JPH01269592A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To provide a recording film having large light absorption near a wavelength of 670nm or near a wavelength of 800nm through easy wet-type coating on any of a variety of plastic bases, by using a specified phthalocyanine coloring matter as a material for an optical recording medium. CONSTITUTION:A recording layer provided on a base comprises a phthalocyanine coloring matter of the formula, wherein M is a metal, a metallic oxide, a metallic chloride or two hydrogen atoms, m is the number of substituent groups R<3>, n is the number of substituent groups YR<4>, such that m+n is not more than 2, each of R<1> and R<2> is an up to 12C alkyl, R<2> is an aryl, aralkyl or fluoroalkyl, R<4> is an aryl, aralkyl, alkyl or fluoroalkyl, and each of X and Y is oxygen, sulfur or NH. The phthalocyanine coloring matter can be synthesized by using, for example, 3,6-dibutyl-4-nitrophthalonitrile and a fluoroalcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical information recording medium such as an optical disk containing a specific phthalocyanine dye as a light absorbing agent in a recording layer.

[Conventional technology and its problems]

In recent years, various materials containing dyes that absorb in the near-infrared region have attracted attention as recording materials that use laser beams.

In particular, information is recorded by making minute pits in the recording layer by irradiating it with a high-power laser beam, and when reproducing information, a low-power laser beam is irradiated onto the recording layer and the reflected light is converted into a playback signal. Materials for use in so-called heat mode write-once recording media are being actively developed.
This material must (a) have high absorption in the near-infrared region of a thin film, (b) be chemically stable, and (c) be easy to form into a thin film.

Many materials of this kind have already been proposed, including cyanine-based (polymethine-based), azo-based, anthraquinone-based, indanthrene-based, triarylmethane-based, naphthoquinone-based, phthalocyanine-based, and porphyrin-based materials. Compounds such as , dithiolar+-i system, croconic methine system, squarylium system, and indoaniline system are mainly studied. However, there is still no recordable recording medium that completely satisfies the above-mentioned conditions required of a write-once recording medium.

Now, the light source used to record and reproduce information using laser light is an AtGaAs semiconductor laser (
wavelength 780-830 nm), AtGaInP semiconductor laser (wavelength 650-690 nm), He-N
e laser (wavelength 633 nm), A, r ion laser
(wavelength 488 nm), etc. Among these, AtGa
InP-based semiconductor radar-1 and especially AtGaAs
In addition to being small and lightweight, semiconductor lasers have become inexpensive to produce, and in practical terms, they are superior to available laser light sources, so there is a need for recording materials that can support these oscillation wavelengths. ing.

Furthermore, optical recording materials are required to have read deterioration resistance. In other words, the optical recording material is required to have enough light absorption ability to form information pits by drilling holes in the layer of the recording material during recording, and at the same time, the pits are required to be formed by reproducing light with a lower output than during recording. When reading, it is required that the unrecorded portion of the recording layer is not deteriorated by the reproducing light.

On the other hand, it is advantageous for the substrate material used for optical recording media to be made from synthetic resins that can be easily molded, such as polymethyl methacrylate (PMMA), polycarbnate, epoxy resin, polyvinyl chloride, polymethyl Pentene, polysulfone, polyetherimide, etc. have been proposed, but they can be made with large diameters (for example, 300 mm in diameter) by injection molding.
Terimethyl methacrylate resin, which can be used to produce disc-shaped substrates (with excellent optical properties and low birefringence), and polycarbonate resin, which can be similarly injection molded and has excellent heat resistance and moisture absorption resistance, are suitable for use with laser beams. It is particularly preferred as an optical disk substrate material because concentric or spiral so-called pregrooves can be formed and transferred at the same time as guide grooves.

Furthermore, methods for forming the recording layer on the substrate can be roughly divided into a dry process in which the recording material is deposited in a vacuum system, and a wet process in which the recording material is attached or coated onto the substrate using a spin coater, dipping, or other means. However, since the former requires heating under high vacuum to cause sublimation or evaporation, the compound used for this process must first be thermally stable, and there must be a thermal decomposition point. In this case, it is essential to operate at a lower heating temperature, and it is more cost-effective than a wet process. In other words, the latter is economically advantageous. However, in the coating method, the compound used is dissolved in a suitable solvent, coated on the surface of the substrate material according to the purpose, and after the solvent evaporates, forms a continuous thin layer with uniform optical properties. is required.

That is, in order to form a thin layer with an appropriate thickness as a recording layer, the solubility of the compound used in the solvent must preferably be 8% or more by weight, although it depends on the type of solvent. Furthermore, it is necessary that the solvent used does not cause changes in the surface condition of the substrate material, such as dissolution, swelling, or penetration. When the substrate material is glass, there are no such restrictions on the solvent used.
The selection of the light absorber used as the recording medium can be made relatively freely, taking into consideration the magnitude of absorption in the near-infrared region and chemical stability, etc.; however, as a substrate material, solvent resistance This point is especially important when using plastics with poor quality.

As described above, when producing an optical information recording medium by forming a recording layer on a glass substrate by a coating method, there are at least three requirements: (1) the oscillation wavelength of the semiconductor laser, that is, around 670 nm; having absorption in the visible region or near-infrared region around 800 nm;
(2) It must be chemically stable, that is, there is no deterioration due to reproduction, and (3) It must have high solubility and the solvent must not have an adverse effect on the substrate material.

Among the materials being studied for use in the write-once recording medium exemplified above, phthalocyanine dyes are known to be particularly chemically stable. Furthermore, the light absorption wavelength thereof is generally 600 to 700 nm, and the material can be made to have absorption near a wavelength of 800 nm by selecting the central metal, etc., if necessary. However, the condition (3) above was not met.

That is, the solubility of phthalocyanine dyes is generally very poor, making it difficult to create optical recording media by coating. Canadian Journal of Chemistry (63) aimed at improving the solubility of phthalocyanine dyes.
Vol., pp. 623-631.

(1985) reported an example in which an alkyl group or an alkoxy group was introduced, but although the solubility in halogenated hydrocarbons was improved, the solubility in other solvents was insufficient. Therefore, it is difficult with such methods to obtain dyes that can be applied directly to plastic substrates such as injection molded polycarnate or injection molded polymethyl methacrylate.

[Means for solving problems]

The present inventors have discovered that a laser beam obtained from a semiconductor radar with an oscillation wavelength of around 670 nm or around 800 nm can be used for recording and reproduction, and can be applied not only to glass substrates but also to various resin substrates, especially injection molded polyester. We are working diligently to obtain an optical recording medium that can be manufactured by directly forming a film on easily available substrate materials such as methyl methacrylate substrates and injection-molded polycarbonate substrates by a coating method, and that does not deteriorate during playback. As a result of research, certain phthalocyanine dyes meet the above conditions (1), f2
), (3) must all be satisfied, that is, wavelength 6
Dogs absorb light around 70 nm or around 800 nm, and 1. It has been discovered that since it is chemically stable and dissolves well in various solvents, it is possible to wet coat not only glass substrates but also various plastic substrates and easily form a recording film by using these solvents. completed.

That is, the present invention provides an optical information recording medium including a support and a recording layer formed on the support, in which the recording layer has the following general formula (1) (where M is a metal, oxidation of the metal represents a compound, a metal chloride, or diatomic hydrogen, m represents the number of substituents R3, and 0
is an integer of ~2, n represents the number of substituents YR', and is 0~2.
2, provided that the value of m+n does not exceed 2, and R1 and R3 each independently have a carbon atom number of 12.
R2 represents an aryl group, an aralkyl group, or a fluorine-substituted alkyl group; R4 represents an aryl group, an aralgyl group, an alkyl group, or a fluorine-substituted alkyl group; X and Y each independently Represents any one of an oxygen atom, a sulfur atom, or a ■ group. ) The present invention relates to an optical information recording medium characterized by containing a phthalocyanine dye represented by:

Specific examples of the above M include Pb, Cu, Co+Ni+F
e, Mn*Sn + metal such as Mg, metal oxide such as vo, metal chloride such as htct, or HX2
(2 atomic hydrogen), etc., but when the absorption wavelength is set to around 800 nm based on the position of the absorption wavelength, etc., VQ * Mnepb etc. is preferable, and the wavelength is 670 nm.
Cu, Co, Mg+Fe if absorption is provided near the
etc., but are not limited to these in any case.

The above R and R are alkyl groups having 12 or less carbon atoms, such as methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-nonyl group, n-
Straight chain alkyl groups represented by dodecyl group, etc. and branched alkyl groups represented by isopropyl group, 2-methylpropyl group, tart-butyl group, tert-J methyl group, neopentyl group, 2-methylpentyl group, etc. selected from.

The above R is selected from an aryl group, an aralkyl group, or a fluorine-substituted alkyl group, and R is selected from an a+J-l group, an aralkyl group, an alkyl group, and a fluorine-substituted alkyl group; The substituents may or may not be the same. R2 and/or R
Aryl groups that can be used for 4 include phenyl group, 4-methylphenyl group, 2-methylphenyl group, 2,
4-methylphenyl group, 4-ethylphenyl group, 4-
In addition to (alkyl-substituted) phenyl or naphthyl groups represented by butylphenyl group, 4-(tert-butyl)phenyl group, 4-/nylphenyl group, β-naphthyl group, etc., 4-methoxyphenyl group, 4- Alkoxy- and/or alkylthio-substituted phenyl or naphthyl groups represented by butoxyphenyl group, 4-octyloxyphenyl group, 4-ethylthiophenyl group, etc., and aromatic groups represented by γ-pyridyl group, 8-quinolyl group, etc. Examples include heterocyclic compound residues, and similar aralkyl groups include hahennor, 2-phenylethyl, (4-methylphenyl)methyl, and (4-ethoxyphenyl)methyl groups. .

The above-mentioned fluorine-substituted alkyl group, which can be similarly used for R2 and/or R4, is a straight-chain or branched alkyl group substituted with one or more fluorine atoms, and specifically has the general formula -CH2( In addition to the linear type represented by CF2)kz (k is an integer of 1 to 5, Z represents a hydrogen atom or a fluorine atom), branched type represented by -CH(CHρCF) can be exemplified. On the other hand, as mentioned above, an alkyl group can be selected as R, but examples of this alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, and n-nonyl group. ,
Linear alkyl groups represented by n-dodecyl group, n-octadecyl group, etc., and isopropyl group, 2-methylpropyl group, tert-butyl group, tert-<methyl group, neopentyl group, 2-methylenthyl group, etc. It can be selected from among the representative branched alkyl groups. Note that the number of carbon atoms in the substituents R2 and R4 is preferably 20 or less per substituent.

In the above, X and Y are each independently selected from an oxygen atom, a sulfur atom, or an open group, and X bonds R2 and a phthalocyanine skeleton as shown in Pc-X-R2,
Similarly, Y bonds R4 and the phthalocyanine skeleton as shown by Pc-Y-R (here, Pc represents a phthalocyanine residue).

The above phthalocyanine dyes are described in Canadian Journal of Chemistry (vol. 63).

623-631. 1985) and others. For example, 3,6-cyptyl-4-nitrophthalonitrile and a fluoroalcohol are reacted in a polar solvent in the presence of potassium carbonate to produce 3,6-cyptyl-4-(fluoroalkoxy)phthalonitrile, which is combined with vC23. When reacted with urea, 8 butyl groups and 4 fluoroalkoxy groups were substituted/? Nanol (vO) phthalocyanine can be synthesized.

To illustrate yet another method for synthesizing phthalocyanine dyes used in the present invention, for example, 3,6-sibutylphthalic anhydride is synthesized using concentrated sulfuric acid or mixed with fuming sulfuric acid,
By reacting with chlorine, 3,6-cyptyl-4
, 5-nochlorophthalic anhydride was synthesized, and this was inorganic chemistry (vol. 23, 1065-1).
071, 1984), the resulting product and p-)luenethiol were mixed in quinoline in the presence of an alkali by adding and heating sulfur trichloride and urea. When heated, 8 butyl groups and 4-
A Z-nasyl phthalocyanine substituted with eight methylphenylthio groups can be synthesized.

The optical information recording medium of the present invention can be used as a write-once memory, such as an optical disk, an optical card, an optical tape, an optical drum, etc., and can also be used as a 9-turn recording material.

In the present invention, the support can be in any shape such as a disk, card, tape sheet, etc., and its material can be glass, metal, glass, ceramics, or any other arbitrary material. type optical disc,
In particular, it is preferable to apply the present invention to a write-once optical disc using a plastic substrate having green loops.

As the plastic mentioned above, any material such as acrylic resin represented by polymethyl methacrylate, polycargonate resin, epoxy resin, polymethyl inten resin, etc. can be used, but transparent glass substrates used for the backside recording method (so-called Ph1lips method) are used. It is preferable to use injection molded polymethyl methacrylate resin substrates and injection molded polycargonate resin substrates onto which pregrooves are transferred during injection molding, because they can be obtained relatively inexpensively.

The phthalocyanine dye used in the present invention may be dissolved in a solvent and applied directly onto the substrate or support.
May be used together with a binder.

The binder may be any known polymeric material, such as polyvinyl acetal resins such as polyvinyl butyral and polyvinyl formal, cellulose derivative resins such as nitrified cotton and acetic acid cotton, as well as polystyrene resins, vinyl chloride resins, vinyl acetate resins, and polyester resins. and various acrylic resins. Also,
It can be appropriately selected from among oligomers corresponding to the above-mentioned polymeric material having a molecular weight of about several hundred to several hundred, and copolymer polymers and/or oligomers synthesized from each component monomer of the above-mentioned polymeric material.

In addition, additives such as stabilizers, lubricants, antistatic agents, surfactants, and plasticizers can be added as necessary.

The film thickness of the recording layer of the optical information recording medium of the present invention is generally 100X to 5 μm, although it depends on whether or not Guingu is used.
, preferably from 200X to 1 μm, and preferably from 200X to 5.0OOX when no binder is used. Note that the recording layer of the present invention may be used with other recording layers and/or
Alternatively, it can be used as a laminated film in combination with a protective layer and a base layer.

The above-mentioned solvents include ketones such as acetone, selonlubs such as methylselonlube, alcohols such as trifluoroethanol, amides such as dimethylformamide, ethers such as noethyl ether, and esters such as methyl acetate. halogenated hydrocarbons such as chloroform, and aromatics such as benzene can be used alone or in combination. At this time, it is of course preferable to select a solvent that does not affect the substrate used. Application or attachment of the above solution can be performed by any means such as spin coating, Dizzo coating, roller coating, etc.

The phthalocyanine dye used in the present invention is preferably used in a wet type as described above, but depending on the case, it can also be used in a dry process such as vapor deposition or CVD.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to synthesis examples and examples of phthalocyanine dyes used in the present invention, but the present invention is not limited to these examples.

Synthesis Example 1 3-Methyl-4,5,6-)lichlorophthalic anhydride 2
．． 4g and pananium trioxide 0.63. ! i' and urea 1
The reaction was carried out at 200° C. for 2 hours in 0 g. After the reaction was completed, the product was cooled to room temperature, 50% methanol was added to sufficiently disperse the solid product, and the solid was dissolved in 50% methanol.
Washed twice. In this way, a crude product of dodecachlorotetramethylphthalocyanine vana sol was obtained.

Next, potassium hydroxide 2.41 and p-toluenethiol 4
．． 6 g of quinoline at 140° C. for 2 hours, the above dodecachlorotetramethylphthalocyanine vanadyl was added, and the mixture was reacted at 180° C. for 2 hours. The reaction slurry was cooled to room temperature, diluted with 300% ethanol, and filtered. The filtered black solid was diluted with 50% of ethanol.
After washing twice to obtain 1.42 g of a crude product, this was purified with a silica ram using chloroform as an eluent to obtain dodeca(4-methylphenylthio)tetramethylphthalocyanine vanadyl (hereinafter referred to as D-1). ) 0.45g was obtained. The absorbance spectrum of the toluene solution of D-1 is shown in FIG. 1, and λmax was 766 nm.

Example 3. Phthalocyanine dye D-1 synthesized in Synthesis Example 1.
Dissolve 5 parts by weight in 100 parts by weight of noisobutyl ketone,
It was filtered using a Teflon filter (-A size 0.2 micron) to obtain a coating solution. This is then injection molded with a diameter of 1, which is the 1.6 micron pitch guide groove of the system stamper.
An optical information recording medium was obtained by coating on a 30 m polycarnate substrate by a spin code method.

The light transmittance of this medium is shown in Figure 2, and 83
The transmittance at 0° C.m was 47%, and the reflectance at 830° C.m measured from the substrate side was 18%.

Furthermore, a semiconductor laser beam of 830° C.m was focused on this recording medium and irradiated from the substrate side. Signal recording was performed by irradiating the irradiated surface with pulsed light at a linear velocity of 4.0 m/see, a power of mW, and a recording frequency of I MHz. When this recording section was focused and irradiated with continuous semiconductor laser light with a power output of 1.0 mW on the irradiation surface and the reflected light signal was reproduced, a C/N ratio of 52 dB was obtained. Although this regeneration operation was continued for 30 minutes, there was no decrease in the C/N ratio at all.

[Brief explanation of the drawing]

Figure 1 shows the fucrocyanine dye D- obtained in Synthesis Example 1.
FIG. 2 shows the light transmittance spectrum of the optical information recording medium of the present invention prepared using the phthalocyanine dye D-1. Patent applicant Daicel Chemical Industries, Ltd. Figure 1 600 700 Boo 9003 Chief (n
m) 3 length (n m)

Claims (1)

[Claims] 1. An optical information recording medium comprising a support and a recording layer formed on the support, wherein the recording layer has the following general formula (
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, M represents a metal, metal oxide, metal chloride, or diatomic hydrogen, m represents the number of substituents R^3,
is an integer from 0 to 2, n represents the number of substituents YR^4,
An integer from 0 to 2, provided that the value of m+n does not exceed 2, R^1 and R^3 each independently represent an alkyl group having 12 or less carbon atoms, R^2 is an aryl group, represents an aralkyl group or a fluorine-substituted alkyl group,
R^4 represents an aryl group, an aralkyl group, an alkyl group, or a fluorine-substituted alkyl group, and X and Y each independently represent any one of an oxygen atom, a sulfur atom, or an NH group. ) An optical information recording medium characterized by containing a phthalocyanine dye represented by: 2. The optical information recording medium according to claim 1, wherein the recording layer is formed by coating the support with a solution containing the phthalocyanine dye. 3. The optical information recording medium according to claim 1 or 2, wherein the support is a plastic molded product. 4. The optical information recording medium according to claim 3, wherein the support is an injection molded disk of acrylic resin or polycarbonate resin with or without pregrooves.