JP3162087B2 - Optical information recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium having a recording layer made of an organic dye-based recording material.

[0002]

2. Description of the Related Art At present, a general CD having a high reflectance is used.
(Compact Disc) An optical information recording medium on which an output signal conforming to the CD format can be obtained and writable information, that is, a write-once CD is actively developed by a player. In this optical information recording medium, a recording layer made of an organic dye-based recording material, a reflective layer made of a metal material and the like, and a protective layer made of a resin material and the like are arranged in this order on at least the predetermined substrate side. It is provided with a configuration.

Meanwhile, an optical information recording medium provided with a recording layer made of an organic dye-based recording material is generally susceptible to deterioration of the recording layer by sunlight or electric light, and particularly when moisture is present, the deterioration is remarkable. Become. It is considered that the cause of this deterioration is that oxygen in the atmosphere is activated in the organic dye by light energy and changes to singlet oxygen, and this singlet oxygen reacts with the unsaturated group of the organic dye. .

[0004] The applicant of the present application firstly described an organic dye recording material such as a cyanine organic dye and a deterioration inhibitor for the organic dye recording material in order to improve the easiness of deterioration of a recording layer made of the organic dye recording material. An optical information recording medium provided with a recording layer containing an added aminium-based dye as a main component was proposed (filed on November 30, 1990). In this optical information recording medium, the light resistance and storage stability of the recording layer can be remarkably improved as compared with those obtained by adding a dithiolene nickel complex as a deterioration inhibitor of the organic dye-based recording material.

[0005]

Needless to say, the recording layer of an optical information recording medium is more preferable as it has superior light resistance and storage stability, and there is no standard that the recording layer is necessary and sufficient. . In order to put an optical information recording medium having a recording layer made of an organic dye-based recording material into practical use and to obtain high reliability, it is necessary to develop a recording layer material having even better light resistance and storage stability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made to further improve the light resistance and preservability of a recording layer in an optical information recording medium proposed by the present applicant. The purpose is to do.

[0007]

In order to achieve the above-mentioned object, the present invention provides two or more kinds of organic dye recording materials, both of which are represented by the formula (4), wherein the alkyl chain A or Two or more organic dye recording materials in which at least one of the alkyl chains B is different, and an aminium-based dye represented by Chemical Formula 5 or 6 added as a deterioration inhibitor for the organic dye recording material In an optical information recording medium provided with a recording layer having, as main components, the number of carbon atoms of the alkyl chains A and B added to the heteroaromatic ring of the organic dye recording material, the number of methine groups of the organic dye recording material When n is 1, the number of carbon atoms in the alkyl chain A is 1 and the number of carbon atoms in the alkyl chain B is 3 to 5, or the number of carbon atoms in the alkyl chain A is 2 and the number of carbon atoms in the alkyl chain B is 2 to 2. 4 or When the number of carbon atoms of the alkyl chain A is 3 and the number of carbon atoms of the alkyl chain B is 1 to 3, and the number n of methine groups of the organic dye recording material is 2, The number of carbon atoms of the alkyl chain B is set to 4 to 6 with the number of carbon atoms being 1; the number of carbon atoms of the alkyl chain B is set to 3 to 5 with the number of carbon atoms of the alkyl chain A being 2; In which the number of carbon atoms of the alkyl chain B is 2 to 4.

[0008]

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[0009]

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[0010]

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Wherein R in the chemical formulas ( ₅ ) and ( ₆ ) represents hydrogen, an allyl group or an alkyl group, and X represents a perchlorate ion (ClO 4-), a hexafluoroantimonate ion (SbF _6- ), Acid ion (AsF ₆
-) Or fluorinated borate ion (BF _6- ). In the above, the (-) symbol in parentheses indicates a negative ion.

[0012]

According to experiments, the number of carbon atoms of the alkyl chains A and B added to the heteroaromatic ring of the organic dye recording material and the number of methine groups of the organic dye recording material are determined by the light resistance and storage stability of the organic dye recording material. When the number of carbon atoms of the alkyl chains A and B added to the heteroaromatic ring of the organic dye recording material is adjusted as described above according to the number of methine groups of the organic dye recording material, The most excellent light fastness and preservability could be obtained.

In the optical information recording medium of the present invention, as the organic dye recording material, at least one of the alkyl chain A and the alkyl chain B added to the heteroaromatic ring is different. Since the organic dye recording material is used, the peak of the absorption wavelength of the recording layer can be broadened, and the matching property with recording / reproducing light (for example, laser light) can be improved.

[0014]

EXAMPLES (Experimental Example 1) In the cyanine-based or polymethine-based organic dye recording material shown in FIG. 1, the alkyl chains A and B added to the heteroaromatic ring are different from the methine-based organic dye recording material. Depending on the number n of the groups, the 18 combined as shown in FIG.
Various kinds of organic dye recording materials were prepared. As shown in FIG. 1, when the number n of methine groups in the organic dye recording material is 1, the number of carbon atoms in the alkyl chain A is set to 1 and the number of carbon atoms in the alkyl chain B is set to 3 to 5, or If the number of carbon atoms in the alkyl chain B is 2 and 4 and the number of carbon atoms in the alkyl chain B is 3 and the number of carbon atoms in the alkyl chain B is 1 and 2
The alkyl chains A and B are selected and combined so as to be any one of the groups A to B. When the number n of the methine groups of the organic dye recording material is 2, the number of carbon atoms of the alkyl chain B is 4 to 4 with the number of carbon atoms of the alkyl chain A being 1.
6, the number of carbon atoms in the alkyl chain A is 2, and the number of carbon atoms in the alkyl chain B is 3 to 5, or the number of carbon atoms in the alkyl chain A is 3, and the number of carbon atoms in the alkyl chain B is 2 to 4. The alkyl chains A and B are selected and combined so as to be any of the following.

Next, a mixed solution of 1,2 dichloroethane and ethyl cellosolve in which each of the organic dye recording materials described above and the aminium dye shown in Chemical formula 7 are dissolved is applied to one surface of a separate disk-shaped polycarbonate substrate. Spin coating,
The substrate with the coating film was baked at 90 ° C. for 3 hours to prepare 18 types of substrates with a recording layer having an organic dye-based recording layer having a thickness of about 100 nm formed on the substrate. The concentration of the aminium dye in the organic dye recording material was 30% by weight.

[0016]

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Further, a gold thin film was formed on the organic dye-based recording layer of the substrate with the recording layer by a vacuum evaporation method to form a reflection layer.

Finally, an ultraviolet curable resin was spin-coated on the reflective layer, and cured by irradiating ultraviolet rays to form an overcoat layer. Thereby, as shown in FIG. 3, the organic dye-based recording layer 2 and the reflective layer 3
And overcoat layer 4 were sequentially laminated to produce 18 types of optical information recording media.

(Comparative Example 1) Instead of the cyanine-based or polymethine-based organic dye recording material used in Experimental Example 1, the optical information recording shown in FIG. A medium was prepared. The kind and concentration of the aminium-based dye added as a deterioration inhibitor of the organic dye recording material, and the method of manufacturing the optical information recording medium are the same as in Experimental Example 1.

[0020]

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(Comparative Example 2) Optical information recording shown in FIG. 3 using a dithiolene nickel complex as a deterioration inhibitor of the organic dye recording material constituting the recording layer 2 instead of the aminium dye used in Experimental Example 1. A medium was prepared. The concentration of the dithiolene nickel complex relative to the organic dye recording material was 30% by weight. Other than that, the manufacturing method of the optical information recording medium is the same as that of the experimental example 1.

The optical information recording media of Experimental Example 1, Comparative Example 1, and Comparative Example 2 described above were subjected to a temperature of 30 ° C. and a relative humidity of 8
The sample was placed in an environment of 0% and illuminance of 9000 lux (xenon lamp) for 500 hours, and the relative deterioration rate of the reflectance of the optical information recording medium was measured. The result is shown in FIG. As is clear from FIG. 2, the optical information recording medium of Example 1 has a significantly lower relative deterioration rate of the reflectance than the optical information recording media of Comparative Example 1 and Comparative Example 2; Is extremely small.

(Experimental Example 2) An organic dye recording material represented by the following chemical formula 9 and a chemical formula 1 shown below
The recording layer 2 was formed from a mixture of an organic dye recording material represented by No. 0 and an aminium-based dye represented by Chemical Formula 7. The organic dye recording material (sum of the organic dye recording material represented by Chemical Formula 9 and the organic dye recording material represented by Chemical Formula 10)
The concentration of the aminium-based dye and the method of manufacturing the optical information recording medium are the same as those in Experimental Example 1.

[0024]

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[0025]

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(Experimental Example 3) The organic dye recording material represented by Chemical Formula 8 and Chemical Formula 9
A recording layer was formed from a mixture of the dye represented by Chemical Formula 10 and an aminium-based dye. The concentration of the aminium-based dye with respect to the organic dye recording material and the method of manufacturing the optical information recording medium are the same as in Experimental Example 1.

The absorption spectra of the recording layer formed on the optical information recording medium of Experimental Example 2 and the recording layer formed on the optical information recording medium of Comparative Example 1 were measured. FIG. 4 shows the results. As is clear from FIG. 4, the recording layer of Experimental Example 2 has a significantly broader absorption peak than the recording layer of Comparative Example 1, which facilitates matching with recording / reproducing light (for example, laser light). ing.

Example 4 A recording layer was formed from a mixture of the organic dye recording material shown in FIG. 1, the aminium dye shown in Chemical formula 7, and a dithiolene nickel complex as another deterioration inhibitor. . The concentration of the aminium-based dye with respect to the organic dye recording material and the method of manufacturing the optical information recording medium are the same as in Experimental Example 1. Also in this case, the same effect as in Experimental Example 1 was obtained.

In the experimental examples 1, 2, 3, and 4, the case where the number n of the methine groups of the organic dye-based recording material is 1 and 2 has been described. Assuming that the number of carbon atoms in the chain B is b, a + b = n + (3
To 5), an organic dye-based recording material having an arbitrary number of methine groups can also be used.

In the experimental example and the comparative example, the recording layer 2 is formed as a single layer. However, as shown in FIG.
The recording layer 2 may be formed by alternately laminating the organic dye-based recording material 2a and the aminium-based dye 2b in multiple layers.

In the above experimental examples and comparative examples, polycarbonate was used as the substrate material. Instead of this, a transparent resin material such as polymethyl methacrylate, polymethyl pentene, epoxy, polyolefin, or a transparent ceramic material such as glass was used. The same effect can be obtained by using such a method.

In the experimental examples and comparative examples, gold was used as the material of the reflective layer. However, similar effects could be obtained by using aluminum, stainless steel, or the like instead.

Further, in the above-mentioned experimental examples and comparative examples, an ultraviolet curable resin was used as a material for the overcoat layer. However, similar effects can be obtained by using an inorganic dielectric such as aluminum nitride, silicon nitride or silicon oxide. Was completed.

[0034]

As described above, according to the present invention,
Since the carbon number of the alkyl chain added to the heteroaromatic ring of the organic dye recording material was appropriately adjusted according to the number of methine groups of the organic dye recording material, the light resistance of the recording layer could be significantly improved, The optical information recording medium can be stably stored for a long time without deteriorating the layer. Further, according to the present invention, as an organic dye recording material, an alkyl chain A or an alkyl chain B added to a heteroaromatic ring is used.
2 in which at least one of the chains is different
Since more than one kind of organic dye recording material is used, the peak of the absorption wavelength of the recording layer is broadened, and the matching property with recording / reproducing light (for example, laser light) can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure of an organic dye recording material constituting a recording layer of a first experimental example.

FIG. 2 is a table showing the effects of the optical information recording medium according to the first experimental example.

FIG. 3 is a sectional view showing a sectional structure of the optical information recording medium according to the present invention.

FIG. 4 is a graph showing the effect of the optical information recording medium according to the second experimental example.

FIG. 5 is a sectional view showing another example of the optical information recording medium according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 organic dye-based recording layer 3 reflection layer 4 overcoat layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Atsushi Yusa 1-88 Ushitora, Ibaraki-shi, Osaka Hitachi Maxell, Ltd. (56) References JP-A-64-40390 (JP, A) JP-A-60 JP-205841 (JP, A) JP-A-2-204089 (JP, A) JP-A-3-142281 (JP, A) JP-A-64-75454 (JP, A) JP-A-60-163245 (JP, A ) JP-A-63-312186 (JP, A)

Claims (1)

(57) [Claims] 1. Two or more kinds of organic dye recording materials represented by Chemical formula 1, wherein at least one of an alkyl chain A and an alkyl chain B added to a heteroaromatic ring is different. An optical information recording medium comprising a recording layer mainly composed of two or more kinds of organic dye recording materials and an aminium dye represented by Chemical formula 2 or 3 added as a deterioration inhibitor of the organic dye recording material. When the number n of methine groups in the organic dye recording material is 1, the number of carbon atoms in the alkyl chain A and the number B of carbon atoms in the alkyl chain A are 1, the number of carbon atoms of the alkyl chain B is 3 to 5, the number of carbon atoms of the alkyl chain A is 2 and the number of carbon atoms of the alkyl chain B is 2 to 4, or the number of carbon atoms of the alkyl chain A is 3 and the alkyl chain is 3. Carbon number of B 1 to 3
When the number n of the methine groups of the organic dye recording material is 2, the number of carbon atoms of the alkyl chain A is set to 1 and the number of carbon atoms of the alkyl chain B is set to 4 to 6, or The number of carbons of the alkyl chain A is set to 2 and the number of carbons of the alkyl chain B is set to 3 to 5;
An optical information recording medium, characterized in that: Embedded image Embedded image Embedded image Here, R in Chemical Formulas 2 and 3 represents hydrogen, an allyl group or an alkyl group, and X represents a perchlorate ion, a hexafluoroantimonate ion, a hexafluoroarsenate ion, or a fluoroborate ion.