JPH01171986A - Optical recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical recording medium which is stable chemically and physically, enables the execution of recording and reproduction with high sensitivity by a laser beam and uses an inexpensive specific naphthalocyanine compound, by a method wherein a recording layer containing a specific phthalocyanine compound is formed on a substrate. CONSTITUTION:An optical recording medium has an organic thin film layer containing at least one kind or more phthalocyanine compounds expressed by the general formula [I] on a substrate. The phthalocyanine compounds expressed by the general formula [I] can be prepared by heating one kind or more orthodicyano compounds and metal salts of various kinds in an organic solvent preferably. As for the substrate used, it has preferably a light- transmittance of 85% or above for writing and reading signals and desirably a small optical anisotropy. A recording layer containing a phthalocyanine dyestuff and formed on the transparent substrate has a thickness of 10mum below, preferably 500Angstrom /2mum.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for writing information using a laser beam,
The present invention relates to optical recording media that can be read and read.

(Prior Art) Conventionally, there are various types of media that record information using laser beams. One of them is a method that locally heats the irradiated area by irradiating a recording layer on a substrate with a laser beam. , there are some that record information by causing physical changes such as melting, evaporation, or decomposition.

Until now, As, Te, Se, T
Thin film layers of metals and alloys such as i have been used.

Optical recording media with such a recording layer generally have relatively high writing sensitivity, and can also be applied to semiconductor lasers where the optical system for recording and reproduction can be made compact. For reasons such as small size, the energy flame of the laser beam cannot be used efficiently during recording, and high-power laser beams may be required to record at high speed scanning. Furthermore, these recording layers are chemically unstable and may deteriorate in the air.

For this reason, in recent years relatively long wavelengths (e.g. 780n) have been
Research has been carried out on optical recording media in which information is written to and read from an organic thin film layer on a substrate using a laser beam with a wavelength of 2.0 m or more.

Such a thin film layer is melted using a semiconductor laser,
Small depressions (pits) easily formed by evaporation or decomposition, etc.
It has the advantage of being able to form

Unexamined Japanese Patent Publication No. 57 (1982) as an optical disc in which an organic thin film layer is formed on a substrate and information is recorded and reproduced using a laser beam.
-82093. Japanese Patent Publication No. 58-56892゜ Japanese Publication No. 60-
89842. Japanese Patent Laid-Open No. 60-15024 3 and other publications are already known. however.

The reality is that a completely satisfactory optical recording medium with high recording sensitivity and a large absorption coefficient for semiconductor laser beams has not been developed.

(Problems to be Solved by the Invention) The present invention provides an optical recording medium using an inexpensive specific naphthalocyanine compound that is chemically and physically stable and capable of recording and reproducing data with high sensitivity using a laser beam.

[Structure of the invention]

(Means for Solving the Problem) As a result of intensive research, the present inventors have found that an optical recording medium having a recording layer containing a phthalocyanine compound having a specific structure on a substrate has various excellent properties. This discovery led to the completion of the present invention.

That is, the present invention is characterized in that a recording layer containing a specific phthalocyanine compound represented by the following general formula (1) is formed on a substrate.

General Formula (1) In the formula, W to W4 each independently represent a benzene ring or a naphthalene ring which may have a substituent. X, to Xa, Y+ to Ya, Z+ to Z4 are each independently -N=N-, -CH=N- or -CH=CH-
represents. AI to A4. Bl to B, C, to C41 each independently represent a phenyl group, a naphthyl group, an anthryl group, or a biphenyl group which may have a substituent.

M is a hydrogen atom, a halogen, a metal atom which may have an oxygen atom, or (OR+)s, (SR2)t.

(N R3R4)tl+ (-0S i R5R6R
? )X represents an optional metal atom. (Here R1
to R7゜hydrogen atom, substituted or unsubstituted aliphatic hydrocarbon group.

Represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group. s, t.

u and v represent integers from O to 2. ) n, p, q, r each independently represent O or 1, and j
, 1. Each m independently represents an integer from O to 4, but not all of them are O at the same time.

Wl or Wa, AI or Aa, B+ or B,,C
, to C4, are explained in more detail: halogen atoms such as chlorine atom, bromine atom, and iodine atom, hydroxyl group, nitro group, and cyano group.

Alkylamino groups such as amino groups, n-butylamino groups, and n-stearylamino groups, and diethylamino groups.

Di-n-hexylamino group, dialkylamino group such as di(2-ethylhexyl)-amino group, methyl5. t
- Alkyl groups such as butyl group, neo-pentyl M, n-decyl group, alkoxy groups such as methoxy group, n-butoxy group, stearyloxy group, phenoxy group, siloxy group such as trimethylsiloxy group, triphenylsiloxy group, etc. , n-butylthio group.

Alkyl such as n-hexylthio group and phenylthio group,
or arylthio group, but is not limited to these substituents.

M is Hz+Naz, t, i2. Cu, Fe, C.

Ni, Zn, Mn, Sn, Pb, Mg, Al-C1゜I
n-Cl, Ti=O, V=O, Si+CI)z.

S i+0H)z, Ge+Cl)2. Ge+0H)
z, S i÷O3i (CH,)3) z,
It represents Ge+O3t (CH,)3), etc.
It also contains many other metals that form metal chelates with phthalocyanine.

The phthalocyanine compound represented by maximum (1) above has large absorption in the visible to near infrared range, and is suitable for recording and reproducing using a semiconductor laser beam.

The phthalocyanine compound represented by maximum (1) above used in the present invention is generally one or more orthodicyano compounds represented by maximum (II) below and various metal salts (not used in the case of metal-free phthalocyanine). Preferably, it can be produced by heating in an organic solvent.

General formula (n) In the formula, rings W, X, Y, Z, A, B and C each represent -maximum WI to w4. in (1). XI to X4. Yl to Y4. ZI or Z4. AI to A4. Bl to B4. and C, to C4.

n is the same as n in the general formula (1), and i is the same as n in the general formula (1).
) represents 1 or m.

When ring W has another substituent, i represents an integer of 0 to 2.

Also - maximum (1) phthalocyanine compound.

It can also be produced using phthalic acids and phthalimides as starting materials.

Alcohols, glycols, xylene, quinoline, α-chloronaphthalene, nitrobenzene, and sulfolane are used in the production of these phthalocyanine compounds.

A general organic solvent such as N--N dimethylformamide can be used, but it can also be obtained without a solvent.

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

Furthermore, various metal salts can be used as the raw material metal salts.

The transparent substrate used in the present invention preferably has a transmittance of light for writing and reading signals of preferably 85% or more and has small optical anisotropy. For example, glass or thermoplastic resins such as alkyl resins, polycarbonate resins, polyester resins, polyamide resins, vinyl chloride resins, polyvinyl ester resins, polystyrene resins, polyolefin resins (poly-4-methylpentene, etc.), and polyethersulfone resins. Examples include substrates using thermosetting resins such as epoxy resins, allyl resins, etc. Among these, the above-mentioned thermoplastic resins are preferred from the viewpoint of ease of molding and ease of providing guide grooves, address signals, etc., and acrylic resins and polycarbonate resins are particularly preferred from the viewpoint of optical properties and mechanical properties.

In the present invention, the thickness of these transparent substrates is .

There is no particular restriction, and it may be in the form of a plate or a film. Also,
Its shape may be nine circles or card-like, and its size is not particularly limited.

Further, the transparent substrate of the present invention usually has unevenness for preformatting, such as guide grooves for position control during recording and reading, address signals, and various marks, as described above. Molding (injection,
It is preferable to apply it using a stamper or the like during compression (compression, etc.).

In the optical recording medium of the present invention (q), in order to fix the recording layer containing a phthalocyanine dye on a transparent substrate, there are two methods, such as vacuum evaporation method, sputtering method, ion plate method, and LB method (Langmuir-Blodgiett method). However, these methods require complicated operations and are inferior in terms of productivity.

The so-called coating method is most preferred. When forming a recording layer by a coating method, the phthalocyanine compound may be a general compound such as alcohols, ketones, amides, sulfoxides, ethers, esters, aliphatic halogenated hydrocarbons, aromatic hydrocarbons, etc. It is applied by dispersing or dissolving it in an organic solvent. On this occasion.

By forming a salt formed by the amino group of the phthalocyanine dye and an organic acid, solubility is increased, so acetic acid and propionic acid are added to the above organic solvent.

It is also possible to use a mixture of organic acids such as butyric acid, oleic acid, and stearic acid. Further, at this time, a polymer binder may be added depending on the case. Examples of the polymer binder 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, or Examples include copolymers of these. In this case, the ratio of resin to phthalocyanine dye is preferably 10 tnt% or less.

Further, it is also possible to use the phthalocyanine compound of the present invention by mixing and dispersing or mixing and dissolving other dyes.

Examples of dyes that can be used in combination include already known aromatic or unsaturated aliphatic diamine metal complexes, aromatic or unsaturated aliphatic dithiol metal complexes, phthalocyanine complexes, naphthalocyanine complexes, and squalium dyes. , naphthoquinone complexes, anthraquinone dyes, and polymethine dyes.

In addition, in order to suppress photobleaching and improve photostability of the phthalocyanine compounds of the present invention, - doublet oxygen quenchers such as carotenes, pigments, amines, phenols, nickel complexes, sulfides, etc. may be mixed and dissolved before use.

The recording layer containing a phthalocyanine dye formed on a transparent substrate has a thickness of 10 μm or less, preferably 500 people/2 μm.
It is m. In addition, by exposing the thin film to the vapor of an organic solvent such as chloroform, tetrahydrofuran, or toluene after coating, the absorption wavelength of the thin film shifts to longer wavelengths, and the sensitivity to light in the oscillation wavelength range of semiconductor lasers can be significantly improved. There is also.

In addition, in order to protect these recording layers, Aft03+
The protective layer may be provided by vapor depositing an inorganic compound such as S ioZI S 1O1S n O. Also as a protective layer.

A polymer may also be applied.

Recording on the recording medium obtained as described above is carried out by irradiating the recording layer provided on the substrate with laser light, preferably semiconductor laser light, focused to about 1 μm.

This is determined by reading the difference in reflectance between the areas irradiated with the laser beam and the areas where the thermal state of the recording layer has changed, such as decomposition, evaporation, or melting due to absorption of laser energy, and the area where no changes have occurred.

As the light source, various lasers such as a He--Ne laser, an Ar laser, and a semiconductor laser can be used, but a semi-integrated laser is particularly preferable in terms of cost and size.

As a semiconductor laser, the center wavelength is 830 nm, 7
Lasers with wavelengths of 80 nm and shorter can be used.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples.

In the example, the middle part is the part by weight.

(Margin below) (Example) [Synthesis Example 1 Synthesis of Compound No. 3] 8.12 parts of orthodicyano compound represented by the above formula.

1.6 parts of vanadium trichloride and 3.0 parts of diazabicycloundezene (DBU) were added to 50 parts of n-amyl alcohol, heated under reflux for 5 hours, and then cooled, followed by methanol s.

Diluting with 0 parts and washing the organism daily with methanol and drying yields 34.8 parts of compound no.

[Synthesis Example 2 Synthesis of Compound No. 8] 9.4 parts of the orisodicyano compound represented by the above formula and 2.0 parts of vanadium trichloride were added to 50 parts of quinoline to give 160 to 1
After heating and stirring at 70°C for 3 hours, cool and methanol 500ml.
0.85.1 part of compound N is obtained by diluting 1 part and washing the organism daily with methanol and drying.

[Synthesis Example 3 Synthesis of Compounds No. 11] 5.5 parts of the orthodicyano compound represented by the above formula, 2.4 parts of 6-tert-butyl-2,3-dicyanonaphthalene, and 2.7 parts of anhydrous aluminum chloride were mixed with α - Added to 100 parts of chloronaphthalene, heated and stirred at 150 to 160°C for 5 hours, cooled, diluted with 800 parts of methanol, and the product was divided into methanol,
After washing with n-hexane and drying, it was dissolved in dichloroethane and separated and purified using an alumina column to obtain compound No.
1.2 parts of 11 are obtained.

Example 1 On a Pyrex substrate, phthalocyanine compound No.
After dropping a solution consisting of 33.0 parts and 97.0 parts of dichloroethane, the substrate was rotated at a speed of 1100 Orp for 15 seconds.

Next, this substrate was dried at 80° C. for 40 minutes to obtain a recording medium.

The thickness of this recording layer was 800. The maximum absorption wavelength of this thin film was 806 nm, and the reflectance for light with a wavelength of 830 parts m was 27%.

This optical recording medium was mounted on a turntable, and the turntable was rotated at 180 rpm.

1.0. 8 30 nm laser 5 focused on crm
mW.

Recordings were made with irradiation at 8 MHz.

When the surface of the optical recording medium on which this recording was performed was observed using a scanning electron microscope, the formation of clear pits was observed. Moreover, 830 copies m were added to this optical recording medium.

When laser light of 0.4 nW was irradiated and one reflected light was detected, the C/N ratio was 45 dB.

Example 2 A solution consisting of 82.6 parts of phthalocyanine compound No. and 98.0 parts of methyl cellosolve was dropped onto a polycarbonate resin substrate, and then the substrate was rotated at a speed of 70 rpm for 20 seconds.

Next, this substrate was dried at 80° C. for 30 minutes under reduced pressure to obtain a recording medium.

The thickness of this recording layer was 650. The maximum absorption wavelength of this thin film was 820 parts m, and the reflectance for light with a wavelength of 830 parts m was 26%.

Further, when recording was performed on this recording medium in the same manner as in Example 1, clear bit formation was observed on the surface of the recording layer.
The C/N ratio was 43 dB.

Examples 3 to 13 Phthalocyanine compound No. 1 on Pyrex substrate
．． 2.4 to 7.9 to 13 were applied in the same manner as in Example 1 to obtain a recording medium.

Table 1 shows the maximum absorption wavelength of this thin film, the reflectance for light with a wavelength of 830 parts m, and the results of recording and reproducing the same recording and reproduction as in Example 1 on this recording medium.

Table 1 3 1 802nm 17% 37 4 2 815nm 30% 45 5 4 806nm 24% 45 6 5 800nm 23% 47 7 6 810na+ 26% 44 8 7 830nm 27% 46 9 9 825nm 32% 4 8 1010 817nm 28% 43 1111 820nm 33% 45 1212 830nn+ 30% 491313 81
5 nm 31% 45 [Effects of the Invention] The present invention has the above-mentioned structure, and has a chemical effect.

It is physically stable and can be recorded and reproduced with high sensitivity using laser beams.

Claims (1)

[Claims] 1. 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] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ In the formula, W_1 to W_4 each independently represent a benzene ring or a naphthalene ring which may have a substituent. X
_1 to X_4, Y_1 to Y_4, and Z_1 to Z_4 each independently represent -N=N-, -CH=N-, or -CH=CH-. A_1 to A_4, B_1
to B_4 and C_1 to C_4 each independently represent a phenyl group, a naphthyl group, an anthryl group, or a biphenyl group which may have a substituent. M is a hydrogen atom, a halogen, a metal atom that may have an oxygen atom, or (OR_1)_s, (SR_2)_
t, (NR_3R_4)_u, (OSiR_5R_6R
_7) Represents a metal atom that may have __v. (Here R
_1 to R_7 represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. s, t, u, and v represent integers from 0 to 2. ) n, p, q, r each independently represent 0 or 1, and j
, k, l, and m each independently represent an integer from 0 to 4, but they cannot all be 0 at the same time.