JP2000057627A - Light-reflecting film and optical recording medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve recording properties and durability by using a light- reflecting film which contains each one or more kinds of elements selected from a first group consisting of Al and Ag and a second group consisting of Bi, Rh and Zn and has specified thermal conductivity and reflectance of specified range for light of a specified wavelength. SOLUTION: The combination of metal elements is made to Al and Bi and/or Rh or Ag ans Bi and/or Zn and the total number of metal atoms in a second group is made to 1 to 49% for the total number of atoms of the first and second metals. The thermal conductivity is made to 140 to 370 W/(m.K) and the reflectance is made to >=70% for light in 830 to 370 nm wavelength range. When a reflecting film having the thermal conductivity above described is applied for a DRAW type optical recording medium using a dye as a recording layer, good pits can be obtd. while maintaining the recording sensitivity and further, good adhesion between the recording layer and a reflecting layer can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light reflection film, and more particularly to a light reflection film for a write-once optical recording medium corresponding to a wavelength from a near infrared laser to a blue laser.

[0002]

2. Description of the Related Art Conventionally, in order to reproduce recorded information as an optical recording medium, a means such as a press is used in advance.
Pre-pits and pre-grooves are formed on a substrate made of translucent polycarbonate or the like, and Au,
A read-only optical recording medium in which a light reflecting layer made of a metal film of Al or the like is formed and a protective layer made of a photocurable resin is further formed thereon has been put into practical use as a compact disk (hereinafter abbreviated as CD). ing. This CD is widely used for storing and reproducing music, images, data, programs and the like. The specification relating to the recording and reproduction signals of the CD is defined as a CD standard, and a reproducing apparatus conforming to the standard is widely used as a CD player.

As a write-once optical recording medium conforming to the CD standard, a CD-Recordable (hereinafter abbreviated as CD-R) has been proposed.
[For example, Nikkei Electronics No.4
65, p.107, January 23, 1989, OPTICAL DATA STORAGE
DIGEST SERIES vol.1, p.45, 1989, JP-A-2-13
2656, JP-A-2-168446, JP-A-3-2
No. 15466, etc.]. In this CD-R, a recording layer, a reflective layer, and a protective layer are laminated in this order on a transparent resin substrate. By irradiating the recording layer with a high-power laser beam, the recording layer is physically or Make chemical changes and record information in the form of pits. The pit information can be reproduced by irradiating the formed pit portion with a low-power laser beam and detecting a change in reflectance. Commercial C
DR has a recording layer containing a dye. The dye is roughly classified into a phthalocyanine dye and a cyanine dye. The reflective layer is provided in close contact with the dye layer. Usually, in order to obtain a reflectivity conforming to the CD standard, the reflective layer is made of an Au thin film having high reflectivity and good corrosion resistance [for example, And JP-A-2-79235].

[0004] These CD-R media are 830-770.
record / reproduce using near-infrared semiconductor laser
Because it complies with CD standards such as Red Book and Orange Book, it has the feature of being compatible with CD players and CD-ROM players. Recently, wavelength 69
A red semiconductor laser of 0 nm to 620 nm has been developed, and high-density recording and / or reproduction has become possible. For example, a high-density recording medium having a recording capacity 5 to 8 times that of a conventional recording medium and a player compatible with the high-density recording medium have been developed. In addition, 530 nm, 42
A laser having a wavelength around 0 nm has been put into practical use.
Semiconductor lasers having wavelengths around 0 nm, 410 nm, and 370 nm are also being developed.

Therefore, an optical recording medium which can be written once at high density using a dye corresponding to these short wavelength lasers has been proposed, and such an optical recording medium has a high reflectance in a short wavelength region. It is necessary to use a reflective film having Furthermore, it is necessary to control the thermal conductivity of the reflective film to optimize the resolution of the recording layer, the sensitivity to laser light, and the like. In JP-A-6-243509, A
Although the thermal conductivity is specified using an alloy such as g-In, Ag-V, or Ag-Nb, the decomposition of the dye recording layer is not considered. In addition, the conventionally used A
When a reflective film made of u, Al, Ag, etc. is used for a write-once optical recording medium containing a dye in a recording layer, and recording and reproduction are performed using a short wavelength laser, problems such as heat control and adhesion may occur. In particular, in the case of Au, the reflectance was extremely reduced at the blue laser wavelength.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical recording medium having a high density by shortening the wavelength of a laser light source, and particularly to a write-once high-density optical recording medium containing a dye in a recording layer. An object of the present invention is to provide a light reflection film which has a high reflectance to light from near infrared to blue wavelengths, has good adhesion to a dye layer, and has an appropriate thermal conductivity for recording.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention provides a first group consisting of Al and Ag, and Bi and R
h, containing at least one element selected from the second group consisting of Zn, and having a thermal conductivity of 140 to 370.
W / (m · K), and has a reflectance of 70% or more with respect to light having a wavelength of 830 to 370 nm. And the light reflecting film according to the above, wherein the metal of the second group is contained in an amount of 1 to 49% with respect to the number of atoms of all the metals of the second group, Al and Bi and / or Rh, or , Ag and Bi and / or Zn. The light reflecting film according to the above or the above, wherein at least a recording layer containing a dye is provided on a transparent substrate, and the reflecting film according to any of the above (1) to (4). An optical recording medium according to any one of the preceding claims, wherein the optical recording medium has a reflectance of 15% or more to a laser beam selected from 450 to 370 nm incident from the substrate side. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The reflective film of the present invention, in which specific elements are combined in a certain ratio, has a high reflectance of 70% or more with respect to light in the near-infrared to blue wavelength region. When applied to a recording medium, it has an appropriate thermal conductivity and good adhesion to a dye layer. The reflective film of the present invention has
l, a first group consisting of Ag, and Bi, Rh,
It contains at least one element selected from the second group consisting of Zn, and the proportion of these elements in the reflective layer is 50% by weight or more. The reflective film of the present invention enables good recording and reproduction in a green to blue wavelength region, particularly in a write-once optical recording medium using a dye for the recording layer.

The laser light referred to in the present invention is 830, 780
near-infrared semiconductor lasers having an oscillation wavelength of around nm, 680, 6
Red semiconductor lasers having oscillation wavelengths of about 50 and 635 nm, green lasers having oscillation wavelengths of about 530 nm and 490 nm, blue semiconductor lasers having wavelengths of about 410 nm and 370 nm, and 530 n by harmonic conversion of YAG lasers
m, a laser having a wavelength around 420 nm. The optical recording medium of the present invention can be reproduced at one wavelength or a plurality of wavelengths selected from these, and has a reflectance of 1 or more.
5% or more.

The specific configuration of the present invention will be described in detail below. The reflective film of the present invention contains at least one element selected from a first group consisting of Al and Ag and a second group consisting of Bi, Rh and Zn. The thermal conductivity of this reflective film is 140 to 370 W / (m ·
K), and has a reflectance of 70% or more for light having a wavelength of 830 to 370 nm. The total number of atoms contained in the metal of the second group is preferably 1 to 49% with respect to the total number of atoms of all the metals of the first and second groups. The conductivity value is determined in consideration of a predetermined value. Particularly preferred is a reflective film containing Al and Bi and / or Rh, or Ag and Bi and / or Zn.

The thermal conductivity of the reflection film of the present invention is 140 to 3
70 W / (m · K). When such a reflective film is applied to an optical recording medium having a dye as a recording layer, heat tends to accumulate in the recording layer in a reflective film having a thermal conductivity of less than 140 W / (m · K), and thus, when recording is performed. In addition, it is difficult to obtain a clear pit due to the influence of heat around the recording pit. On the other hand, when the reflective film is larger than 370 W / (m · K), the heat of the recording layer tends to escape and the recording sensitivity tends to decrease. Further, when the reflective film of the present invention is used, the adhesion between the recording layer and the reflective layer is improved, and the durability of the medium is improved.

The reflection film of the present invention mainly contains the metals of the first and second groups, but may contain other metals, such as Cu,
V, Ta, Cr, Mo, W, Mn, Fe, Co, Ni,
Pd, Pt, Au and the like can be mentioned. In the reflective film of the present invention, the total content (total number of contained atoms) of one or more metals selected from these other metals is Al and / or A
20% or less based on the total number of atoms of g. Examples of the method for forming the reflection film of the present invention include a sputtering method, an ion plating method, a chemical vapor deposition method, and a vacuum vapor deposition method. Particularly, a sputtering method using a multimetal target or an alloy target is preferable.

Next, an optical recording medium using the reflection film of the present invention as a reflection layer will be described. The optical recording medium in the present invention refers to both a read-only optical reproduction medium on which information is recorded in advance and an optical recording medium on which information can be recorded and reproduced. Here, as an appropriate example, an optical recording medium capable of recording and reproducing the latter information, particularly an optical recording medium in which a recording layer, a reflective layer and a protective layer are formed in this order on a substrate, and a substrate on the reflective layer surface The bonded optical recording medium will be described. Note that another layer may be interposed between the substrate and the recording layer, between the recording layer and the reflective layer, between the reflective layer and the protective layer, between the reflective layer and the substrate, and the like.

Basically, the material of the substrate only needs to be transparent at the wavelength of the recording light and the reproducing light. For example, an acrylic resin such as a polycarbonate resin, a vinyl chloride resin, and polymethyl methacrylate, a polymer material such as a polystyrene resin and an epoxy resin, and an inorganic material such as glass are used. These substrate materials are formed into substrates in a disk shape by an injection molding method or the like. In the case of a write-once optical recording medium, a groove may be formed on the substrate surface as necessary.

The recording layer mainly contains a substance which has an appropriate absorption in a laser wavelength range and which is physically / chemically deformed, deteriorated and decomposed by irradiation with a laser beam having a certain energy or more. Layer, and the invention includes a dye. For example, the recording / reproducing wavelength is 450 nm to 370 n
A material having an effective recording ability when m is λ
It is preferable that the max is around 350 nm, the refractive index at 450 to 370 nm is large, and the absorbance is small. Specifically, spiro dyes, stilbene dyes, fluorein dyes, imidazole dyes, perylene dyes And phenazine dyes, phenothiazine dyes, polyene dyes, quinone dyes, cyanine dyes, acridine dyes, acridinone dyes, coumarin dyes, carbostyril dyes, porphine dyes, and squarylium dyes. Preferred are polyene dyes, stilbene dyes, and quinone dyes. In the present invention, as the dye contained in the recording layer, the above dye may be used alone, or two or more dyes may be mixed or laminated.

Further, if necessary, additives such as a quencher, a dye thermal decomposition accelerator, an ultraviolet absorber, and an adhesive are mixed with the dye, or a group having such performance is introduced as a substituent. It is also possible. As the quencher, metal complexes such as acetylacetonate-based, bisdithio-α-diketone-based and bisphenyldithiol-based bisdithiol-based, thiocatechol-based, salicylaldehyde oxime-based, and thiobisphenolate-based metal complexes are preferable.
Also, amines are suitable.

The dye thermal decomposition accelerator is not particularly limited as long as it can confirm the promotion of the thermal decomposition of the dye by thermal weight loss analysis (TG analysis) and the like. For example, a metal anti-knocking agent, a metallocene compound, Metal compounds such as acetylacetonate-based metal complexes are exemplified. Examples of metal-based anti-knocking agents include tetraethyl lead, other lead-based compounds, and Simantrene [Mn (C ₅ H ₅ ) (CO) ₃ ].
Examples of a Mn-based compound such as an iron biscyclopentadienyl complex (ferrocene)
, Ti, V, Mn, Cr, Co, Ni, Mo,
Ru, Rh, Zr, Lu, Ta, W, Os, Ir, S
There are biscyclopentadienyl metal complexes such as c and Y. Among them, ferrocene, ruthenocene, osmocene, nickelocene, titanocene and derivatives thereof have a good thermal decomposition promoting effect.

Other iron-based metal compounds include, in addition to metallocene, iron acid organic compounds such as iron formate, iron oxalate, iron laurate, iron naphthenate, iron stearate and iron butyrate; iron acetylacetonate complex; Phenanthroline iron complex, bispyridine iron complex, ethylenediamine iron complex,
Iron complexes such as iron complexes of ethylenediaminetetraacetate, iron complexes of diethylenetriamine, iron complexes of diethyleneglycol dimethylether, iron complexes of diphosphino and iron dimethylglyoximate, iron complexes such as carbonyl iron complexes, cyanoiron complexes and ammineiron complexes, Examples thereof include iron halides such as iron, ferric chloride, ferrous bromide, and ferric bromide; inorganic iron salts such as iron nitrate and iron sulfate; and iron oxide. It is desirable that the thermal decomposition accelerator used here is soluble in an organic solvent and has good wet heat resistance and light resistance. The above-mentioned various quenchers and dye thermal decomposition accelerators may be used as a mixture of various types, if necessary, or an additive substance such as a binder, a leveling agent, or an antifoaming agent may be added.

The recording layer may be formed by a coating method such as a spin coating method or a casting method, a sputtering method, a photo CVD method,
There are an ion plating method, an electron beam evaporation method, a chemical evaporation method, a vacuum evaporation method and the like, and there is no particular limitation. However, in the present invention, the production by the coating method is preferable in that the degree of freedom and easiness in dye selection, medium design, and production are further expanded. The solvent used in the coating method must be one that easily dissolves or disperses the dye and does not damage the substrate. For example, alcohol solvents (methanol, ethanol, propanol, etc.), halogenated alcohol solvents (2,2,3,3-tetrafluoro-1-propanol, hexafluoroisopropanol, etc.), hydrocarbon solvents (hexane, cyclohexane, etc.) Ethylcyclohexane, cyclooctane, dimethylcyclohexane, octane, benzene, toluene, xylene, etc.), halogenated hydrocarbon solvents (dichloromethane, chloroform, tetrachloride hydrocarbon, tetrachloroethylene, dichlorodifluoroethane, etc.), ether solvents (tetrahydrofuran, diethyl ether) , Dipropyl ether, dibutyl ether, dioxane, etc.), cellosolve solvents (methylcellosolve, ethylcellosolve, etc.), ketone solvents (acetone, cyclohexanone, methylethylketone, etc.), Ester solvents (such as ethyl acetate and butyl acetate). These solvents are used alone or as a mixture of two or more.

As a coating method, the binder resin is dissolved in a solvent so as to be 20% by weight or less, preferably 0%, and the pigment is 0.05 to 30% by weight, preferably 0.5 to 20% by weight. The method of applying with a spin coater is preferred.
The thickness of the recording layer is usually 30 to 1000 nm,
Preferably it is 50 to 500 nm. Needless to say, if the film thickness is too small, for example, less than 30 nm, heat radiation to the metal reflection layer cannot be avoided, and the sensitivity may be reduced. The film thickness is set so that the absorbance of the recording layer with respect to the light of the reproduction laser wavelength becomes appropriate.

The reflection layer is formed on the recording layer by the above-described method. In order to increase the reflectance and improve the adhesion, the reflection amplification layer and the reflection amplification layer are provided between the recording layer and the reflection layer. An adhesive layer can also be provided. On the reflective layer, a protective layer can be further formed by a known method. As the material of the protective layer, if the material protects the reflective layer from external force,
Any of organic and inorganic substances may be used, and there is no particular limitation.
Organic materials include thermoplastic resin, thermosetting resin, UV
Curable resins and the like can be mentioned, and among them, UV curable resins are preferable. As the inorganic substance, SiO ₂ , Si
O, SnO ₂ , Si ₃ N ₄ , MgF ₂ , AlN, and the like.

When a thermoplastic resin, a thermosetting resin or the like is used, a protective layer can be formed by dissolving in an appropriate solvent, applying a coating solution on the reflective layer, and drying. In the case of a UV curable resin, a protective layer can be formed by applying the coating liquid as it is or after dissolving it in an appropriate solvent to prepare a coating liquid and irradiating with UV light to cure the coating liquid. . As UV curable resin,
For example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or as a mixture, or may be used not only in one layer but also in a multilayer film.

As a method for forming the protective layer, a coating method such as a spin coating method or a casting method, a sputtering method, a chemical vapor deposition method, and the like are used as in the recording layer. Among them, the spin coating method is preferable. In general, the thickness of the protective layer is set to 0.
In the range of 1 to 100 μm, in the present invention, it is 3 to 100 μm.
A film thickness of 30 μm is preferred.

The optical recording medium of the present invention has such a layer structure that a protective sheet or a substrate is bonded to the reflective layer surface, or two optical recording media are bonded to each other with the reflective layer surfaces facing each other. You may. In the optical recording medium of the present invention, printing of a label or the like can be further performed on the protective layer.

[0025]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited by these examples. Example 1 A disc-shaped substrate made of polycarbonate resin and having a continuous guide groove (track pitch: 0.7 μm) and an outer diameter of 120 mm and a thickness of 0.6 mm was used. On this substrate, a dye solution obtained by dissolving 0.25 g of a polyene compound represented by the following formula (Formula 1) in 10 ml of 2,2,3,3-tetrafluoro-1-propanol was used.
Spin coating was performed at rpm, and drying was performed at 70 ° C. for 2 hours to form an optical recording layer having a thickness of about 100 nm.

[0026]

Embedded image

On this recording layer, binary DC sputtering using an Al target and a Bi target was performed by using a sputtering apparatus manufactured by Shimadzu Corporation to obtain an Al-B having a thickness of 100 nm.
An i reflection film was formed. An argon gas was used as a sputtering gas, a sputtering power of 0.5 A and a sputtering gas pressure of 1.0.
The test was performed under the conditions of × 10 ⁻³ Torr. As a result of surface analysis of the formed reflective film, the atomic number% of Bi / (Al + Bi) was about 8%. At the same time, a 100 nm thick Al-Bi alloy film was provided on a 5 cm square glass plate, and the spectral reflectance and thermal conductivity were measured. As a result, the reflectance is 830 nm to 3
73% or more in a wavelength region of 70 nm and a thermal conductivity of 19%
0 W / (m · K). Furthermore, after a UV curable resin was spin-coated on the reflective layer, a substrate similar to the above-mentioned substrate without a guide groove was mounted thereon, and irradiated with ultraviolet rays to bond the substrates, thereby producing an optical recording medium.

On this medium, the shortest pit was reduced to 0 using an optical disk evaluation device (DDU-1000) manufactured by Pulstec Industrial equipped with a 430 nm blue harmonic conversion laser head (NA = 0.65) and an EFM encoder manufactured by KENWOOD. The EFM modulated signal of .4 μm was converted to a linear velocity of 5.6.
m / s and recording with a laser power of 10 mW. After recording,
A signal was reproduced with the laser output set to 0.5 mW using the evaluation apparatus, and the reflectance, error rate, and jitter were measured. At the time of reproduction, an equalization process was performed. The recorded medium was subjected to an accelerated deterioration test (85% RH, 80 ° C.
00 hours), and the reflectivity and the error rate after the test were measured. As a result, it was confirmed that the change was small and the durability was excellent.

Example 2 Binary DC sputtering using an Al target and a Rh target was performed to a thickness of 100 nm.
An optical recording medium was produced in the same manner as in Example 1, except that the Al-Rh reflection film was formed. As a result of surface analysis of the formed reflective film, the atomic number% of Rh / (Al + Rh) was about 20%.
%Met. At the same time, on a 5 cm square glass plate,
A 00 nm Al-Rh alloy film was provided, and the spectral reflectance and thermal conductivity were measured. As a result, the reflectance is 830 nm to 37.
75% or more in a wavelength region of 0 nm and a thermal conductivity of 200
W / (m · K). In the same manner as in Example 1, recording was performed on the produced medium using an optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial equipped with a 430 nm blue laser head and an EFM encoder manufactured by KENWOOD. After recording, the same measurement as in Example 1 was performed. As a result, good recording characteristics and durability were shown.

[Example 3] Ternary DC sputtering using Al, Rh and Bi targets was carried out to a thickness of 100 nm.
An optical recording medium was produced in the same manner as in Example 1, except that the Al-Rh reflection film was formed. As a result of surface analysis of the formed reflective film, the atomic number% of (Rh + Bi) / (Al + Rh + Bi) was about 40%, and the atomic number ratio of Bi / Rh was about 1/7.
Met. At the same time, on a 5 cm square glass plate,
An Al-Rh-Bi alloy film having a thickness of nm was provided, and the spectral reflectance and the thermal conductivity were measured. As a result, the reflectance is 830 nm to 3
It is more than 72% in the wavelength region of 70 nm and the thermal conductivity is 16
0 W / (m · K). An optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial having a 430 nm blue laser head mounted on the manufactured medium in the same manner as in Example 1.
And KENWOOD EFM encoder. After recording, the same measurement as in Example 1 was performed. As a result, good recording characteristics and durability were shown.

Example 4 The procedure was performed except that an Ag—Bi reflective film having a thickness of 100 nm was formed by performing DC sputtering using an alloy target of Ag and Bi (atomic ratio: Ag: Bi = 85: 15). An optical recording medium was produced in the same manner as in Example 1. As a result of surface analysis of the formed reflective film, Bi / (A
The atomic number% of g + Bi) was about 15%. 5c at the same time
An Ag-Bi alloy film having a thickness of 100 nm was provided on an m-square glass plate, and the spectral reflectance and the thermal conductivity were measured. As a result, the reflectance is 75 in the wavelength range of 830 nm to 370 nm.
%, And the thermal conductivity was 270 W / (m · K). In the same manner as in Example 1, an optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial and E manufactured by KENWOOD equipped with a 430 nm blue laser head on the manufactured medium.
Recorded using an FM encoder. After recording, Example 1
As a result, good recording characteristics and durability were shown.

Example 5 The procedure was performed except that DC sputtering was performed using an alloy target of Ag and Zn (atomic ratio: Ag: Zn = 60: 40) to form an Ag-Zn reflective film having a thickness of 100 nm. An optical recording medium was produced in the same manner as in Example 1. As a result of surface analysis of the formed reflective film, Zn / (A
g + Zn) was about 39%. 5c at the same time
An Ag-Zn alloy film having a thickness of 100 nm was provided on an m-square glass plate, and its spectral reflectance and thermal conductivity were measured. As a result, the reflectance is 72 in the wavelength range of 830 nm to 370 nm.
%, And the thermal conductivity was 290 W / (m · K). In the same manner as in Example 1, the optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial and E manufactured by KENWOOD equipped with a 430 nm blue laser head on the manufactured medium.
Recorded using an FM encoder. After recording, Example 1
As a result, good recording characteristics and durability were shown.

Example 6 The procedure was performed except that DC sputtering was performed using an alloy target of Ag and Zn (atomic ratio: Ag: Zn = 80: 20) to form an Ag-Zn reflective film having a thickness of 100 nm. An optical recording medium was produced in the same manner as in Example 1. As a result of surface analysis of the formed reflective film, Zn / (A
g + Zn) was about 19%. 5c at the same time
An Ag-Zn alloy film having a thickness of 100 nm was provided on an m-square glass plate, and its spectral reflectance and thermal conductivity were measured. As a result, the reflectance is 75 in the wavelength range of 830 nm to 370 nm.
%, And the thermal conductivity was 340 W / (m · K). In the same manner as in Example 1, the optical disk evaluation device DDU-1000 manufactured by Pulstec Industrial and E manufactured by KENWOOD equipped with a 430 nm blue laser head on the manufactured medium.
Recorded using an FM encoder. After recording, Example 1
As a result, good recording characteristics and durability were shown.

Example 7 Alloy target of Ag, Bi and Zn (atomic ratio: Ag: Bi: Zn = 65: 5:
An optical recording medium was manufactured in the same manner as in Example 1 except that DC sputtering using the method 30) was performed to form an Ag-Bi-Zn reflective film having a thickness of 100 nm. As a result of the surface analysis of the formed reflection film, (Bi + Zn) / (Ag + Bi + Z)
The atomic number% of n) was about 34%, and the atomic number ratio of Bi / Zn was about 1/6. At the same time, an Ag-Bi-Zn alloy film having a thickness of 100 nm was provided on a 5 cm square glass plate, and the spectral reflectance and the thermal conductivity were measured. As a result, the reflectance is 830n.
It was 72% or more in the wavelength range of m to 370 nm, and the thermal conductivity was 310 W / (m · K). In the same manner as in Example 1, an optical disk evaluation device DDU-1 manufactured by Pulstec Industrial Co., Ltd. equipped with a 430 nm blue laser head
000 and KENWOOD EFM encoder. After recording, the same measurement as in Example 1 was performed. As a result, good recording characteristics and durability were shown.

Comparative Example 1 An optical recording medium was prepared in the same manner as in Example 1, except that Al was DC-sputtered on the recording layer using a sputtering apparatus manufactured by Shimadzu Corporation to form a reflective layer having a thickness of 100 nm. Was prepared. At the same time, an Al alloy film having a thickness of 100 nm was provided on a 5 cm square glass plate, and the spectral reflectance and the thermal conductivity were measured. As a result, the reflectance is 830
It was 80% or more in the wavelength region of nm to 370 nm, and the thermal conductivity was 220 W / (m · K). An optical disk evaluation device DDU-10 manufactured by Pulstec Industrial having a 430 nm blue laser head mounted on the manufactured medium in the same manner as in Example 1.
00 and KENWOOD EFM encoder. After recording, the same measurement as in Example 1 was performed. As a result, good recording characteristics were shown, but durability was poor.

Comparative Example 2 An optical recording medium was produced in the same manner as in Example 1, except that a reflective layer having a thickness of 100 nm was formed on the recording layer by DC sputtering of Ag using a sputtering apparatus manufactured by Shimadzu Corporation. Was prepared. At the same time, an Ag alloy film having a thickness of 100 nm was provided on a 5 cm square glass plate, and the spectral reflectance and the thermal conductivity were measured. As a result, the reflectance is 830
It was 80% or more in the wavelength region of 370 nm to 370 nm, and the thermal conductivity was 408 W / (m · K). An optical disk evaluation device DDU-10 manufactured by Pulstec Industrial having a 430 nm blue laser head mounted on the manufactured medium in the same manner as in Example 1.
00 and KENWOOD EFM encoder. After recording, the same measurement as in Example 1 was performed. As a result, the recording sensitivity was poor, good recording characteristics could not be obtained, and the durability was poor.

The values of the reflectance, error rate, and jitter before and after the accelerated deterioration test (initial and after the tests) performed on the recorded media obtained in Examples 1 to 7 and Comparative Examples 1 and 2 are shown in Table 1. ).

[0038]

[Table 1]

[0039]

The reflection film of the present invention having an appropriate thermal conductivity by using an appropriate element and limiting the composition ratio is 830.
It has a high reflectance in the wavelength region of ３370 nm, has good adhesion to the dye layer, and by using this reflective film,
It has become possible to provide an optical recording medium having good recording characteristics and durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 5/08 B41M 5/26 Y F term (Reference) 2H042 DA01 DA11 DA17 DC02 DC03 DC04 DC08 DE00 DE07 2H111 EA03 EA12 EA39 FA12 FA33 FA35 FA36 FA37 FB42 FB43 FB46 FB60 FB63 GA02 GA03 GA07 5D029 JA04 JB47 MA13 MA17

Claims (5)

[Claims] 1. A semiconductor device comprising one or more elements selected from a first group consisting of Al and Ag and a second group consisting of Bi, Rh and Zn, and having a thermal conductivity of 1 or more.
40 to 370 W / (m · K) and 830 to 3
A light reflection film having a reflectance of 70% or more for light having a wavelength of 70 nm. 2. The method according to claim 1, further comprising a first group of metals as a main component.
The light reflecting film according to claim 1, wherein the light reflecting film contains the metal of the second group in an amount of 1 to 49% based on the total number of atoms of the metal of the second group. 3. Al and Bi and / or Rh, or
The light reflecting film according to claim 1, comprising Ag, Bi, and / or Zn. 4. An optical recording medium comprising, on a transparent substrate, at least a recording layer containing a dye and the reflective film according to claim 1. 5. 450 to 370 nm incident from the substrate side
5. The optical recording medium according to claim 4, wherein the reflectance to the laser light selected from the group consisting of 15% or more.