JP2000289341A - Optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a write-once optical recording medium having a recording layer having a uniform thickness in a disk radial direction of a recording layer and having a recording layer that can be coated by a dipping method. SOLUTION: The write-once optical recording medium has a recording layer, an intermediate layer and a protective layer on a substrate, and the recording layer is substituted with a cyanine dye having a fluorinated alkyl group having 3 or more carbon atoms as shown in the following structural formula. It is formed by applying a solution dissolved in ether on a substrate by a dipping method. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium provided with a recording layer containing an organic dye, and more particularly, to a write-once optical information medium having excellent productivity, excellent recording characteristics and excellent storage stability. It relates to a recording medium.

[0002]

2. Description of the Related Art In recent years, with the development of information technology, an optical recording medium which is a small and large-capacity recording medium has been used. Such optical recording media are CD-ROM, DVD-RO
Read only media such as M, CD that can be written only once
-R (compact disk-recordable) and rewritable media typified by MO and DVD-RAM. Among these, in the write-once type recording medium, an organic dye is usually used as a recording material of a recording layer. In a write-once type recording medium, recording is performed by irradiating a laser beam to a recording layer when information is recorded, changing the organic dye constituting the recording layer by its thermal energy, and changing its optical characteristics. As an organic dye used in the recording layer of such a write-once type recording medium, a cyanine dye is known (Japanese Patent Application Laid-Open No. 58-112790;
JP-A-59-24692 and JP-A-5-67349.

[0003]

SUMMARY OF THE INVENTION Cyanine dyes have high solubility in polar organic solvents such as alcohols and acetylene glycol. However, since the polar organic solution has a large surface tension, the film thickness tends to be uneven in the drying step, and therefore, it is practically impossible to form a film by the dipping method excellent in productivity. Therefore, in order to form a recording layer using a solution in which a cyanine dye solution is dissolved in a polar organic solvent, it was necessary to use a spin coating method and to control the ambient temperature, humidity, and vapor pressure with high precision. .
In the spin coating method, a recording film having a uniform film thickness can be formed with respect to the circumferential position of a write-once optical disc by forced drying using a strong centrifugal force and Bernoulli flow. However, a difference in film thickness is likely to occur at the radial position of the disk, and extremely precise control is required to form a uniform film thickness on the inner and outer circumferences.

Furthermore, the spin coating method requires applying a dye solution to each disk, and the coating operation per disk takes about several tens of seconds. In, the dye application step was rate-determining. In order to improve this and increase the throughput, it is necessary to provide a plurality of high-precision and high-performance spin coaters in one production line. As a result, there is a problem that the production equipment becomes large and the production cost increases. Was.

Further, polar organic solvents such as alcohols and acetylene glycol have high hygroscopicity, and particularly in the spin coating process, the hygroscopicity is further accelerated by heat of vaporization of the solvent. When water molecules are adsorbed on the recording layer composed of an organic dye, recording and reproduction characteristics such as an increase in jitter are deteriorated. In addition, it adversely affects adhesion to a layer adjacent to the recording layer composed of a cyanine dye, for example, a reflective film composed of a metal film and a second recording layer composed of a phase change film, and causes a deterioration in recording characteristics. Had become.

JP-A-3-142281 discloses an information recording medium using a specific cyanine dye and having excellent sensitivity and light resistance.
4, a cyanine dye modified with a fluorinated alkyl group is used. However, this document does not disclose that a recording layer is formed by a dipping method using a solution of a cyanine dye dissolved in a fluorine-substituted ether as disclosed in the present invention.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide an optical information recording medium capable of forming a recording layer containing a cyanine dye without using a polar organic solvent. Is to provide. Also,
An object of the present invention is to provide a disk-type write-once optical information recording medium in which the thickness of a recording layer in the radial direction is uniform. A further object of the present invention is to provide an optical information recording medium having a cyanine dye-based recording layer, which is capable of forming a recording layer by a dipping method and has excellent productivity and recording characteristics.

[0008]

According to the present invention, there is provided an optical information recording medium provided with a recording layer containing a cyanine dye on a substrate, wherein information is recorded / reproduced by light irradiation. An optical information recording medium represented by the general formula (1), wherein the recording layer is formed by a dipping method using a fluorine-substituted ether solution of the cyanine dye, is provided.

[0009]

Embedded image General formula (1):

In the formula, R and R ′ may be the same or different and each represents a fluorine-substituted alkyl group;
_Preferably, -CH ₂ C 3 _{F 7} or _-CH 2 _C 2 _{F 5}
It is. n represents a polymerization number and is an integer of 0 to 3, preferably 2. Z represents a hydrogen atom, an alkyl group, an alkoxyl group, an alkylhydroxy group, an aralkyl group, an alkenyl group, an alkylcarboxyl group, an alkylsulfone group, or a halogen, and is preferably hydrogen, a methyl group, or chlorine. When n is 2 or more, Z may be the same or different. Y and Y ′ may be the same or different, respectively, and C (CH ₃ ) ₂ , HCＣＨCH, S
Or O, preferably C (CH ₃ ) ₂ . X
⁻ Represents a counter ion, represents a halogen ion or an ion of a halogen compound, and is, for example, ClO ₄ ⁻ , P
F ₆ ⁻ , SbF ₆ ⁻ , halogen and ZnCl ⁻ . In the formula, A and A ′ may be the same or different and each is an atom group constituting a benzene ring or a substituted benzene ring, and a benzene ring or a naphthalene ring is preferable. As the cyanine dye represented by the formula (1), particularly, the cyanine dyes represented by the structural formulas (5) and (6) used in Examples described later are preferable.

Since the surface tension of the fluorine-substituted ether is generally extremely low, the use of the cyanine dye represented by the general formula (1) as a solvent makes it possible to form a recording film by a dipping method, thereby producing an optical information recording medium. The performance is improved. The cyanine dye represented by the general formula (1) is compatible with the fluorine-substituted ether because it has a fluorinated alkyl group. As the fluorine-substituted ether, for example, nonafluorobutyl methyl ether and nonafluorobutyl ethyl ether are preferable.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an organic dye constituting the recording layer of the optical information recording medium of the present invention, another cyanine dye may be added to the cyanine-based organic dye represented by the general formula (1). Other cyanine dyes include dyes such as squarylium dyes, polymethine dyes such as azurenium dyes, macrocyclic azaannulene dyes such as phthalocyanine dyes, and dithiol dyes.
They may be used alone or in combination of two or more. Further, a cyanine dye deterioration inhibitor may be added to the recording layer. The share of the deterioration inhibitor is preferably 5 to 30% by weight.
If it is less than 5% by weight, the effect of preventing deterioration is not sufficiently exhibited,
On the other hand, when the share ratio exceeds 30% by weight, it is not easy to control the recording pits by the laser beam. As the deterioration inhibitor, a dithiol metal complex, an amino compound, an azo compound, or the like can be used. For example, the following general formula (2)
To (4).

[0013]

Embedded image General formula (2):

In the formula (2), R1, R2, R3 and R4
May be the same or different, and each represents a hydrogen atom,
Group, alkyl fluoride group, amine group, alkyl group, alcohol
Xyl group, alkylhydroxy group, aralkyl group,
Kenyl group, alkyl carboxyl group, alkyl sulfoni
Or an aromatic ring having these functional groups. X⁻Is
Represents a counter anion, such as halogen or ha
It is a logenide. n represents the ionic valence of the compound and 1
Or 2. Compounds of the general formula (2) are represented by R1, R
2, R3 and R4 are each a dialkylaminoben
Ben and X⁻Is ClO₄ ⁻, PF₆ ⁻, Sb
F₆ ⁻, BF₄ ⁻, ZnCl⁻, Or CF₃SO ₃ ⁻
Are preferred. n can be 1 or 2.

[0015]

Embedded image General formula (3): In the formula (3), A and A ′ may be the same or different, and each represents a hydrogen atom, a hydroxyl group, a fluoroalkyl group, an amine, an alkyl group, an alkoxyl group, an alkylhydroxy group, an aralkyl group, an alkenyl group, an alkyl group. It represents a carboxyl group, an alkylsulfonyl group or an aromatic ring having these functional groups. M represents a transition metal, for example,
Copper and nickel are preferred. X represents a counter cation, for example, preferably tetrabutylammonium.
n represents the ionic valence of the compound and is 1 or 2. For example, the trade name PA available from Mitsui Toatsu (Mitsui Chemicals)
A dithiol compound such as -1006 may be used.

[0016]

Embedded image General formula (4):

Wherein R1, R2, R3, R4, R5, R
6, R7, R8, R9, R10, R11 and R12 are
Each may be the same or different, and may be a hydrogen atom, a hydroxyl group, a fluoroalkyl group, an amine group, an alkyl group, an alkoxyl group, an alkylhydroxy group, an aralkyl group, an alkenyl group, an alkylcarboxyl group, an alkylsulfonyl group, or a functional group thereof. Represents an aromatic ring having In particular,
R1, R2, R3, R4, R5, R6, R7, R8, R
The groups of 9, R10, R11 and R12 are preferably methyl, halogen, nitro group, hydroxyl group, amine and alkyl fluoride group. For example, o-Tolenazo-β-naph can be obtained as a pigment material having a trade name such as Oil Orange SS.
can be thol.

The recording layer of the optical information recording medium of the present invention may contain, if necessary, a resin such as an acrylic resin, a polycarbonate resin, a polyester resin, a fluororesin, and a polyvinyl alcohol.

In order to form the recording film on a substrate, the cyanine dye constituting the recording film is added to a fluorine-substituted ether in a concentration of 0.1%.
It is desirable to prepare a solution in which a solution of 01 to 5% is dissolved, and dipping a substrate by immersing the substrate in this solution. The thickness of the recording layer is suitably from 30 to 500 nm.
It is also possible to add a small amount of an alcohol, such as methanol, an ether, a ketone, or a hydrocarbon solvent to the fluorine-substituted ether in order to improve the solubility of the deterioration inhibitor and the like. However, if the evaporation rates of the fluorine-substituted ether, which is the main component, and these additional solvents are significantly different, a concentration gradient will occur on the substrate during the drying step, causing uneven coating. In particular, when the evaporation rate of the above-mentioned additive solvent is lower than the evaporation rate of the fluorine-substituted ether, the coating unevenness becomes significant. Therefore, the evaporation rate of the additive solvent is:
It is desirable to select an additive solvent which has almost the same or higher evaporation rate than the fluorine-substituted ether which is the main solvent. The amount of the added solvent depends on the polarity of the added solvent, but is preferably 10% by weight or less. If the proportion of the added solvent is larger than that, the surface tension of the solvent is increased, which is not preferable.

The optical information recording medium according to the present invention may have a structure in which a first intermediate layer, a recording layer, a second intermediate layer, and a protective layer are laminated on a substrate. Of these, one or two of the first intermediate layer, the second intermediate layer, and the protective layer may be omitted.
A structure may be employed in which a set of laminates having the above-described configuration is prepared, and the laminates are laminated via an adhesive layer such that the substrate is on the outside or inside. Further, a lubricating layer for reducing damage due to contact with the head may be provided on the recording / reproducing light incident surface, and printing for protecting or decorating the lower layer may be performed on the opposite surface.

Acrylic, polycarbonate, polymethyl methacrylate, polymethyl pentene,
A transparent resin substrate such as polyolefin or epoxy can be used. The substrate can be formed by injection molding using a stamper in which preformat signals are formed in the form of pits. Alternatively, a transparent ceramic plate such as glass having a replica layer of a photocurable resin formed on one surface can be used as the substrate.

The intermediate layer has improved reflectance characteristics.
Reflection layer, laser beam or recording layer
The heat diffusion layer and the recording layer
Reaction to accelerate the reaction or by photoexcitation of the recording layer
Is promoted, the second recording layer separates the recording layer from external stress
Air layer provided by a hard layer, spacer, etc.
A lube layer or the like may be provided as necessary. The middle layer is
Gold, aluminum, silver or copper or their main components
Alloy, SiO_Two, SiN, AlN, Al_TwoO _ThreeSuch
Of hard inorganic materials and alloys containing rare earth metals
Amorphous phase change film, color with optical properties different from cyanine dye
Element layer etc. can be used.
The film can be formed by a dry process such as brushing.

The protective layer can be formed by, for example, screen printing or spin coating an organic material such as an ultraviolet curable resin, a thermosetting resin, a two-part mixed curable resin, or a room temperature curable resin on the intermediate layer.

Hereinafter, embodiments of the optical information recording medium of the present invention will be described, but the present invention is not limited to these embodiments.

Embodiment 1 In this embodiment, as shown in FIG. 1, a recording layer 2, an intermediate layer 3, and a protective layer 4 are laminated on a substrate 1, and the recording layer has a cyanine dye and deterioration suppression. O-Tolenazo as an agent
A write-once optical recording disk 10 including -β-naphthol is manufactured.

A polycarbonate substrate was injection molded to produce a transparent substrate on a disk having a preformat pattern formed and having a center hole at the center. FIGS. 1 and 2 show outlines of a cross-sectional structure and a planar structure of a substrate obtained by molding, respectively. The preformat pattern on the substrate 1 includes a guide groove 5 for causing a recording / reproducing laser beam to follow, a recording track 8 defined by the guide groove 5, a prepit 6 for displaying a sector address and a reference clock. Is formed. The guide groove 5 is formed in a concentric spiral or concentric shape with the center hole 7. The guide groove 5 may be a wobble groove, whereby information such as a tracking signal can be detected from the wobble groove. In this embodiment, the guide groove 5 employs a wobble groove. Further, as shown in FIG. 1, the guide groove 5 and the pre-pit 6 are formed at different depths.

The polycarbonate substrate 1 thus obtained
Were prepared, and a recording layer was formed on each substrate by using a dipping method described below. First, a cyanine dye represented by the following structural formula (5) was prepared. The cyanine dye represented by the structural formula (5) can be easily synthesized by, for example, substituting 2-methylindolenine with an alkyl fluoride group, reacting cyanyl, formate, or the like, ion-exchanging, and then purifying with methanol. can do. The synthesis method is described, for example, in “Halogenated Indocyanine” by Walter Grahn et al.
s: Synthesis, Conformational Behavior ”Liebigs A
nn. 1995, 1003-1009. 19 parts by weight of this cyanine dye and 1 part by weight of o-Tolenazo-β-naphthol were dissolved in 1980 parts by weight of nonafluorobutyl ethyl ether. The obtained solution was filtered with a 0.45 μm filter. The filtrate was filled in a disk immersion tank. Next, in a low humidity atmosphere, the plurality of polycarbonate substrates 1 were hung on a hanger, immersed in the solution in the tank, and raised at a lifting speed of about 0.5 cm / s. A 70 nm-thick dye layer (recording layer) was uniformly formed on each polycarbonate substrate.

Next, after drying the dye layer, Ag / A was deposited on the dye layer on one side of the substrate by using a sputtering apparatus.
An intermediate layer made of a u alloy was formed to a thickness of 50 nm. After forming the intermediate layer, the dye on the other side of the substrate was washed with alcohol, and finally, an ultraviolet curable resin was applied on the intermediate layer by screen printing to form a protective layer having a thickness of 10 μm. Thus, a write-once optical recording medium having a sectional structure as shown in FIG. 1 was obtained.

[0029]

Embedded image Structural formula (5):

Example 2 19 parts by weight of a cyanine dye represented by the structural formula (5) and o-Tole
One part by weight of nazo-β-naphthol was dissolved in 3980 parts by weight of nonafluorobutyl methyl ether. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a plurality of polycarbonate substrates in the same manner as in Example 1 by using the above-described dip method, and each had a film thickness of 70 n.
m of the dye layer was formed.

After the dye layer is dried, Ag / Au is deposited on the dye layer adhered to one surface of the substrate by using a sputtering apparatus.
An intermediate layer made of an alloy was formed to a thickness of 50 nm. After forming the intermediate layer, the dye adhering to the other surface side of the substrate was washed with alcohol, and finally an ultraviolet curable resin was applied on the intermediate layer by screen printing to form a protective layer having a thickness of 10 μm.

Example 3 10 parts by weight of a cyanine dye represented by the structural formula (5), 9 parts by weight of a cyanine dye represented by the following structural formula (6), and a dye material having a trade name such as Oil Orange SS from TCI. Was dissolved in 1980 parts by weight of nonafluorobutyl ethyl ether. The cyanine dye represented by Structural Formula (6) can be synthesized by a method similar to Structural Formula (5) using a mixture of benzoindolenine and 2-methylindolenine as a starting material. After the obtained solution was filtered with a 0.5 μm filter, the filtrate was applied on a plurality of polycarbonate substrates in the same manner as in Example 1 using the above-described dip method, and a film thickness of 70 nm was formed on each substrate. (Recording layer) was formed.

[0033]

Embedded image Structural formula (6):

After drying the dye layer, Ag / Au is deposited on the dye layer adhered to one surface of the substrate by using a sputtering apparatus.
An intermediate layer made of an alloy was formed to a thickness of 50 nm. After forming the intermediate layer, the dye adhering to the other surface of the substrate was washed with alcohol, and finally, an ultraviolet curable resin was applied on the intermediate layer by screen printing to form a protective layer having a thickness of 10 μm.

Example 4 19 parts by weight of a cyanine dye represented by the structural formula (5) and o-Tole
1 part by weight of nazo-β-naphthol was dissolved in a mixed solvent of 1800 parts by weight of nonafluorobutylethyl ether and 180 parts by weight of methanol. It was found that the solubility of the dye in the solvent was improved as compared with the case of Example 1. After the obtained solution was filtered through a 0.45 μm filter, the filtrate was applied on a plurality of polycarbonate substrates in the same manner as in Example 1 using the above-described dip method, and a film thickness of 70 nm was formed on each substrate. Was formed.

After drying the dye layer, Ag / Au is deposited on the dye layer adhered to one side of the substrate by using a sputtering apparatus.
An intermediate layer made of an alloy was formed to a thickness of 50 nm. After forming the intermediate layer, the dye adhering to the other surface of the substrate was washed with alcohol, and finally, an ultraviolet curable resin was applied on the intermediate layer by screen printing to form a protective layer having a thickness of 10 μm.

Comparative Example 1 19 parts by weight of a cyanine dye represented by the following structural formula (7) and o-
1 part by weight of Tolenazo-β-naphthol was mixed with 1980 parts by weight of nonafluorobutyl ethyl ether. The obtained mixture was filtered with a 0.45 μm filter. However, the cyanine dye was hardly soluble in nonafluorobutyl ethyl ether, and the dye was filtered through a filter.

[0038]

Embedded image Structural formula (7):

Comparative Example 2 Cyanine dye 1 represented by the structural formula (7) used in Comparative Example 1
9 parts by weight and 1 part by weight of o-Tolenazo-β-naphthol were dissolved in 1980 parts by weight of methanol. 0.4 of the obtained solution
After filtration through a 5 μm filter, the filtrate was applied on a plurality of polycarbonate substrates 1 using the above-described dip method in the same manner as in Example 1 to form a dye layer on each substrate.

The dye film thickness on the optical recording disks obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was measured as follows. The recording track area of the substrate after the dip coating of the cyanine dye was irradiated with white light to obtain 680, which is the maximum absorption wavelength of the cyanine dye used in Examples.
The thickness of the dye coated on the substrate was estimated by measuring the absorption intensity in nm. The maximum film thickness and the minimum film thickness of the dye applied in the recording area of one substrate (disk) are obtained, and the difference between the film thicknesses is shown in Table 1. In the optical recording disks of Examples 1 to 4 according to the present invention, the difference in film thickness was 10 n.
m to 15 nm. As described above, in the case of Comparative Example 1, the dye hardly dissolved, so that the dye was filtered by the filter, and the cyanine dye could not be applied on the substrate. In Comparative Example 3 in which coating was performed by dipping using only methanol as a solvent, it was found that coating was possible but coating unevenness was remarkable.

The optical recording disks obtained in Examples 1 to 4 were rotated at a linear velocity of 1.2 m / sec, and the wavelength 780 n
The EFM signal was recorded using a semiconductor laser having an output of 14.0 mW and an aperture of NA = 0.50. The signal of each optical recording medium on which the signal was recorded was converted to a signal having a wavelength of 783 nm and an aperture of N.
The data was read by a reproducing apparatus using a semiconductor laser having A = 0.45 and an output value of 0.4 mW, and the jitter value was measured by a jitter meter. As a result, the jitter values of the optical recording media of Examples 1 to 4 according to the present invention were all 23% or less, indicating that the recording media had sufficient performance.

Table 1 Solvent Thickness distribution (nm) of recording layer in recording area Example 1 Nonafluoroethyl ethyl ether 10 nm Example 2 Nonafluoroethyl methyl ether 10 nm Example 3 Nonafluoroethyl ethyl ether 10 nm Example 4 Nona Fluoroethyl ethyl ether + methanol 15 nm Comparative Example 1 Nonafluoroethyl ether (no coating possible) Comparative Example 2 Methanol 120 nm

In the above embodiment, the present invention has been described using a write-once optical recording medium. However, the optical recording medium of the present invention is not limited to this, and any optical recording medium containing an organic dye in the recording layer It is adaptable to. Further, the laminated structure is not limited to the structure of the embodiment, and a laminated optical recording medium in which an intermediate layer is further interposed or two laminated structures are laminated may be formed.

[0044]

In the present invention, since a cyanine dye having a fluorine-substituted alkyl group is used in combination with a fluorine-substituted ether solvent, the dye can be applied to a substrate by a dipping method. Therefore, it is possible to apply a dye to a plurality of substrates at the same time, and the productivity is improved. Further, since a low-polarity fluorine-substituted ether is used as the solvent, the thickness in the radial direction of the disk-shaped substrate can be made uniform, and an optical recording medium having good recording / reproducing characteristics can be provided. .

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an optical recording disk according to an embodiment of the present invention.

FIG. 2 is a plan view of an optical recording disk according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Dye layer 3 Intermediate layer 4 Protective layer 5 Guide groove 6 Pit 7 Center hole 8 Track 10 Optical recording medium

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Ohara 1-1-88 Ushitora, Ibaraki City, Osaka Prefecture Inside Hitachi Maxell Co., Ltd. (72) Takuhiro Yoshimizu 1-188 Ushitora, Ibaraki City, Osaka Prefecture Hitachi Maxell Co., Ltd. (72) Inventor Takahiro Otsuka 1-88 Ushitora, Ibaraki-shi, Osaka F-term within Hitachi Maxell Co., Ltd. 2H111 EA03 EA12 EA22 EA40 FA01 FA14 FA23 FB43 FB60 FB61 GA06 5D029 JA04 JA10 JC17

Claims (6)

[Claims] 1. An optical information recording medium having a recording layer containing a cyanine dye on a substrate and recording / reproducing information by light irradiation, wherein the cyanine dye is represented by the following general formula (1):
And represented by the following general formula (1): (In the formula, R and R ′ may be the same or different and each represents a fluorine-substituted alkyl group. N represents a polymerization number, and is an integer of 0 to 3. Z is a hydrogen atom or an alkyl group. And when n is 2 or more, Z may be the same or different, and Y and Y ′
May be the same or different, and C (CH ₃ ) ₂ , HC
= CH, S or O is shown. X ⁻ represents a counter ion, and represents a halogen ion or an ion of a halogen compound. A
And A ′ may be the same or different, and represent an atom group forming a benzene ring or a substituted benzene ring. The optical information recording medium, wherein the recording layer is formed by a dipping method using a fluorine-substituted ether solution of the cyanine dye. 2. The optical information recording medium according to claim 1, wherein a carbon number of the fluorine-substituted alkyl group of the cyanine dye is 3 or more. 3. The optical information recording medium according to claim 1, wherein the recording layer is formed by a dipping method using a solution containing 90% by weight or more of the fluorine-substituted ether. 4. The optical information recording medium according to claim 1, wherein the fluorine-substituted ether is nonafluorobutyl methyl ether or nonafluorobutyl ethyl ether. 5. The optical information recording medium according to claim 1, wherein said recording layer contains 5 to 30% by weight of a deterioration inhibitor. 6. An intermediate layer and a protective layer are sequentially formed on the recording layer, and the intermediate layer is made of a metal selected from the group consisting of gold, silver, copper and aluminum or an alloy thereof. The optical information recording medium according to any one of claims 1 to 5, wherein: