JPS5965950A - Optical recording element - Google Patents

Abstract

PURPOSE:To hold a stable characteristic extending over a long period of time by forming at least a part of an auxiliary layer by a resin sheet which is made to adhere by an adhesive layer and an adhesive layer, in an optical recording element formed by laminating an optical recording layer and an auxiliary layer. CONSTITUTION:An optical magnetic material such as FeTbGd, etc. or an optical recording material such as tellurium oxide, etc. is made to form a film as a recording layer 22a on a substrate 21a consisting of glass, etc. by means of vapor-deposition, etc. Subsequently, an adhesive layer 23a is provided, and a resin sheet 24a is made to adhere in the final process. In this case, the adhesive layer 23a is provided for the purpose of prevention of oxidation of the recording layer and adherence with the metallic plate, and for instance, it consists of a hardening type adhesive agent, a hot melt adhesive agent, a tacky agent, etc. Also, the resin sheet has sufficient tensile strength itself, and for instance, a resin sheet consisting of polyester, polysulfon, nylon, polyolefin, etc. can be used. Also, it is also possible to provide other auxiliary layer in conformity with a recording and reproducing device to be used, and to constitute so that both surfaces are covered with a recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical recording element suitable for a source memory, and more particularly to an optical recording element with excellent maintenance safety and antioxidation effect.

Today, the optical memory field is attracting attention due to technological advances in laser light sources and optical devices, but the recording mode used in the optical memory field so far has generally been to irradiate the recording layer with a laser. A heat mode method that forms a cut is known. As one of the systems using such a mode, a thermomagnetic recording element used on a recording layer made of a magnetic thin film is known. Such a recording element is made by applying an external magnetic field to a recording layer made of a magnetic polycrystalline thin film such as MnB1, and performing spot irradiation with a laser beam. If the heating exceeds 7, a reversal of the bidding occurs in the irradiated part. The magnetically recorded data thus formed can be read out.

However, in addition to MnB1 mentioned in flfl, MuCuBi and T
bF'eO.

It is known to use crystalline 51fiM4 as a recording layer, but these recording layers have drawbacks such as a high Keeley point and a small IC resistance or magnetic Kerr effect. Amorphous thin films have been proposed in which transition metals such as , Co, and Ni and rare earth metals such as Tb, Dy, Gd, and NO are co-deposited by sputtering. These are, for example, qi Kai 51-6
No. 3492, No. 51-63493, ll'152-3
17 (1'd is shown in Publication No. 13 etc. Especially,
It has been found that a ternary thin film of FeTbGd has excellent properties as a thermomagnetic recording element, such as a magnetically uniform composition, a suitable Chieri temperature, and a relatively large magneto-optic effect.

In addition to the optical recording element using the magneto-optic effect as described above, an inorganic vapor-deposited film of tellurium, tellurium oxide, tellurium alloy, bismuth, etc., or a decomposed film of phthalocyanine, cyanine dye, etc. is used as the recording layer. Information recorded by a change in the refractive index of the recording layer, a change in the reflectance, or a change in the shape of the recording layer,
Optical recording elements with optical readout are known.

An example of the construction of a conventional optical recording element as described above is shown in the schematic cross-sectional view of FIG. In FIG. 1, a recording layer 12 made of the above-mentioned magneto-optical material or other optical recording material is formed on a substrate 11 made of glass, resin, etc. by a method such as vapor deposition or sputtering. The recording element is composed of organic polymers, etc. Here, the substrate 11 is made of thin glass, plastic, or the like, which has good surface dust resistance from an optical standpoint, as described above. For this reason, conventional optical recording JJ! In its original form, it had the disadvantage of being weak against shock. In particular, in devices that rotate disk-shaped optical recording elements to perform recording and playback, if the disk breaks during rotation, there is a possibility that fragments will fly out of the device and damage the toilet beach.V9 feet.

Furthermore, in the optical recording element described above, the properties of the optical recording material forming the recording layer 12 may change due to oxidation. Furthermore, the protective layer 13 made of an organic polymer or the like is mainly used to protect the surface of the recording layer from scratches, etc., and is not sufficiently effective in preventing such oxidation. Therefore, in conventional optical recording elements, the recording layer oxidizes, especially in high temperature and humid environments, resulting in the disadvantage that stable recording of the type Q and J properties cannot be maintained over a long period of time. are doing.

In view of the above facts, the present invention aims to provide an optical recording element having excellent safety and stable characteristics over a long period of time.

The present invention provides an optical recording element comprising an optical recording layer and an auxiliary layer laminated on a substrate, in which at least a part of the auxiliary layer is an adhesive layer and a resin sheet adhered by the adhesive layer. This achieves the above objective.

A second schematic cross-sectional view of an example of the configuration of the optical recording element of the present invention.
(a), (b), (c), (d) and (e
). In configuration example (a), a magneto-optical material such as FeTbGd or other optical recording material such as tellurium oxide is formed as a recording layer 22a on a substrate 21a made of glass or plastic by a method such as vapor deposition. It is something. Next, an adhesive layer 23a is provided, and a resin sheet 24a is bonded in the final step. Here, the adhesive layer 23a is
The purpose is to prevent oxidation of the recording layer and to ensure close contact with the metal plate, such as hardening adhesives, hot melt adhesives,
Consists of adhesive, etc. Further, the resin sheet itself has sufficient tensile strength, and for example, a resin sheet made of polyester, polysulfone, nylon, polyolefin, etc. can be used.

Furthermore, the optical recording element of the present invention is provided with C1 and other auxiliary layers in accordance with the recording and reproducing apparatus to be used, and has a recording layer' on both sides.
It is also possible to have a configuration where c4>#.

For example, the schematic cross-sectional view of FIG. 2(b) shows another embodiment, in which a heat insulating layer 25b and an antireflection layer 26b2 are sequentially laminated as auxiliary layers on a substrate 21b, and then a recording layer is layered as in the structure (a). 22b1 (resin sheet adhered to sawtooth layer 23b)
24b can be used as a recording element.

The auxiliary layer may include a layer in which index marks, dragging marks, etc. are written in addition to those described above.

In addition, FIGS. 2(c) and 2(d) respectively show the above-mentioned configuration (a).
and (b), an auxiliary plate 28 made of a material having the same physical properties as the substrate via an adhesive layer 27c or 27dτ.
c or 28dt glued. Here, each 2
1c and 21dt are substrates, 22c and 22d are recording layers, 23c and 23d are adhesive layers, 24c and 24d are resin sheets, 25d is a heat insulating layer, and 26d is an antireflection layer.

This configuration has the advantage that the flatness of the recording layer is not impaired even if temperature changes occur because plates with equal thermal expansion are provided on both sides of the recording layer, resin sheet, etc. .

Furthermore, FIG. 2(e) shows a recording element having recording layers on both sides, in which there are two substrates 2]e on which recording layers 22e are formed,
The resin sheets 24e are sandwiched and overlapped with adhesive layers 23e.

These structural examples (a) to (e) all have resin sheets adhered to each other, and therefore the safety and corrosion resistance of the recording layer are significantly improved as shown in the examples below.

The film thickness and plate thickness of each layer structure of the recording element of the present invention can be arbitrarily selected depending on the purpose, but in order to obtain sufficient strength, for example, a polyester resin sheet has a thickness of 25 μm or more. This is desirable.

Hereinafter, the present invention will be explained according to examples.

Example 1 A disc-shaped smooth glass substrate with a diameter of 1201111 x a thickness of 2 cm was cleaned using an ultrasonic cleaner, and one side of the substrate was coated with a spill-length coater and cured silicone resin (manufactured by Toshi Silicone Co., Ltd.). ;5R-2410 resin) with a dry film thickness of 1.2
It was coated to a thickness of μm. Drying conditions were a temperature of 150° C. for 2 hours. The silicone resin was provided to prevent the dissipation of heat generated when the magnetic recording layer is irradiated with a beam.

Next, record no F on the surface of the silicone resin layer.
An amorphous thin film having a composition of EYA Gd12 Tb11 was formed to a thickness of 0.2 μm using a sputtering apparatus. Furthermore, the same silicone resin as above was coated to a thickness of 1.2 μm, and after drying, an adhesive (Sumitomo 3M Co., Ltd.; Scotch 467) was coated with a t-coat, and a polyester resin sheet with a door thickness of 50 μm (black) was applied. (Product name: Mylar) R Glued. Furthermore, the above-mentioned pressure-sensitive adhesive was applied again to the upper surface, and a glass plate having a thickness of 1.2 PIA was adhered to produce a light recording element.

Bit recording and reading were performed on this optical recording element using an optical head from the glass surface side. The recording optical head is a semiconductor laser (820 nm) with an output power of 7 mW.
) The i light source is configured to irradiate the surface of the recording layer with a minute spot of 1.2 μΦ, and furthermore, 1a & stone are arranged so as to apply a magnetic field perpendicular to the surface of the recording layer.

Example 2 In the same manner as in Example 1, a recording element was prepared using two glass plates made of polymethyl methacrylate group/Ji having a diameter of 120 ax and a thickness of 2 Wm.

This recording element was tested in the same manner as in Example 1 and was found to have excellent recording-reproducing characteristics.

Example 3 The recording elements prepared in Examples 1 and 2 were tested for stiffness and corrosion resistance. Corrosion test is carried out at a temperature of 40℃ and 95%
The test was carried out by leaving it in an environment with RH humidity and 100 ppm Maison Impurity for 60 days. The presence or absence of corrosion was determined by observing the surface of the recording layer with an optical microscope.

In addition, as a comparison sample for the corrosion test, the following was used all around.

Comparative Example 1 A recording element having a structure similar to the recording element of Example 1 except for an adhesive layer, a resin sheet, and a glass plate adhered to the resin sheet.

Comparative Example 2 In the recording material of Example 1, polymethyl methacrylate was coated to a film thickness of 10μ in place of the adhesive layer and the resin sheet upper plate (recording of a structure using a protective layer). element.

The results of the corrosion test are shown in Table 1. The table shows the number of days for corrosion to start under the JL environment for each valley sample.

Table 1 Example 4 A breakage test was conducted on the elements B[2] prepared in Example 4 and 2. A comparative example similar to Example 3 was used as a comparative sample. The experiment was carried out by rotating an inwardly expanding recording element (hereinafter referred to as a disk) at 2000 r, p, m, and applying a concentrated load tm of 51'p/mm2 to the disk surface. As a result, in Comparative Examples 1 and 2, all of the disks were broken into pieces, and glass powder of several μm was scattered into pieces of about 10 cm square. It was also disclosed that there is a risk of glass powder flying out from the gaps in the device, causing injury to the user. On the other hand, in Examples 1 and 2 of the present invention, radial cracks occurred in the glass plate or polymethyl methacrylate plate at the location where the load was applied to the disk. There was hardly any peeling between the Iif\ sheet and these glass plates or polymethyl methacrylate plates, and hardly any scattering of the glass plates or polymethyl methacrylate plates.

In Example 5, an example of an optical recording element using the magneto-optic effect is shown, but as mentioned above, the invention is not limited to such magnetic recording, but also includes changes in refractive index, reflectance, etc. It can also be applied to other optical recording elements that utilize shape changes, etc.

As explained above, the present invention improves C1 in the conventional optical recording element. This has the effect of stably maintaining reproduction characteristics.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view showing an example of the configuration of a conventional optical mQ recording element, Figure 2 (a), Figure 2 (b), Figure 2 (c) +
a'r FIG. 2(d) and FIG. 2(e) are respectively schematic cross-sectional views showing a configuration example τ of the optical recording element of the present invention. 11, 21a, 21b, 21c, 21d, 21
e...Substrate 12, 22a, 22b, 22c,
22d, 22e-recording layer 13...retention layer 23a, 23b, 23c, 23d, 23e,
27c, 27d・i$124a, 24b, 24c
, 24d, 24e - Resin sheet 25b... heat insulation layer 26b... antireflection layer 28c, 28d - auxiliary plate applicant Canon Co., Ltd.! ,・,!呵

Claims (2)

[Claims] (1) In an optical recording element formed by laminating an optical recording layer and an auxiliary layer on a substrate, at least a part of the auxiliary layer is bonded by an adhesive layer and the adhesive layer 7' (resin sheet). An optical recording element characterized by: (2) Claim 1 further comprising an adhesive layer and a plate made of a material having the same physical properties as the substrate bonded by the adhesive layer on the opposite side of the resin sheet from the substrate 1iJ. Optical recording element as described.