JPS5968851A - Manufacture of optical information recording medium - Google Patents

Abstract

PURPOSE:To attain the recording in low power, ease of reading of a pit, and high S/N, by heating uniformly a recording layer to increase the reflecting performance of non-recorded part, after recording informaton on the recording layer including a blackened silver on a support. CONSTITUTION:In Figure, 1 is the support, 2 is an optical information recording layer, being an organic high polymer layer where blackened silver is scattered. The blackened silver is formed by applying photographic processing to a silver halide emulsion on the support, a density gradient is produced to the silver content near the surface by the heat treatment of the recording layer and an optical recording medium having glittered reflecting performance is attained. The increase in the reflactance due to the heat treatment takes place substantically at about <=250 deg.C, and the increase in the reflactance takes place within several minutes at a higher temperature, e.g., up to 380 deg.C. The figure shows the state that recording is executed onto the recording medium with a high density energy beam 5. In the figure, 6 indicates pits formed by blowing out the organic high polymer layer 2 in which the blackened silver is scattered with the high density energy beam, and 7 is parts not subject to recording.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording and reproducing method for an optical information recording medium in which information is recorded using a high-density energy beam and reproduced using an energy beam having a lower power than the energy beam.

In recent years, there has been an increasing demand for so-called optical discs, which are capable of high-density recording and have short access times, as information recording media. This optical disc uses a laser beam that can provide high-intensity and short-time exposure to record metal or semimetal thin films by forming dots (fine molten depressions), chalcogen glass-based thin films, and quality - amorphous state. It must be manufactured by the Tutu type vacuum evaporation method or sputtering method using semimetallic thin films, which are recorded by changes in optical properties due to oxidation, and the manufactured thin films have poor stability over time and are toxic. The disadvantage was that there were quite a few that had this.

In order to solve the above-mentioned drawbacks of the prior art,
Japanese Patent No. 10491 discloses a recording medium in which an optical information recording layer is a coated thin film of a colloidal dispersion of a single-transfer metal or its oxide. Such Japanese Patent Application Laid-open No. 56-10
According to Publication No. 491, bits (fine molten depressions) are formed on the surface of the coated thin film of the colloidal dispersion using a laser beam, recording 17 is performed, and the difference in reflectance with the non-recording area is used to make use of the difference in reflectance E7. An optical information recording medium for reproduction is shown.

However, it has the disadvantage that only a small amount of ashing of the colloidal dispersion layer of the information recording medium can be recorded. Furthermore, the colloid dispersion layer is often transparent at the wavelength of the recording laser beam, which has the disadvantage of requiring excessive recording energy. Moreover, there was a disadvantage that the colloidal dispersion liquid had to be produced in a closed system taking care to avoid carbon monoxide, which was a rearrangement control method involving a reduction reaction of a toxic metal carbonyl.

Furthermore, JP-A-55-108995 discloses an optical information recording medium that has a reflective metallic luster by heat-treating a layer of filamentary blackened silver in a gelatin binder, and a method for manufacturing the same. ing. This recording medium has increased reflectivity, making it easy to read bits, but it has the disadvantage that it cannot be recorded with low power, making it difficult to increase the recording speed and make the light source smaller.

Furthermore, in Takeko No. 43-26929, a support having a recording layer made of a non-metallic material is irradiated with focused laser light of high energy density to melt and deform or evaporate the irradiated portion of the recording layer. A recording method using
There is no mention of a regeneration method that increases the ratio.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing an optical information recording medium that allows recording with low power, makes it easy to read bits, and provides high S/N and lhi.

Still another object of the present invention is to provide a method for producing an optical information recording medium that is non-toxic and safe at all stages of production, recording, reproduction, and storage.

Still another object of the present invention is to provide a method for manufacturing an optical information recording medium that can be manufactured by coating and is relatively inexpensive to manufacture.

As a result of intensive studies by the present inventors regarding the above, a method for manufacturing an optical information recording medium in which information is recorded using a high-density energy beam and reproduced with an energy beam having a lower power than the energy beam. In the present invention, a leather which can be achieved by a method for manufacturing a recording optical information recording medium containing blackened silver on a support was found.

That is, according to the present invention, 0.5 μm-addition μm on the support
By heating the disc for 1 minute to 10 minutes, the reflectivity of the unrecorded area increases, allowing it to be easily read and reproduced with a low-power energy beam.

Next, the present invention will be explained in detail based on a typical embodiment shown in the drawings ('--).

FIG. 1 shows a cross section of an optical information recording medium used in the recording and reproducing method of the present invention. In the figure, 1 is a material with high dimensional stability at high temperatures, such as glass, silver, ceramic, or polyimide resin, and may be transparent, translucent, or opaque.

5- Next, the method for producing the optical information storage layer will be described in more detail.The method is a conventional method of coating a silver halide emulsion on a support, exposing it to light, developing it, and fixing it. . Alternatively, it can be obtained by a method in which blackened silver particles are dispersed in an organic polymer and then coated on a support.

The silver halide emulsion on the above support is photographically processed to form blackened silver, and the heat treatment for recording creates a density gradient in the silver component near the surface, resulting in a glossy, reflective optical record. Become a medium. Here, the photographic processing includes the steps of exposure and development, and if necessary, also includes the step of fixing. That is, the silver halide emulsion on the support is intensely exposed to actinic radiation by a tungsten lamp, mercury arc lamp, incandescent lamp, or xenon flood lamp, and then developed. In this case, either high-illuminance short-time exposure or low-illuminance long-time exposure may be used.

After that, it is fixed as necessary. At this stage of operation, 6
- A black zone (blackened silver) is formed for conversion into a reflective optical recording medium.

Development is performed as a photographic process to turn the silver halide emulsion into blackened silver, and wet chemical development is used for this. The developer contains p-phenyl diamine, p-methylaminophenol, hydroquinone, 1-phenyl-3-pyrazolidone, trihydroxybenzene, ferrous oxalate, etc. as a reducing agent for silver halide, and a pH buffer. As borax, sodium carbonate, sodium borate, sodium hydroxide, and other antioxidants such as sodium sulfite,
Common acrylic acids, such as capri inhibitors such as potassium bromide,
Water-soluble polyacrylamide resins, polyvinyl butyral, cellulose acetate, vinyl chloride resins, vinyl acetate resins, acrylic resins, phenol resins, and epoxy resins are used, and gelatin is preferred among these.

Dispersion media for the silver halide emulsion used in the present invention include gelatin, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, hydroxypropylmethylcellulose, methylcellulose, polyacrylamide, polyethylene oxide, hydroxyethylcellulose, polyethylene glycol, and the like. , a water-soluble binder is used.

In addition, silver halides include AgBr, AgI, kgcl
A chemical sensitizer, a capri inhibitor, a stabilizer, a surfactant, a hardening agent, and other photographic additives may be appropriately added to the silver halide emulsion of the present invention in which any silver halide, such as, is used. may be done.

In chemical sensitization of silver halide emulsions, sulfur sensitization is
For example, it can be carried out by using sodium thiosulfate, thiourea, allylthiourea, etc., and gold sensitization can be carried out by using, for example, sodium chloroaurate, gold thiocyanate, etc. Furthermore, for gold-sulfur sensitization, chemical sensitization can be carried out using at least one of the above-mentioned sensitizers in combination. In this case, ammonium thiocyanate, etc. may be further added for chemical sensitization. You can also do it.

In addition to the sulfur sensitization method described above, a selenium sensitization method can also be used for the silver halide emulsion used in the present invention.6 For example, U.S. Pat. Specification No. 574,944, Specification No. 3,591,385, Japanese Patent Publication No. 43-13849
The method described in Japanese Patent Publication No. 44-15748 can be adopted.

Furthermore, conventionally known methods can be applied to reduction sensitization. For example, aging can be carried out using a low pAg atmosphere, using a suitable reducing agent, or using electromagnetic waves such as light and γ rays.

Furthermore, as stabilizers and capri inhibitors, for example, U.S. Pat.
German Patent No. 3,512,982, German Patent No. 3,342,596, German Patent No. 1,189°380, German Patent No. 205,86
No. 2, Specifications of No. 211,841, Special Publication No. 1973-
No. 4183, No. 39-2825, JP-A-50-226
26 and No. 50-25218, etc., using stabilizers and capri inhibitors may be used, and a particularly preferred compound is 5,6-drimethylene-7-hydroxy-S-triazolo. (1,5
-a) Pyrimidine, 5,6-titramethylene-7-hydroxy-g-)riazolo(1,5-a)pyrimidine, 5
-Methyl-7-hydroxy-8-triazolo(1,5-
a) Pyrimidine, 7-hydroxy-1-)riazolo(1
, 5-a) Pyrimidine, gallic acid ester (e.g., isoamyl gallate, dodecyl gallate, propyl gallate, sodium gallate, etc.), mercaptans (e.g., 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzthiazole, etc.) , benztriazoles (e.g., 5-bromobenztriazole, 4-methylbenztriazole, etc.), benzimidazoles (e.g., 6-nidropenzimidazole, etc.), and the like.

The silver halide emulsion of the present invention can be spectrally sensitized with cyanine dyes, merocyanine dyes, etc. For example, in the Regi-Ra area, JP-A-55-2756;
-14743, and in the ortho region -10-, JP-A-48-56425 and JP-A-51-312.
As described in No. 28 and Japanese Patent Publication No. 47-25379, they can be used alone or in combination. Further, spectral sensitization on the long side can be carried out using, for example, a cyanine dye with a longer methine chain described in JP-A No. 51-126140, and supercolor sensitization can be achieved by combining the benefits of dyes. Feelings can also be done arbitrarily.

Furthermore, as a hardening agent, for example, an aldehyde type,
Aziridine series (e.g. PR Report, 19921, U.S. Patent No. 2,950,197, U.S. Patent No. 2,964,404)
No. 2.983,611, No. 3,271,17
5 specifications, Japanese Patent Publication No. 46-40898, and Japanese Patent Publication No. 50-91315), isoxazole type (for example, those described in US Patent No. 331,609) , epoxy systems (e.g. U.S. Pat. No. 3,
No. 047,394, West German Patent No. 1.085,663,
Specifications of British Patent No. 1,033,518, Japanese Patent Publication No. 4
8-35495), vinyl sulfone type (e.g. PR Report 19,920. West German Patent No. 1)
, 100,942, British Patent No. 1,251,091, Japanese Patent Application No. 45-54236, Japanese Patent Application No. 48-110996, U.S. Patent No. 353.964, British Patent No. 3,490,91.
1), acryloyl type (e.g. Japanese Patent Application No. 48-27949, U.S. Patent No. 3,640,
No. 720), carbodiimides (e.g., U.S. Pat.
(mentioned in the specification), other maleimide-based, a7ethylene-based, methanesulfonic acid ester-based, triazine-based,
Polymer type hardeners can be used. In addition, thickeners such as those described in U.S. Pat.
0,404-Q specification, Japanese Patent Publication No. 43-4939, and Japanese Patent Application Laid-Open No. 48-63715), as well as latexes such as U.S. Patent No. 766.979, French Patent No. 1,395, Specifications of No. 544, Special Publication No. 1973
-43125, and as a matting agent, those described in British Patent No. 1,221,980 can be used.

Furthermore, desired coating aids can be used, such as saponin or nulphosuccinic acid surfactants, such as those described in British Patent No. 548,532 and Japanese Patent Application No. 47-8963.
0, or as a synionic surfactant, for example, Japanese Patent Publication No. 43-18166, U.S. Patent No. 3,514,293, French Patent No. 2.0.
Those described in each specification of No. 25,688, Japanese Patent Publication No. 10247/1983, etc. can be used.

The content of the blackened silver is such that the solid content is from % to 70% by weight.
It is preferable that

A dispersion solution of silver black or silver halide is applied onto a substrate and dried to form a dispersed thin film. As the coating method, any known method such as blade coating, air knife coating, bar coating, and roll coating can be used.

The thin film of the dispersion layer is preferably about 0.5 .mu.m to 0.5 .mu.m from the viewpoint of redness and coating equipment conditions. That is, 0.
If the thickness is less than 5 μm, it is difficult to obtain a stable thin film;
This is because if the thickness is 0 μm or more, the dispersion layer used will not be used effectively as an information recording medium.

Within the dispersion layer, the blackened silver can be considered to be substantially uniformly dispersed, but the high density energy 13-[;SL-F,;-'L:''in,-,L,-1+
,,,r,A+tw,-+v%1m-+-1+ ,,
++-2] After recording with light, heat treatment is performed under suitable conditions to increase the reflectivity of the surface of the unrecorded area.
The distribution of silver particles becomes biased, and the distribution decreases in the depth direction from the surface to the substrate. The advantages of heat treatment are increased reflectivity, hardening of the film due to reduction in film thickness,
and silver particle backing (high density stabilization). 1
° That is, the reflectance increases from about 10% to +70%,
Preferably, it increases to % (%) to 70%, and it is possible to obtain an optical information recording medium that is very easy to read by reflection during reproduction.

The increase in reflectance due to heat treatment begins to occur substantially above about 250°C, and at higher temperatures, such as up to 380°C, the increase in reflectance occurs within minutes.

If the temperature is higher than 380°C, excessive decomposition or incineration of the gelatin or other polymer compounds will become significant, which is not preferable.

The heating time is 1 minute to 1 minute, but when gelatin is used as a dispersion medium, the typical heating condition is about 320° C. for 10 minutes. A radiation method is preferred so that heating can be performed uniformly over the entire surface of the dispersion layer, but heating methods using a convection oven or a contact heat source are also included. The heating atmosphere is carried out under normal pressure or reduced pressure and in the presence or absence of oxygen, preferably in the presence of oxygen. Heating under reduced pressure reduces the film thickness at a greater rate than under normal pressure, and also greatly improves reflectance. When heat-treated at normal pressure in the presence of oxygen, some of the silver particles may be oxidized, but there is no problem with recording and reproduction.

In the present invention, as shown in FIG. 2, a translucent waist-retaining layer and antireflection layer 3 may be coated on the optical information recording layer 2 after the heat treatment.

The antireflection layer 3, which also serves as a protective layer, can be made of, for example, epoxy resin, transparent melamine, silicone, polycarbonate, or acrylic resin.

For example, a subbing layer 4 of gelatin, cellulose polymer, etc. may be applied. Further, even if a silane coupling agent or a titanium coupling agent is added to the undercoat layer 4 or the recording layer 2, the adhesion can be improved without affecting the recording properties.

Furthermore, the present invention can also be configured as shown in FIG. That is, FIG. 4 is a combination of the functions shown in FIGS. 2 and 3. During reflection, recording on the optical information recording medium according to the present invention is accomplished by removing the recording layer surface with, for example, a laser beam focused on the surface of the information recording layer 2 and generating bits. Since the reflectance of the recorded portion is smaller than that of the non-recorded portion after heat treatment, reflective information reading is possible with a high S/N ratio.

High-density energy beams that can be used in the present invention include:
Examples include a mercury arc lamp, a xenon flash lamp, and a laser beam. Among them, a laser beam is preferable as a high-density energy beam for recording and reproducing bit information on the optical information recording medium of the present invention. Both wave oscillation and pulse oscillation can be used, specifically ruby laser, argon ion laser, gas laser,
He No laser, Kr ion laser, ) (e-
Examples include a Cd+ laser, a dye laser, and a semiconductor laser.

The recording laser is, for example, an Ar ion laser, H・-N・
A gas laser, a semiconductor laser, etc. can be used.

In particular, in the present invention, since recording can be performed with low power, it is preferable to use a semiconductor laser from the viewpoint of miniaturizing the device.

The same laser as the recording laser can be used as the reproducing laser, and in that case, it is necessary to use a lower power than that for recording, and a semiconductor laser is particularly preferable because the device can be miniaturized.

A schematic diagram of the recording/reproducing method according to the present invention will be explained using, for example, the recording medium of FIG. 1 with reference to FIGS. 5 and 6.

FIG. 5 shows a state in which recording is performed on the recording medium of FIG. 1 using a high-density energy beam 5 for recording.

6 represents a bit formed by dispersing blackened silver (17) with a high-density energy beam. 7 represents an unrecorded portion.

Next, the material obtained in FIG. 5 is heat-treated to increase the reflectance of the surface of the organic polymer layer in which blackened silver is dispersed. FIG. 6 shows the recording medium shown in FIG. 5 subjected to heat treatment and then read out with a high-density energy beam 8 for reproduction. Reference numeral 9 represents the portion 7 in FIG. 5, where the surface reflectivity was enhanced by heat treatment.

Next, the present invention will be specifically explained using examples.

Note that it goes without saying that the present invention is not limited to the following examples, but can be modified and made without departing from the spirit of the present invention.

Example 5 AKURA HIG) (RESOLUTION PL) is a photographic plate manufactured by Konishiroku Photo Industry ■, the applicant of this application.
ATE (8T T )PH0TO5ENSITOM
Ivy was exposed using ATERMODEL K S-7B (manufactured by Seiki Kogyo Co., Ltd.) for 100 to 20,000 MS. Above exposed Hlgh Re5solution1
8-Plate was immersed in Sakushi CDH-100 developer (manufactured by Konishiroku Photo Industry ■) at +/-0.5°C for 5 minutes for development, and then washed with water at 19-21°C for seconds. After that, in Sakushi CFL-X fixer [manufactured by Konishi Rokugoshin Kogyo ■], 1
After fixing by soaking for 3 minutes at 9-21℃, 19-21℃
It was washed with water for 5 to 10 minutes and air dried.

The reflectance of the above plate sample was measured using a corrected A1 reflector using a 557 dual-wavelength spectrophotometer (manufactured by Hitachi, Ltd.).
It was measured as efference. As a result, wavelength 63
The value at 0 nm was 7%.

1.4μ for the obtained recording medium sample according to the present invention.
Write recording in which bits are formed by scanning a He-Ne laser beam focused to a beam diameter of 100 m/sec at a scanning speed of 10.0 m/sec using a rotating beam, and applying a 200n88C pulse signal to an acousto-optic modulator. I did this. Thereafter, the plate sample was heated for 31 minutes using a radiant heating device.
Heated at 0±10°C for 10 minutes. The reflectance of the reflective surface produced by heating was 40%. As a result, the recorded values had a remarkable difference in reflectance, good signal contrast was obtained, and optical reading was easily possible. The writing threshold/laser power at this time was 1.0 mW on the recording surface, and the recording/reproducing S/N ratio was 50 dB or more.

Comparative Example 1 The plate obtained in Example 1 was heat-treated before recording under the same conditions as Example 1, and when recording was performed, the threshold laser power for writing was 1On+M on the recording surface, and the recording/reproducing S/ The N ratio was 40 dB.

Therefore, it can be seen from this result that a high S/N ratio can be obtained with low power by using the present invention.

[Brief explanation of the drawing]

1 to 4 represent cross-sectional views of the optical information recording medium according to the present invention. 1...Support 2...Recording layer 3...Antireflection layer 4...Undercoat layer Figure 5.6 shows the recording method and reproduction method in the optical information recording medium according to the present invention. Represents a conceptual diagram. 5... High-density energy beam for recording 6... Bit 7... Unrecorded portion 8... High-density energy beam for reproduction 9... Unrecorded portion agent with increased reflectivity Yoshi Kuwahara Beauty 21-

Claims (1)

[Claims] In an optical information recording medium method in which information is recorded using a high-density energy beam and reproduced using an energy beam with lower power than the energy beam, blackened silver on a support is included. A method for manufacturing an optical information recording medium.