JPS6228291A - Optical information-recoding medium - Google Patents

Abstract

PURPOSE:To prevent oxidation deterioration of a coloring matter or lowering of light absorbance from occurring, by producing a recording medium by providing a thin film layer comprising as a main constituent an organic coloring matter comprising 0.01-30wt% of an amine compound of a specified general formula on a base. CONSTITUTION:An amine compound of formula I, wherein each of R1, R2, R4 and R5 is 1-6C alkyl, and R3 is -OR6 or formula II, III, IV or V (wherein R6 is phenyl, alkoxyl, amino or hydrogen, each of R7 and R8 is 1-6C alkyl, X is O or S, and Y is O or S) is dissolved in a solvent to prepare a coating liquid. The coating liquid is applied to the base 1, and is dried to provide a recording layer 2 comprising as a main constituent an organic coloring matter comprising the amine compound, thereby obtaining an optical information- recording medium. It is necessary that the amine compound be contained in the recording layer 2 in an amount of 0.01-30wt%.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical information recording medium.

[Prior art and problems]

2. Description of the Related Art Conventionally, optical information recording devices for writing and reproducing data using laser light have been known. Media used for these recordings include those mainly made of metal such as TerBlrA3, and those in which silver halide emulsion is coated and heated to form a reflective recording layer, and these have been put to practical use. However, in the former method, the medium is produced by a thin film formation method using vapor deposition, which has the disadvantage of high cost and toxicity, which poses problems when discarded. In addition, the latter method is superior in mass production because the recording film is prepared by coating, but it has the disadvantage that noise may be included in the reproduced signal because the recording layer is of a silver particle dispersion type.

Therefore, it has been proposed to form a thin pigment film with metallic luster by a coating method (Japanese Patent Laid-Open No. 58-11279
0). In particular, cyanine dyes and merocyanine dyes not only have a large extinction coefficient but also have a reflectance of 20 to 40% near the absorption maximum wavelength, and reflective readout is possible without a special metal reflective film.

In addition, cyanine dyes have the characteristic that by selecting the number of methine chains connecting heterocycles, it is possible to obtain a recording film with a desired absorption maximum wavelength, and since recording and reproduction using a semiconductor laser is possible, the device It has the advantage of being smaller and lower in cost. However, these dyes
It has the disadvantage that it reacts with oxygen in the air due to light and heat (especially from the readout source), reducing light absorption and reflectance, resulting in a reduction in recording sensitivity, readout signal S/N ratio, and C/N ratio. was. As a means to solve this problem, it is possible to provide a protective layer on the dye recording layer (JP-A-59-203252) and to include an antioxidant in the dye-recording layer (JP-A-59-203252).
13039,), and to seal the space above the recording layer and allow an inert gas and an oxygen absorbent to exist in the sealed space (Japanese Patent Application Laid-Open No. 151346/1983), but satisfactory results have not been obtained. .

The present invention was made in view of the above circumstances, and prevents the oxidative deterioration of the dye, which is a component of the recording layer, due to heat and light such as reproduction light and sunlight, thereby reducing the light absorption rate and reflectance of the recording layer. The objective is to provide an optical information recording medium that suppresses the noise and has stable recording and reproducing characteristics.

[Means and effects to be solved by the invention] The present invention is directed to the general formula [where R1r R2r R4* R5 represents an alkyl group having 1 to 6 carbon atoms]. R3 is 10-R6゜alkyl group, alkoxy group, amine group, hydrogen, R,, R8:
C1-C6 alkyl group, X; O.

s, y; o, s)] An optical information recording medium characterized by having a thin film layer mainly composed of an organic dye containing 0.01% to 30% by weight of an amine compound represented by It is.

The amine compound represented by the above general formula acts as a photothermal antioxidant. The reason for limiting the content of such amine compounds in the organic dye to the above range is that if the content is 0.01% by weight, the thin film layer (recording layer) will be oxidized by light and heat. If the deterioration prevention effect cannot be achieved and the content exceeds 30 weights, the amount of organic dye in the recording layer decreases, resulting in a decrease in sensitivity and reproduction performance. A more preferable content of the amine compound is in the range of 0.05 to 10% by weight.

The organic dyes mentioned above are, for example, mainly cyanine dyes, merocyanine dyes, and triphenylmethane dyes, and other dyes such as phthalocyanine dyes, anthodiquinone dyes, azo dyes, and xanthine dyes can also be used. Further, a polymer may be added to these dyes in order to improve thermal stability and adhesion to the film-forming substrate. As the polymer, single substances or copolymers of vinyl chloride resin, vinyl acetate resin, acrylic resin, polyester resin, nitrocellulose, polycarbonate resin, epoxy resin, polyethylene resin, polypropylene resin, polybutyral, etc. are used.

In order to form a recording layer containing the above-mentioned organic dye as a main component, a method is adopted in which the organic dye, amine compound, etc. are dissolved in a solvent and a film is formed on the substrate by a spinner method or a dipping method. The film thickness is 10 to 1000 nm, preferably 50 to 300 nm. Examples of the substrate used here include glass, resin, metal, etc. In addition, acrylic resin, polycarbonate, polyolefin resin, 7I? It is also possible to use a film-like substrate made of polyester resin, polyamide resin, polyimide resin, or the like.

In the present invention, an intermediate layer and a protective layer may be provided in addition to the recording thin film containing the dye. For the intermediate layer, the /J inder polymer of the dye recording thin film mentioned above can be used.
It is formed by the spinner method or the Diff method, and has the effect of strengthening the adhesiveness of the recording layer and preventing the recording layer from aging and deteriorating due to moisture and gas oxygen. The protective layer is provided to protect the recording layer from scratches and dust, and from oxidative deterioration caused by moisture and gaseous oxygen, and has the same structure and formation method as the intermediate layer.

Next, the structure of the optical information recording medium of the present invention will be explained with reference to the drawings.

FIG. 1 shows the basic structure of an optical information recording medium, which is composed of a substrate 1 and a recording layer 2 formed on the substrate 1, the main component of which is an organic dye containing an amine compound. Irradiation of the focused laser beam 3 during recording and reproduction is performed on the substrate 1 side,
Either side of the recording layer 2 may be used.

FIG. 2 shows a recording medium having a structure in which an intermediate layer 4 is provided between the substrate 1 and the recording layer 2, and a protective layer 5 is provided on the recording layer 2. In this case, either the intermediate layer 4 or the protective layer 5 may be omitted.

In FIG. 3, two recording media having the same configuration are arranged with a spacer 6 in between so that the recording layer 2 side faces each other. In addition, 7 in FIG. 3 indicates an air gear lug, and 8 indicates a spindle hole.

In such a configuration, since recording and reproduction are performed by irradiating the focused laser beam 3 from the substrate 1 side, the influence of dirt and rubber can be suppressed.

Figure 4 shows an example in which a recording layer 2 whose main component is an organic dye contains a polymer binder, etc., and a reflective layer is provided when the recording layer lacks reflectance. A reflective film 9 is provided between the layers 2, and a reflective layer 9 is provided on the recording layer 2 in FIG. 2B. In a recording medium with such a structure, the focused Radhe beam 3 may be irradiated on either the substrate 1 side or the recording layer 2 (or reflective layer 9) side, but in the case of FIG. ), it is desirable from the point of view of recording sensitivity to make the focused laser beam 3 enter from the substrate l side.

[Embodiments of the invention]

The present invention will be explained in detail below.

Example 1 The following (I) was added to the cyanine dye represented by the following formula (1).
Add 1% by weight of (2,2,6,6-tetramethyl-4piperituno)benzoate shown in formula I), dissolve this in dichloromethane to make a 1% solution, and then add this solution to a thickness of 1%. , coated on two glass substrates using a spinner method,
A recording layer having a thickness of 55 nm was formed by drying, and a recording medium was manufactured.

・・・・・・・・・(1) Therefore, semiconductor radar light with a wavelength of 830 nm was focused on a 1.2 μm diameter spot on the recording medium of Example 1, and writing was performed from the substrate side at a linear velocity of 3 W'sec. As a result, the recording energy threshold was 3.5 nj/spot, and the CN ratio was 48 dB.

Example 2 To a cyanine dye represented by the following formula (III), 1 part of the amine compound represented by the following formula (■) was added in a weight ratio, and a recording layer with a thickness of 45 nm was formed on a glass substrate in the same manner as in Example 1. A recording medium was manufactured.

(III) When writing and reproducing were performed on the recording medium of Example 2 in the same manner as in Example 1, the recording energy threshold was 2.8 nj/spot, and the ratio was 45. It was dB.

In addition, the recording media of Examples 1 and 2 were heated at 40°C, R, H65.
% atmosphere under 500 W tungsten light (50 frames apart from the surface of the recording medium) for 100 hours, and the changes in absorbance and reflectance before and after being left were examined, and the results are shown in the table below. Obtained. In addition, in the table, evaluations of recording media having a recording layer formed only from the cyanine dyes of formulas (1) and (III) are also listed as Comparative Example] and 2.

Table [Effects of the Invention] As detailed above, the present invention can provide an optical information recording medium that can improve stability against light and heat, and has excellent repeated recording and reproduction characteristics and storage stability.

[Brief explanation of drawings]

1 to 4 are schematic diagrams showing optical information recording media of the present invention, respectively. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Recording layer, 3...Focusing radar
Light, 4... Intermediate layer, 5... Protective layer, 9... Reflective layer. Applicant's representative Patent attorney Atsushi Tsuboi Figure 1 Figure 2

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [However, R_1, R_2, R_4, and R_5 in the formula represent an alkyl group having 1 to 6 carbon atoms. R_3 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼ -O-R_6, ▲ has mathematical formulas, chemical formulas, tables, etc. ▼, ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_6: phenyl group, alkyl group, alkoxy group, amino group, hydrogen, R_7,
R_8: alkyl group having 1 to 6 carbon atoms, X; O, S, Y;
1. An optical information recording medium comprising a thin film layer mainly composed of an organic dye containing 0.01% to 30% by weight of an amine compound represented by O, S).