JPH0341634A - Information carrier disk - Google Patents

Abstract

PURPOSE:To improve moisture resistance and long-term storage property by a simple constitution by sticking a first and a second substrate with an adhesive in which metal powder is dispersed. CONSTITUTION:The adhesive 3 is thermosetting resin or UV curing resin, into which one kind of metal powder 4 selected from Ti, Al, Mg, Bi, Ta, Si, W, Cl, Pd, etc., is almost homogeneously dispersed. The adhesive 3 is applied on the recording film of the substrate 1, to which a protective plate 5 is stuck to obtain the information medium disk 6. By using the adhesive 3 with metal powder 4 dispersed, oxygen contained in the water which intrudes into the adhesive reacts with the metal to produce oxides. Thereby, intrusion of oxygen into the recording film can be prevented. Thus, oxidation deterioration of the recording medium layer can be prevented and long-term storage property of the medium can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical information carrier disk that records and reproduces information by irradiating it with an energy beam such as a laser beam.

2. Description of the Related Art Conventionally known members for recording information using laser light can be broadly classified into two types. One is a member that cannot be erased once information is recorded, and is used as a so-called write-once optical disc. The other is a material that allows different information to be written on the same material over and over again.For rewritable optical discs, holes are formed by locally irradiating a metal film, pigment film, etc. with a laser beam modulated according to the recorded information. A phase change method is known in which a material or film is crystallized or made amorphous and the difference in reflectance is utilized. In addition, Te (Ge-As), which utilizes crystal-amorphous phase transition, is used as a rewritable optical disk.
Te-based alloys such as Te-Ge-5m and Tv-3b-Te are known. Te-based alloys that are highly compatible with this chalcogenide glass are considered to be promising as rewritable recording materials. In chalcogenide glass, the values of refractive index and absorption rate change during an amorphous-crystalline transition. Therefore, there are large changes in optical properties such as reflectance and transmittance.
FIG. 2 shows the structure of a write-once optical disk using a phase change flower-shaped recording film made of an e-based alloy. 1 is a transparent substrate, and a polycarbonate substrate with low hygroscopicity is generally used from the viewpoint of optical properties, ease of handling, and cost. A Te-based recording film 2 is formed on this substrate 2 by a thin film forming method such as stacking or vapor deposition. In order to protect this recording film, a protective plate 4 is bonded to the recording film via an adhesive 3.

The thickness of the adhesive 3 is approximately 50 to 100 μm. When a disk configured in this manner is used in a high temperature and humidity atmosphere, there is a problem in that the recording film 2 absorbs moisture and deteriorates, making it impossible to record, or in the worst case, the recorded information may disappear. . The cause of such film deterioration due to moisture absorption is that moisture, oxygen, etc. enter from the outer periphery of the 3-disk adhesive layer, which is particularly thin, and the adhesive layer on the bonded end surface of the center hole in the center, causing the recording film to move inward. The phenomenon was that the deterioration progressed.

In the case of a recording film using a Te-based alloy, since it is easily oxidized, reaction with oxygen becomes a particular problem.

Problems to be Solved by the Invention Accordingly, an object of the present invention is to provide an information recording medium having a simple structure, excellent moisture resistance, and excellent long-term storage stability without the above-mentioned drawbacks.

Means for Solving the Problems That is, the present invention provides an information recording method in which a first substrate having a recording medium layer formed on at least one surface of a transparent substrate and a second substrate are bonded together with the recording medium layer inside. In the medium, the first and second substrates are bonded together using an adhesive in which metal powder is dispersed.

Function The function of the present invention is to add TtSAj! to the metal powder dispersed in the adhesive. , Mg, B i, Ta, W.

A metal element such as Gj2.5iSPd is used.

By dispersing the metal powder as described above, oxygen contained in the moisture that has entered reacts with the metal to form an oxide. Therefore, it is possible to prevent oxygen from entering the recording film. Therefore, there is no influence on the recording layer, and long-term storage stability is improved.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a sectional view of a disk laminated with the metal powder of the present invention dispersed in an adhesive. Reference numeral 1 is a polycarbonate substrate having track grooves (not shown) for guiding laser light on one surface. 2 is a recording film that absorbs the energy of laser beam irradiation, melts at an elevated temperature, and evaporates to form holes, or records by utilizing a crystal-amorphous phase transition by rapidly cooling the melted area at an elevated temperature. It is something to do. 3 is an adhesive, which is a thermosetting resin or an ultraviolet curing resin. 4 is T i, AffiSMg, B i, Ta, Si, W, G
j! , Pd, etc., and has a particle size of 5 to 20 μm, and is almost uniformly dispersed in the adhesive 3. The amount of this metal powder is 5~20wt
A range of % is good. This metal powder is combined with oxygen contained in moisture that has entered from the substrate 1, the protective plate 5, and the adhesive layer 5 to form an oxide. This oxide combined with oxygen has low water absorption, so even if it is dispersed in the adhesive, it will not have any effect; on the contrary, it will prevent moisture from entering.
Since it serves as a layer, it can prevent oxidative deterioration of the recording film 2. If the amount of the metal powder 4 is less than the above range, the amount of metal powder 4 combined with oxygen to form an oxide is small, so that the metal powder 4 does not perform its function satisfactorily. On the other hand, if the amount exceeds the above range, the amount combined with oxygen to form an oxide increases, which is good for the Paris 3 layer, but the adhesive strength decreases, which is not preferable.

Then, the above-described metal powder 4 was dispersed in the adhesive 3 and applied onto the recording film of the substrate 1, and the protective plate 5 was attached to obtain the information carrier disk 6. When we tested a disk with this configuration in an environment of 80°C and 80% PH, we found that
No changes were observed in the optical properties such as reflectance and absorptance for more than one month, and no peeling or cracking was observed.

The explanation so far has been based on the configuration of a phase-change write-once optical disk, but it can also be applied to a rewritable optical disk in which a dielectric layer is formed on both sides of a phase-change recording film, or a magneto-optical disk. Of course it can be used.

Effects of the invention As explained above, the first layer on which the recording medium layer is formed
When bonding the second substrate with this recording medium layer on the inside, using an adhesive containing dispersed metal powder that easily binds to oxygen, it is possible to prevent oxidative deterioration of the recording medium layer. We were able to improve long-term storage stability.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a disc made by dispersing Honharu's metal powder in an adhesive and bonded together, and Fig. 2 is a cross-sectional view of a conventional disc construction. 1...Substrate, 2...Recording film, 3...
...Adhesive, 4...Metal powder, 5...
・Protection plate.

Claims (4)

[Claims] (1) A first substrate having a recording medium layer formed on at least one surface of a transparent substrate, and a second substrate with the recording medium layer inside.
1. An information carrier disk comprising two substrates bonded together, the first and second substrates being bonded together using an adhesive containing metal powder dispersed therein. (2) Metal powders include Ti, Al, Mg, Bi, Ta, and Pd.
, Si, W, and Gl. Claim (1)
Information carrier disc as described. (3) The information carrier disk according to claim (1), wherein the adhesive is an ultraviolet curing resin. (4) The information carrier disk according to claim (1), wherein the adhesive is a thermosetting resin.