JP2507738B2 - Optical recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an optical recording medium capable of writing and reading information by a laser beam.

(Prior Art) Conventionally, there are various media for recording information by using a laser beam, and one of them is to irradiate a laser beam to a recording layer on a substrate to locally heat the irradiated portion. , Records information by causing physical changes such as melting, evaporation or decomposition.

Until now, thin film layers of metals and alloys such as As, Te, Se and Ti have been used as recording layers on substrates. An optical recording medium having such a recording layer generally has a relatively high writing sensitivity and can be applied to a semiconductor laser which can be downsized in a recording / reproducing optical system, but has a large thermal conductivity and a high reflectance. Due to the small size, the energy of the laser beam cannot be used efficiently during recording, and a high-power laser beam may be required for high-speed scanning recording. Further, these recording layers are chemically unstable and may be deteriorated in the air.

Because of this, in recent years relatively long wavelengths (eg 780 nm
Studies have been made on optical recording media in which information is written in and read from the organic thin film layer on the substrate using the above laser beam.

Such an organic thin film layer has the advantage that small recesses (pits) can be easily formed by melting, evaporation or decomposition using a semiconductor laser.

An optical disk in which an organic thin film layer is formed on a substrate and information is recorded and reproduced by using a laser beam.
82093, JP58-56892, JP60-89842, JP60-15
Each publication such as 0243 is already known. However,
The reality is that an optical recording medium having a large absorption coefficient for a semiconductor laser beam and high recording sensitivity, which is completely satisfactory, has not been developed.

(Problems to be Solved by the Invention) The present invention provides an optical recording medium using an inexpensive specific phthalocyanine compound that is chemically and physically stable and can be recorded and reproduced with high sensitivity by a laser beam.

[Structure of Invention]

(Means for Solving the Problem) As a result of intensive studies by the present inventors, an optical recording medium having a recording layer containing a phthalocyanine compound having a specific structure on a substrate has various excellent characteristics. The inventors have found that and completed the present invention.

That is, the present invention is an optical recording medium characterized by having an organic thin film layer containing at least one phthalocyanine compound represented by the following general formula [I] on a substrate.

General formula [I] (In the formula, A ₁ , A ₂ , A ₃ , and A ₄ each independently represent a coupler residue represented by one of the following general formulas [II] to [VII], and M is a hydrogen atom, an oxygen atom, or a chlorine atom. Represents a metal atom which may have an atom, and k, l, m or n each independently represents an integer of 0 to 4, but not all are 0 at the same time.) The above general formula [I] The coupler residue of A ₁ , A ₂ , A ₃ , and A ₄ in is represented by the general formulas [II] to [VII].

General formula (II) General formula (III) General formula (IV) General formula [V] General formula [VI] General formula (VII) (In the formula, R ₁ represents a hydrogen atom, a hydroxyl group, an amino group or an alkylamino group. R ₂ represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group, an alkoxy group, a carboxylic acid group, a carboxylic acid ester group. , A sulfonic acid group or a metal sulfonate group, R ₃ , R ₄ or R ₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an aralkyl group or an aryl group, and X represents a substituted or unsubstituted aromatic carbon group. represents a divalent aromatic heterocyclic ring containing divalent group or a nitrogen atom of the hydrogen in the ring.) It then formula (I) free for a substituent (VII), to further illustrate, R ₁ is hydrogen Represents an atom, a hydroxyl group, an amino group or an alkylamino group, and examples of the alkylamino group include a methylamino group, an n-butylamino group, a stearylamino group, a dimethylamino group, a diethylamino group and a dibutyl group. An amino group, R ₂ is a hydrogen atom, a halogen atom,
Represents a nitro group, a cyano group, an alkyl group, an alkoxy group, a carboxylic acid group, a carboxylic acid ester group, a sulfonic acid group, a sulfonic acid metal base, and a halogen atom is a chlorine atom, a bromine atom, an iodine atom, or the like. The group is a methyl group, an ethyl group, an n-butyl group, a t-butyl group, a stearyl group, etc., and the alkoxy group is a methoxy group, an ethoxy group, a stearyloxy group, a phenoxy group,
A naphtheroxy group and the like, and a carboxylic acid ester group such as a methylcarboxylic acid ester group, an ethylcarboxylic acid ester group, and an n-butylcarboxylic acid ester group.
Examples of the metal sulfonate group include sodium sulfonate group, magnesium sulfonate group, and calcium sulfonate group, but are not limited to these substituents.

R ₃ , R ₄ and R ₅ are each a hydrogen atom; an unsubstituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group;
Substituted alkyl groups such as chloromethyl group, hydroxyethyl group, diethylaminoethyl group; unsubstituted aralkyl groups such as benzyl group, phenethyl group, cinnamyl group, naphthylmethyl group; methylbenzyl group, methoxybenzyl group,
Substituted aralkyl group such as chlorobenzyl group; Unsubstituted aryl group such as phenyl group, naphthyl group, anthryl group, pyrenyl group; Tolyl group, methoxyphenyl group, xylyl group, methylnitrophenyl group, chlorophenyl group, dichlorophenyl group, nitrophenyl Group, dinitrophenyl group, chloronitrophenyl group, trifluoromethylphenyl group, cyanophenyl group, phenylchloronaphthyl group of sulfonate, substituted aryl groups such as nitronaphthyl group; pyridyl group, phthalazinyl group, benzothiazolyl group, carbazolyl group, etc. Unsubstituted aromatic heterocyclic group; represents a substituted aromatic heterocyclic group such as methylbenzothiazolyl group and chlorocarbazolyl group.

X is a divalent group of an unsubstituted aromatic hydrocarbon such as a phenylene group or a naphthylene group; a substituted aromatic hydrocarbon such as a tolylene group, a xylylene group, a chlorophenylene group, a nitrophenylene group, a methoxyphenylene group or a methylnaphthylene group. A divalent group of an unsubstituted aromatic heterocycle such as a pyridinediyl group, a triazolediyl group or an imidazoldiyl group; a divalent group of a substituted aromatic heterocycle such as a methylpyridinediyl group or a chloroquinolinediyl group Represent

M in [I] is H, Na, Li, Cu, Fe, Co, Ni, Zn, Mn, Pb, Si, Mg,
It represents Al-Cl, In-Cl, Ti = O, V = O, etc., but also contains many metals forming a metal chelate with phthalocyanine.

The phthalocyanine compound represented by the above general formula has a large absorption in the visible to near-infrared region and is suitable for recording / reproducing with a laser beam.

The phthalocyanine-based compound represented by the above general formula [I] used in the present invention preferably contains a nitrile represented by the following general formula [VII] and various metal salts (not used in the case of a metal-free phthalocyanine). It can be produced by heating in an organic solvent.

General formula [VIII] (In the formula, Y is the same as A ₁ , A ₂ , A ₃ and A _{4 in the} general formula [I], and k,
l, m or n represents an integer of 0 to 4. In addition, various phthalocyanine compounds can be obtained by mixing and reacting nitriles having different substituents represented by the general formula [VIII]. The general formula [I]
The phthalocyanine compound can also be produced by using phthalic acids and phthalimides as starting materials.

For the production of these phthalocyanine compounds, general organic solvents such as alcohols, glycols, xylene, quinoline, α-chlornaphthalene, nitrobenzene, sulfolane and N, N-dimethylformamide can be widely used, but no solvent is used. But you can get it.

Further, it may be preferable to use an alkali or an organic amine such as diazabicycloundecene (DBU) or cyclohexylamine as a catalyst.

In addition, various metal salts can be used as the metal salt as a raw material.

Typical examples of the phthalocyanine compound represented by the general formula [I] used in the present invention include the compounds shown in the following table as more specific examples.

In the present invention, as the substrate material for providing the recording layer,
Various materials such as glass, plastic, paper and metal plate can be used.

Examples of plastic include vinyl chloride resin, acrylic acid resin, polyester resin, polyethylene resin, polyamide resin, polycarbonate resin, epoxy resin, methacrylic acid resin, vinyl acetate resin, nitrocellulose, polypropylene resin, polyethylene terephthalate resin, phenol resin, and the like. And copolymers thereof.

As a method for forming a recording layer containing a specific phthalocyanine compound of the present invention on a substrate, vacuum deposition method, sputtering method, ion plate method, casting method, spinner method, spray coating method, blade coating method, L
There are chemical and mechanical methods such as method B.

In the present invention, the spinner method is most preferable. Further, if necessary, it may be mixed with a polymer binder. As the polymer binder, plastics used for the above substrate material can be used.

When coating by the spinner method, phthalocyanine compounds are used for general organic compounds such as alcohols, ketones, amides, sulfoxides, ethers, esters, aliphatic halogenated hydrocarbons and aromatic hydrocarbons. Disperse or dissolve in a solvent and apply. At this time, a polymer binder is added depending on the case. The recording layer containing phthalocyanine formed on the substrate has a thickness of 10 μm or less, preferably 500 Å to 2 μm
It is the following. In some cases, the absorption wavelength of the thin film can be shifted to a long wavelength and the sensitivity to laser light can be remarkably improved by exposing it to vapor of an organic solvent such as chloroform, tetrahydrofuran, or toluene after coating.

In addition, in order to protect these recording layers, Al ₂ O ₃ , SiO ₂ ,
A protective layer may be provided by vapor-depositing an inorganic compound such as SiO or SnO. A polymer used as a substrate material may be applied as a protective layer.

The optical recording medium obtained by the present invention is capable of writing / reading / reading by not only He—Ne laser beam but also various laser beams such as ruby, Ar and semiconductor laser beam.

Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.
The middle part is part by weight.

(Examples) [Synthesis Example 1: Synthesis of compound (1)] 3.0 parts of the nitrile represented by the above formula and 1.6 parts of diazabicycloundecene (DBU) were added to 100 parts of n-amyl alcohol, and the mixture was refluxed for 6 hours, then cooled, separated by filtration, washed with methanol and acetone, and the compound ( 1) 2.3 parts were obtained.

[Synthesis Example 2: Synthesis of compound (7)] 4.5 parts of the above-mentioned nitrile, 0.3 part of cuprous chloride, 1.6 parts of diazabicycloundecene (DBU) were added to 100 parts of n-amyl alcohol, and the mixture was refluxed for 6 hours, cooled, and the reaction solution was 400 parts of methanol. The reaction mixture was diluted with, filtered and washed with methanol to obtain 2.0 parts of compound (7).

[Synthesis Example 3: Synthesis of compound (10)] 4.5 parts of nitrile shown above, 0.4 vanadium trichloride
Parts and DBU 1.6 parts were added to n-amyl alcohol 100 parts and refluxed for 6 hours, then cooled, the reaction solution was diluted with 300 parts of methanol, filtered and washed with methanol to obtain 3.0 parts of compound (10). Was given.

[Synthesis Example 4: Synthesis of compound (14)] 4.5 parts of nitrile and 0.5 parts of titanium tetrachloride shown in the above formula were added to 100 parts of quinoline, heated at 180-190 ° C for 6 hours and stirred, cooled, diluted with 500 parts of methanol, and then filtered, methanol After washing with water, 2.1 parts of compound (14) was obtained.

[Synthesis Example 5: Synthesis of compound (16)] 4.2 parts of the above-mentioned nitrile and 0.3 part of cuprous chloride are added to 100 parts of nitrobenzene, heated at 190 to 200 ° C for 6 hours and stirred, cooled, and the reaction solution is diluted with 500 parts of methanol,
After filtration and washing with methanol, 2.3 parts of compound (16) was obtained.

[Synthesis Example 6: Synthesis of compound (22)] 4.4 parts of nitrile shown above, 1.6 vanadium trichloride
Part to 80 parts of sulfolane and heated at 190-200 ℃ for 6 hours,
After stirring, the reaction mixture was cooled, diluted with 500 parts of methanol, washed with methanol, acetone, and then the compound (2
2) 2.8 parts were obtained.

Example 1 2.5 parts of compound (10) was dissolved in 100 parts of acetone, and this solution was applied on a polycarbonate resin substrate by a 500 rpm spinner coating method, and then dried at 80 to 90 ° C. for 1 hour to obtain about 8 parts.
I got a recording layer of 00Å.

Attach the optical recording medium manufactured in this way to the turntable, rotate the turntable at 1600 rpm,
5mW and 8MHz gallium-aluminum-arsenic semiconductor laser beam (830nm) focused to a spot size of 0.6μ
Recording was performed by irradiating the recording layer with a track shape. Clear pits were observed with an electron microscope on the recording layer where recording was completed. When a low-power gallium-aluminum-arsenic semiconductor laser beam was incident on this optical recording medium and the reflected light was detected, a waveform having an S / N ratio sufficient for practical use was shown.

Example 2 The compound (7) was replaced with the compound (10) in Example 1.
The same result was obtained when 2.0 parts of was used.

Example 3 2.5 parts of compound (14) was dissolved in 200 parts of xylene, and this solution was applied onto a Vyrex substrate by a 500 rpm spinner coating method and then dried at 130 to 140 ° C. for 2 hours to form a recording layer of about 700 Å. Obtained.

Recording was performed on the optical recording medium thus manufactured in the same manner as in Example 1. As a result, clear pits were observed in the recording layer with an electron microscope, and detection of reflected light of an incident laser beam similar to that in Example 1 was detected. S / S
A waveform with N ratio was obtained.

Example 4 Instead of the compound (14) in Example 3, the compound (17)
Was used with similar results.

Example 5 2.5 parts of compound (8) was dissolved in 200 parts of acetone, and this solution was applied on an acrylic substrate by a 500 rpm spinner coating method and dried at a temperature of 80 to 90 ° C. for 1 hour, and then about 1000Å
To obtain a recording layer of.

Recording was performed on the optical recording medium thus manufactured in the same manner as in Example 1. As a result, clear pits were observed in this recording layer with an electron microscope, and reflected light of an incident laser beam similar to that in Example 1 was observed. The result of detection is enough for practical use.
The waveform with S / N ratio is shown.

Example 6 3 parts of a commercially available nitrocellulose resin was dissolved in 10 parts of methyl ethyl ketone, 4 parts of the compound (22) and 200 parts of ethyl acetate were mixed with the above resin and dispersed in a ball mill for 4 hours. After applying the obtained coating liquid on an acrylic substrate by a 500 rpm spinner coating method, it is dried at a temperature of 90 ° C. for 2 hours,
A recording layer of about 900Å was obtained.

Recording was performed on the optical recording medium thus manufactured in the same manner as in Example 1. As a result, clear pits were observed in this recording layer with an electron microscope, and reflected light of an incident laser beam similar to that in Example 1 was observed. The result of detection is enough for practical use.
The waveform with S / N ratio is shown.

Example 7 Instead of the compound (22) in Example 6, the compound (1)
When 5 parts of was used, the same result was obtained.

Example 8 Compound (5) was vapor-deposited on an acrylic substrate having a thickness of 1 mm at a vacuum degree of 10 ⁻⁷ Torr to give a film thickness of 1500 Å.

Recording was performed on the optical recording medium thus manufactured in the same manner as in Example 1. As a result, clear pits were observed in this recording layer with an electron microscope, and reflected light of an incident laser beam similar to that in Example 1 was observed. The result of detection is enough for practical use.
The waveform with S / N ratio is shown.

Example 9 Instead of the compound (5) in Example 8, the compound (1)
Was used with similar results.

〔The invention's effect〕

The present invention is configured as described above and is characterized by being chemically and physically stable and capable of recording and reproducing with high sensitivity by a laser beam.

Claims (1)

(57) [Claims] 1. An optical recording medium having an organic thin film layer containing one or more phthalocyanine compounds represented by the following general formula [I] on a substrate. General formula [I] (Wherein A ₁ , A ₂ , A ₃ or A ₄ each independently represents a coupler residue represented by any of the following general formulas [II] to [VII], and M is a hydrogen atom, an oxygen atom or a chlorine atom. Represents a metal atom which may have an atom, and k, l, m or n each independently represents an integer of 0 to 4, but not all are 0 at the same time.) General formula [II] General formula (III) General formula (IV) General formula [V] General formula [VI] General formula (VII) (In the formula, R ₁ represents a hydrogen atom, a hydroxyl group, an amino group or an alkylamino group. R ₂ represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group, an alkoxy group, a carboxylic acid group, a carboxylic acid ester group. Represents a sulfonic acid group or a metal sulfonate group, R ₃ , R ₄ or R ₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an aralkyl group or an aryl group, and X represents a substituted or unsubstituted aromatic carbon group. It represents a divalent group of hydrogen or an aromatic heterocyclic divalent group containing a nitrogen atom in the ring.)