JPS5968850A - Information storage medium - Google Patents

Abstract

PURPOSE:To prevent the deterioration of an information forming layer and to make information processing stable for a long term, by forming a layer made of a material having low moisture permeability between the outside and an information forming layer, and adopting a sealed structure clipping layer from both sides. CONSTITUTION:A vapor-deposition layer made of SiO2 or magnesium fluoride is formed in 1,000Angstrom thick on both sides of two acrylic plates, 1.5mm. thick as a transparent base 1 so as to form a protecting layer 5 to the base. Then, A Te recording layer 3, 500Angstrom thick, is formed onto an opposite side to the side formed with the protecting layer 5 to the base of the transparent base 1 by the vacuum deposition. Further, an adhesives of rubber, epoxy, acrylic or silicon system is applied. Before the adhesives being the bonding layer 4 is cured, the two layers 3 clip an intermediate base 2 made of 1.5mm. thick acrylic or polycarbonate plate. The thickness of the bonding layer 4 is 50-200mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a digital audio disc (
Con-gect disc (CD) used for DAD)
It is read-only, such as optical video discs, or it is used for recording and reproducing, such as image files and computer output memory (COM), and at least the information can be read using a focused laser beam. This invention relates to improvements in optical information storage media that can be achieved.

[Technical background of the invention and its problems]

As an information storage medium structure, F of USP-3665483
As shown in ig-7, there is one in which an intermediate substrate 2 is interposed between two transparent substrates 1.1. This is the first
As shown in the figure, for example, Te is formed as a recording layer 3 as an information forming layer on two transparent substrates 1 made of transparent acrylic material with a thickness of 1.5 by 500X vacuum evaporation. Thereafter, an epoxy adhesive is applied over the entire surface of the recording layer 3 to form an adhesive layer 4. Then, before the adhesive as the adhesive layer 4 hardens, the two transparent substrates 1.1 are bonded to a thickness of 1.5 m.
An intermediate substrate 2 made of an In acrylic plate is sandwiched between the two and bonded together.

In this way, when a hole is formed in the recording layer 3 in a device having the intermediate substrate 2, the transmitted light may be reflected by the recording layer 3 on the opposite side and have an adverse effect on reading. It is even more effective if the transmitted light can be blocked and stable information processing can be performed.

However, the structure shown in FIG. 1 has the following problems. That is, when transparent plastics such as acrylic, polycarbonate, and vinyl chloride are used as the material for the transparent substrate 1, water vapor from the outside air passes through the transparent substrate 2 and reaches the recording layer 3 because of their high moisture permeability. Accelerates deterioration of layer 3. For this reason, there is a problem in that stable information processing cannot be performed over a long period of time, even if care is taken regarding storage locations and the like.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to prevent the formation of a recording layer or a light reflecting layer due to the intrusion of moisture from the outside air in a device in which an intermediate substrate exists between two transparent substrates. The object of the present invention is to provide an information storage medium that can prevent deterioration of the information forming layer of the information storage medium and perform stable information processing over a long period of time.

[Summary of the invention]

In order to achieve this object, the present invention forms layers each made of a material with low moisture permeability between at least the outside world and the information forming layer, and sandwiching the two information forming layers from both sides. It has a shield structure.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIG. This consists of adhesive layers 4 on both sides of the intermediate substrate 2. Recording layer 3. A transparent substrate 1 and a protective layer 5 for the substrate are sequentially laminated.

For example, the thickness of the transparent substrate 1 is 1.5-2.
A 1000X vapor-deposited film of 5IO2 or magnesium fluoride is formed on one side of each of the acrylic plates to form a protective layer 5 for the substrate. (However, an inorganic transparent film was used as the protective layer 5 for the substrate to prevent water and oxygen from permeating, but an organic polymer film such as polystyrene or epoxy was used as the protective layer 5 for the substrate to protect the substrate surface from damage. ) After that, a recording layer 3 is formed on the surface of the transparent substrate 1 opposite to the surface on which the protective layer 5 is formed.
500X of Te is formed by vacuum evaporation.

5- Tsukini, rubber-based, epoxy-based, acrylic-based.

Or apply a silicone adhesive. Then, before the adhesive that becomes the adhesive layer 4 is fixed, the intermediate substrate 2 made of an acrylic plate or a polycarbinate plate with a thickness of 1.5 mm is sandwiched between them and the two sheets are bonded together. It will be done.

The thickness of the adhesive layer 4 at this time is 50 to 200 μm.

The intermediate substrate 2 is an acrylic plate or a polycarbinate plate with a thickness of 1.5 mm, but any metal plate, ceramic plate, glass plate, or polymeric plastic plate may be used as long as it alone has sufficient strength.

The information storage medium having this laminated structure has the following advantages.

(1) Water vapor in the outside air penetrates into the recording layer 3 and
This can prevent the deterioration of the product from occurring.

(11) Water vapor in the outside air can be prevented from being absorbed into the transparent substrate 1 and bending the transparent substrate 1.

In the above embodiment, the recording layer 3 and the adhesive layer 4 are in direct contact with each other, but the present invention is not limited to this.

For example, as shown in FIG. 3, in addition to the layer shown in FIG. 2, an upper forming layer 6 may be formed between the adhesive layer 4 and the recording layer 3.

The method for making this information storage medium is as follows:
．． A 2000X S s O2 film or 10
Form a transparent organic film of ~50 μm.

Thereafter, Te is psooz formed as a recording layer 3 on the surface of the transparent substrate 1 opposite to the surface on which the protective layer 5 is formed by vacuum evaporation.

Further, epoxy, styrene, or the like is applied thereon to a thickness of 10 to 20 μm as the upper forming layer 6.

Next, there are rubber-based, industrial-grade, and acrylic-based.

Or apply a silicone adhesive. Then, before the adhesive that becomes this adhesive layer 4 is fixed, the thickness is 1.5 w.
It is made by gluing two sheets together with an intermediate substrate 2 made of an acrylic plate or a polycarbonate plate sandwiched therebetween. The thickness of the adhesive layer 4 at this time is 50 to 200 IJ/n
It is 1.

In addition to the advantages of the first embodiment (FIG. 2) described above, this laminated structure information storage medium has the following advantages.

(1) The recording layer 3 can be protected from mechanical scratches that are likely to occur during adhesion.

(11) Since it is possible to touch the recording layer 3, which is the coating of the adhesive special upper forming layer 6, the workability during adhesion is improved.

(iiD Any adhesive with high adhesive strength can be selected as the adhesive layer 4.

(V) Even if an adhesive with high water permeability and low water resistance is selected, deterioration of the recording layer 3 can be prevented by using a material with high water resistance or water resistance as the upper forming layer 6.

In the above-mentioned first and second embodiments (FIGS. 2 and 3), the protective layer 5 for the substrate was formed on the outer surface side of the transparent substrate 1. The protective layer 5 for the substrate must be made of a material with low moisture permeability and must be transparent. Inorganic materials such as ZnOp, MgOt, and At2 can be used as the material of the protective layer 5 for the substrate.
05 eSiOt 5i02 + ZrO□, Ce0
Oxides such as 2t In2O2 and 5nO2pT i O2 and fluorides such as MgF2 t CaF t CaF4 are suitable. The thickness is 2,000 to 5,000X, and as organic substances, there are transparent ones with low moisture permeability, and shite polyglobylene,
(Ethylene-vinylidene acetate copolymer, vinylidene chloride, mash cardenate, vinyl chloride-vinylidene acetate copolymer, vinylidene chloride-acryloni) copolymer of IJ, some polyamides with relatively low moisture permeability, polystyrene , polyacrylonitrile is suitable. The thickness is preferably 10 to 50 μm.

Above is the first part. In the second embodiment (FIGS. 2 and 3), the case where the protective layer 5 for the substrate as a "layer with low moisture permeability" is formed on the outer surface side of the transparent substrate 1 has been described. A layer with a low concentration may be formed on the inner surface side of the transparent substrate 1.

That is, as shown in FIG. 4, a transparent substrate 1 and a recording layer 3
A lower intermediate layer 7 may be formed between the two. This information storage medium is manufactured by forming 2,000 layers of SiO□ on two 1.5-thick acrylic plates as transparent substrates 1 by vacuum deposition to form a lower intermediate layer. Furthermore, Te is vacuum-deposited at 400X on this to form the recording layer 3.

Next, apply an acrylic, epoxy, or rubber adhesive. Then, before the adhesive that becomes the adhesive layer 3 is fixed, the intermediate substrate 2 made of an acrylic plate or a polycarbonate plate having a thickness of 1.5 tm is sandwiched between the two plates and bonded together. The thickness of adhesive layer 4 is 50
~200 μm. Note that the thickness of the intermediate substrate 2 is 2.
Although a 0+ra acrylic plate was used, any metal plate such as an aluminum plate with a thickness of 2.0 m, a ceramic plate, or a polymeric plastic plate may be used. The lower intermediate layer 7 is preferably transparent and has low water permeability and low oxygen permeability since it serves to prevent oxygen and moisture from entering the recording layer 3 from the outside. For the lower intermediate layer 7, various oxides, nitrides, and fluorides can be used in addition to SiO□. In addition, when plastic is used for the transparent substrate 110-, C0OH group, C-0 group,
Some are locally polarized, such as OH groups.

On the other hand, when the lower intermediate layer 7 is formed of a substance consisting of two or more elements with a large gap between each electronegativity, such as ZnO, MgO, MgF2, etc., the lower intermediate layer 7 and the transparent substrate 1
The adhesion strength between the two is increased. Furthermore, if the lower intermediate layer 7 and the recording layer 3 are laminated or partially overlapped in a vacuum (without breaking the vacuum once), the adhesion strength between the lower intermediate layer 7 and the recording layer 3 will be increased. .

However, this laminated structure information storage medium has the following advantages.

(i) Moisture in the outside air is transferred to the recording layer 3 by the lower intermediate layer 7.
This prevents the recording layer 3 from early deterioration.

(11) The lower intermediate layer 7 increases the adhesion strength between the recording layer 3 and the transparent substrate 1, and even if moisture intrudes, deterioration such as part of the recording layer peeling off is unlikely to occur.

(iiiD) Since the lower intermediate layer 7 acts as a binder and increases the adhesion strength between the recording layer 3 and the transparent substrate 1, the recording layer 3 is less likely to be scratched when the adhesive layer 4 is formed.

(X/) The lower intermediate layer 7 creates a heat insulating effect and does not adversely affect the transparent substrate 1 during information processing.

Further, as shown in FIG. 5, between the transparent substrate 1 and the recording layer 3, a surface uneven layer 8 is located on the transparent substrate 1 side and has signal information or a tracking guide. The lower intermediate layer 7 may be formed on the recording layer 3 side. To make this information storage medium, the transparent substrate 1 has a thickness of 1.5 mm.
A surface uneven layer 8 is formed using a photopolymer on each of the acrylic plates, and then a transparent inorganic film made of an oxide such as silicon or tin or a fluoride such as Mg is formed as a lower intermediate layer 7 thereon. 500 to 2000X is formed by vapor deposition.

Further, Te was formed at 400X by vacuum evaporation to form a recording layer 3 on this, and then an epoxy-based layer was formed.

Apply acrylic, rubber, or silicone adhesive. Then, before the adhesive that becomes the adhesive layer 4 is fixed, the intermediate substrate 2 made of a 1.5 fm thick acrylic plate or an I-licarbonate plate is sandwiched between them, and the two sheets are bonded together on the entire surface. . The thickness of the adhesive layer 4 is 50-3
00 μm.

In order to accurately transfer the uneven shape of the base to the upper surface of the lower intermediate layer 7, it is desirable that the material of the lower intermediate layer 7 has a dense structure. The lower intermediate layer 7 needs to be transparent because the laser light passes through it. The material of the lower intermediate layer 7 that meets these requirements is ZnO# MgOeAt.
20. t SiOs 8102t Zr02t Ce
Oxides such as O2e In205eSn02 t TiO2 and fluorides such as MgF2 a CaF 2 t Ce F4 are suitable. The thickness is 200-1000X.

Therefore, in addition to the advantages of the third embodiment (FIG. 4) described above, the information storage medium having the laminated structure can facilitate information processing.

13- Also, as shown in FIG. 6, between the transparent substrate 1 and the recording layer 3, there is a lower forming layer 7. located on the transparent substrate 1 side. Recording layer 3
A surface roughness layer 8 having signal information or a tracking guide may be formed on the side. This information storage medium is manufactured by forming a lower intermediate layer 7 on two 1.5 m thick acrylic plates serving as transparent substrates 1, respectively. As this lower intermediate layer 7, 5i02 + Nesa film etc.
Form 00-4000X. Next, a surface unevenness layer 8 having signal information or a tracking guide is formed using a photocurable resin, and To is vacuum-deposited at 400X on this layer to form a recording layer 3. Next, apply silicone-based, acrylic-based, epoxy-based, or rubber-based adhesive. Then, before the adhesive that becomes adhesive layer 3 solidifies,
It is made by sandwiching an intermediate substrate 2 made of an acrylic plate or a polycarbinate plate with a thickness of 1.5 mm and gluing the two plates together. The thickness of the adhesive layer 3 is 50 to 400 μm
It is.

Therefore, this laminated structure information storage medium has the same advantages as the fourth embodiment (FIG. 5) described above.

In the first to fifth embodiments (FIGS. 2 to 6), the recording layer 3 as an information forming layer is formed on the transparent substrate 1 side, but the present invention is not limited to this. The present invention is not limited to this, and the basic structure may be such that the recording layer 3 is formed on both surfaces of the intermediate substrate 2. Next, with reference to FIGS. 7 to 9, sixth to eighth embodiments having this basic structure will be described.

In the sixth embodiment (FIG. 7), an intermediate substrate 2 is centered, and recording layers 3. Adhesive layer 4. Transparent substrate 1
．． and a protection layer 5 for the substrate are sequentially laminated.

The method for making this information storage medium is to have a thickness of 1.0 to 1.0 mm.
T@5 is deposited as the recording layer 3 on both sides of the intermediate substrate 2 made of a 5 tran acrylic plate or polycargonate plate by either suction deposition or vacuum deposition.
Form 00X. Further, a photocurable resin is applied by a spinner coating method or a diazo method, and then it is sandwiched from both sides between two transparent substrates 1, 1 made of acrylic plates or polycarbonate plates having a thickness of 1.2 to 1.5 mm.

The photocurable resin is cured by irradiating ultraviolet rays from both sides at once to form the adhesive layer 4. The thickness of the adhesive layer 4 at this time is 20
~150 μm is suitable. Furthermore, an ethylene-vinyl chloride copolymer or polycarnate proprietary organic polymer having low moisture permeability is coated on the outside of the transparent substrate 1 by the Ditsuno method or the spinner coating method to form a protective layer 5 for the substrate. The thickness of the protective layer 5 at this time is suitably 5 to 50 μm.

In addition, as the protective layer 5 for the substrate, 8102v
A transparent inorganic material such as magnesium fluoride can be formed by vacuum deposition or sputter deposition. The thickness is 500
~20001 is appropriate.

Further, as shown in FIG. 8, in addition to the structure shown in FIG. 7, an upper forming layer 6 may be formed between the adhesive layer 4 and the recording layer 3. The thickness of this information storage medium is 1.0 to 1.
．． Te or At 500× is formed as a recording layer 3 on both sides of an intermediate substrate 2 made of a 5 m thick acrylic plate or a polycargonate plate by either horn evaporation or vacuum evaporation. Thereafter, epoxy, styrene, ethylene-vinyl acetate copolymer, silicone, or the like is further coated thereon to a thickness of 5 to 30 μm by a dip method or a spinner coating method to form the upper forming layer 6. moreover,
An adhesive liquid made of a photocurable resin is applied onto this upper forming layer 6 by a dip method or a spinner coating method, and then a protective layer 5 for the substrate is applied in advance to a thickness of 1.2 mm.
It is sandwiched from both sides by two transparent substrates 1.1 made of a transparent organic material such as acrylic or polycarbonate with a thickness of ~1.5 cm.

Then, ultraviolet rays are irradiated from both sides at once to cure the photocurable adhesive to form the adhesive layer 3.

Furthermore, instead of forming the protective layer 5 for the substrate on the outer surface of the transparent substrate 1 as shown in FIG. 9, a waterproof layer 9 may be formed between the transparent substrate 1 and the adhesive layer 4. . To make this information storage medium, a waterproof layer 9 is formed on one surface of a transparent substrate 10 made of acrylic or polycarbonate and having a thickness of 1.0 to 1.5 m. The appropriate thickness of this waterproof layer 9 is about 5000X when it is made of an inorganic substance, and about 40 μm when it is made from an organic substance. On the other hand, a recording layer 3 of To is formed at 500× by vacuum deposition or sputter deposition on the front and back surfaces of an intermediate substrate 2 made of acrylic or polycarbonate having a thickness of 2.0 to 3.0 mm.

Then, as in the case of the eighth embodiment (FIG. 9) described above, they are overlapped with each other via an adhesive, and the adhesive is fixed to form the adhesive layer 4. A photocurable adhesive is used as the adhesive, and the thickness of the adhesive layer 4 is preferably about 1000 μm.

However, in the sixth to eighth embodiments (FIGS. 7 to 9), the layer made of a material with low moisture permeability is the waterproof layer 9 or the protective layer 5 for the substrate. In either case, the recording or reading laser beam passes through it, so it needs to be transparent. As the material of the waterproof layer 9 or the protective layer 5 for the substrate, the following materials can be used as transparent materials with low moisture permeability.

Inorganic materials include ZnOp MgOm At203t
SiO.

5to2t ZrO2) ceo2# IrzO3,S
Oxides such as nO2, 'rto2, MgF'2j CaF
2t Fluoride such as CaF4, thickness 2000-500
0 zz The organic materials include polypropylene, ethylene-vinyl acetate copolymer, vinylidene chloride, POV-carbonate, vinyl chloride-vinyl acetate copolymer, vinylidene chloride-acrylonitrile copolymer, and relatively moisture permeable copolymer. There are some polyamides, polystyrene, and polyacrylonitrile that have low percentages.

As described above, in the sixth to eighth embodiments (FIGS. 7 to 9), at least the insulation layer 5 as a layer made of a material with low moisture permeability or waterproofing is provided between the outside world and the recording layer 3. The recording layer 3, which has 92 layers, is sandwiched between the layers 9 made of a material with low moisture permeability and shielded from both sides. Another feature is that the layer made of a material with low moisture permeability is present in close contact with at least one surface of the transparent substrate 1.

The sixth to eighth embodiments have the following advantages.

(1) Since the waterproof layer 9 or the protective layer 5 for the substrate is made of a material with low moisture permeability, moisture in the outside air is absorbed into the transparent substrate 1.
It is possible to prevent this from penetrating through the adhesive layer 4 to the recording layer 3 and promoting deterioration of the recording layer 3.

(11) If the intermediate substrate 2 is made of a material that has high water absorption and easily causes a volume change due to water absorption, the intermediate substrate 2 absorbs water and causes a volume change for the same reason as above. can be prevented from occurring.

(11) In the case of the waterproof layer 9 or the protective layer 5 for the substrate, it is necessary to transfer minute irregularities on the underlying layer, such as tracking guides, signal information bits, etc., to the layer above it. Therefore, the thickness can be made sufficiently thick.

6ψ In the sixth embodiment (Fig. 7) and the seventh embodiment (Fig. 8), since the protective layer 5 for the substrate made of a material with low moisture permeability exists on the outermost side, a material with high water absorption rate is used. Even when used as the transparent substrate 1, the transparent substrate 1 will not absorb moisture in the atmosphere and will not change in volume or shape.

Appendix) In the eighth embodiment (Fig. 9), the waterproof layer 9 made of a material with low moisture permeability is exposed to the outside and is strong, so when handling the completed information storage medium, mechanical scratches may occur from the outside. , part of the waterproof layer 9 is damaged, and moisture in the outside air does not enter the recording layer 3 through the gap created at that time.

In addition, in the description of the above-mentioned first to eighth embodiments (FIGS. 2 to 9), the information forming layer is referred to as the recording layer 3.
Although the above description has been made on the case where the layer is a light reflecting layer, it may be used as a light reflecting layer.In short, it is sufficient as long as it is an information forming layer that can at least read information using a beam of light.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

21- [Effects of the Invention] As explained above, in the case where an intermediate substrate is present between two transparent substrates, the present invention provides a structure in which an intermediate substrate is provided between at least the outside world and the information forming layer, each having a low moisture permeability. Since the shield structure is made by forming two layers of material and sandwiching the information forming layer from both sides, it is possible to prevent deterioration of the information forming layer as a recording layer or a light reflecting layer due to the intrusion of moisture from the outside air. The effect is that stable information processing can be performed over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a conventional example, FIG. 2 is a schematic sectional view showing one embodiment of the present invention, and FIGS. 3 to 9 show other different embodiments of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Transparent substrate, 2... Intermediate substrate, 3... Information forming layer consisting of a recording layer or light reflection layer, 4... Adhesive layer, 5... Protective layer for substrate, 6... upper cambium,
7...Lower intermediate layer, 8...Signal information layer has an uneven surface layer with a tracking guide, 9...;...Waterproof layer. 22- Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (6)

[Claims] (1) An intermediate substrate, transparent substrates provided on both sides of this intermediate substrate, an information forming layer consisting of a recording layer or a light reflecting layer formed between both transparent substrates and the intermediate substrate, and this It has a laminated structure with an adhesive layer provided on the surface side of the information forming layer and bonding the intermediate substrate and the transparent substrate, and at least a layer made of a material with low moisture permeability between the outside world and the information forming layer. An information storage medium characterized in that it has a seal structure in which two information formation layers are formed and sandwiched from both sides. (2) The information storage medium according to claim 1, wherein the information forming layer is formed on the intermediate substrate side. (3) The information storage medium according to claim 1, wherein the information forming layer is formed on the transparent substrate side. (4) The information storage medium according to claim 1, characterized in that a layer made of a material with low moisture permeability is formed in close contact with at least one surface of a transparent substrate. (5) The information storage medium according to claim 4, characterized in that a layer made of a material with low moisture permeability is formed on the outer surface side of the transparent substrate. (6) The information storage medium according to claim 4, characterized in that a layer made of a material with low moisture permeability is formed on the inner surface side of the transparent substrate.