JPH02166643A - Information recording medium - Google Patents

Abstract

PURPOSE:To improve the reflectance of the medium by providing an intermediate layer between two metal layers of a reflecting layer and a recording layer and specifying the materials and thicknesses of the reflecting layer, intermediate layer and recording layer. CONSTITUTION:The reflecting layer 12 consists of at least one kind of metal selected from Au, Pd, Ag, Pt, Al and Cu with the thickness of 120-230Angstrom , on which the intermediate layer 13 consisting of a high polymer compound with the thickness of 200-600Angstrom is deposited. Further, the recording layer 14 contg. Te and Se with 200-1,600Angstrom thickness is deposited thereon. Informations are written in or read out by irradiating the recording layer with laser light. By this constitution, high reflectance (>=70%) can be obtained. When CD format signals are recorded in this medium, they can be read out with a commercial CD player.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an information recording medium on which information that can be written and/or read by laser light is recorded.

[Technical Background of the Invention] In recent years, information recording media that use high energy density beams such as laser light have been developed and put into practical use. This information recording medium is called an optical disk, and is used as a video disk, an audio disk, and even a nanometer image file and a disk memory for a large-capacity computer. Among these information recording media, compact discs (CDs) are widely put into practical use for reproducing audio such as Japanese music.

Normal D RAW (Direct Read Af
t, cr Write.

The basic structure of the information recording medium is a disc-shaped transparent substrate made of plastic, glass, etc., and a metal or semimetal such as Bi, Sn, In, Te, etc. provided on this substrate. 4r recording layer. Information is written into a recording medium by, for example, irradiating the recording medium with a laser beam, and the irradiated portion of the recording layer absorbs the light and locally increases in temperature, causing physical problems such as bit formation. Information is recorded by changing its optical properties by causing chemical changes such as physical or phase changes. Reading information from an optical disc is also performed by irradiating the optical disc with a laser beam 1, and the reflected light or "
Information is reproduced by detecting transmitted light.

On the other hand, compact discs for playing audio such as music have a CD size of 1.2 to 1.5 mm, based on the CD standard.
By rotating and recording at a constant linear speed of 4 m/s,
Within the range of signal surface inner diameter 45 mm and signal surface outer diameter 116 mm, pit width 0.4 μm, track pitch 1.6
It is required to have a maximum recording time of 63 to 74 minutes in μm. Conventional audio CDs have pits formed on the substrate in advance (therefore, they do not have a recording layer) and are only for playback, and have the disadvantage that information cannot be recorded or edited. Therefore, the development of a DRAW type CD is desired.

In addition, files such as text-2, data, and static images can also be stored on a CD-ROM (Read Only Memo
ry) or CD-1 (Interactive)
A DRAW type optical disc for use in the computer is desired.

However, in the conventional DRAW type information recording medium, since the optical disk is rotated at a high linear velocity during recording, information cannot be recorded unless a wide pit interval is maintained, and high-density recording is performed at a slow linear velocity. It was not possible to write information using the above-mentioned CD method. Further, even if information could be recorded, commercially available CD players, which require a high reflectance to the laser beam during reproduction, could not read the information. Also, for conventional DRAW type information recording media, the high reflectance required by CD players provides excellent latitude and is extremely useful.

For example, an information recording medium (Japanese Patent Publication No. 35356/1983) having a recording layer made of Se and Te is known as an information recording medium with high recording sensitivity and high reading accuracy, which is mainly used in conventional DRAW type. Furthermore, in addition to excellent recording properties, an intermediate material layer made of Cu, Ag, Au, etc. with a layer thickness of 5 to 200X and a layer of 5e with a layer thickness of 100 to 400X are used for the purpose of improving adhesion with the substrate. −
An information recording medium (Japanese Unexamined Patent Application Publication No. 71834/1983) has been proposed that includes a recording layer made of Te, As-Te, or the like. Further, in order to improve the sensitivity, attempts have been made to achieve this by providing a layer of a polymer compound such as a synthetic resin between the recording layer and the substrate to prevent heat conduction.

However, although these information recording media have relatively good recording sensitivity, their reflectance is still insufficient, so commercially available CD players cannot read the information, so they are not suitable for use in DRAW-type CDs. is not applicable.

Further, even conventional DRAW type optical discs did not have sufficient latitude.

[Object of the Invention] An object of the present invention is to provide an information recording medium having high recording sensitivity and high reflectance of 70% or more.

In the present invention, a CD format signal is recorded and its 15
The number is city! The object of the present invention is to provide an information recording medium that can be played back by a CD player.

[Summary of the Invention] The present invention provides a substrate with a layer J″J of at least one metal selected from the group consisting of Au, Pd, Ag, Pt, An, and Cu in a range of 120 to 230 layers. A certain reflective layer, an intermediate layer made of a polymer compound with a layer J layer in the range of 200 to 600 layers, and a Te layer with a layer thickness in the range of 200 to 1600 layers on which information can be written and/or read by laser light.
The information recording medium has a recording layer containing Se and Se, which are laminated in this order, and has a reflectance of 70% or more for incident light from the substrate side.

Preferred embodiments of the information recording medium of the present invention are as follows.

An information recording medium characterized in that the polymer compound described in 1) is any one of fluorinated polyolefin, chlorinated polyolefin, borisdylene, and nitrocellulose.

2) Uni+17 report recording medium, characterized in that the reflective layer is made of Au.

3) The recording layer is made of Cd, Zn, A11. ,sb,Ga
, In, S, P, Ge, Sb% Bi, Si, Sn, P
The above information recording medium is characterized in that it contains at least one metal selected from the group consisting of Ta, Cu, Au, Ag, and Tl.

4) The information recording medium, wherein the recording layer contains Te, Se, and PB in a tun I11 ratio of 94 to 70:5 to 20:1 to 10.

5) The sum of the layer thickness of the binary reflective layer and the recording layer is 80
The above information recording medium is characterized in that the information recording medium is "0 ku since".

[Effects of the Invention] The information recording medium of the present invention having the above configuration has high sensitivity and has a high reflectance of 70% or more. Therefore, as a normal DRAW type optical disc,
In addition to the recording sensitivity being ah, the latitude is also good, so it has excellent recording i1G raw characteristics.

Furthermore, since the information recording medium of the present invention has high sensitivity as described above, by irradiating light from the substrate side of the information recording medium, high-density recording such as EFM signals of CD format can be performed with an irradiation power of 6 to 15 mW. Accurate aging can be achieved at slow linear speeds (used in CD format, etc.). Since it exhibits a reflectance of 70% or more on the (brain) V-plane, it can be read on a commercially available CD player, and is particularly useful for use as a DRAW type compact disc.

[Detailed Description of the Invention] The information recording medium of the present invention has a basic structure of a
It has a structure in which a reflective layer, an intermediate layer, and a recording layer are laminated in this order.

FIG. 1 shows a schematic cross-sectional view of the basic layer structure of the information recording medium of the present invention.

In FIG. 1, a substrate 11, a reflective layer 12, an intermediate layer 13, and a recording layer 14 are laminated in this order.

In conventional information recording media, the metal reflective layer and the metal recording layer both play the role of recording layers, and are provided in contact with each other. When an intermediate layer made of a polymeric substance is provided, it is formed under these layers. In general, such an intermediate layer can increase sensitivity, but
There is a problem in that it causes a decrease in reflectance.

The inventors' research has shown that by providing an intermediate layer between the two metal layers, the reflective layer and the recording layer, as shown in Figure 1, the performance of both reflectance and sensitivity can be significantly improved. It became clear. Furthermore, in order to improve the performance of both, the type and thickness of the metal used for the reflective layer, the type of material and layer used for the intermediate layer, and the type of metal and layer used for the recording layer are strictly specified. It turned out that it was necessary to do so.

That is, the information recording medium of the present invention has Au, P and
d, Ag, Pt, Afl, and Cu, and has a layer thickness of 120 to 2
A reflective layer with a layer thickness of 30 to 600, an intermediate layer made of a polymer compound with a layer J of 200 to 600, and a layer thickness of 200 to 200, which allows information to be written and/or read by laser light. It is necessary that a recording layer containing Te and Se in the range of 1600λ is laminated in this order, and 1. It is necessary that the reflectance for incident light from the plate side is 70% or more. . Such a structure is particularly advantageous in terms of the thickness of the reflective layer and the recording layer, compared to the layer J of the intermediate material layer (corresponding to the reflective layer) and the layer L of the recording layer shown in the prior art of the surface layer. Something thick is roaring. However, by providing an intermediate layer between these two metal layers, it is possible to obtain an information recording medium that has high reflectance while maintaining high sensitivity, and when a CD format signal is recorded on the medium, commercially available CD Can be read by a player. Also, regarding conventional DRAW type optical discs,
In addition to the excellent recording sensitivity, the latitude is also good, so it has excellent recording and reproducing characteristics.

The information recording medium used in the optical information recording method of the present invention is
For example, it can be manufactured by the following method.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information crime media. Optical properties, flatness, processability of the substrate,
In terms of ease of handling, stability over time, and manufacturing cost,
Examples of substrate materials include glass such as soda lime glass; acrylic resins such as cell cast polymethyl methacrylate and injection molded polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; epoxy resins; and polycarbonate. ; Examples include amorphous polyolefins. Among these, preferred are polymethyl methacrylate, polycarbonate, epoxy resin, amorphous polyolefin and glass.

The surface of the substrate on which the recording layer is provided has improved flatness,
Improving adhesive strength and preventing deterioration of the recording layer [! may be provided with an undercoat layer. The material for the undercoat layer is
For example, polymeric substances such as polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, nitrocellulose, polyethylene, polypropylene, polycarbonate;
Organic substances such as silane coupling agents: and inorganic oxides (Si02, A220, etc.), inorganic fluorides (MgF2
) and other inorganic substances.

In the case of a "glass" substrate, the recording layer may be damaged by alkali metal ions and alkaline earth metal ions released from the substrate7! In order to prevent this, it is desirable to provide a 'F coating layer made of a polymer having a hydrophilic group and/or a maleic anhydride group, such as a styrene/maleic anhydride copolymer.

The undercoat layer can be formed, for example, by dissolving or dispersing the above-mentioned substance in a suitable solvent and then applying this coating solution to the substrate surface by a coating method such as spin cord, dip coat, or extrusion coat.

Further, a pregroove layer may be provided on the substrate for the purpose of forming tracking grooves or unevenness representing information such as address signals. The material for the pre-groove layer is
A mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester, and tetraester and a photopolymerization initiator can be used. The layer thickness of the pre-groove layer is generally in the range of 0.05 to 100 μm, preferably 0.1 μm.
~50 μm. Furthermore, in the case of a plastic substrate, pregrooves may be formed directly on the substrate surface.

The reflective layer of the present invention is provided on the above substrate (via a pregroove layer and/or an undercoat layer if desired).

Materials for the reflective layer include Au, Pd, Ag, Pt, and Af.
It needs to be either i or Cu. These metals may be used alone or in combination. Thereby, the reflectance from the substrate side of the information recording medium can be efficiently increased with a small layer thickness. Among these, Au is particularly preferred.

By providing the reflective layer of the present invention, when an intermediate layer and a recording layer, which will be described later, are provided thereon, the reflectance from the J and C plate sides can be significantly improved. The thickness of the reflective layer needs to be in the range of 200 to 400 mm. If it is less than 200, the improvement in reflectance is not sufficient, and 4
If it exceeds 00, the sensitivity will decrease, which is not preferable.

It is necessary to provide the intermediate layer of the present invention on the reflective layer.

Materials for the intermediate layer include polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, nitrocellulose, polystyrene, polyethylene, polypropylene, polycarbonate, chlorinated polyolefin, and fluorinated polyolefin (preferably polytetrafluoroethylene). . Among these, nitrocellulose, polystyrene, chlorinated polyolefin and fluorinated polyolefin are preferred.

This can reduce loss of thermal energy due to laser beam irradiation due to heat transfer from the recording layer to the substrate. Therefore, it is possible to increase recording sensitivity and reduce readout (τ: differential bit error rate).

The above chlorinated polyolefin generally has a chlorination rate of 3
0% or less, preferably 50% or more,
Particularly preferably, those having a chlorination rate H in the range of 50 to 70% are used. Further, from the viewpoint of thermal stability and solubility, among these chlorinated polyolefins, chlorinated polyethylene and chlorinated polypropylene are particularly preferred.

F For the instep layer, prepare a coating solution by dissolving chlorinated polyolefin, and then apply this coating solution onto the substrate (where e/
It can be provided by coating (via an undercoat layer etc.) and drying.

Examples of solvents for dissolving chlorinated polyolefins include toluene, xylene, ethyl acetate, butyl acetate, cellosolve acetate, methyl ethyl ketone, 1,2-dichloroethane, methyl isobutyl ketone, cyclohexanone, cyclohexane, tetrahydrofuran, ethyl ether, dioxane, etc. can be mentioned. Various additives such as ζif plasticizer and lubricant may also be added to the coating liquid depending on the purpose.

As the coating method 1j-i, a spray method, a spin code method, a dip method, a roll coating method, a blade coating method, a doctor roll method, a screen printing method, etc. can be used.

Further, the intermediate layer of fluorinated polyolefin may be, for example, polytetrafluoroethylene [e.g. Teflon (Dubo:/
(manufactured by Du Pont, Inc.)] in 4. By sputtering on the plate-L, it can be submerged.

The layer iso of the intermediate layer ranges from 200 to 600^.

A recording layer containing Te and Se according to the present invention is provided on the earth and mud intermediate layer. Se content jj+ in the recording layer is 5~
501j It is preferable that it is in the range of star%. Also Te
In addition to Se, metals and semimetals that the recording layer may contain include Sb, Ga, S, and Ge.
, Sb, Bi, Sn.

Examples include Pb, Ti, Cu, Ag, and Tb. Among these, pb is preferred. By including at least one of these metals and metalloids, recorded bits can be made uniform in size, which is preferable. It is particularly preferable that the recording layer of the present invention contains Te, Se, and PB in a ratio of 94 to 70:5 to 20:1 to 10 at 1°C.

The thickness of the recording layer needs to be in the range of 200 to 1600 mm. If it is less than 200X, the reflectance will not be sufficient, and if it exceeds 1600X, the reflectance and sensitivity will decrease, which is not preferable.

Furthermore, in order to obtain a high reflectance, it is preferable that the sum of the layer J of the reflective layer and the layer J of the recording layer L is 800 or more.

Such an information recording medium of the present invention has high sensitivity, and 11
A high reflectance of over 70% has been achieved. For this reason,
As a normal DRAW type optical disc, it has excellent recording sensitivity, good latitude, and excellent recording + IG raw characteristics.

Furthermore, since the information recording medium of the present invention has high sensitivity as described above, by irradiating light from the substrate side of the information recording medium, EFM signals etc. can be accurately transmitted at a slow linear velocity with an irradiation power of 6 to 15 mW. It is possible to do old-age-1-. In addition, it exhibits a reflectance of 70% or more on a blank surface and can be read on a commercially available CD player, making it especially suitable for D.
It is useful for use as a RAW type compact disc.

The reflective layer and the recording layer described above are formed using the above-mentioned materials by a known method such as vapor deposition, sputtering, or ion blasting, so that the reflective layer is formed on the substrate and the recording layer is formed on the intermediate layer.

The recording layer may be a single layer or a multilayer, but the total layer Ft is preferably within the above range from the viewpoint of optical density required for optical information recording.

A protective layer may be removed on top of the recording layer. The protective layer is preferably a laminate of a soft protective layer made of a soft resin material and a hard protective layer made of a hard resin material. This laminate is
It is laminated on the recording layer with the soft protective layer side facing the recording layer side.

Examples of the soft resin material include polyurethane, polyvinylidene chloride, ethylene/vinyl acetate copolymer, silicone rubber, styrene/butadiene rubber, polyvinylidene chloride, and polyacrylic acid ester. Usually, these are applied onto the recording layer by methods such as solution coating, latex coating, and melt coating, and are subjected to treatments such as drying and heating as necessary to form a soft protective layer. The thickness of the soft protective layer is usually in the range of 100 to 5 μm, preferably in the range of 0.3 to 3 μm. Examples of hard resin materials include ultraviolet curing resins and thermosetting resins. Usually, these are coated 15 on the soft protective layer by a method such as solution coating, and if necessary, subjected to treatments such as ultraviolet irradiation and heating to form a hard protective layer. The thickness of the hard protective layer is usually in the range of 0.1 to 10 μm, preferably 1 to 10 μm.
It is in the range of 3 μm.

The surface of the substrate opposite to the side on which the recording layer is provided is coated with inorganic substances such as silicon dioxide, tin oxide, and magnesium fluoride, or thermoplastic resins and photocurable resins to improve scratch resistance and moisture resistance. A thin film made of a polymeric material such as mold resin may be provided by a method such as vacuum deposition, sputtering, or coating.

Next, a method for recording information on the information recording medium of the present invention will be described. Since the information recording medium of the present invention is particularly useful for recording CD format signals and reproducing them using a CD player, a method for recording and reproducing CD format signals will be explained as an example.

First, while rotating the information recording medium at a constant linear velocity of 1.2 to 1.4 m/sec within i times, recording light such as semiconductor laser light is irradiated from the substrate side. Generally, a semiconductor laser beam having an oscillation wavelength in the range of 750 to 850 nm is used as the recording light. The information recording medium of the present invention can record with a laser power of 15 mW or less, and has high sensitivity.

By the above recording method, bits are formed in the recording layer in a circular or spiral shape. A CD format signal is then written to the recording layer.

During recording, it is preferable to perform tracking control using a tracking pregroove. When a pregroove is provided on the recording medium, the signal may be recorded either at the bottom of the group or in the area between the groups.

With this method, for example, if the inner diameter of the signal surface is 50 mm,
A recording medium with an outer diameter of 115 mm allows recording for 60 minutes or more.

Information can be reproduced by rotating the recording medium at the same constant linear velocity as described above, irradiating semiconductor laser light from the substrate side, and detecting the reflected light. In the present invention, since the recording layer has a high reflectance of 70% or more on a plain plane, it can be read satisfactorily using a commercially available CD player.

Note that the information recording medium of the present invention includes a CD-ROM, a CD-ROM, and a CD-ROM.
It is wood-compatible with media recorded in the CD format.

Next, examples of the present invention will be described. However, each of these aspects does not limit the invention.

[Example 1 and Comparative Example 1] A disc-shaped polycarbonate substrate for forming tracking grooves (outer diameter: 120 mm, inner diameter: 15 mrr+, J size: 1.2 mm, depth 0 in the range of inner diameter 45 mm to outer diameter 116 mm) .07μm, width 0.8μm, pitch 1.6μm
(with spiral grooves), Au
A reflective layer was formed by vapor deposition with the layer thickness varied between 0 and 230 mm, and five substrates each having a reflective layer were prepared.

An intermediate layer having a thickness of 300 mm was formed on each reflective layer by sputtering PTFE (polytetrafluoroethylene). Then, on the intermediate layer, Te, Se, and PB were added at 82 weights, 411%: 12 weight%, and 6 weight%, respectively.
A recording layer having a layer thickness of 700^ was formed by ternary sputtering at a ratio of .

In this way, an information recording medium consisting of a substrate, a reflective layer, an intermediate layer, and a recording layer was manufactured.

The case where the layer thickness of the reflective layer is 120 or more corresponds to Example 1, and the case where it is less than 120 corresponds to Comparative Example 1.

[Example 2 and Comparative Example 2] On the same substrate used in Actual HFI Example 1, a reflective layer with a thickness of 120 layers was formed by vapor-depositing Au, and four substrates each having a reflective layer were created. did. On top of each reflective layer, PT
An intermediate layer having a thickness of 300X was formed by sputtering FE (polytetrafluoroethylene). Then, 82% Te, Se, and PB were each added on the four intermediate layers.
Weight %: ternary sputtering at a ratio of 12 weight V% = 6 weight % to form a layer JIX of 200 to 160
A recording layer was formed by changing the wavelength between 0λ.

In this way, an information recording medium consisting of a plate, a reflective layer, an intermediate layer, and a recording layer was manufactured.

The range in which the reflectance is 70% or more corresponds to practical example 2,
The range of less than 70% corresponds to Comparative Example 2.

[Example 3] On the same substrate used in Example 1, Au was evaporated to form a layer J'.
) A reflective layer of 230X was formed, and four substrates each having a reflective layer were prepared. For each reflective layer, P
An intermediate layer having a thickness of 300λ was formed by sputtering TFE (polytetrafluoroethylene). Then, on the above four intermediate layers, Te, Se and PB were added at 8
2 weight%: 12 weight%: 6 weight! The layer J7 was formed by ternary sputtering at a ratio of i1% to 200 to 1
A recording layer was formed by varying the light intensity between 600X and 600X.

In this way, an information recording medium consisting of a substrate, a reflective layer, an intermediate layer, and a recording layer was manufactured.

[Example 4] On the same substrate used in Example 1, Au was evaporated to form a layer pl.
230 reflective layers are formed, and seven of the reflective layers are made of PT.
An intermediate layer having a layer thickness of 500× was formed by sputtering FE (polytetrafluoroethylene). Then, on the intermediate layer, 827 [j amount %:
Three-way sputtering was performed at a ratio of 12% by weight: 6% by weight to form a recording layer with a layer thickness of 1000 layers.

In this way, an information recording medium consisting of a substrate, a reflective layer, an intermediate layer, and a recording layer was manufactured.

[Example 5] An information recording medium was produced in the same manner as in Example 4 except that the intermediate layer was formed by coating using chlorinated polyolefin instead of PTFE (polytetrafluoroethylene).

[Example 6] An information recording medium was produced in the same manner as in Example 5 except that the intermediate layer was formed by coating polystyrene instead of chlorinated polyolefin.

[Example 7] An information recording medium was produced in the same manner as in Example 5 except that the intermediate layer was formed by coating nitrocellulose instead of the chlorinated polyolefin.

The obtained information recording medium was evaluated by the following method.

[Evaluation of information recording medium] Specular reflectance from the substrate side of the obtained information recording medium was 1ijl.
I decided. The measuring device used was a transmittance/reflectance measuring device manufactured by Mizojiri Optical Co., Ltd., and a halogen lamp (used wavelength: 820 nm, spot diameter: 1 mm) was used as a light source.

Next, a disc evaluation device (N
akamichi Disk evaluation device 0MS-1000
) and an EFM encoder (EN-WOOD) at a constant linear velocity of 1.3 m/s and a reference signal (8.15 Hz).
was recorded as an EFM-CD format signal. The recording power required at that time was measured.

Five information recording media obtained in Example 1 with different thicknesses of the reflective layers were measured using the above measurement method. The relationship between the layer J2 of the obtained reflective layer and the reflectance is shown in Figure 2.
FIG. 3 shows the relationship between the thickness of the reflective layer and the recording power.

In Examples 2 and 3, measurements were performed using the above measurement method on information recording media in which recording layers were provided with varying layer thicknesses on substrates having reflective layers of 120 layers and 230 layers, respectively. FIG. 4 shows the relationship between the layer thickness and reflectance of the obtained recording layer.

The information recording media obtained in Examples 4 to 7 were measured by the above method to examine the influence of the type of polymer compound in the intermediate layer on recording sensitivity and reflectance. The results are shown in Table 1.

Table 1 Recording power (mW) Reflectance (%) Example 4 6. 5 70 Example 5
8.0 70 Example 6 9. 5
72 Example 7 10.0 75 Figure 2 shows that when the intermediate layer and recording layer have the configuration shown in Example 1, a reflectance of 70% or more can be obtained when the thickness of the Au reflective layer is 120λ or less. This indicates that the Further, FIG. 3 shows that when the layer J of the Au reflective layer is 200λ or less, the recording power is 12.5 mW or less.

FIG. 4 shows that when the reflective layer and the intermediate layer have the configurations shown in Examples 2 and 3, when the reflective layer has 120 layers, the recording layer has a layer thickness of 70% or more in the range of 350 to 1100 A. When the reflective layer is 230^, the thickness of the recording layer is 20
It is shown that a reflectance of 70% or more can be obtained in the range of 0 to 1000. The highest reflectance was obtained when the thickness of the recording layer was 700 mm. Therefore, since FIG. 3 shows the relationship between the recording power and the reflective layer thickness when the recording layer has a thickness of 700 mm, the recording power of the present invention is
It can be seen that it is possible to maintain a reflectance of 70% or more and still lower it.

Table 1 shows that although there are differences in the above characteristics depending on the type of intermediate layer, the information recording medium having the structure of the present invention is superior in recording sensitivity and reflectance.

Therefore, from the results shown in FIGS. 2 to 4 and Table 1 above, it is clear that the information recording medium of the present invention has high reflectance and high recording sensitivity.

[Brief explanation of the drawing]

FIG. 1 shows a schematic cross-sectional view of the J and ζ terminal layer structure of the information recording medium of the present invention. Figure 2 shows 1. Example 1 and comparative example! The information obtained from f1
11 is a graph showing the relationship between the layer thickness of the reflective layer and the reflectance of the No. 11 recording medium. FIG. 3 is a graph showing the relationship between the layer thickness of the reflective layer and recording power of the information recording media obtained in Example 1 and Comparative Example 1. Figure 4 shows the results of Example 2 (including Comparative Example 2) and Example 3.
3 is a graph showing the relationship between the layer thickness of the recording layer and the reflectance of the information recording medium obtained by II. Substrate: 11, Reflective layer = 12, Intermediate layer: 13 Recording layer: 14 Patent applicant: Fuji Photo Film Co., Ltd. Agent: Yasushi Yanagikawa +A+ Diagram Recording layer thickness (mm)

Claims (1)

[Claims] 1. On the substrate, a layer made of at least one metal selected from the group consisting of Au, Pd, Ag, Pt, Al and Cu, and has a layer thickness of 12
A reflective layer with a thickness in the range of 0 to 230 Å, an intermediate layer made of a polymer compound with a layer thickness in the range of 200 to 600 Å, and a layer thickness in the range of 200 to 1600 Å that allows information to be written and/or read by laser light. Te in
An information recording medium in which a recording layer containing: