JP4084251B2 - Recording medium manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a write-once or rewritable recording medium that records and reproduces information such as a document, audio, and video, and a manufacturing apparatus therefor. Furthermore, the present invention relates to a method for manufacturing a recording medium having a recording layer containing fine particles, and an apparatus for manufacturing the recording medium.
[0002]
[Prior art]
The recording medium containing fine particles in the recording layer has been researched and developed for its advantages such as a decrease in activation energy for forming a recording bit, an improvement in light absorption efficiency, and a stabilization of the recording bit. Discloses a technique of a recording medium having a recording layer containing fine particles having a fine particle diameter of 100 nm or less. Japanese Patent Laid-Open No. 2004-228561 states that by reducing the particle diameter to 100 nm or less, light scattering can be suppressed, so that the loss of energy supplied from the outside for forming a recording bit is reduced.
[0003]
The basic structure of the recording layer is a binder and fine particles dispersed in the binder. As a method for producing a recording layer having such a structure, in Patent Document 1, fine particles prepared in advance are kneaded into a binder made of a thermosetting resin, a photocurable resin, an electron beam curable resin, or the like. And a method of curing after coating is disclosed.
[0004]
The fine particles used in the above method are produced by a method such as adiabatic expansion and quenching of vapor or a laser evaporation method.
[0005]
Patent Document 2 discloses a technique for forming a recording layer in which metal fine particles are dispersed in a chalcogen compound using a sputtering method. However, a manufacturing method using a vacuum apparatus, such as a sputtering method or a co-evaporation method, is complicated and expensive, and has a low productivity because a film is formed at a low speed.
[0006]
[Patent Document 1]
JP-A-4-59285
[0007]
[Patent Document 2]
JP-A-5-62239
[0008]
[Problems to be solved by the invention]
Since fine particles have a higher surface area to volume ratio and become more reactive than the bulk state, fine particles produced as a single substance are prone to agglomerate during storage and easily deteriorate. And it takes time to handle. Moreover, since it is easy to aggregate, it is difficult to disperse | distribute uniformly in a polymer. In order to improve dispersibility, there is a technique for coating fine particles with other materials, but the original function of the fine particles may be reduced by the coating material.
[0009]
Accordingly, an object of the present invention is to provide a method for easily and inexpensively producing a recording layer having good dispersion and uniformity of fine particles in a binder in a recording medium having a recording layer containing fine particles. To do.
[0010]
[Means for Solving the Problems]
In the method for producing a recording medium having a recording layer containing fine particles of the present invention, not only as a method for producing organic material fine particles, but also while forming organic material fine particles, the fine particles formed without interfering with the process The present invention relates to a method of uniformly dispersing in an organic material different from the organic material fine particles without impairing the function.
[0011]
A method for producing a recording medium having a recording layer containing organic fine particles according to the present invention includes a first solution in which a first organic material is dissolved or dispersed in a first solvent, and a second organic material as a second solvent. Mixing the dissolved or dispersed second solution to form a third solution in which fine particles of the second organic material are dispersed in the mixed solution of the first solution and the second solution; And a step of supplying the solution onto a substrate to form a recording layer of a mixed film in which fine particles of the second organic material are dispersed in the first organic material.
[0012]
In the conventional method, in order to produce a mixed material in which fine particles made of the second organic material are dispersed in the first organic material, the fine particles made of the second organic material are first produced alone, In order to mix uniformly in one organic material, a method such as kneading had to be used. However, according to the production method of the present invention, the production of the fine particles of the second organic material, The process of mixing the first organic material is a single process, and the process is simplified. Further, since the fine particles of the second organic material are not handled as a single substance or a dispersion liquid, there is no fear of aggregation or deterioration during storage, and no effort is required for storage and handling. Further, it is easy to uniformly disperse, and there is no need for a treatment such as coating fine particles with another material in order to improve dispersibility.
[0013]
The solubility of the second organic material in the first solvent is preferably smaller than the solubility of the second organic material in the second solvent. When the solubility of the second organic material in the first solvent is smaller than the solubility of the second organic material in the second solvent, in the third solution obtained by mixing the first solution and the second solution, The solubility of the second organic material in the third solution becomes small, the second organic material becomes supersaturated, and the second organic material is likely to precipitate as fine particles.
[0014]
In the present invention, the step of supplying the third solution onto the substrate to form a mixed film in which the fine particles of the second organic material are dispersed in the first organic material includes spin coating, spraying, and screen printing. Any of the inkjet printing methods can be employed.
[0015]
The spin coating method, spray method, screen printing method, and inkjet printing method are basically methods in which a third solution is supplied onto a substrate and a solvent is removed while forming a film to form a solid thin film. Therefore, it is possible to form a thin film extremely easily and at a low cost as compared with other thin film forming methods such as vacuum deposition. In addition, an ink-jet method or a screen printing method can easily form a thin film having an arbitrary pattern.
[0016]
In the present invention, the second organic material may be a crystalline organic compound. If the second organic material is a crystalline organic compound, crystalline fine particles can be formed. The crystalline fine particles are heated by applying energy from the outside and rapidly cooled to be in an amorphous state. The amorphous fine particles are heated by applying energy from the outside, and are slowly cooled to be in a crystalline state. It is known that the state and the amorphous state can be reversibly changed. In general, it is well known that physical properties such as light absorptivity and reflectance are different between a crystalline state and an amorphous state. Therefore, by utilizing such a change in physical properties, a rewritable recording medium is used. Can be realized.
[0017]
The first organic material may be a polymer. Polymers can control insulators, semiconductors, and conductors by methods such as introduction of substituents and doping, and thin films can be easily formed by methods such as spin coating, spraying, screen printing, and inkjet printing. Can be formed. In addition, the shape flexibility is high, so it is hard to break.
[0018]
The first organic material is a monomer, oligomer, or precursor, and is converted to a polymer after the step of forming a mixed film in which fine particles of the second organic material are dispersed in the first organic material on the substrate. May be. A polymer such as a polymer may have a limited solvent in which it is soluble or may have extremely low solubility. This tendency becomes more pronounced as the degree of polymerization (molecular weight) increases. On the other hand, by using a monomer, an oligomer, or a precursor as the first organic material, the range of selection of a copolymer or a solvent that can be used is widened.
[0019]
In the present invention, the step of transforming the monomer, oligomer, or precursor into the polymer may be performed by heating, light irradiation, microwave irradiation, electron beam irradiation, particle beam irradiation, or a combination thereof. There may be. When light irradiation, microwave irradiation, electron beam irradiation, or particle beam is used, a predetermined pattern is formed by transforming only the irradiated part by irradiating through a predetermined mask and then removing the unirradiated part Is possible. Further, when the modification is performed by heating, it is possible to heat only the irradiated portion by irradiating light such as a laser, so that a predetermined pattern can be formed in the same manner as the above method. For example, a grooved structure (land-groove structure) that can be used for tracking can be easily formed.
[0020]
According to the above-described manufacturing method, a recording medium manufacturing apparatus having a recording layer containing organic fine particles has a means for preparing a first solution by dissolving or dispersing a first organic material in a first solvent; A means for preparing a second solution in which an organic material is dissolved in a second solvent, the first solution and the second solution are mixed, and a third solution in which fine particles of the second organic material are dispersed. Means for forming a solution, and means for supplying the third solution onto a substrate to form a recording layer of a mixed film in which fine particles of the second organic material are dispersed in the first organic material. Is realized.
[0021]
Also, when removing the solvent of the third solution from the film applied on the substrate, or when changing from monomer, oligomer, or precursor to polymer, heating, light irradiation, microwave irradiation, electron It is good also as a manufacturing apparatus provided with the means to perform beam irradiation or particle beam irradiation.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a recording medium manufacturing method according to the present invention will be described below. The present invention is not limited to these examples.
[0023]
(Embodiment 1)
<Manufacturing process of recording layer>
FIG. 1A to FIG. 1C are flowcharts showing manufacturing steps of a recording layer of a recording medium according to the present invention.
[0024]
First, the first organic material is dissolved or dispersed in a first solvent to prepare the first solution 11. The material constituting the first organic material may be in the form of a molecule and dissolved in the first solvent, or may form a molecular aggregate (for example, a colloid or a micelle) to form the first organic material. It may be dispersed in the solvent. The concentration of the first organic material is not particularly limited, but is preferably in a state where it is stably dissolved or dispersed in the solution. For example, the first organic material aggregates and precipitates due to a slight temperature change or the like. Such a concentration near the saturated concentration is not preferable. Only what passes through the filter may be used in the next step. By passing through a filter, insoluble impurities and precipitates can be removed.
[0025]
Next, the second organic material is dissolved or dispersed in the second solvent to produce the second solution 12. The material constituting the second organic material may be in the form of a molecule and dissolved in the second solvent, or may form a molecular aggregate (for example, a colloid or a micelle) to form the second organic material. It may be dispersed in the solvent. The concentration of the second organic material is not particularly limited, but it is preferably in a state where it is stably dissolved or dispersed in the solution, and the second organic material aggregates with a slight change in conditions (for example, temperature change). A concentration in the vicinity of the saturated concentration that precipitates is not preferable. Only what passes through the filter may be used in the next step. By passing through a filter, insoluble impurities and precipitates can be removed.
[0026]
If the solubility of the second organic material in the second solvent is not sufficient at a temperature of about room temperature and atmospheric pressure, a high-temperature and high-pressure supercritical fluid may be used as the second solvent.
[0027]
Next, as shown in FIGS. 1A and 1B, the first solution 11 and the second solution 12 are mixed and stirred to disperse the fine particles 14 of the second organic material. The third solution 13 is formed. In general, a solution containing an organic material for which fine particles are to be formed is put into the other solution. The diameter of the fine particles can be controlled by the concentration of the first solution 11 and the second solution 12, the temperature of the first solution 11 and the second solution 12, the stirring speed, and the like. The temperature at the time of mixing is generally in the range of 0 ° C to 100 ° C, and is preferably about room temperature. The stirring speed is preferably in the range of 100 rpm to 5000 rpm. The pressure is preferably about atmospheric pressure.
[0028]
Next, as shown in FIG. 1C, the third solution 13 is supplied onto the substrate 15, and the mixed film 17 in which the fine particles 14 made of the second organic material are dispersed in the first organic material. Form. Specific examples of the mixed film forming method include a spin coating method, a spray method, a screen printing method, and an ink jet printing method. Heating may be performed after the recording layer of the mixed film 17 is formed. By heating at a temperature in the vicinity of the boiling point of the solvent, the solvent and impurity components remaining in the recording layer can be removed. When heating, it is desirable to be in an environment such as a vacuum, an inert gas atmosphere, or a reducing atmosphere such as a hydrogen gas atmosphere.
[0029]
FIG. 3 shows a cross-sectional view of an example of a recording medium obtained by the manufacturing method.
A recording layer 37 of a mixed film in which fine particles 34 made of the second organic material are dispersed in a binder of the first organic material 36 is formed on the substrate 35 on which the layer is formed.
[0030]
The average diameter of the fine particles 34 is preferably 1 nm to 500 nm, more preferably 1 nm to 100 m, and particularly preferably several nm to several tens of nm. The structure of the fine particles 34 is not particularly limited, and may be amorphous, polycrystalline or single crystal. The mixing ratio of the fine particles 34 made of the second organic material and the first organic material 36 is about 4: 1 to 1: 100, preferably about 4: 1 to 1:10 by volume. The dispersed state of the fine particles 34 is desirably dispersed in the first organic material 36 with a uniform density.
[0031]
The dispersion state can be evaluated by, for example, the ratio of the area of the fine particle region made of the second organic material to the area of the first organic material region in the cross section of the recording medium. The accuracy can be improved by measuring at several to several tens of points and taking the average value. As for the cross section of the recording layer, the cross section of the recording layer can be obtained using a cutting device such as a microtome, and the cross section can be observed with an optical microscope, a scanning electron microscope (SEM), or a fluorescence microscope. In the cross section, the region of the fine particles made of the second organic material and the region of the first organic material are the difference in light reflectance in the optical microscope, and the difference in electron beam reflectance and secondary electron generation efficiency in the SEM. In a fluorescence microscope, it is distinguished as a difference in wavelength and intensity of fluorescence generated by absorption of incident light.
[0032]
The recording medium according to the present invention may be provided with a protective layer 48 on the surface side of the recording layer 47 formed on the substrate 45 as shown in FIG. The method for producing the protective layer 48 is not particularly limited, and for example, a vapor deposition method, a sputtering method, a CVD method, a spin coating method, a spray method, a screen printing method, an ink jet printing method, or the like can be used. Providing the protective layer has an effect of preventing gas or liquid from the outside from entering the recording layer 47 and preventing mechanical scratches.
[0033]
The recording medium of the present invention may include a reflective layer 59a or a reflective layer 59b as shown in FIG. 5 (a) or (b). The reflection layer is disposed at a position opposite to the recording layer with respect to the light incident side. For example, as shown in FIG. 5A, the reflective layer 59a may be disposed between the substrate 55a and the recording layer 57a and covered with the protective layer 58a, or may be covered on the substrate 55b as shown in FIG. 5B. The reflective layer 59b may be disposed on the surface side of the formed recording layer 57b and covered with the protective layer 58b. Due to the presence of the reflective layer, the light incident on the recording layer is reflected by the reflective layer and is incident on the recording layer again, so that the light can be effectively used for recording and reproduction.
[0034]
The recording medium of the present invention may have a layer made of a material having a refractive index lower than that of the recording layer on at least one side of the recording layer. By having a layer made of a material having a refractive index lower than that of the recording layer, it becomes possible to effectively use light in recording and reproduction due to the light confinement effect.
[0035]
<First organic material and second organic material>
As the second organic material constituting the fine particles forming the recording bit, for example, polymethine dyes, porphyrin dyes, phthalocyanine dyes, naphthalocyanine dyes, naphthoquinone dyes, dithiol metal complex dyes and the like can be used. Further, as the second organic material, the following organic materials exhibiting photochromism can be used. For example, spiropyran, fulgide, dihydropyrene, thioindigo, piperidine, aziridine, polycyclic aromatic, azobenzene, salicylideneaniline, xanthene, and oxazine materials can be used.
[0036]
As the first organic material constituting the binder, thermosetting resins such as polyurethane and epoxy resins, photo-curing resins using UV, etc., and electron beam curable resins can be used. In addition, water-soluble polymers such as polyvinyl alcohol, polyethylene oxide, sodium polyacrylate, polyvinyl pyrrolidone, polyvinyl isobutyl ether, polyvinyl amine, polyacrylamide, and polyvinyl phenol can be used.
[0037]
As a combination of the first organic material constituting the binder and the second organic material constituting the fine particles, a combination in which the solubility of the other organic material in the solvent of the one organic material is small is used. The solubility of the first organic material in the solvent can be controlled by adding an appropriate functional group or side chain to the molecule. For example, it is possible to improve the solubility in a nonpolar solvent by adding a functional group having an alkyl chain such as an alkyl group or an alkoxy group, and a carboxyl group, a sulfate group, a hydroxyl group, a sulfonium group, etc. By adding a functional group containing, it is possible to improve the solubility in water or a polar solvent. Further, the added functional group is formed by forming a mixed film in which fine particles made of the second organic material are dispersed in the binder of the first organic material, and then heating, light irradiation, microwave irradiation, It may be removed by electron beam irradiation, particle beam, or a combination thereof.
[0038]
<Solvent>
Regarding the first solvent and the second solvent, the solubility of the first organic material and the second organic material in the solvent in which the other one of the organic materials is dissolved or dispersed is small or hardly dissolved. is required. Moreover, it is desirable that the first solvent and the second solvent are compatible. Examples of such solvent combinations include water and acetone, water and alcohols, alcohols and acetone, but are not limited thereto, and the first organic material and the second organic are not limited thereto. A suitable material is selected depending on the material.
[0039]
<Board>
The material and thickness of the substrate used in the present invention are not particularly limited. Examples thereof include metals such as stainless steel, alloys, glass, resin, paper, and cloth. When light is incident from the substrate side, a material having a predetermined transparency in a wavelength range required by the element is used. Particularly preferred materials include polycarbonate, acrylic resin, polyolefin, polystyrene, glass and the like.
<Protective layer>
For the protective layer, for example, an organic material such as an inorganic substance such as silicon oxide, silicon nitride, or tin oxide, a thermosetting resin, a thermoplastic resin, a photo-curing resin using UV, or the like is used. The thickness of the protective layer is from several tens of nm to several hundreds of μm, and preferably from several hundreds of nm to several tens of μm. The protective layer is produced by a vacuum deposition method, a sputtering method, a CVD method, a coating method, or the like.
<Material of reflective layer>
As the material for the reflective layer, metals such as gold, platinum, and aluminum, or materials containing one or more of these metals such as alloys are used. The film thickness is not particularly limited as long as sufficient reflectance can be obtained, but is preferably about several tens nm to 1000 nm.
<Recording medium manufacturing apparatus>
The present invention is an apparatus for producing a recording medium having a recording layer containing organic fine particles.
[0040]
Here, the recording medium manufacturing apparatus of the present invention includes the following means (1) to (4).
(1) Means for preparing a first solution by dissolving or dispersing a first organic material in a first solvent.
(2) Means for producing a second solution in which the second organic material is dissolved in the second solvent.
(3) Means for mixing the first solution and the second solution to form a third solution in which fine particles of the second organic material are dispersed in the first solution.
(4) Means for supplying the third solution onto a substrate to form a mixed film of the first organic material and fine particles made of the second organic material.
[0041]
<Effects of manufacturing method and apparatus>
Conventionally, in order to produce a mixed material in which fine particles made of a second organic material are dispersed in a first organic material, the fine particles made of the second organic material are first produced as a single substance, which is then used as the first organic material. In order to mix uniformly in the material, a method such as kneading had to be used. According to the production method and the production apparatus of the present invention, the production of the fine particles of the second organic material and the step of mixing the fine particles with the first organic material may be performed in a single step. Since the fine particles of the organic material are not handled as a single substance or a dispersion liquid, there is no fear that the fine particles are aggregated or deteriorated during storage, and there is no need for trouble in storage and handling. Further, it is easy to uniformly disperse, and there is no need for a process of coating fine particles with another material in order to improve dispersibility.
[0042]
As a method for forming a mixed film of the first organic material and the second organic material, the spin coating method, the spray method, the screen printing method, and the ink jet printing method basically include the third solution on the substrate. It is a method to form a solid thin film by supplying and removing the solvent while forming a film, so it can be formed very easily and at a lower cost than other thin film forming methods such as vacuum deposition. is there. In addition, an ink-jet method or a screen printing method can easily form a thin film having an arbitrary pattern.
[0043]
(Embodiment 2)
A case will be described in which after the step of forming the mixed film on the substrate, the first organic material such as a monomer, oligomer, or precursor is transformed into a polymer to form a mixed film. The first organic material is a polymer and the second organic material is a monomer, oligomer, or precursor, which may be modified to become a polymer, or the first organic material and the second organic material Both of them may be monomers, oligomers or precursors, and these may be modified into polymers.
[0044]
Further, the recording medium of the present invention has a layer made of a material having a lower refractive index than the recording layer on at least one side of the protective layer, the reflective layer, and the recording layer, as described in the first embodiment. Also good.
[0045]
<Manufacturing method>
2 (a) to 2 (d) are flowcharts showing the manufacturing process of the recording medium according to the present invention.
[0046]
A first solution 21 in which a monomer, oligomer, or precursor of the first organic material is dissolved or dispersed in a first solvent is prepared.
[0047]
As shown in FIGS. 2A and 2B, a second solution 22 in which a second organic material is dissolved in a second solvent is introduced into the first solution 21, and the fine particles of the second organic material. A third solution 23 in which 24 is dispersed is formed, and the third solution 23 is supplied onto a substrate 25 on which a first electrode has been formed in advance, and the first organic as shown in FIG. The process is the same as that described in Embodiment 1 until the mixed film 271 in which the fine particles of the second organic material are dispersed in the material is formed.
[0048]
Next, as shown in FIG. 2 (d), a recording composed of a mixed film of fine particles made of the second organic material and a polymer by modifying the oligomer or precursor of the first organic material. Layer 272 is formed. As a method of modifying the mixed film, for example, there is a method of performing heating, light irradiation, microwave irradiation, electron beam irradiation, or particle beam irradiation on the mixed film 271. As a heating method, there is a method of heating the whole in a heating furnace, but a method of heating only the vicinity of the irradiated portion by irradiating light such as laser or infrared light can also be used. Therefore, it is also possible to form a desired pattern by partially causing polymerization by a method such as heating, light irradiation, microwave irradiation, electron beam irradiation, or particle beam irradiation.
[0049]
<First organic material and second organic material>
As the monomer, oligomer, or precursor material, the monomer, oligomer, or precursor that produces the polymer material described in Embodiment 1 can be used.
[0050]
Suitable examples include, but are not limited to, acrylic acid monomers such as methyl acrylate and methacrylic acid monomers such as methyl methacrylate.
[0051]
The precursor as the first organic material may be a water-soluble sulfonium salt polymer or an organic solvent-soluble polymer having an alkoxy group. For example, a water-soluble sulfonium salt polymer that is a precursor of poly (arylene vinylene) s or an organic solvent-soluble polymer having an alkoxy group is highly soluble in a solvent and is converted into poly (arylene vinylenes) by heating or the like. It can be transformed relatively easily.
[0052]
Here, the water-soluble sulfonium salt polymer can use water as a solvent. Many organic semiconductors are hardly soluble or insoluble in water, and water is compatible with a relatively large number of organic solvents, and thus is suitably employed in the present invention.
[0053]
The materials used for the first solvent, the second solvent, and the substrate 25 are the same as those described in the first embodiment. Also in the second embodiment, a protective layer can be provided on the surface side of the recording layer 272. In that case, a material and a manufacturing method similar to those described in Embodiment Mode 1 can be used.
<Recording medium manufacturing apparatus>
The recording medium manufacturing apparatus of the present invention is configured by further adding the following means (5) to the manufacturing apparatus of the first embodiment including the means (1) to (4) described above.
(5) When monomers, oligomers or precursors are used for the first organic material and / or the second organic material, light irradiation, microwaves are used to transform these components in the mixed film into a polymer. Means for irradiation, electron beam irradiation, or particle beam irradiation.
<Effects of manufacturing method and manufacturing apparatus>
According to the manufacturing method and the manufacturing apparatus of the present invention, in addition to the same effects as those described in the first embodiment, the following effects can be obtained.
[0054]
In the polymer, a soluble solvent may be limited or the solubility may be extremely small, and this tendency becomes more prominent as the degree of polymerization (molecular weight) increases. On the other hand, monomers, oligomers, or precursors are generally highly soluble in solvents, so that the range of solvent selection is wide.
[0055]
In the case of using light irradiation, microwave irradiation, electron beam irradiation, or particle beam, by polymerizing only the irradiated part by irradiating through a predetermined mask, by removing the monomer state part of the unirradiated part, It is possible to form a predetermined pattern. In addition, in the case of a monomer that is polymerized by heating, it is possible to heat only the irradiated portion by irradiating light such as a laser, so that a predetermined pattern can be formed in the same manner as described above.
[0056]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but is not limited thereto.
[0057]
Example 1
In FIG. 1, an acetone solution (about 0.5 mM) of perylene as the second solution 12 is dropped into an aqueous solution (about 1 wt%) of polyvinyl alcohol as the first solution 11 being stirred. A third solution 13 in which perylene fine particles as crystalline fine particles 14 were dispersed was prepared. The average diameter of the fine particles 14 was about 80 nm. Next, on the glass plate as the substrate 15, the third solution 13 in which the crystalline perylene fine particles were dispersed was applied by a spin coating method to form a mixed film having a film thickness of about 300 nm. Next, the recording layer 17 was formed by heating the substrate on which the mixed film was formed at a temperature of about 100 ° C. in a nitrogen atmosphere. Through the above process, a recording layer 17 of a mixed film in which the perylene fine particles 14 of the second organic material are dispersed in the polyvinyl alcohol of the first organic material is formed on the ITO. Next, an aluminum thin film having a thickness of about 150 nm was formed on the mixed film 17 as a reflective layer by vacuum deposition.
[0058]
Through the above steps, an optical recording medium based on the present invention was formed.
In order to evaluate the dispersibility of the perylene fine particles in the recording layer of the optical recording medium produced by the above steps, the recording medium was cut with a microtome and the cross section was observed with a scanning electron microscope. In the cross-sectional image of the recording layer, it was observed that the area of the perylene fine particles was distributed in the area of the polyvinyl alcohol layer, and the area of the perylene fine particles was almost uniformly distributed in the area of the polyvinyl alcohol. The cross section of 10 locations of the optical recording medium was observed, and the average value of the ratio of the area of the polyvinyl alcohol area to the area of the perylene fine particle area was calculated to be about 1: 0.3.
[0059]
(Example 2)
In FIG. 2, the acetone solution (about 0.5 mM) of perylene as the second solution 22 is dropped into the methanol solution (about 1.5 wt%) of methyl methacrylate of the first solution 21 being stirred. A third solution 23 in which perylene fine particles as crystalline fine particles 24 were dispersed in a methanol solution of methyl methacrylate was formed. The diameter of the fine particles was about 80 nm. A solution obtained by adding a polymerization initiator (azobisisobutyronitrile) to the third solution 13 in which perylene fine particles, which are the crystalline fine particles 24, are dispersed, is applied onto a glass plate as a substrate 25 by spin coating. Then, a mixed film 271 having a film thickness of about 300 nm was formed. Next, the substrate on which the mixed film 271 was formed was heated to polymerize methyl methacrylate to obtain a recording layer 272 having a thickness of about 280 nm. Next, an aluminum thin film having a thickness of about 150 nm was formed on the recording layer 272 by a vacuum deposition method to form a reflective layer.
[0060]
Through the above steps, an optical recording medium based on the present invention was formed.
In order to evaluate the dispersibility of the perylene fine particles in the recording layer of the optical recording medium prepared by the above steps, the recording medium was cut with a microtome and the cross section was observed with a scanning electron microscope. In the cross section of the recording layer, it was observed that the perylene fine particle region was distributed in the PMMA layer region, and the perylene fine particle region was almost uniformly distributed in the PMMA region. The cross section of 10 locations of the optical recording medium was observed, and the average value of the ratio of the area of the PMMA region to the area of the perylene fine particle region was calculated to be about 1: 0.2.
[0061]
【The invention's effect】
According to the present invention, in a recording medium having a recording layer containing fine particles, a recording layer in which fine particles are uniformly dispersed can be produced easily and at low cost.
[Brief description of the drawings]
FIG. 1 is a flowchart showing manufacturing steps of a recording medium based on Embodiment 1 of the present invention.
FIG. 2 is a flowchart showing manufacturing steps of a recording medium based on Embodiment 2 of the present invention.
FIG. 3 is a cross-sectional view of the recording medium of the present invention.
FIG. 4 is a cross-sectional view of the recording medium of the present invention.
FIG. 5 is a cross-sectional view of the recording medium of the present invention.
[Explanation of symbols]
11, 21 First solution, 12, 22 Second solution, 13, 23 Third solution, 14, 24, 34, 44, 54a, 54b Fine particles of second organic material, 15, 25, 35, 45 , 55a, 55b substrate, 36, 46, 56a, 56b first organic material, 271 mixed film, 17, 272, 37, 47, 57a, 57b recording layer, 48, 58a, 58b protective layer, 59a, 59b reflective layer .

Claims (9)

In a method for producing a recording medium having a recording layer containing organic fine particles,
A first solution in which a first organic material is dissolved or dispersed in a first solvent is mixed with a second solution in which a second organic material is dissolved or dispersed in a second solvent, and the second organic material is mixed. Forming a third solution in which fine particles are dispersed in a mixed solution of the first solution and the second solution; supplying the third solution onto a substrate; and adding the third solution into the first organic material. A method for producing a recording medium, comprising a step of forming a recording layer of a mixed film in which fine particles of a second organic material are dispersed. 2. The method of manufacturing a recording medium according to claim 1, wherein the solubility of the second organic material in the first solvent is smaller than the solubility of the second organic material in the second solvent. The step of supplying the third solution onto the substrate to form a mixed film in which the fine particles of the second organic material are dispersed in the first organic material includes a spin coating method, a spray method, a screen printing method, and an ink jet printing method. The recording medium manufacturing method according to claim 1, wherein the recording medium is a recording medium. The method for producing a recording medium according to claim 1, wherein the second organic material is a crystalline organic compound. The method for producing a recording medium according to claim 1, wherein the first organic material is a polymer. The first organic material is a monomer, an oligomer, or a precursor, and includes a step of converting to a polymer after the step of forming the mixed film on a substrate. The manufacturing method of the recording medium in any one. The process of converting from a monomer, oligomer or precursor to a polymer is one of heating, light irradiation, microwave irradiation, electron beam irradiation, particle beam irradiation, or a combination thereof. A method for manufacturing a recording medium according to claim 6. An apparatus for producing a recording medium having a recording layer containing fine particles, the first organic material being dissolved or dispersed in a first solvent to produce a first solution, and the second organic material being a second Means for preparing a second solution dissolved in the solvent, and a mixture of the first solution and the second solution, wherein the second organic material fine particles are dispersed in the first solution. And a means for supplying the third solution onto a substrate to form a mixed film in which fine particles of the second organic material are dispersed in the first organic material. A recording medium manufacturing apparatus. 9. The recording according to claim 8, further comprising means for performing light irradiation, microwave irradiation, electron beam irradiation, or particle beam irradiation in order to convert the monomer, oligomer, or precursor in the mixed film into a polymer. Medium production equipment.

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