JP2545558B2 - 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.
2093, JP 58-56892, JP 60-89842, JP 60-150243
Each of the above publications is already known. However, as a matter of fact, as an optical recording medium having a large absorption coefficient for a semiconductor laser beam and a high recording sensitivity, a completely satisfactory one 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 characterized in that a recording layer containing at least one specific phthalocyanine compound represented by the following general formula [I] is formed on a substrate.

In the formula, A ₁ , A ₂ , A ₃ , and A ₄ each independently represent a benzene ring, a naphthalene ring, an anthracene ring, or a nitrogen-containing heterocycle represented by the following formula, However, _{1 to 3 of} A ₁ , A ₂ , A ₃ or A ₄ is one of the above nitrogen-containing heterocycles.

X ₁ , X ₂ , X ₃ and X ₄ are each independently a hydrogen atom, halogen atom, cyano group, nitro group, carboxylic acid group, sulfonic acid group, substituted or unsubstituted aliphatic hydrocarbon group, substituted or Unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, -OR ₁ , -SR ₂ , -NHCOR ₉ , -CO ₂ R ₁₀ , -N = N-R ₁₁ (where R ₁ to R
₁₁ represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group. ) M represents a hydrogen atom, a metal atom which may have a halogen atom or an oxygen atom, or a metal atom which may have (OR ₁₂ ) p, (OSiR ₁₃ R ₁₄ R ₁₅ ) q. (Where R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅
Is the same as R ₁ to R ₁₁ . p and q represent an integer of 0 to 2. ) K, l, m and n each independently represent an integer of 0 to 4.

Further explaining the substituents, X ₁ , X ₂ , X ₃ X ₄ are a hydrogen atom or a halogen atom such as a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carboxylic acid group, a sulfonic acid group or a methyl group, Substituted or unsubstituted aliphatic hydrocarbon groups such as ethyl group, t-butyl group, n-stearyl group, trichloromethyl group, aminomethyl group, hydroxymethyl group,
Substituted or unsubstituted aliphatic hydrocarbon groups such as phenyl group, naphthyl group, anthryl group, 2-methylphenyl group, 4-chloromethyl group, 4-dimethylaminonaphthyl group, or pyridyl group, carbazolyl group, dibenzofuryl group, Substituted or unsubstituted aromatic heterocyclic group such as benzothiazolyl group, 4-methylpyridyl group, methoxy group, ethoxy group, stearyloxy group, phenoxy group, hexylthio group, t-
Butylthio group, a phenylthio group, an amino group, n- butyl group, diethylamino group, diphenylamino group, dibenzylamino _{group, -SO 2 NHnC 4 H 9,} -SO 2 N (CH 3) 2, Etc., but is not limited to these substituents.

M is H, Na, Li, Cu, Fe, Co, Ni, Zn, Mn, Pb, Si, Mg, Al-Cl, I
n-Cl, Ti = 0, V = 0, SiOC ₂ H ₅ ) ₂ , Al-OnC ₅ H ₁₁ , SiOSi
(CH ₃ ) ₃ ] ₂ etc., but is not limited thereto.

k, l, m and n each independently represent an integer of 0 to 4, preferably 1 to 2.

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

The phthalocyanine compound represented by the above general formula [I] used in the present invention is generally prepared by mixing nitriles represented by the following general formulas [II] and [III] at an appropriate molar ratio to obtain various metal salts ( It is not used in the case of a metal-free phthalocyanine compound) and is preferably heated in an organic solvent.

In the formula, A ₅ represents a benzene ring, a naphthalene ring or an anthracene ring, and X ₅ is the same as X ₁ , X ₂ , X ₃ or X _{4 in the} general formula [I]. r represents an integer of 0 to 4.

In the formula, A ₆ represents a nitrogen-containing heterocycle represented by the following formula.

X ₆ is the same as X ₁ , X ₂ , X ₃ or X ₄ in the formula [I]. S represents an integer of 0 to 4.

General organic solvents such as alcohols, glycols, xylene, quinoline, α-chlornaphthalene, nitrobenzene, sulfolane and N-N dimethylformamide can be widely used for the production of these phthalocyanine compounds, 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.

Various metal salts can be used as the metal salt as a raw material.

Representative examples of the phthalocyanine compound represented by the general formula [I] used in the present invention are shown in more detail in the following table.

In the formula Are the same as those in the general formula [I].

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.

Plastics 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 These copolymers etc. are mentioned.

The method for forming the recording layer containing the specific naphthalocyanine compound of the present invention on the substrate includes 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 the spinner method is used, the phthalocyanine compound is a general organic solvent such as alcohols, ketones, amides, sulfoxides, ethers, esters, aliphatic halogenated hydrocarbons and aromatic hydrocarbons. Disperse or dissolve in and apply. At this time, a polymer binder is added depending on the case. The recording layer containing naphthalocyanine formed on the substrate is 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 ₂ . 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.

(Example) [Synthesis example 1 Synthesis of compound No. 1] To 35 parts by weight of nitrobenzene, 2.3 parts of nitrile (IV) represented by the above formula, 1.3 parts of (V) and 0.5 part of cuprous chloride are added, and 180
After heating at ~ 200 ° C for 6 hours, stirring, cooling, dilution with 500 parts of methanol, filtration of the product, washing with methanol and drying to obtain 2.4 parts of compound No. 1 crude product. The crude product is separated and purified by an alumina column to obtain 1.2 parts of a purified product of Compound No. 1.

[Synthesis Example 2 Synthesis of Compound No. 6] In 90 parts of n-amyl alcohol, 3.6 parts of nitrile (VI) represented by the above formula, 2.5 parts of (VII), 0.8 part of vanadium trichloride, D
Add 3.0 parts BU and reflux for 8 hours, then cool, methanol 500
After diluting with 1 part, separating the product by filtration, washing with methanol and drying, 4.4 parts of Compound No. 6 crude product is obtained. The crude product is separated and purified with an alumina column to obtain 2.9 parts of a purified product of Compound No. 6.

[Synthesis Example 3 Synthesis of Compound No. 2] In Synthesis Example 2, nitriles (IV) and (VII) were replaced with 2.9 parts of nitriles (VIII) and (IX) 1.3 represented by the above formulas, respectively.
Part of compound No. 2 crude product was obtained by the same synthesis. The crude product is separated and purified on an alumina column to obtain 1.6 parts of a purified product of Compound No. 2.

[Synthesis Example 4 Synthesis of Compound No. 9] Nitrile (X) 2.9 represented by the above formula in 80 parts of quinoline
Part, (XI) 2.0 parts, nickel chloride 0.7 parts, and added at 180 ℃
After heating and stirring for an hour, cooling, diluting with 500 parts of methanol, separating the product by filtration, washing with methanol and drying, 4.1 parts of crude compound No. 9 is obtained. The crude product is separated and purified with an alumina column to obtain 2.5 parts of a purified product of Compound No. 9.

Example 1 3 parts by weight of Compound No. 1 was dissolved in 100 parts of methyl cellosolve, and this solution was applied onto a polycarbonate resin substrate by a 500 rpm spinner coating method, and then dried at 90 to 100 ° C. for 1 hour and recorded at about 700 Å. Layers were obtained.

While attaching the optical recording medium produced in this way to the turntable and rotating 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 3 parts by weight of a commercially available nitrocellulose resin was dissolved in 10 parts by weight of methyl ethyl ketone, 5.0 parts by weight of compound No. 6 and 200 parts by weight of ethyl cellosolve were mixed and dissolved with the above resin solution. Add this solution to a Pyrex substrate at 500 rpm
It is applied by the spinner coating method, and at the temperature of 120 ℃, 2
After drying for about an hour, a recording layer of about 800Å was obtained.

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

Example 3 At a vacuum degree of 10 ^-7 Torr, the substrate temperature was set to room temperature on an acrylic substrate having a thickness of 1 mm, and Compound No. 2 was vapor-deposited to a film thickness of 600 Å.

Recording was performed on the optical recording medium thus produced 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. S / N sufficient for practical use when detected
A waveform with a ratio is shown.

Example 4 3 parts by weight of Compound No. 9 was dissolved in 100 parts by weight of ethyl cellosolve, and this solution was placed on a polycarbonate resin substrate in an amount of 500 r.
After applying by the pm spinner coating method, it was dried at 100-110 ° C. for 2 hours to obtain a recording layer of about 700Å. When recording was performed in the same manner as in Example 1, clear pits were observed with an electron microscope, and an S / N ratio sufficient for practical use was obtained.

〔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 / reproducing with high sensitivity by a laser beam.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09B 47/12 C09B 47/12 47/18 47/18 47/20 47/20 47/22 47 / 22 47/24 47/24 47/26 47/26 47/30 47/30 G11B 7/24 516 8721-5D G11B 7/24 516 (56) Reference JP 62-121939 (JP, A) JP JP 62-222893 (JP, A) JP 62-233287 (JP, A) JP 62-233288 (JP, A) JP 1-103495 (JP, A) JP 64-34791 (JP , A)

Claims (1)

(57) [Claims] 1. An optical recording medium comprising an organic thin film layer containing at least one phthalocyanine compound represented by the following general formula [I] on a substrate. In the formula, A ₁ , A ₂ , A ₃ , and A ₄ each independently represent a benzene ring, a naphthalene ring, an anthracene ring, or a nitrogen-containing heterocycle represented by the following formula, However, _{1 to 3 of} A ₁ , A ₂ , A ₃ or A ₄ is one of the above nitrogen-containing heterocycles. X ₁ , X ₂ , X ₃ and X ₄ are each independently a hydrogen atom, halogen atom, cyano group, nitro group, carboxylic acid group, sulfonic acid group, substituted or unsubstituted aliphatic hydrocarbon group, substituted or Unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, -OR ₁ , -SR ₂ , -NHCOR ₉ , -CO ₂ R ₁₀ , -N = N-R ₁₁ (where R ₁ to R
₁₁ represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group. ) M represents a hydrogen atom, a metal atom which may have a halogen atom or an oxygen atom, or a metal atom which may have (OR ₁₂ ) p, (OSiR ₁₃ R ₁₄ R ₁₅ ) q. (Where R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ is R
Same as ₁ through R ₁₁ . p and q represent an integer of 0 to 2. ) K, l, m and n each independently represent an integer of 0 to 4.