JPS58111141A - Information recording medium - Google Patents

Abstract

PURPOSE:To improve the protective effect of a recording medium without the reduction of read/write characteristics, by coating the external side of a silicone resin layer applied to the upper and lower surfaces of a recording layer with a transparent protective layer made of an inorganic material. CONSTITUTION:After forming an SiO2 layer 2 as a protective layer made of an inorganic material on a transparent acrylic base plate 1 and then a silicone resin layer 3 on the SiO2 layer, a Te film 4 as a recording layer is formed on the layer 3. A silicon resin layer 5 and a SiO2 layer are formed on said layers successively. The Te film 4 and the SiO2 layers 2, 6 are formed by vacuum vapor deposition and the silicone resin layers 3, 5 are formed by spin coating. The SiO2 and silicone resin can form the same films as said layers also by a CVD method.

Description

[Detailed Description of the Invention] (υ Technical Field) The present invention relates to an information recording medium using an optical disk system, and more particularly to an information recording medium that is characterized by improving eel preservation effectiveness without deteriorating recording characteristics. It is.

(2) Background technology An information recording medium based on the disk method is a transparent disk made of acrylic resin, glass, etc., coated with vapor-deposited tellurium gold, and has microscopic holes as small as one electrification in a radar system. (by selectively forming (writing) a large number of on the skeleton tellurium film)
, which plays the role of an information recording medium. The main advantages of optical discs are that their capacity is extremely large, and that the radar light is emitted from the transparent disc side.
The radar illumination light emitting device (write head) does not touch the recording layer directly. However, since the former, such as acrylic resin and glass, tend to be highly hygroscopic and absorb and permeate gases, tellurium, etc., reacts with moisture and is oxidized, resulting in deterioration of the shape of micropores, that is, information loss. There is a problem that it becomes difficult to read.

(3) Problems with the prior art As a countermeasure to the above problem of deterioration in the shape of micropores, conventional methods have been to provide an organic or inorganic protective layer on the recording layer (T/vapor deposited film) to protect the optical disc, or to apply an air sandwich. It is known that the structure is However, the recording layer Kv
The protective layer deposited with B prevents T. from being melted and perforated by radar light, thereby degrading the recording characteristics. - In the case of an air-sealed structure using 10,000 glass sticks, the recording layer cannot be protected from moisture because the glass sticks are moisture permeable.

(4) Purpose of the Invention The purpose of the present invention is to protect the recording layer in which fine pores are formed by radar light from the external environment such as humidity, and to prevent deterioration of the recording properties and deterioration of the shape of the fine pores caused by this protective bag. )
The goal is to achieve all goals at the same time except for.

(5) Structure of the Invention The present invention provides an information recording medium for an optical disk, in which the upper and lower surfaces of the recording layer are covered with a silicone resin layer), and at least the surface on the outside side of the silicone resin layer is made of an inorganic material. The present invention provides an information recording medium that is covered with a protective layer 9 and the protective layer on the outer side is transparent.

One of the requirements of the present invention in the structure of the original disk is to provide thin silicone resin layers on the upper and lower surfaces of the information recording layer made of a thin metal film.

The advantage of silicone resin is that it can be used as a protective film for radar recording on metal thin films, and even if it is formed directly on the recording layer, it does not affect sensitivity or R/W % such as 87N like other resins. Furthermore, since silicone resin has low thermal conductivity, it also has the advantage that when the upper and lower surfaces of the information recording layer are touched, local heating by the laser is promoted, resulting in high writing sensitivity. However, the disadvantage of silicone resin is that it has high gas permeability to gas molecules, which can cause deterioration of the recording layer due to the ingress of water vapor and oxygen. By providing the inorganic material layer, it is possible to prevent the recording layer from deteriorating due to gas molecules present in the outside world. As the inorganic material layer, transparent inorganic compounds such as silicon oxide, silicon nitride, glass, and other materials can be used.

In the present invention, if an inorganic material layer (not necessarily transparent) is provided on the inner silicone resin layer in addition to the outer layer of the optical disc, the preservation effect will be even better. Further, in an optical disk having an air sandwich structure, the upper and lower recording layers of the sandwich structure are formed with the above-described laminated structure.

However, it is essential that each recording layer has at least one protective layer provided on the outside side of the recording layer.

(6) Examples Example 1 FIG. 1 shows a cross-sectional view of an optical disc, in which 8 fish 02 with a thickness of 2° Am were formed as an inorganic material protective layer on a transparent acrylic substrate 1.
After forming layer 2 and a silicone resin layer 3 with a thickness of 30 am thereon, a T film 4, which is a recording layer, is formed with a thickness of 30 am. Saisa so on top.

fim silicone resin layer 5, further above 20 m 81
02 layer 6 is set to nine. In addition, T/film 4 and 81
02 layer 2.6 is formed by vacuum deposition, silicone resin layer 3.
5 was formed by spin cord. Note that a similar film can be formed using 8tO and silicone resin by the CVD method.

A R/W test was conducted using radar light on the optical disk thus prepared. The characteristics are exactly the same as those of a disk made by forming 30n-T on an acrylic substrate without layer 2.6.9 Also, this disk has -R/W characteristics after one year in a normal office product term. No deterioration of W% property was observed at all.

Embodiment 2 This embodiment is an example in which an optical disk 10 having an air sandwich structure as shown in FIG. 812 is constructed according to the present invention. In Figure 2, IIA and IIB are transparent acrylic disks, Xmu and xl are on the outside side of each recording layer, and
is a spacer. 1 thickness 1■ as shown in Figure 3
transparent acrylic disk (11mm, 30μm 8 on the first stitch)
101 layers (22mm, 22B) are formed, and 30A is formed on it.
A silicone resin layer (23m, 23B) of m is formed.

An OTo film (24mm, 24B) with a thickness of 30 mm is formed thereon to serve as a recording layer. Furthermore, a 30 μm silicone resin layer (25 μm, 25B), a 30 μm 8102 layer (26A,
26B) are formed sequentially. The transparent acrylic disks (IIA, IIB) thus produced were adhered via spacers (12mm, 12B) so that their recording surfaces faced each other.

ζ Now, the layers (26mm, 26B) should be formed so as to surround the entire T film (24mm, 24B) as a recording layer. /W test results in 8103 layers (22, 26
), the R/Wl value was exactly the same as that of the comparative example in which the silicone resin layer (23, 25) was not provided and the R/Wl was applied directly to the Ts 30 mm thick film on the acrylic disk. Furthermore, no deterioration of the R/W characteristics was observed in the optical disc of this example even after one year in a normal office environment.

(7) Effects of the Invention According to the present invention, the retention effect of the recording medium can be greatly improved without deteriorating the R/W characteristics.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the original disk according to the present invention. Figure m2 is a cross-sectional view of the air sandwich type optical disk, and Figure 3 is a detailed cross-sectional view of Figure 2. 1.11...Acrylic disk, 2.6, 22, 26...
- 8102 layer, 3, 5, 23.25... silicone resin layer, 4.24... T film. Figure 1 Figure 2

Claims (1)

[Claims] In an information recording medium for an optical disk, the upper and lower surfaces of the recording layer are covered with a silicone resin layer, and at least the surface of the silicone resin layer facing the outside world is covered with a protective layer made of an inorganic material, so that it is protected from the outside world. An information recording medium with a transparent protective layer on the side.