JPH04201385A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To obtain an optical information recording medium of additionally writing type having an organic dye recording layer remarkably superior in light resistance and shelf stability by a method wherein one or more of anti- oxidizing agents or deterioration inhibitors of an aluminum dye or an organic dye having a specific structural formula is added in the recording layer. CONSTITUTION:In an optical information recording medium provided with a recording layer 2 mainly composed of a recording material of a hardly water- soluble organic dye on a predetermined substrate 1 for conducting recording and regeneration using a laser light, the recording layer contains an aluminum dye shown by a formula I or II as a inhibitor for inhibiting the deterioration of the organic dye recording material (in the formula, R represents alkyl group or the like, and X represents perchloric ion or the like). The aluminum dye is contained in the concentration of 5-60wt.% per the organic dye recording material. As the deterioration inhibitor, dithiolene nickel complex is incorporated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical information recording medium, and more particularly to a write-once optical disc having an organic dye-based recording layer with excellent light resistance and storage stability.

[Conventional technology]

Currently, CDs have a high reflectance and are used to play back recorded information.
2. Description of the Related Art Writable optical information recording media, so-called write-once CDs, which can obtain output signals conforming to the (compact disc) format, are being actively developed. This write-once type C
In configuration D, a recording layer made of an organic dye material is formed on a predetermined substrate, and a reflective layer made of metal is provided thereon.

However, organic dye-based recording layers are generally deteriorated by sunlight, and the deterioration is particularly noticeable when moisture is present. The cause of this deterioration is thought to be that atmospheric oxygen is activated in the organic dye by light energy and turns into singlet oxygen, and this doublet oxygen reacts with the unsaturated groups of the organic dye. There is.

In order to improve the light resistance of the organic dye-based recording layer, an optical information recording medium with a singlet oxygen quencher added to the recording layer (
For example, Japanese Patent Laid-Open No. 59-55795) is known, but an organic dye-based recording medium that can withstand sunlight for a long time has not yet been realized.

On the other hand, optical information recording media using aminium-based dyes as organic dye-based recording materials (for example, Japanese Patent Laid-Open No. 60-2043
No. 94) has been proposed, but the light resistance and storage stability of the recording layer have not yet been fully satisfied.

[Problem to be solved by the invention]

As mentioned above, conventional optical information recording media having a recording layer made of an organic dye-based recording material have a problem of poor light resistance and storage stability.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an optical information recording medium in which recording and reproduction is performed using laser light, in which the recording layer does not deteriorate even when used for a long time. An object of the present invention is to provide a write-once optical information recording medium having an organic dye-based recording layer having excellent light resistance and storage stability.

[Means to solve the problem]

In order to achieve the above-mentioned objects of the present invention, 1. An optical information recording medium that has a recording layer made of a water-insoluble organic dye-based recording material on a disk-shaped substrate, and performs recording and reproduction using a laser beam. - in the recording layer, one selected from an aminium dye having a structural formula represented by the following formula (1) or (2), an antioxidant for an organic dye, or a deterioration inhibitor; This is achieved by adding more than one species.

(In the formula, R is hydrogen, an alkyl group such as C4H, or C
H,= Allyl group such as CHCH2, X is perchlorate ion, hexafluoroantimonate ion.

Hexafluoroarsenate ion, fluoroborate ion, etc.) As an antioxidant or an antioxidant having reducing properties to be added to the recording layer made of the organic dye-based recording material of the present invention,
For example, indoles, conjugated 6π electron compounds, conjugated dienes such as 5-membered ring conjugated dienes, allyl olefins, phenol derivatives, aromatic amine derivatives, etc. can be suitably used.

Furthermore, in addition to the aminium dye or antioxidant added to the recording layer, it is also effective to use an organic dye deterioration inhibitor mixed with the above additives.

Examples of organic dye-based heat mode recording materials constituting the recording layer of the optical information recording medium of the present invention include polymethine dyes, anthraquinone dyes, cyanine dyes, phthalocyanine dyes, triphenylmethane dyes, pyrylium dyes, Examples include azulene dyes and metal-containing azo dyes.

In the optical information recording medium of the present invention, the concentration of the aminium dye added to the organic dye recording layer is preferably in the range of 5 to 60% by weight based on the organic dye recording material, and if it is less than 5%, the light resistance will be improved. is small, and even if the amount exceeds 60%, no significant improvement in light resistance can be expected. Also,
The amount of the organic dye antioxidant or deterioration inhibitor added is preferably 100 parts by weight or less per 100 parts by weight of the organic dye-based recording material, and if it exceeds 100 parts by weight, the characteristics of the recording layer may change, so it is preferable. do not have.

The thickness of the organic dye recording layer containing the aminium dye of the present invention, or the aminium dye and an organic dye antioxidant or deterioration inhibitor, is preferably in the range of 30 to 150 r++1, and if it is less than 30 nm, the recording layer will deteriorate. This is not preferable because the deterioration becomes significant, and the thicker the recording layer is, the smaller the deterioration will be. However, if the recording layer is made too thick, the optical properties of the organic dye-based recording material are likely to change.
m or less is desirable.

As the substrate material used in the optical information recording medium of the present invention, transparent resin materials such as polycarbonate, polymethine methacrylate, polymethylpentene, epoxy, transparent glass materials, transparent ceramic materials, etc. can be used.

[For production]

In the optical information recording medium of the present invention, the aminium dye added as a deterioration inhibitor of the organic dye-based recording material constituting the recording layer is, for example, when added to the organic dye-based recording layer consisting of cyanine dye. The light resistance is as shown in Table 1. In addition, the O mark in the table is the best, the Q mark is good,
A Δ mark indicates good, and an x mark indicates no effect, each indicating an effect of improving light resistance.

Table 1 From Table 1, it can be seen that when R in the aminium dye is an allyl group with an unsaturated group, the effect of improving the light resistance of the recording layer is even greater.This is because the position of the double bond of the allyl group This is thought to be because singlet oxygen binds to form a stable aminium dye.

〔Example〕

Embodiments of the present invention will be described below in more detail with reference to one drawing.

(Example 1) FIG. 1 is a schematic diagram showing an example of the cross-sectional structure of the optical disk produced in this example. )
1 in which an aminium dye having the structural formula shown by the formula and a cyanine dye which is an organic dye heat mode recording material are dissolved.
Using a mixed solution of 2-digloloethane and ethyl cellosolve, spin coding was performed to form an organic dye recording layer 2 containing an aminium dye. Note that the concentration of the aminium dye to the cyanine dye is 10°20.30.
An optical disc having four kinds of organic dye-based recording layers 2 containing 60% by weight was produced.

Next, a gold (Au) film is formed by vacuum evaporation on the organic dye-based recording layer 2 containing the aminium dye, and the reflective layer 3
Further, after spin-coding an ultraviolet curable resin on the reflective layer 3, the resin was cured by irradiation with ultraviolet rays to form an overcoat layer 4, thereby producing an optical disc.

(Comparative Example 1) An optical disc was produced in the same manner as in Example 1, except that a dithiolene nickel complex was used as a deterioration inhibitor for the organic dye-based material constituting the recording layer instead of the aminium-based dye used in Example 1. was created.

The optical discs produced in Example 1 and Comparative Example 1 above were heated at a temperature of 30°C, a relative humidity of 80%, and an illuminance of 900012x (
The disc was placed under an environment of a xenon lamp), and the rate of increase (%) in reflectance of the disc was measured. The results are shown in FIG.

As is clear from the figure.

The aminium dyes prepared in Example 1 were 1o to 6.
The optical disc containing 0% by weight had a significantly smaller rate of increase in reflectance than the optical disc using the dithiolene nickel complex of Comparative Example 1, indicating that the recording layer was significantly less degraded by light.

In Example 1, when the concentration of the aminium dye to the cyanine dye was 30% by weight, the rate of increase in reflectance was the smallest, and even if the amount exceeded 60% by weight, the organic dye recording layer This indicates that little improvement in light resistance can be expected.

Furthermore, in this example, the aminium dye was used as a deterioration inhibitor for the organic dye recording material, but it goes without saying that it can also be used as a binder for the recording layer.

(Example 2) In the same manner as in Example 1, the film thickness of the organic dye-based recording layer was set to 10
Ten types of optical discs were manufactured with different wavelengths ranging from nm to 1100 nm. This is carried out at a temperature of 30°C and a relative humidity of 80%.
Place it in an environment with an illuminance of 9000Rx (xenon lamp),
The time (h) until the reflectance of the optical disc increased by 5% was measured. The results are shown in FIG. As is clear from the figure, the larger the thickness of the organic dye-based recording layer, the less the deterioration of the organic dye-based recording layer of the optical disc. However, if the thickness of the organic dye-based recording layer is made too large, the optical properties of the organic dye recording material may change and information may not be recorded.
It is preferable to set it as the range of 150 nm.

(Example 3) N,N'-diphenyl-P was added as an antioxidant to an organic dye recording layer containing 30% by weight of an aminium dye.
- In addition to adding phenylenediamine in an amount of 100 parts by weight or less per 100 parts by weight of the organic dye-based recording material,
An optical disc was produced in the same manner as in Example 1.

(Comparative Example 2) An optical disc was produced in the same manner as in Example 3, except that the addition of the antioxidant was omitted.

The optical discs produced in Example 3 and Comparative Example 2 above were
The optical disc was placed in an environment with a temperature of 30° C., a relative humidity of 80%, and an illuminance of 9000ΩX (xenon lamp), and the rate of increase (%) in reflectance of the optical disc was measured to examine light resistance. As is clear from the results shown in Figure 4, the optical disc of Example 3, in which the aminium dye and antioxidant were added to the organic dye recording layer, had significantly improved light resistance. I understand.

(Example 4) Instead of the aminium dye used in Example 1, N, N
Four types of optical discs were prepared in the same manner as in Example 1 except that '-diphenyl-P-phenylenediamine was used.
When the rate of increase in reflectance was measured, almost the same results as in Example 1 (■ to ■) shown in FIG. 2 were obtained, and it was found that there was an effect of improving light resistance.

(Example 5) Instead of the antioxidant (N,N'-diphenyl-p-phenylenediamine) used in Example 3.

An optical disc was prepared in the same manner as in Example 3, except that a dithiolene nickel complex was used as the deterioration inhibitor for the organic dye-based recording material, and the rate of increase in reflectance of the optical disc was measured. The results are shown in Figure 4. Almost the same effect of improving light resistance as in Example 3 was obtained.

〔Effect of the invention〕

As explained in detail above, an appropriate amount of an aminium dye, an organic dye antioxidant or a deterioration inhibitor is added to the recording layer made of the poorly water-soluble organic dye material of the present invention, and the film of the organic dye recording layer is Since the light resistance can be significantly improved by controlling the thickness, the optical information recording medium can be stored stably for a long period of time without deteriorating the recording layer.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the structure of an optical disk manufactured in Example 1 of the present invention, and FIG. 2 shows the relationship between the environmental test time and the rate of increase in reflectance of the optical disk in Example 1 and Comparative Example 1. 3 is a graph showing the relationship between the film thickness of the recording layer of the optical disc in Example 2 and the rise time of reflectance. FIG. 4 is a graph showing the relationship between the environmental test time and reflection of the optical disc in Example 3 and Comparative Example 2. It is a graph showing the relationship between the rate of increase and the rate of increase.

Claims (1)

[Claims] 1. An optical information recording medium that has a recording layer mainly composed of a poorly water-soluble organic dye-based recording material on a predetermined substrate, and performs recording and reproduction using laser light, The recording layer contains the following structural formula (
Optical information recording medium characterized by containing the aminium dye shown in 1) or (2) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼... (1) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ ...(2) (In the formula, R 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.) 2. In claim 1, the concentration of the aminium dye contained in the recording layer is 5 to 50% relative to the organic dye recording material.
An optical information recording medium characterized by containing 60% by weight. 3. An optical information recording medium that has a recording layer mainly composed of a poorly water-soluble organic dye-based recording material on a predetermined substrate, and performs recording and reproduction using a laser beam. Indole, as an antioxidant for organic dye-based recording materials.
An optical information recording medium comprising at least one compound selected from a conjugated 6π electron compound, a conjugated diene, an allyl olefin, a phenol derivative, and an aromatic amine derivative. 4. The optical information recording according to claim 3, wherein the concentration of the antioxidant contained in the recording layer is 100 parts by weight or less based on 100 parts by weight of the organic dye-based recording material. Medium. 5. An optical information recording medium according to claim 1 or 2, characterized in that it contains the antioxidant according to claim 3 or 4. 6. The optical information recording medium according to any one of claims 1 to 5, which contains a dithiolene nickel complex as a deterioration inhibitor of the organic dye-based recording material constituting the recording layer. Characteristic optical information recording media. 7. The optical information recording medium according to any one of claims 1 to 6, wherein the organic dye recording material constituting the recording layer is a cyanine dye. . 8. The optical information recording medium according to any one of claims 1 to 7, wherein the recording layer has a thickness of 30 to 15
An optical information recording medium characterized by having a particle diameter of 0 nm.