JPS6283190A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical information recording medium having high reflectivity and high recording sensitivity and showing high stability to high humidity and generating no public nuisance, by providing a recording layer containing an org. dye represented by a specific formula. CONSTITUTION:The dye contained in a recording layer is represented by formula (I) [wherein R1 and R2 are hydrogen, halogen or an alkyl group, R3 is an alkyl group or a phenyl group, X is iodine, chlorine or bromine, Y is an alkyl group, -R4OH or -R4COOH, m is an integer of 1 or 2, Z is -CN or -OCF3 when m is 1 and an alkyl group or a halogen atom when m is 2 and n is an integer of 0-2. Z is desirably an electron withdrawing group such as -CN, -OCF3 or -(Cl)2 from the viewpoint especially enhancing the optical or chemical stability of the dye].

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to writing using a radar, particularly a semiconductor radar,
The present invention relates to an optical memory medium on which playback and recording are performed.

[Prior art and problems]

In general, optical dinuks store high-density information by forming optically detectable small (e.g., approximately 1 μm) pits formed in a thin film recording layer provided on a substrate in the form of a spiral or circular track. I can do it. To write information on such a disk, a focused radar beam is scanned over the surface of the radar-sensitive layer, and bits are formed only on the surface that is irradiated with the radar beam. It is formed in the form of , ri, etc. This sensitive layer can absorb laser energy to form optically detectable pits. For example, in the heat mode recording method, the recording layer absorbs laser energy, and the irradiated area is locally heated, causing physical changes such as melting, evaporation, or aggregation, resulting in an optical difference (X reflectance) between the recording layer and the non-irradiated area. , absorption rate, etc.) and read them.

As such optical recording media, inorganic materials such as metal thin films such as aluminum vapor-deposited films, bismuth thin films, tellurium-based thin films, and chalcogenide-based amorphous glass films have been proposed.

These have the advantage that thin films can be obtained by vapor deposition, sputtering, etc., and semiconductor radars can be used because they absorb light even in the near-infrared region, but on the other hand, they have high reflectance, high thermal conductivity, and high specific heat. There is a drawback. In particular, when the reflectance is high, the energy of the Raded light cannot be used effectively, so the optical energy Z1 required for recording becomes large, and a high-output Raded light source is required. As a result, the recording apparatus becomes large and expensive. In addition, thin films of tellurium, bismuth, selenium, etc. have a drawback of being toxic.

For these reasons, research proposals have recently been made on optical memory media that use dye thin films as recording layers because they allow selection of absorption properties, have high absorption rates, low heat conduction, good productivity, and low toxicity. It is coming. Typical dyes include cyanine dyes (JP 58-112790), anthraquinone dyes (JP 58-224448), naphthoquinone dyes (JP 58-224793), and 7-talocyanine dyes (JP 58-224793). -48396), etc., and is an optical recording medium in which a compound consisting of these alone or in combination with a self-oxidizing resin is formed on a substrate by a spinner coating dipping method, a gradama method, a vacuum evaporation method, or the like.

This dye thin film system has the above-mentioned advantages, and in particular, cyanine-based dyes are structurally capable of having an absorption wavelength in the near-infrared, are dust free, and have O advantages such as low solubility in solvents and low melting points, so they are often used. It is being considered. On the other hand,
It has been said that there are problems with long-term storage and playback stability (stability against readout light) due to light deterioration, instability with heat, and humidity deterioration. A proposal has been proposed. Specifically, a protective film is provided on the recording layer (Japanese Unexamined Patent Publication No. 55-22961).

57-66541), mixing a substance that prevents discoloration due to oxygen (JP-A-59-55795), and forming a metal complex that absorbs light in the long wavelength range (JP-A-59-21).
5892) etc. have been proposed. However, these proposals do not sufficiently solve the problem, and furthermore, problems arise in that the additives cause a decrease in film formability, reflectance, and absorbance.

For these reasons, a coating type recording medium using a cyanine dye represented by the following general formula is attracting attention from the viewpoint of recording density and reflectivity.

[However, in the formula, A is O, S, S*, C, However, they also have the essential problem of lacking film-forming properties and heat-light stability. Regarding film formability, the number of methine chains (n)
It is known that the solubility in a solvent decreases with an increase in the number, and that the solubility varies depending on the type of heterocycle at both ends and the type of substituent. Regarding thermophotostability, it is known that as the number of methine chains increases, it becomes more unstable to heat and light, and oxidative degradation is more likely to occur, and that the stability to heat and light differs depending on the type of heterocycle. It is being

The present invention was developed in view of the above circumstances, and has high reflectance and high recording sensitivity, enables stable writing and reproduction of optical signals, and is capable of handling light and sunlight during reproduction.
The present invention aims to provide a pollution-free optical information recording medium that is highly stable against humidity.

[Means and effects for solving the problems] The present invention has the following features:
General formula (ph: phenyl group), R3 is an alkyl group having 1 to 6 carbon atoms, an aralkyl group, a phenyl group, X is berchlorate,
Fluoroplate, iodide, chloride, bromide, p-toluenesul 7-R4C0OH, -R40R
5, -1t4COR5, -R4COOR5, R5: alkyl group having 1 to 18 carbon atoms), m is an integer of 1 or 2, and 2 is -R60H when m = 1.

-R6CN, =ORa, -OH, -COOH, -CO
R,, phenyl group, -CN, -0CF3, -0SF3,
-NH2N(R,)2, -NHcOR,, group, preferably an alkyl group having 1 to 10 carbon atoms, R7: 1 to 18 carbon atoms
an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms or a phenyl group), and in the case of m = 2, an alkyl group having 1 to 10 carbon atoms
is an alkyl group or a halogen atom, n is O or an integer of 1 or 2.

Durability compared to organic dyes whose structure is only methine chains,
A recording layer with excellent light resistance, environmental resistance, and playback deterioration characteristics can be formed. R1 and R2 of the cyclo ring are as described above, but chlorine, bromine or a furkyl group having 1 to 3 carbon atoms are particularly preferred.

However, by introducing a cyclo ring into the methine chain,
Since the solubility of the dye in the solvent is slightly reduced, the solvent is limited and it becomes difficult to form a uniform film.

Therefore, the organic dye of the present invention has -OH as z in the benzene ring constituting the indole.

By introducing substituents such as -COOH, -COR, etc., it is possible to control the dye tip, chemical stability, and maximum absorption wavelength, and also to improve solvent solubility and film formability. The above 2 is
As already mentioned, -CN, -0CF, -(c))2, especially from the viewpoint of improving the light and chemical stability of the dye.
It is desirable to use an electron-withdrawing group such as Also,
Regarding the substitution position on the benzene ring of 2, the 5th position is most preferable for monosubstitution, but any of the 4, 6, and 7 positions are possible. - VC that improves strength, solvent solubility, and film formability is desirable as 2, but is preferably selected in consideration of the substituent (2) to be introduced into indole.

In addition, the organic dye used in the present invention is a 14-structure in which the above-mentioned i:'r and substituent (7) are introduced into indole, but it is preferable to introduce it, taking into consideration film formability and solvent solubility. In this case, -COOH1-COOR5, -R4 as Y
COOR5, -R40R5 are desirable.

As mentioned above, the organic dyes having the structure in which the above-mentioned substituents are introduced are disclosed in Japanese Patent Application Laid-open Nos. 59-150795 and 58-194595.
Compared to the unsubstituted dye with the following structural formula disclosed in the issue, it has superior light and chemical stability, solvent solubility, and film formability. Reduction of noise components in reproduced signal waveform due to defects, environmental resistance,
An optical information recording medium with improved reproduction deterioration characteristics can be obtained.

Specific examples of the dye represented by the above general formula include:
Examples include those shown in Structural Formulas (1) to eM below.

---(1') ---(Riichi--CG) ---("7) Eleven-(wa---(+05 ---(+3)) ---(+Ri---( +7) ---(+Ten) A recording layer containing a dye represented by the above general formula can be prepared by dissolving the dye in a solvent such as ethyl acetate, toluene, acetone, methyl isobutyl ketone, methylene chloride, alcohol, etc., and applying a spinner method. It is obtained by forming a thin film on a substrate using a dipping method, a doctor blade method, a roll coater method, etc.The thinner the thickness of this recording layer, the higher the recording sensitivity, but the reflectance depends on the film thickness. Therefore, 10nm
~11000n, preferably 30nm to 500nm is suitable. Further, as the substrate, commonly used materials such as glass, plastic, metal, etc. can be used, but films of acrylic resin, polycarnate, polyolefin, polyester, and polyimide may also be used.

The recording layer is formed by the method described above. Furthermore, by adding 1 to 40% by weight, preferably 3 to 20 times, of a binder resin to the dye, a film can be formed, and the film formability, heat resistance, and moisture resistance can be improved. Examples of the binder resin used here include acrylic, ester, nitrocellulose, ethylene, propylene, and
Examples include homopolymers of 4-)', ethylene terephthalate, epoxy, butyral, vinyl chloride, vinyl acetate, styrene, and copolymers thereof.

In addition, by mixing other dyes in place of the binder resin or creating a multilayer structure in which dye layers are stacked, film formability, heat resistance, and moisture resistance can be improved.

The light resistance can be improved, and an optical information recording medium with high density, high sensitivity, and excellent durability without reproduction deterioration etc. can be obtained. In this case, it is also possible to layer other dyes to improve heat resistance, moisture resistance, and light resistance. Examples of the dyes used here include cyanine dyes, merocyanine dyes, anthraquinone dyes, triphenylmethane dyes, xanthine dyes, and phthalocyanine dyes.

For example, amine compounds represented by the following general formulas (4) and (B) or notothiolate metal complexes represented by the following general formula (C) are added to prevent deterioration of the optical properties of the recording layer due to light, oxygen, and moisture. It is also possible to do so.

However, R11R21R41R5 in the formula has 1 to 6 carbon atoms, and R represents an alkyl group having 1 to 6 carbon atoms.

......(8) However, R in the formula is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X is an anion such as a perchlorate ion, a fluoroborate ion, a hexafluoroate ion, m is O or an integer of 1 or 2; A is the above-mentioned m=o, 1 (both are Nippon Kayaku Co., Ltd. dyed surface product names), and so on.

However, R1-R4 in the formula is an alkyl group or a phenyl group,
X, Y are hydrogen, alkyl group, halogen group, M is NI,
This indicates metals such as Co, Fe, and Cr.

For example, as such four gold FA bodies, [PA1001-10
06 (both are Mitsui Toatsu Fine Co., Ltd. dyed surface product names), N
-bis(0-xylene-4,5-nol)tetra(t-
butyl) ammonium salts, etc.

In addition to the recording layer containing the dye of the above general formula, an intermediate layer and a protective layer may be provided as necessary. The intermediate layer is provided for the purpose of improving adhesion and protecting from oxygen and moisture, and is mainly formed from a resin or an inorganic compound. Examples of the resin include t[vinyl chloride, vinyl acetate, acrylic,
Single or copolymers of ester, nitrocellulose, carbonate, epoxy, ethylene, propylene, butyral, etc. can be used, and if necessary, antioxidants, ultraviolet light absorbers, leveling agents, water repellents, etc. are included. It is possible to do so. These are formed by a spinner method, a dipping method, or a doctor grade method. Examples of inorganic compounds include SIOSIO, AJ20. .

2g SnO, MgF'2, etc. are used, and a thin film is formed by an ion beam, an electron beam, or a sputtering method.

The protective layer also has the same structure as the intermediate layer, and is used to protect the recording layer from light, oxygen, and moisture, and from scratches, dust, and the like.

Next, a configuration example of the optical information recording medium of the present invention will be described with reference to the drawings.

FIG. 1 shows the basic structure of an optical information recording medium, in which a recording layer 2 containing a general formula dye is provided on a substrate. Recording and reproduction are performed by condensing the laser beam 3 onto the recording layer 2 using a condensing lens into a spot having a size of 0.8 to 1.5 μm. The radar light 3 for recording and reproduction may be irradiated from the recording layer 2, but when the substrate 1 is made of a transparent material, it is generally better to irradiate from the substrate 1 side to reduce the influence of dirt and dust.

FIG. 2 shows a structure in which an intermediate layer 4 is provided between the substrate 1 and the recording layer 2, and a protective layer 5 is provided on the recording layer 2.

In FIG. 3, two media with the same configuration are arranged so that the recording layers 2 face each other. 6.

In addition, 7 in FIG. 3 is an air gap, and 8 is a spindle hole. According to this configuration, the characteristics are good,
Furthermore, it has the advantage that the influence of dirt and dust on the recording layer 2 can be suppressed.

Furthermore, in the configurations of FIGS. 1 to 3 described above, the AU
, Ag, or other reflective films may be provided between the substrate and the recording layer.

[Embodiments of the invention]

Examples of the present invention will be described in detail below.

Example 1 As described above. The dye of structural formula (1) was dissolved in methyl ethyl ketone to form a 2-thi solution, which was coated onto a 1.2 mm thick glass substrate using a spinner coater and dried to form a 75 nm thick recording layer. A recording medium was produced.

Example 2 The dye of structural formula (5) described above was dissolved in methylene chloride,
After making a 2% solution, it was coated with a spinner coater to a thickness of 1.
A recording medium was manufactured by coating and drying on two glass substrates to form a recording N having a thickness of 80 nm.

Example 3 The above-mentioned dye of structural formula 07) was dissolved in methylene chloride to make a 2-layer solution, which was then coated with a spinner coater to a thickness of 1.5 mm.
A recording medium was manufactured by coating and drying on two glass substrates to form a recording layer with a thickness of 70 nm.

Example 4 The dye with the structural formula Qυ described above was dissolved in methylene chloride, and 2
% solution, this was coated with a spinner coater to a thickness of 1.2%.
A recording layer having a thickness of 65 nrn was formed by coating and drying on a glass substrate of 65 nrn to produce a recording medium.

Example 5 An acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd.: Dianal BR-) as a binder resin was added to the dye of structural formula (2) described above.
60) was added and dissolved in methyl ethyl ketone to make a 3% solution.The solution was coated on a 1.2 mm thick glass substrate using a spinner coater and dried to form a 95 nm thick glass substrate. A recording medium was manufactured by forming a recording layer.

Implementation 916 The dye having the structural formula Oq described above and an infrared absorber (trade name: IRG-003, manufactured by Nihon Kapaku Co., Ltd.) were mixed at a weight ratio of 3:1, and this was dissolved in methyl ethyl ketone to obtain 1
After making a 0% solution, this solution was applied onto a glass substrate with a thickness of 1.2 mm using a spinner coater, and dried to a thickness of 80 nm.
A recording medium was manufactured by forming a recording layer.

Example 7 The above-mentioned dye with the structural formula α→ and the dye with the following structural formula and 'i[
They were mixed in a quantitative ratio of 2=1, dissolved in the same manner as in Example 1, applied onto a substrate, and dried to form a recording layer with a thickness of 75 nm to produce a recording medium.

Example 8 Structural formula (1
) After forming a recording layer with a thickness of 60 nm consisting of a dye of Comparative Example 1 A dye having the following structural formula (1) was dissolved in methylene chloride to form a 2-layer solution, and this solution was coated with a spinner coater to a thickness of 1.5 nm.
Coated on a 2H glass substrate and dried to a thickness of 80 nm.
A recording layer was formed to produce a recording medium.

Comparative Example 2 A dye having the following structural formula (n) was dissolved in the same manner as in Comparative Example 1, coated on a glass substrate, and dried to form a recording layer with a thickness of 70 nm to produce a recording medium.

Comparative Example 3 A dye having the following structural formula ([l)] was dissolved in the same manner as in Comparative Example 1, coated on a glass substrate, and dried to form a recording layer with a thickness of 70 nm to produce a recording medium.

Comparative Example 4 A dye having the following structural formula was dissolved in the same manner as in Comparative Example 1, coated on a glass substrate, and dried to form a recording layer with a thickness of 70 nm to produce a recording medium.

For the recording layers of the recording media of Examples 1 to 8 and Comparative Examples 1 to 4, the reflectance of light with a wavelength of 830 nm was measured from the recording layer side using a spectrophotometer. Furthermore, the absorbance of each recording layer to light having a wavelength of 830 nm was measured. Furthermore, semiconductor radar light with a wavelength of 830 nrn was focused on a nupot with a diameter of 1.2 μm so that the medium surface output was 4 mW, and the focused radar light was moved from the substrate side of each recording medium at a speed of 9 m/sec. Write under the conditions,
Reproduction was performed using the same radar light at a reproduction output of 0.4 mW, and the recording sensitivity (recording energy threshold) and the φ value of the reproduction signal were measured. Furthermore, the recording media of Examples 1 to 8 and Comparisons N1 to 4 were left at 50° C. in a 95% atmosphere for 150 hours,
A heat-humidity resistance test was conducted to measure the absorbance decrease rate and reflectance decrease rate before and after standing. Each recording medium was irradiated with 500 W tungsten light (t-50 cut) for 100 hours in an atmosphere of 25°C and 60 inches, and a light emission test was conducted to measure the absorbance reduction rate and reflectance reduction rate before and after irradiation with tungsten light. . These results are shown in the table below.

〔Effect of the invention〕

As detailed above, the present invention has high reflectance and high recording sensitivity, enables stable writing and reproduction of optical signals, and has low stability against reproduction light, sunlight, and humidity. A highly pollution-free optical information recording medium can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are schematic diagrams showing optical information recording media of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording layer, 3... Rade light, 4
... Intermediate layer, 5... Protective layer, 6... Spacer. Applicant's agent Patent attorney Tsuboi Ukitsutsu 1 Leap 2 Figure 3 Procedure net 1''i Roni's letter January 60, 1985 Wait 1;'1 Office Commissioner Kuro 1) Mr. Akira Yu - Indication of the case Patent application No. 60-224394 - Name of the invention Optical information recording medium - Relationship to 111 cases of people who straighten their sleeves Patent applicant (037) Olympus Optical Industry Co., Ltd., Agent 3-7-2 Kasumikaseki, Chiyoda-ku, Tokyo UBE building 6,
Ura IE Subject Specification 7, Contents of Amendment (1), page 3, line 17 of the specification, "(ex reflectance, absorptance, etc.)" is replaced with "(e.g. reflectance, absorptance, etc.)" (2), on page 4 of the specification, lines 6-7, it says, "On the other hand, it has a large reflectance, high thermal conductivity, and a large specific heat." It has disadvantages such as high thermal conductivity and high specific heat. Corrected to J. (3), Ming Shaojie Chu, page 4, line 15, says, "It has a high absorption rate, low heat conduction, and good productivity." (4) In Meiheisho, page 5, line 19, the word "formation" is replaced with "addition". (5), The general formula on page 6, line 7 of the specification is corrected as follows. Correct. Note (7), the general formula on page 21, line 4 of Meihi-sho, is corrected as follows. Note R7 (8), "Metal as a body" in Specification S Middle East, page 22, line 5 from the bottom. Correct the statement to "metal complex."
Correct "Ni-bis" to "Ni-bis". (10) The @ formula on page 28, line 4 of the specification is corrected as follows. Record

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [However, R_1 and R_2 in the formula are hydrogen atoms, halogen atoms, alkyl groups having 1 to 6 carbon atoms, or ▲ Numerical formula, chemical formula, table, etc. ▼ (ph; phenyl group), R_3 is an alkyl group having 1 to 6 carbon atoms, an aralkyl group, a phenyl group, and X is selected from perchlorate, fluoroborate, iodide, chloride, bromide, p-toluenesulfonate Anion, Y is an alkyl group with 1 to 18 carbon atoms, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -R_4OH,
-R_4COOH, -R_4OR_5, -R_4COR
_5, -R_4COOR_5, ▲Mathematical formulas, chemical formulas, tables, etc.▼(R_4; Alkyl group with 1 to 20 carbon atoms, R
_5; alkyl group having 1 to 18 carbon atoms), m is an integer of 1 or 2, z is when m = 1, -R_6OH, -R_6CO
OH, -R_6OR_7, -R_6COR_7, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -OR_7, -OH, -
COOH, -COR_7, phenyl group, -CN, -OC
F_3, -OSF_3, -NH_2N(R_7)_2,
-NHCOR_7, ▲Contains mathematical formulas, chemical formulas, tables, etc.▼
, (R_6; alkyl group having 1 to 20 carbon atoms, R_7; alkyl group having 1 to 18 carbon atoms or phenyl group), when m = 2, an alkyl group having 1 to 10 carbon atoms or a halogen atom,
1. An optical information recording medium comprising a recording layer containing an organic dye represented by the following formula: n is an integer of 0, 1, or 2.