5.6-cyoxymethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4.5, 6
．． 7-titrahydrobenzoselenazole), naphthoselenazole series nuclei (e.g. nando(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), l-inquinoline series nuclei (e.g. isoquinoline, 3,4-dihydroisoquinozone), 3-inquinoline series nuclei (e.g. inquinoline), 3,3-dialkylindolenine series nuclei (e.g. 3,3-dimethylindolenine, 3,3-dimethyl-5-chloroindolenine, 3,3,5-trimethylindolenine, 3,3,7-trimethylindolenine), pyridine series nuclei (e.g. pyridine, 5-methylpyridine), hensiimidazole series nuclei (e.g. 1-methylpyridine),
Ethyl-5,B-dichlorobenzimidazole, 1-and droxyethyl-5,6-dichlorobenzimidazole, ■-ethyl-5-chlorobenzimidazole, 1-ethyl-5,6-dibromobenzimidazole, 1-ethyl-5- Phenylbenzimidazole, 1-ethyl-5
-Fluorobenzimidazole, 1-ethyl-5-cyanobenzimidazole, ■-(β-acetoxyethyl)
-5-cyanobenzimidazole,]-]ethyl-5-
Chloro-6-diatubenzimidazole l-ethyl-5
-Fluoro-6-cyanobenzimidazole, l-ethyl-5-acetylbenzimidazole, 1-ethyl-5
-carboxybenzimidazole, l-ethyl-5-ethoxycarbonylbenzimidazole, 1-ethyl-5
-Sulfamylbenzimidazole, 1-ethyl-5-
N-ethylsulfonylbenzimidazole, 1-ethyl-5,6-difluorobenzimidazole, 1-ethyl-5,6-dicyazbenzimitazole, l-ethyl-5-ethylsulfonylbenzimidazole, ■=ethyl-5 -methylsulfonylbenzimidazole, ■=ethyl-5-trifluoromethylbenzimidazole, l
-ethyl-5-trifluoromethylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.) × represents chloride ion, bromide ion, iodide ion, perchlorate ion, benzenesulfonate ion, p-toluenesulfonate ion, methyl sulfate-r ion, ethyl sulfate ion, propyl sulfate ion represents an anion such as, X is R1
and/or R2 itself is an anionic group, e.g. -503, -0SO
3.■ Does not exist when it is included. M represents a cation such as a hydrogen cation, a sodium cation, an ammonium cation, a potassium cation, or a pyridium cation. n and m are 0 or l.

In general formula (II[) (rV), R3o, l- and R4
represents an alkyl group such as methyl, ethyl, propyl, butyl. Further, R3 and R4 can also form a ring such as morpholino, piperidinyl, or pyrrolidino together with the nitrogen atom. R5, R6, R7 and R8 are hydrogen atoms, alkyl groups (methyl, ethyl, propyl, butyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy,
(butoxy, etc.) or bitroxy group. Furthermore, R'' and R6 can be combined to form a benzene ring, and R5 and R6 can be combined with R7 and R8, respectively, to form a benzene ring.

Next, typical examples of the square aryllium dye used in the present invention are listed below, but for convenience, general formula [I] or [I
It is expressed in the form of a betaine structure of I[]. 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 of general formula [13, [rrl (2)　　　　　　　　　　.

(3)　　　　　　　　　　.

(4)　　　　　　　　.

■ (7).

(8).

(9)　　　　　　　　　　.

(lO)　　　　　　　　　.

(11)　　　　　　　　　.

(+3) On (+4) Q(+5)
0 (1B)
0(IT) (3(1)
8).

(19) O(21)
O general formula [I11],'
[Representative Examples of IVl The squarelillium dyes (1) to (42) above 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 DA compound 3 and the square aryllium dye 4 is formed on a substrate 1, and in FIG. 2, a stiff mixed monomolecular cumulative film is formed. 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-Prodgett method (hereinafter abbreviated as LB method) developed by Langmuir et al. In the LB method, when a produced molecule has a parent wood group and a hydrophobic group in the molecule, and the balance between the two (amphiphilic balance) is maintained appropriately, this molecule lowers the parent wood group on the water surface. This is a method of creating a monolayer film or a film with m molecular layers, by utilizing the fact that it becomes a monomolecular layer directed toward . 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.

Furthermore, a so-called mixed m-molecular film or a 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 group. 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 compound D and square lylium dye constituting the recording layer of the present invention is produced, for example, as follows. First, a DA compound and a square lium 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 spread layer from spreading freely on the water phase and spreading too much, a partition plate (or float) is provided to limit the area of the spread layer and control the aggregation state of these compounds. Obtain a proportional surface pressure ■. By moving this partition plate, the developed area can be reduced to control the aggregation state of the film material, and the surface pressure can be gradually increased to set a surface pressure n suitable for producing a cumulative film. By gently moving the clean substrate vertically up and down while maintaining this surface pressure, a mixed monomolecular film of the DA compound and the square aryllium dye is transferred onto the substrate. A mixed monomolecular layer film is produced in this manner, and a mixed monomolecular layer cumulative film having a desired degree of accumulation is formed by repeating the above-mentioned operations.

In order to transfer the monomolecular film onto the substrate, in addition to the above-mentioned vertical dipping method, methods such as horizontal deposition method and rotating cylinder method can be employed. 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 across the water surface, a monomolecular layer with the parent group of the compound facing the substrate is formed on the substrate. be done.

As the substrate is moved up and down, one layer of the mixed monolayer 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 in which the parent wood group and the hydrophilic group and the hydrophobic group and the hydrophobic group face each other between each layer.

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

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

The method of transferring the monomolecular layer onto the substrate is not limited to these methods, and when using a large-area substrate, a method of extruding the substrate from a substrate roll into an aqueous phase may also be used.

Furthermore, the orientation of the aforementioned parent wood group and hydrophobic group toward the substrate is a general rule, and can be changed by surface treatment of the substrate, etc.

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

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

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 occurs by irradiation with ultraviolet rays, etc., and does not occur simply by the application of thermal energy. As a result of this polymerization, the recording layer 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;
- The recording layer that has changed from blue to dark color does not return to a colorless transparent film. Furthermore, when this polyacetylene derivative compound that has changed to blue or dark color is heated to about 50° C. or higher, it now has a maximum absorption wavelength of about 540 r+m and 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 polymerizes and changes into a polyacetylene derivative compound, thereby changing the recording layer 2 into a blue to dark-colored film. Then, as shown in Figure 3,
When a predetermined position of this recording medium is irradiated with a semiconductor laser beam 6 with a wavelength of 800 to 900 nm that blinks in response to an information signal, the polyacetylene derivative compound does not absorb this laser beam 6, but the square aryllium dye 4 in the recording layer This laser beam 6 is absorbed and heat is generated. The heat generated by the square lyllium 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 square aryllium dye or a cumulative film thereof, it has high density and a high degree of order, thus enabling high density and homogeneous recording. It is.

(2) Since the recording layer contains square aryllium dye that absorbs light with a wavelength of 800 to 900 r+m 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,2)+25-CEC-CmiC-CB)(16
1 part by weight of a diacetylene derivative compound represented by -(:001() and 1 part by weight of the above dye, a square lylium dye represented by /L(1), were dissolved in chloroform at 1
3 moles/! The solution was developed on an aqueous phase with a p)I of 6.5 and a cadmium chloride concentration of 1xlO'mol/l. After removing the solvent chloroform, the surface pressure was increased to 20 dyne/cm and kept constant, and the glass substrate, which had been thoroughly washed and whose surface had become hydrophilic, was moved at a vertical speed of 1.0 cm/min in the direction across the water surface. The mixed monomolecular film of the DA compound and square lium dye was transferred onto the substrate by gently moving it up and down.
Optical recording media were prepared in which mixed monomolecular cumulative films of one layer and 41 layers were formed on a substrate.

Example 2 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 2 parts by weight per 1 part by weight of the square aryllium 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 squareylium dye.

Example 4 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 15 parts by weight per 1 part by weight of the square thulium 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 squareylium dye.

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

Recording Test 1 The optical recording media prepared in Examples 1 to 4 and Comparative Example 1.2 were uniformly and sufficiently irradiated with 254r++n ultraviolet rays to turn the recording layer into a blue film. Next, the output is 3mW and the wavelength is 830nm.
A semiconductor laser beam having a beam diameter of ip was irradiated onto 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. Evaluation is based on recording sensitivity, image resolution, and image density.
Particularly good results are marked as ◎, good results are marked as ○, and those that cannot be recorded or are defective are marked as ×.

Table 1 Comparative Example 3 A solution prepared by dissolving 3 parts by weight of square aryllium dye and 1 part by weight of nitrocellulose in 11 parts by weight of methylene chloride was used as a coating solution, without using a diacetylene derivative compound, and as in Example 1. The thickness of the recording layer was 2000 mm by the same method.
Recording test 2 in which a human optical recording medium was created The irradiation time of the semiconductor laser beam was variously changed for the optical recording medium having the 21-layer mixed monomolecular cumulative film created in Example 2 (irradiation time ioo ~ 800 ns/ Recording was performed in the same manner as in Recording Test 1, except that 1 bit) was used. 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 on the top (irradiation time 50
0 ns to 5 μS/1 bit), and recording was performed by forming pits.

For the optical recording medium of Example 2, the irradiation time was 200
A particularly good record for ns or more, or real JJ&, but
As for the optical recording medium prepared in Comparative Example 2, as a result of microscopic observation, it took 2 μs to clearly form one bit.
It was found that the irradiation time was longer than that required.

Example 5 General formula C,2H2s-CE C-1j C-C3H,6
In place of the diacetylene derivative compound represented by -00011, the general formula C8H,7-CE (nee CEC
An optical recording medium was prepared in the same manner as in Example 1 except that 4-C00H was used.

Examples 6 to 9 In place of the square lyllium dye represented by Dye Makoto (1),
Optical recording media were prepared in the same manner as in Example 1, except that square aryllium dyes represented by /FL(23), (31), (37), and (42) were used, respectively.

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 9. The evaluation of this recording result is shown in Table 2.

Table 2

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views illustrating the structure of the optical recording medium of the present invention, and FIG. 3 is a schematic cross-sectional view schematically illustrating the optical recording method using the optical recording medium of the present invention. It is a diagram. 1: Substrate 2: Recording layer 3 Nidiacetylene derivative compound 4: Square aryllium dye 5: Recording region 6: Laser beam

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 squarerylium dye, or a cumulative film thereof.