JPS6143595A - Optical recording medium - Google Patents

Abstract

PURPOSE:To enhance stability of Te with time while maintaining the high sensitivity of Te, by dispersing Te into a discharge-polymerized film of a pyridine. CONSTITUTION:The recording medium is obtained by evaporating Te under glow discharge in a vacuum vessel charged with a monomer gas of a pyridine so that a discharge-polymerized film 2 of the pyridine with amorphous Te dispersed therein is formed on a substrate 1. The pyridine may be, for example, pyridine or quinoline, which may be either unsubst. or subst. by alkyl such as methyl or aryl such as phenyl. A source of Te may be Te or a Te-containing compound, e.g., PbTe, MoTe2 or TeO2. With Te thus vapor-deposited, activated points of Te are covered by the polymerized film 2, thereby enhancing the stability with time.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an optical recording medium that records by locally heating it by irradiating it with a laser beam and forming holes or convexities in the heated area. It is.

(Prior Art) It has been known to use 're' as an optical recording medium in which bits are formed by irradiating a thin film formed on a substrate with a laser beam. Te
Since it has a low melting point and low thermal conductivity, it exhibits high sensitivity in recording by the above method. However, Te is easily oxidized, and when it is oxidized, it becomes transparent and recording cannot be performed.

Examples of methods that have improved the above problems include those made of a Te f alloy, low oxides of Te, and those in which Te is dispersed in an organic film. (For example, JP-A-3-3110
Gu issue publication, Tokukaisho! ♂-j'133♂ Publication, JP-A-Sho!
7-9♂39g publication).

(Object of the Invention) As a result of intensive studies, we have discovered that by dispersing Te in a pyridine discharge polymerized film, the above-mentioned problem of Te's instability over time can be solved while maintaining the high sensitivity of Te. This has led to the present invention.

That is, the gist of the present invention resides in an optical recording medium characterized by comprising a substrate and a pyridine discharge polymerized film containing Te deposited on the substrate.

(Means for solving problems) The present invention will be explained in detail below.

The recording medium according to the present invention is produced by performing glow discharge in a vacuum container into which a pyridine gas is introduced, and evaporating Te to form a discharge polymerized film of pyridine in which amorphous Te is dispersed on a substrate. This can be obtained by forming .

Examples of pyridines include pyridine or quinoline, as well as alkyl groups such as methyl group -CH3, etc.
Examples include compounds substituted with an aryl group such as a phenyl group.

Further, as a raw material for Te, Te1 or a compound containing To such as PbTs, MoTe2. Teo□ is used, and further contains Bi, Se, etc. [Hypolyte compounds can also be added as other components depending on the purpose.

Examples of the substrate include glass, acrylic resin, plastics such as polycarbonate resin, or metals such as aluminum, and the thickness thereof is generally /~/, j 1lli
Selected based on degree.

Glow discharge can be performed by conventional methods such as a high frequency method or a direct current method, and a discharge polymerized film of pyridine is formed by generating radicals and ionic species. The substrate temperature is maintained at room temperature or below the softening point of the substrate.

The thickness of the pyridine discharge polymerized film containing Te1 is normal!
It is about OA to /μ, preferably about 200 to θOOA.

When 're is vapor-deposited in this way, the discharge polymerized film of pyridine blocks the activation site of To, and the stability over time can be increased. Here, the film obtained by the above method may be subjected to heat treatment to disperse crystallized Te, thereby producing a discharge polymerized film of resins.

Hereinafter, the present invention will be explained in further detail with reference to the drawings.

Figure 1 shows an example of an apparatus for producing an optical recording medium according to the present invention, in which (3) is a reaction vessel, (4) i-1
: Pyridine gas inlet, (5) is the substrate, (6) is the high frequency coil, (7) is the resistance heater for 're deposition, (8) is the film thickness monitor, (9) is the shutter, α0) is the exhaust It is the mouth. The preparation of a discharge polymerized film of pyridine is carried out in a reaction vessel (3
) is evacuated to about 10"-fi Torr, pyridine neck gas is introduced through the inlet (4), and the internal pressure of the reaction vessel (3) is adjusted to 1 x 10-5 to 7-3 Torr. After introducing the gas, a high frequency is applied to the high frequency coil (6) to cause a discharge. At the same time, Te is evaporated from the resistance heater for vapor deposition (7), and a pyridine discharge polymer film containing Te is formed on the substrate (5). The amount of evaporated Te is monitored with a film thickness monitor (8).The content of Te can be determined by changing the deposition rate of Te or the deposition rate of a pyridine discharge polymerized film by changing the polymerization conditions. The 're content can be controlled by changing either of the following values: !θV and !θV so that the obtained film shows sufficient absorption at the wavelength of the semiconductor laser.
It is preferable that it is OI% or more.

FIG. 1 shows the structure of an optical recording medium according to the present invention obtained as described above. In the figure, (1) is a polymethyl methacrylate (PMMA) substrate, and (2) is a 're-containing pyridine discharge polymerized film.

The recording medium according to the present invention is formed by forming the discharge polymerized film on the substrate as described above, and the substrate shown in FIG.
Between 1) and the polymer film (2), in order to improve recording sensitivity, modify the substrate surface, improve pore shape, etc., for example, a pyridine discharge polymer film containing no diazo organic dye (vapor deposition) or Te. For example, an amorphous 5-inch film may be provided on the polymer film 2 to protect the recording medium.
2. A MgF2 film or the like may also be provided as a protective film.

The optical recording medium according to the present invention is useful as an optical disc recording medium, and can be formed by forming holes or protrusions by heating it by irradiating it with a laser beam, or by utilizing phase transformation. recording.

(Effects of the Invention) The recording medium according to the present invention can improve the stability over time while maintaining the custom-designed sensitivity of Te at a level equal to or higher than that of the prior art.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not limited only to the Examples.

Example/ After evacuating the vacuum container to J x 10 = Torr, pyridine monomer gas was evacuated to s x 10-4 TOrr.
r r Introduction L/ 1 coiled electrode / 3.66
A high frequency voltage of MHz is applied to cause discharge and T
evaporate from the molybdenum boat to form a discharge polymerized pyridine film containing 're on the substrate. When polymethyl methacrylate (PMMA) is used as a substrate and discharge is performed for 7 minutes at a pyridine monomer gas flow rate of j8ccms, a discharge power of 100W, and a Te deposition rate of approximately 4t00A/-, a film thickness of 9t! is deposited on the substrate! A pyridine discharge polymerized film containing OA Te was formed.

When recording was performed on a film formed on a PMMA substrate using a semiconductor laser with a wavelength of ♂°3θ nm, the sensitivity was 2 to 3 times higher than that of a Te film alone.

In addition, in terms of stability, when we measured the decrease in reflectance after storing it at 60°C and %RH, we found that the film obtained by the method described above decreased to 73% of its initial value in a week. No decrease in reflectance was observed.

Example After evacuating the vacuum container to 3×10-' TOrr,
Introducing pyridine monomer gas at 6×1O-5 Torr,
A high frequency voltage is applied to the electrode to generate a discharge and 'r
e is evaporated to form a Tθ-containing pyridine discharge polymerized film on the substrate. PMMAr, r was used as the substrate, pyridine monomer gas flow rate/sccms discharge power/θ0W,
When discharging for 6 minutes at a Te deposition rate of about 1000^/-, the film thickness on the substrate/! A pyridine discharge polymerized film containing 00^ Te was formed. When a film formed on a pMMA substrate was recorded using a semiconductor laser, it showed twice the sensitivity as compared to a Te film alone. With this film, recording could be performed using the convex portions. In addition, in terms of stability, Otsu0°C1l0%
No decrease in reflectance was observed even after 2 weeks of storage in RH.

Example 3 After evacuating the vacuum container at 3×1O-6 Torr i, quinoline monomer gas was released! ×10-” Torr and apply a high frequency voltage to the electrode to cause discharge and evaporate Te to form a To-containing quinoline discharge polymerized film on the substrate. Using PMMA as the substrate, quinoline monomer gas flow rate tsccm, Discharge power 100W% Te
When discharge is performed for 73 seconds at a deposition rate of J' 00 A/mtn, a quinoline discharge polymerized film containing Te with a film thickness of 300 A is formed on the substrate. When a semiconductor laser was used to record on a film formed on a PMMA substrate, Te
It showed twice the sensitivity compared to a single membrane. Also, in terms of stability, 60℃? After 2 weeks of storage in /% RH, the decrease in reflectance from the initial value was 10%.

[Brief explanation of the drawing]

FIG. 1 shows a configuration example of a recording medium according to the present invention, and FIG. 2 shows an example of an apparatus for manufacturing a recording medium according to the present invention. In the figure, (1) is the substrate, (2) is the discharge polymerized film, (3) is the reaction vessel, (4) is the gas inlet, (5) is the substrate, (6) is the high frequency coil, and (7) is Te vapor deposition. The respective resistance heaters are shown below.

Claims (1)

[Claims] (1) Substrate and Te (tellurium) deposited on this substrate
An optical recording medium comprising a pyridine discharge polymerized film containing