JPH01133790A - Optical recording medium - Google Patents

Abstract

PURPOSE:To enable additional writing through using a condensed beam of a semiconductor laser, by providing a recording layer comprising a specified compound, on a transparent substrate. CONSTITUTION:An organic thin film layer comprising a compound of the formula is provided on a substrate. The recording layer comprising the compound of the formula is provided by applying a coating material in a thickness of not more than 1mum, and exposing the coated film to a vapor of a solvent such as chloroform and toluene, whereby the absorption wavelength of the thin film is shifted to the longer wavelength side, and the sensitivity to rays in the oscillating wavelength region of a semiconductor laser is markedly enhanced. In the formula, each of rings A1-A4 is a benzene ring, naphthalene ring or anthracene ring, M is Al, Ga, In, Tl, Si, Ge, Sn or Pb, X is a halogen atom., hydroxyl, alkyl, aryl or heterocyclic ring radicle, Z is -OR9, -SP10, -SeR10 or -NR10, wherein R9 is -R6- NR7R8, R10 is an alkyl, cycloalkyl, aryl, acyl radicle, polyether group or -R6-NR7R8, wherein R6 is an alkyl radicle, and each of R7 and R8 is an alkyl radicle or a heterocyclic ring containing N, O or S.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an optical recording medium on which additional recording can be performed using a focused beam of a semiconductor laser. external memory.

The present invention relates to optical recording media used to record various types of information such as images and audio.

(Conventional technology) The above-mentioned recordable optical recording medium is tellurium.

Recording media having inorganic recording layers made of thin films of low-melting metals such as tellurium alloys and bismuth alloys are beginning to be put into practical use. However, these recording media have low productivity because they use thin film formats in a vacuum such as vacuum shrinkage and sputtering, and there is a limit in terms of recording density because the heat transfer rate of the recording layer is high. There is a problem in terms of hygiene because it uses toxic substances such as.

In order to solve these problems, in recent years, methods of using organic dyes as recording media have been studied.
A recording medium with a recording layer made of an organic dye that absorbs in the semiconductor laser oscillation wavelength region, such as naphthoquinone (Japanese Patent Application Laid-open No. 112793/1983), phthalocyanine dye (US Pat. No. 4,298,975), and naphthalocyanine dye (US Pat. No. 4,492,750). Proposed. However, in the recording media using organic dyes that have been proposed so far,
1liiJ Kusu.

In terms of reflectance, they have disadvantages in that sufficient characteristics cannot be obtained, their solubility in solvents is poor, and thin film formation methods using economically advantageous coating methods cannot be applied.

(Means for Solving the Problems) In order to improve the problems of recording media using organic dyes, the inventors of the present invention have made intensive studies and found that the recording medium has excellent practical characteristics and is also economically advantageous. This led to the invention of a new optical recording medium.

That is, the present invention provides an information recording medium in which recording is performed by causing a state change by irradiation with high-density energy such as a laser beam.
This is an optical recording medium having a recording layer containing a compound represented by l.

(Left below) 14 = General formula (1) In the formula, rings 1 to A4 represent a benzene ring, a naphthalene ring or an anthracene ring.

M is ACGa, In, Tj2. Represents Si, Ge, Sn or pb.

X may be the same or different, and each independently represents a halogen atom, a hydroxyl group, an alkyl group that may have a substituent, an aryl group that may have a substituent, or a heterocycle that may have a substituent. Group, -OR,, -3R,, -NR2R3, S○zN
RaRs, -CONR, R1°=6-CH2NHCOCH2NR4R, -COORR.

NO2,3(): represents +H or -CN.

Here, R2 is an alkyl group having 1 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an acyl group having 4 or more carbon atoms, or a polyether.

R2 and R3 may be the same or different, and each is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, or R2 and R3 are They may be taken together to form a 4- to 7-ring heterocycle containing a nitrogen atom. R4 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. R5 is a hydrogen atom, an alkyl group that may have a substituent, or an aryl group that may have a substituent.

Heterocyclic group which may have a substituent or -R6-NR7R
11, where R6 is an alkyl group having 11 to 4 carbon atoms,
R,, Ra may be the same or different. An alkyl group which may each have a substituent or R7 and R8 taken together represents a heterocycle containing a nitrogen atom, an oxygen atom or a sulfur atom.

Z is ORq, SR+o, S e RIo,
represents NR10R11, where R7 is -Rb N
R7Re represents hydrogen, an alkyl group having 1 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an acyl group having 4 or more carbon atoms, polyether or -R6-NR7R8. Also represents R +
+ is the same as RIo.

k, β, m, and n are each integers of 0 to 8.

Represents the number of X. p is an integer of 1 or 2 and represents the number of Z.

The compound represented by the general formula (1) is 1, for example, the following - Clothing [
II) [In the formula: Ring A represents a benzene ring, a naphthalene ring, or an anthracene ring.

The substituent X is a halogen, a hydroxyl group, an alkyl group which may have a substituent, or an aryl group which may have a substituent.

Heterocyclic group which may have a substituent, -OR,, -3R+
, N R2R3, S O2N l74Rs,
CONRa Rs, CH2N HCOCH□N R
a Rs, -COOR5, -NO2, -3O3H or -CN.

Here, R1 is an alkyl group having 1 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an acyl group having 4 or more carbon atoms, or a polyether.

R2 and R3 may be the same or different, and each represents hydrogen,
An alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 4 to 1 = carbon atoms, an aryl group having 6 or more carbon atoms, or a 4 to 7 scrap ring in which R2 and R3 together contain a nitrogen atom. It may form a heterocycle.

R4 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. R5 represents a hydrogen atom, an alkyl group that may have a substituent, an aryl group that may have a substituent, a heterocyclic group that may have a substituent, or -R, -NR1R8: where R6 is an alkyl group having 1 to 4 carbon atoms.

R? +RBs may be the same or different. An alkyl group which may each have a substituent or R7 and R8 taken together represents a heterocycle containing nitrogen, oxygen or sulfur atoms.

k, ρ, m, n are each independently an integer of 0 to 8,
Represents the number of X. ] A compound of -Fukudai (I[l) is synthesized from the 0-dicyano compound represented by the formula and a metal chloride according to a known method. [For example, 8, I'1.5notv, N, L, Ja
rvis, J. Am, Chem.

Soc, Vol, 106. No. 174706-4
711 (1984)] - general formula I [l) e then - a compound of -Fukudai CI [[], and HOR9°HS' RIo, HS e RIo or HNR
l. By reacting RI+ in the presence of pyridine, -Fukudai CI
] can be obtained.

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, in order to fix the recording layer containing the compound represented by [■] on a transparent substrate, 1, for example, a vacuum evaporation method, a sputtering method, an ion plate method, and an LB method (Langmuir method) are used. The film can be made into a thin film by methods such as the Blodgett method, but these methods require complicated operations and are inferior in terms of productivity, so a so-called coating method is most preferred.

When forming a recording layer by a coating method, - Clothes cost [I
] Compounds represented by alcohols and ketones.

amides, sulfoxides, ethers, esters,
It is applied by dispersing or dissolving it in a general organic solvent such as aliphatic halogenated hydrocarbons or aromatic hydrocarbons. On this occasion,
- When the compound represented by Hatsushiro [I) has an amino group, the solubility increases by forming a salt with an organic acid, so acetic acid, propionic acid, It is also possible to use a mixture of organic acids such as acetic acid, oleic acid, and stearic acid. Further, at this time, a polymer binder may be added depending on the case. Examples of polymer binders include vinyl chloride resin, acrylic acid resin, polyester resin, polyethylene resin, and polyamide resin.

Polycarbonate resin, epoxy resin, methacrylic acid resin, vinyl acetate resin, nitrocellulose, polypropylene resin, polyethylene terephthalate resin.

Examples include phenol resins and copolymers thereof. In this case, the ratio of the resin to the compound represented by the general formula [I] is preferably 10 wt% or less.

Further, it is also possible to use the two organic compounds of the present invention by mixing and dispersing or mixing and dissolving other dyes. Examples of the dyes that can be used in combination include known aromatic or unsaturated aliphatic diamine metal complexes.

Aromatic or unsaturated aliphatic dithiol metal complexes.

Phthalocyanine complexes, naphthalocyanine complexes.

Examples include squalium dyes, naphthoquinone complexes, anthraquinone dyes, and polymethine dyes.

The recording layer containing the compound represented by the general formula [I] formed on the transparent substrate has a thickness of 10 μm or less, preferably 500 μm or less.
person/2 μm. Also after applying 5 chloroform,
By exposing the thin film to the vapor of an organic solvent such as tetrahydrofuran or toluene, the absorption wavelength of the thin film shifts to longer wavelengths, and in some cases, the sensitivity to light in the oscillation wavelength range of the semiconductor laser can be significantly improved.

In addition, in order to protect these recording layers, A6203+
A protective layer may be provided by depositing an inorganic compound such as 5jOz, SfO, or sno. 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 semiconductor 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.

Examples of the compound represented by general formula (1) are shown below.

(Margin below)! Otsu S ♂−m′? %, >=7 ,,,= Storen, yytorana□ri 1C)
z 0 / \ 1 ,, z (J (to = uO : r' -〇) Next, the present invention will be explained in more detail with reference to Examples, but the present invention is limited to the following Examples. The numbers in the middle are parts by weight.

Example 1 A solution consisting of 2.5 parts of compound (a) and 97.5 parts of chloroform was dropped onto an acrylic resin substrate, and then the substrate was rotated at a speed of 1100 Orp for 10 seconds.

Next, this substrate was dried at 45° C. for 20 minutes to obtain a recording medium. The thickness of this recording layer was 900.

The maximum absorption wavelength of the thin film was 790'nm, and the reflectance for light with a wavelength of 830 parts m was 27% on the surface of the compound (a)i film and 18% through the acrylic resin substrate.

Mount this optical recording medium on the turntable.

While rotating the turntable at 180 rpm.

1. 830 parts m laser 8 mW focused at 0 μm;
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, clear bits were observed.

In addition, this optical recording medium has a power of 830 copies and a power of 0°8mW.
When the laser beam was irradiated and two reflected lights were detected, the S/N ratio was 48 dB.

Example 2 Two parts of nitrocellulose resin were dissolved in 10 parts of methyl ethyl ketone, and 6 parts of phthalocyanine derivative (b) and 95 parts of dichloroethane were mixed and dissolved with the above resin solution.

After dropping this solution onto the Pyrex substrate, the substrate was rotated at 2000 rpm for 10 seconds. next.

This substrate was dried at 90° C. for 2 hours to obtain a recording medium.

The thickness of this recording layer was 600.

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 29% on the surface side of the phthalocyanine derivative (BL thin film) and 21% through the Pyrex substrate.

Further, when recording was performed on this recording medium in the same manner as in Example 1, clear focus was observed on the surface of the recording layer, and the same S/N ratio as in Example 1 was obtained.

Examples 3 to 14 Phthalocyanine derivatives (C) to (n) shown in Table I below were applied onto a polycarbonate resin substrate in the same manner as in Example 1 to obtain recording media.

Table III shows the maximum absorption wavelength of this thin film, the reflectance for light having a wavelength of 830 parts m, and the results of recording and reproducing data on this recording medium at 414 vtr in the same manner as in Example 1.

Table ■ 3 c 830 29 20 524 d
Boo 28 20 505 e 810
29 21 506 f 790 25
17 4B7 g 795 25 18 4
88 h 760 23 17 459 i
800 27 18 4610 j 81
0 2B 20 4811 k810 30
22 5013 m 810 29 20
4914 n 814 29 '19 4
7 [Effects of the Invention] The present invention has the above structure, is chemically and physically stable, and has sufficient absorption in the semiconductor laser oscillation region.

It has a characteristic that it has a reflectance, and furthermore, a recording medium can be created by a highly productive coating method.

Claims (1)

[Scope of Claims] 1. An optical recording medium characterized by having an organic thin film layer containing at least one 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, rings A_1 to A_4 represent a benzene ring, a naphthalene ring, or an anthracene ring. M represents Al, Ga, In, Tl, Si, Ge, Sn or Pb. X may be the same or different, and each independently represents a halogen atom, a hydroxyl group, an alkyl group that may have a substituent, an aryl group that may have a substituent, or a heterocycle that may have a substituent. group, -OR_1, -SR_1, -NR_2R_3,
-SO_2NR_4R_5, -CONR_4R_5, -
CH_2NHCOCH_2NR_4R_5, -COOR
Represents _5, -NO_2, -SO_3H or -CN. Here, R_1 is an alkyl group having 1 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an acyl group having 4 or more carbon atoms, or a polyether. R_2 and R_3 may be the same or different, and each is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, or R_2 and R_3 are They may be taken together to form a 4- to 7-membered heterocycle containing a nitrogen atom. R_4 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R_4
5 represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heterocyclic group, or -R_6-NR_7R_8, where R_6 is The alkyl group having 1 to 4 carbon atoms, R_7, and R_8 may be the same or different. An alkyl group, which may each have an exchange group, or R_7 and R_8 taken together represent a heterocycle containing a nitrogen atom, an oxygen atom, or a sulfur atom. Z is -OR_9, -SR_1_0, -SeR_1_0,
-NR_1_0R_1_1, where R_9 is -R
_6-NR_7R_8, and R_1_0 is hydrogen, an alkyl group having 1 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an acyl group having 4 or more carbon atoms, polyether or -R_6- NR_7R
Represents _8. Further, R_1_1 is similar to R_1_0. k, l, m, and n are each integers from 0 to 8, and represent the number of X. p is an integer of 1 or 2 and represents the number of Z.