JPS583143A - Information recording medium - Google Patents

Abstract

PURPOSE:To improve the humidity resistance, by laminating an information recording layer with a transparent ceramic layer and a transparent organic substance layer. CONSTITUTION:An acrylic base 1 is provided, transparent ceramic layers 3 and 3' made of oxide, nitride and fluoride are arranged on both sides of an information recording layer 4 made of Te, and transparent organic substance layers 2 and 2' are located at the outside of the layers 3 and 3'. As the constituent for the transparent organic substance layers 2 and 2', paraffinic hydrocarbons having >=15 carbon atoms, fatty acid salt selected from salts of Zn, Al, Ba, Mg, Pb, and Te and having >=15 carbon numbers, wax, oil, polyolefin and derivative of polyolefin having >=40 deg.C melting point are preferred. The SN ratio can be improved by heat treatment of the organic layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information recording medium, and more specifically, a light beam is focused on the medium, a hole is punched in the medium for recording, the hole is read out, and a moonlight beam is irradiated to determine whether or not there is a hole. The present invention relates to an information recording medium in which information is read out by determining information by detecting reflected light or transmitted light.

Sensitivity is a requirement for information recording media.

Three conditions are considered: signal/noise (S/N), and stability (long-term storage), and if any one of these three conditions is missing, the quality of the medium will deteriorate. Among these conditions, To ensure stability, 1. Corrosion-resistant material is used for the recording material. 2. The sandwich structure mechanically protects the recording layer. 3. Forming a protective film on the recording layer may be considered. When a corrosion-resistant material is used as a recording material, the material can be divided into single metals and alloys. Table 1 shows the advantages and disadvantages of these materials in relation to sensitivity and S/N stability.

Table 1 also shows that chalcogenide glasses, which do not belong to the above materials, have excellent moisture resistance from the standpoint of stability, but are prone to amorphous-crystalline transitions, are thermally weak, and easily change optical properties. Highly toxic. Regarding the sandwich structure in which the recording material is sandwiched between both sides, this sandwich structure was developed to provide mechanical protection and stability to the recording layer, and stability is improved by using glass as the substrate. However, using PMMA (polymethyl methacrylate) for the substrate increases the mechanical strength and reduces the cost, but on the other hand, water enters from the substrate side and the chemistry of the recording layer deteriorates. stability deteriorates. The method of forming a protective film, which is one of the conditions for increasing stability mentioned above, mainly involves increasing the film thickness to obtain mechanical strength, and many methods ignore corrosion resistance and recording characteristics, resulting in poor sensitivity. decreased. The iD and S/N have deteriorated. As described above, it has not been possible to guarantee all the sensitivity S/N and stability required for information recording media.

An object of the present invention is to provide an optical information recording medium that guarantees stability without deteriorating sensitivity or S/N.

The object of the present invention is to provide a recording layer made of a metal or semimetal, an organic dye, etc. on a substrate, focus an energy beam on the recording layer, use the thermal energy to form a hole in the recording layer, and to form a hole in the recording layer. In an optical information recording medium in which information is read by irradiating a light beam and detecting the reflected light or transmitted light, a transparent M material layer is provided as a first layer on a substrate, and a transparent M material layer is further provided as a second layer on a substrate. A transparent ceramic layer is provided, a recording layer is provided as a third layer on top of the recording layer, a ceramic layer is provided as a fourth layer on top of the recording layer, and a transparent organic material is further provided as a fifth layer on top of the ceramic layer. This is achieved by an information recording medium characterized by arranging layers.

That is, in the present invention, in order to protect the recording layer, the recording layer is sandwiched between transparent ceramic layers on both sides, that is, in a sandwich structure, and transparent organic layers are formed above and below the ceramic layer on the substrate. It has a unique structure. It is an information recording medium using light.

According to the present invention, most of the transparent ceramic layers in which the recording layer has a sand-inch structure have low air permeability and water permeability, and do not change the optical properties of the recording layer. In addition, the above-mentioned transparent organic layer has low thermal conductivity, low melting point, and good moisture resistance, and improves sensitivity and stability. Improvements were made.

In the present invention, an oxide, a nitride, or a fluoride is used as the transparent ceramic layer, and the oxide further includes St, B, Be, Az, TitV, C
r, Mn, Co, Ni, Zn, Ge, Cd, In, 5n
An oxide of at least one element selected from the group consisting of lSblTe, W, Pb, and Bi, and the fluoride includes Co and MP.

The fluoride nitride of at least one element selected from among is preferably a nitride of one element selected from Si and Qa.

Generally, the corrosion resistance of metallic materials is increased by coating the surface with a passivating material, and a transparent ceramic layer is effective as a passivating layer in the present invention. Also the second and fourth
The thickness of the ceramic layer as a layer is several tens to several tens
OA, preferably several A to 100A.

In addition, the transparent organic substances used in the present invention include paraffinic hydrocarbons having 15 or more carbon atoms, Zn, At, Ba, Mf, Pb having 15 or more carbon atoms.
, Tt.

fatty acid salts obtained from at least one metal selected from the group consisting of
"C or higher is preferable. The above-mentioned material has low thermal conductivity,
It is characterized by a low melting point and good moisture resistance. It is preferable to coat the surface of the recording layer with the above-mentioned organic substances by vacuum evaporation for paraffin-based hydrocarbons, fatty acid salts and waxes, by plasma polymerization for polyolefins, and by spin coating or vacuum evaporation for oils and fats. The port used in the vacuum evaporation method, which is a method of coating the surface of the recording layer with the rough-in type hydrocarbon described above, is preferably a date for sublimation material.

Further, in order to flatten the organic layer, heat treatment is preferably performed. When an organic substance is heated above its melting point, it becomes liquid and naturally levels and becomes flat8.If the organic substance is held at a temperature 5 to 10 degrees Celsius higher than the melting point and quenched by exposing it to cold air, the organic substance layer becomes glass. become Heat treatment is also effective for improving the S/N ratio, especially on the substrate side.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an information recording medium according to the present invention.Paraffin 2 is vacuum-deposited as a first layer on an acrylic substrate 1 to a thickness of 100A at a temperature of lOOoC. After annealing, a cold air is applied to flatten the paraffin 2, and a Si0 layer 3 as a second layer is vacuum-deposited to a thickness of 25A on the paraffin 2, and a third Si0 layer 3 is further deposited on the 810 layer 3.
A Te4 layer was deposited to a thickness of 300 Å, and a fourth and fifth Si0 layer 3' halafine 2' was similarly deposited to a thickness of 151.200 Å. Second
Figure 3 shows a comparison of the temperature of this example and Te/glass, and a comparison of the stability of this example and Te/acrylic, respectively.The rotation speed was set to 180 Orpm, the writing frequency was further set to 1:5 h, and JτL was lower. Read/Write under the conditions of
rite) is 0/N. That is, the writing laser is 1dAr laser 4880'A and the reading radar is H.
An e-Ne laser 6328A was used.

5 is the constituent medium of the present invention, and 6 is the case of Te300A/glass. Compared to configuration 6, configuration 5 has the same C/N.
Figure 3 shows the durability of the present invention, which was approximately 4% lower than that of stone.

5 has the same configuration as in Fig. 1, and 8 has the Te300 A/
It is acrylic. Further, 9 is acrylic. The media Nos. 5 and 8 were tested for about 1000 hours under conditions of 70° C. and RH 90q6. As a result, Te/acrylic became white and transparent within 100 hours i)! 1. There was almost no change in medium 5 according to the present invention. Further, even after 1000 hours, no deterioration in sensitivity or C/N was observed, indicating that the optical disc memory was sufficient for long-term storage.

[Brief explanation of the drawing]

Figure i1 is a schematic cross-sectional view showing one embodiment of the information recording medium according to the present invention, and Figures 662 and 3 respectively compare the sensitivity of this embodiment and Te/glass, and the sensitivity of this embodiment and Te/glass.
It is an explanatory view showing a comparison of stability of acrylic. 1...Acrylic substrate, 2.2'...Paraffin, 3
゜3'...810 layers, 4...Te, 5...In the case of the example, 6...In the case of Te/glass, 8...T
e/In the case of acrylic, 9...acrylic, 10...glass.

Claims (1)

[Claims] 1. A recording layer made of metal, metalloid, organic dye, etc. is provided on a substrate, an energy beam is focused on the recording layer, and holes are formed in the recording layer using the thermal energy. , an information recording medium in which information is read by irradiating a light beam into the hole and detecting the reflected light or transmitted light,
``A transparent organic material layer is provided as a first layer on a substrate, and a transparent ceramic layer is further provided as a second layer,''
A recording layer is provided as a third layer on top of the recording layer, a transparent ceramic layer is provided as a fourth layer on top of the recording layer, and a transparent organic layer is further provided as a fifth layer on top of that. Information recording medium. 2. An oxide, a nitride, or a fluoride is used as the ceramic layer, and the oxide further includes St.
, B, Be, AA, Ti, V, Cr, Mn, Co
. Ni, Zn, Ge, Cd, In, Sn, Sb, Te,
An oxide of at least one element selected from the group consisting of W, Pb, and Bi; the fluoride is a fluoride of at least one element selected from Ce and Mf; and the nitride is St. The information recording medium according to claim 1, characterized in that it is made of a nitride of one element selected from Ga. 3. Examples of organic substances include paraffinic hydrocarbons having 15 or more carbon atoms, and Zn having 15 or more carbon atoms. A/, , Ba, Mf, Pb, TL
Fatty acid salts, wax series, oils and fats, polyolefins obtained from at least one metal selected from the group consisting of
and a polyolefin derivative and whose melting point temperature is 4.
The information recording medium according to claim 1, characterized in that the medium has a temperature of 0° C. or higher.