JP2006213939A - Organic and inorganic compound thin film, method of manufacturing the same, and optical recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic and inorganic compound thin film which is used for an optical recording element of an optical card of large capacity, a method of manufacturing the same, and an optical recording medium using the same. <P>SOLUTION: The organic and inorganic compound thin film has a polymer having a regularly two-dimensional lattice-like pattern on a substrate, and contains metal super-fine particles in each hole part of the lattice. The organic and inorganic compound thin film has high light resistance, and sufficiently demonstrates new functions such as the electronic nature, the conductive nature and the optical nature. Further, by using the organic and inorganic compound thin film for a recording layer of an optical recording medium, the area of a metal super-fine particle part can be formed smaller than the diffraction threshold of the irradiating light. The recording and reproduction can be performed with the recording density exceeding the diffraction threshold of a pickup lens, and the recording/reproducing signal having the reproduction stability can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a functional composite material that exhibits new functions such as electronic properties, conductive properties, and optical properties, and in particular, an organic-inorganic composite thin film used for an optical recording element of a large-capacity optical card, The present invention relates to a manufacturing method thereof and an optical recording medium using the same.

  Producing sub-micron sized functional materials is an important technology for obtaining materials that exhibit new functions such as electronic properties, conductive properties, optical properties, and magnetic properties. There has been research and development of metal-organic composite materials using ultrafine metal particles (metal nanoclusters) as functional materials.

  However, the reproducibility and uniformity of a two-dimensional regular lattice structure is still insufficient, and an organic material that can fully exhibit new functions such as electronic properties, conductive properties, optical properties, magnetic properties, etc. At present, it has not reached inorganic composite thin films.

  On the other hand, in the field of optical information recording, recordable optical recording media (CD-R, DVD-R) corresponding to CD standard and DVD standard, which are optical recording media having a reflective layer on a substrate, have been commercialized. . In the future, further improvement in recording capacity, miniaturization, and improvement in recording density are required for such optical recording media.

  As elemental technologies for improving the recording capacity in the current system, there are a recording pit miniaturization technique and an image compression technique represented by MPEG2. In particular, in the recording pit miniaturization technology, it has been studied to shorten the wavelength of recording / reproducing light and increase the numerical aperture NA of the optical system, but recording / reproducing exceeding the diffraction limit is impossible.

  Therefore, recently, super-resolution technology capable of recording / reproduction exceeding the diffraction limit and optical recording media / systems using near-field light have been researched and developed, but they have not yet been put into practical use. .

  In response to these problems, a polymer having a two-dimensional regular lattice structure, an organic thin film characterized by containing a functional dye in the pores of the lattice, a method for producing the same, and light using the same A recording medium was proposed. According to this proposal, after forming a submicron size pattern in a lattice pattern on the substrate surface, an organic thin film in which functional dyes are regularly arranged in submicron size is embedded by embedding functional dyes in the holes of the lattice. I was able to get it. Furthermore, by using the organic thin film as an optical recording medium, an optical recording medium having a new structure overcoming the above-described conventional problems has been proposed.

In the optical recording medium to which the organic thin film described in Patent Document 1 is applied, recording layer dots (functional portions) that are highly ordered exist discontinuously. In addition, since the recording layer dots are formed in a uniform sub-micron size, the minimum recording pit size is determined only by the recording layer dots to be formed without being determined by the laser oscillation wavelength or lens NA. Thus, a recording medium having an arbitrary recording density can be designed. Furthermore, since the outermost peripheral edge of the pit is also determined by the structure of the organic thin film, high quality signal characteristics with no pit variation can be obtained by recording the entire recording layer dot. It becomes possible.
Japanese Patent Application Laid-Open No. 2003-12312

  However, the above invention has the following problems.

  Conventional organic thin films have a problem that light resistance is weak, reproduction light stability as an optical recording medium is poor, and an error rate increases when reproduction is repeated. In addition, this organic thin film has low light resistance, and there is a problem that new functions such as electronic properties, conductive properties, optical properties, magnetic properties gradually deteriorate, and noise due to the morphology of the polymer matrix. There is a problem that recording / reproduction with a high S / N signal is impossible. Further, even in an optical recording medium using the same, there is a problem that the reproduction light stability is poor and the error rate increases when reproduction is repeated.

  Therefore, the present invention has a function capable of recording / reproducing at a recording density exceeding the diffraction limit of the pickup lens, which has been impossible to realize in the past, instead of the conventional organic thin film made of polymer / dye, and has a submicron size. Organic-inorganic composite thin film with a new form of regenerative light stability and light resistance, containing ultrafine metal particles in the pores of a two-dimensional regular lattice structure, a method for producing the same, and optical recording using the same The purpose is to propose a medium.

  By utilizing the regular lattice structure formed by the polymer, ultrafine metal particles are included in the pores, and new functions such as the desired electronic properties, conductive properties, and optical properties are exhibited. As a functional material, an organic-inorganic composite thin film having excellent light resistance was obtained. In addition, because the ultrafine metal particle part in the organic / inorganic composite thin film can form an area smaller than the diffraction limit of the irradiated light, it can be recorded / reproduced at a recording density exceeding the diffraction limit of the pickup lens, and has excellent reproduction light stability. It has been found that a recording medium can be obtained, and the present invention has been achieved.

  The organic-inorganic composite thin film according to claim 1 is characterized in that it has a polymer having a regular two-dimensional lattice pattern on a substrate, and contains ultrafine metal particles in pore portions of the lattice.

  According to a second aspect of the present invention, in the organic-inorganic composite thin film according to the first aspect, the polymer is made of a polyion complex, and contains ultrafine metal particles in the holes of the lattice.

  According to a third aspect of the present invention, in the organic-inorganic composite thin film according to the first or second aspect, a lattice-like pattern is formed by the polymer being regularly arranged in a self-organized manner, and a metal super It contains fine particles.

  According to a fourth aspect of the present invention, in the organic-inorganic composite thin film according to any one of the first to third aspects, the polymer is soluble in a hydrophobic organic solvent, and ultrafine metal particles are formed in the holes of the lattice. It is characterized by containing.

  According to a fifth aspect of the present invention, in the organic-inorganic composite thin film according to any one of the first to fourth aspects, the ultrafine metal particles on the substrate are hydrophilic.

  The invention according to claim 6 is the organic-inorganic composite thin film according to any one of claims 1 to 5, wherein the substrate is hydrophilic.

  The invention according to claim 7 is the method for producing an organic-inorganic composite thin film according to any one of claims 1 to 6, wherein a lattice-like pattern is formed by casting a hydrophobic organic solvent solution of a polymer on the substrate. And forming a film by casting the metal ultrafine particle dispersion from above.

  The invention according to claim 8 is the method for producing an organic-inorganic composite thin film according to any one of claims 1 to 6, wherein a lattice-like pattern is formed by casting a hydrophobic organic solvent solution of a polymer on the substrate. After the formation, the substrate is immersed in a metal ultrafine particle dispersion to form a film.

  An optical recording medium according to claim 9 has the organic-inorganic composite thin film according to any one of claims 1 to 6 as a recording layer.

  According to a tenth aspect of the present invention, in the optical recording medium according to the ninth aspect, the maximum absorption wavelength of plasmon absorption of the organic-inorganic composite thin film is in the vicinity of the wavelength of a recording / reproducing laser.

  According to an eleventh aspect of the present invention, in the optical recording medium according to the ninth aspect, the maximum refractive index of the organic-inorganic composite thin film is in the vicinity of the wavelength of a recording / reproducing laser.

  According to a twelfth aspect of the present invention, in the optical recording medium according to any one of the ninth to eleventh aspects, the ultrafine metal particles of the organic-inorganic composite thin film are gold, silver, or platinum.

  The present invention has a light resistance by an organic-inorganic composite thin film characterized in that it has a polymer having a regular two-dimensional lattice pattern on a substrate and contains ultrafine metal particles in the holes of the lattice. And can sufficiently exhibit new functions such as electronic properties, conductive properties, and optical properties.

  In addition, the present invention uses the organic-inorganic composite thin film for the recording layer of the optical recording medium, so that the metal ultrafine particle portion can be formed with an area smaller than the diffraction limit of the irradiation light, and the recording density exceeds the diffraction limit of the pickup lens. A recording / reproducing signal that can be recorded and reproduced and has excellent reproduction stability can be obtained.

  Hereinafter, an embodiment of the present invention will be described in detail.

  FIG. 1 is a view showing a first configuration example of an organic-inorganic composite thin film A of the present invention, where (a) is a plan view and (b) is a cross-sectional view.

  The organic-inorganic composite thin film A of the present invention shown in FIG. 1A has a polymer 5 having a regular two-dimensional lattice pattern (structure) on a substrate 1 (see FIG. 1B). The metal ultrafine particles 4 are contained only in the holes of the lattice.

  The organic-inorganic composite thin film A is characterized in that the ultrafine metal particles 4 are regularly present in a submicron size. The regular pattern (structure) utilizes the arrangement of the polymer 5, but in consideration of productivity, the arrangement is preferably formed in a self-organizing manner. At that time, the polymer 5 is preferably soluble in an organic solvent, particularly a hydrophobic organic solvent, and can be formed into a film by casting. Since the metal ultrafine particles 4 are introduced into the pores after forming the lattice pattern, the dispersion solvent of the metal ultrafine particles 4 is preferably one that does not attack the lattice pattern of the polymer 5, and the metal ultrafine particles 4 are the same as the substrate 1. It is preferably hydrophilic.

  Further, it is preferable that the substrate 1 has a hydrophilicity opposite to that of the polymer 5 in terms of assisting self-organization, and it is preferable that the substrate 1 has the same hydrophilicity as the metal ultrafine particles 4 in terms of adsorbing the metal ultrafine particles 4.

  By regularly rearranging the submicron-sized ultrafine metal particles 4 in this way, the light resistance as a functional material that exhibits new functions such as electronic properties, conductive properties, and optical properties is excellent. An organic-inorganic composite thin film can be obtained.

  2A and 2B are diagrams showing a second configuration example of the organic-inorganic composite thin film A of the present invention, where FIG. 2A is a plan view and FIG. 2B is a cross-sectional view.

  As is apparent from FIG. 2, this configuration example is different from the first configuration example in that a layer of metal fine particles 4 is laminated on a polymer lattice pattern (see FIG. 2B). Also in this case, when viewed from the substrate 1 side, the metal fine particles 4 are embedded in the holes of the lattice pattern of the polymer 5.

  Next, the manufacturing method of the organic inorganic composite thin film of this invention is described. It is known that a film having a submicron size pattern can be obtained by casting a solution of polymer 5 having a specific structure on a substrate 1 as a regular patterning technique for a lattice-like surface. The present invention has been invented based on such a phenomenon.

  That is, after patterning the surface of the substrate 1 in a lattice shape by the above-described method, the dispersion of the metal ultrafine particles 4 is further cast to embed the metal ultrafine particles 4 in the holes of the lattice. An organic-inorganic composite thin film A regularly arranged in submicrons can be obtained.

  Similarly, the metal ultrafine particles 4 can be embedded in the holes of the lattice by immersing the network of the polymer 5 in the dispersion of the metal ultrafine particles 4 after patterning.

  Both the first configuration example and the second configuration example can be manufactured by the above method. However, the manufacturing methods of the first configuration example and the second configuration example differ depending on the affinity between the metal fine particle dispersion and the surface of the substrate 1 and the lattice pattern surface of the polymer 5. That is, when the affinity between the metal fine particle 4 dispersion and the surface of the substrate 1 is high, and the affinity between the metal fine particle 4 dispersion and the lattice pattern surface of the polymer 5 is low, the first configuration example can be manufactured. If both the surface of the substrate 1 and the surface of the lattice pattern of the polymer 5 have high affinity, the second configuration example can be manufactured.

  Next, an optical recording medium B using this organic-inorganic composite thin film as a recording layer will be described with reference to FIG. (A) is sectional drawing explaining the structural example which has only the board | substrate and recording layer which are the 1st embodiment, (b) is the structural example laminated | stacked in order of the board | substrate which is 2nd embodiment, a recording layer, and a reflection layer. FIG. 6C is a cross-sectional view illustrating a configuration example in which a substrate, a reflective layer, and a recording layer according to a third embodiment are laminated in this order.

  The recording layer of the conventional optical recording medium is a continuous layer, which is irradiated with a laser beam, and recording is performed by forming some change corresponding to the shape of the laser beam on the recording material. Therefore, since the size of the minimum recording pit depends on the laser beam diameter determined by the oscillation wavelength and the NA of the lens, in the conventional recording / reproducing system, the increase in the density is basically the laser oscillation wavelength and the lens NA. It has been influenced by practical technology.

  In addition, because the beam shape is a Gaussian distribution and there is almost no material that changes with a clear threshold for heat or light as the recording material, the size and amount of change in the outermost circumference of the pits formed are uniform. However, there are variations in the reproduction signal quality, and there is a limit to obtaining high quality signal characteristics.

  The optical recording medium B of the present invention is characterized in that the above-mentioned organic-inorganic composite thin film A is used as the recording material 2. By using the organic / inorganic composite thin film A as the recording material 2, the reproduction stability is excellent, and the size of the minimum recording pit is determined only by the recording layer dots to be formed without being determined by the laser oscillation wavelength or the lens NA. Therefore, a recording medium having an arbitrary recording density can be designed. Furthermore, since the outermost peripheral edge of the pit is also determined by this organic-inorganic composite thin film structure, high quality signal characteristics with no pit variation can be obtained by recording the entire recording layer dot. Can be realized.

<Configuration of recording medium>
The recording medium of the present invention may have a structure that is a normal write-once type optical disk (a so-called air sandwich or a close-bonding structure in which two sheets are bonded together) or a CD-R medium structure. Further, it may be a structure in which a CD-R structure is bonded or a structure of a DVD-/ + R medium. Hereinafter, each layer constituting the recording medium will be described in order.

<Board>
The necessary characteristics of the substrate 1 must be transparent to the laser beam used only when recording / reproducing is performed from the substrate 1 side. When recording / reproducing is performed from the recording layer 2 side, the substrate 1 needs to be transparent. Absent.

  As the material of the substrate 1, for example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, polyimide or other plastic, (quartz) glass, ceramic, silicon wafer, metal, or the like can be used.

  In the organic-inorganic composite thin film A of the present invention, the ultrafine metal particles 4 need to be adsorbed to the pores of the polymer 5, and therefore, the ultrafine particle adsorption surface of the substrate 1 is preferably a hydrophilic material. In order to impart hydrophilicity to the material of the substrate 1 made of a hydrophobic material, a generally known method such as an ultraviolet irradiation method or a plasma treatment method can be used. A tracking guide groove or guide pit, and a preformat such as an address signal may be formed on the surface of the substrate 1.

<Recording layer>
Recording layer 2 An optical change caused by laser light irradiation and information can be recorded / reproduced by the change, and the recording layer 2 is formed in a two-dimensional regular lattice shape on the substrate 1 It consists of a polymer 5 having a pattern and a structure containing metal ultrafine particles 4 in the pores of the lattice. The optical characteristics of the ultrafine metal particles 4 preferably have a maximum absorption wavelength in the vicinity of the laser wavelength when reproducing using the change in absorption characteristics with respect to the recording / reproducing laser wavelength. When reproducing using the change in refractive index, it is preferable to have a maximum refractive index near the laser wavelength.

  Examples of the polymer 5 capable of forming a lattice pattern include a polyion complex represented by polystyrene sulfonic acid and a long-chain dialkylammonium salt, a block copolymer such as polystyrene and polyparaphenylene, and acrylamide as a main chain skeleton. Examples include amphiphilic polymers with long-chain alkyl (hydrophobic part) and carboxylic acid or sugar (hydrophilic part) in the chain, and are easy to control molecular weight distribution and amphiphilicity, and are regular in two dimensions. A polyion complex that can easily obtain a simple lattice structure is particularly preferred. These polymers may be used alone or in combination of two or more.

  Nanometer-sized ultrafine metal particles are usually obtained by dissolving a metal compound and its reducing agent in an organic solvent and heating. The ultrafine metal particles 4 of the present invention preferably use ultrafine metal particles protected with a dispersant, and the production method thereof involves dissolving a metal compound and its reducing agent in an organic solvent, and in the presence of the dispersant. Obtained by heat reduction.

  The dispersant is a pigment-affinity group having a strong adsorptive power to the surface of the ultrafine metal particles (for example, for organosol: tertiary amino group, quaternary ammonium group, heterocyclic group having basic nitrogen, hydroxy group) , Carboxyl group, etc. with respect to hydrosol: phenyl group, lauryl group, stearyl group, dodecyl group, oleyl group, etc.) and a part having a solvent affinity group (solvation) Since it is necessary to adsorb the ultrafine metal particles to this portion, it is preferable to be hydrophilic like the substrate.

  In the optical recording medium of the present invention, ultrafine metal particles protected with all dispersants such as gold, silver, platinum, copper, tin, rhodium, iridium, etc. can be used. Particularly preferred are ultrafine metal particles protected with a dispersant of platinum and its alloys. The above ultrafine metal particles may be used alone or in combination of two or more.

  Furthermore, a functional dye can be mixed for the purpose of improving the optical properties of the ultrafine metal particles. Examples of functional dyes include polymethine dyes that change their optical constants in the heat mode (thermal decomposition, etc.) depending on the irradiation energy of laser light, naphthalocyanine-based, phthalocyanine-based, squarylium-based, croconium-based, pyrylium-based, naphthoquinone-based, anthraquinone (Indanthrene), xanthene, triphenylmethane, azulene, tetrahydrocholine, phenanthrene, triphenothiazine dyes, metal chelate compounds, etc. Frugides, diarylethenes, azobenzenes, spiropyrans, stilbenes, dihydropyrenes, thioindigos, bipyridines, aziridines, aromatic polycycles, allylidene anilines, oxalides that change their optical constants Photochromic materials such as ten such can be mentioned as examples.

  Further, stabilizers (transition metal complexes, etc.), ultraviolet absorbers, dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers, etc. are added to the recording layer 2 for the purpose of improving the characteristics. Also good. The dot diameter of the metal ultrafine particles 4 is suitably 0.05 to 5 μm.

<Underlayer>
The undercoat layer is (a) improved adhesion, (b) a barrier such as water or gas, (c) improved storage stability of the recording layer, (d) improved reflectance, (e) substrate from solvent And (f) formation of guide grooves / guide pits / preformats, etc.

For the purpose of (a), polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers and various other polymer substances, and silane coupling agents are used. For the purposes of (b) and (c), in addition to the polymer material, inorganic compounds such as SiO ₂ , MgF ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, metals, or Semimetals such as Zn, Cu, Ni, Cr, Ge, Se, Au, Ag, Al, etc. can be used. For the purpose of (d), metals such as Al and Ag, and organic thin films having metallic luster such as methine dyes and xanthene dyes can be used. For the purposes of (e) and (f) In contrast, an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The thickness of the undercoat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.

<Reflective layer>
The reflective layer 3 is made of a metal, semi-metal, etc. that is highly resistant to corrosion and is not easily corroded. Examples of materials include Au, Ag, Cr, Ni, Al, Fe, Sn, Cu, etc. Au, Ag, Al, and Cu are most preferable from the viewpoint of rate and productivity, and these metals and metalloids may be used alone or in combination of two or more. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 5000 mm, preferably 100 to 3000 mm.

<Protective layer, substrate surface hard coat layer>
The protective layer or substrate surface hard coat layer (a) protects the recording layer (reflection / absorption layer) from scratches, dust, dirt, etc. (b) improves the storage stability of the recording layer (reflection / absorption layer), (c ) Used for the purpose of improving the reflectance. For these purposes, the materials shown in the intermediate layer can be used. In addition, SiO, SiO ₂ etc. can be used as an inorganic material, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin, aromatic hydrocarbon resin as organic material, Thermal softening and heat melting resins such as natural rubber, styrene butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin can also be used.

  Among these materials, the most preferable example of the protective layer or the substrate surface hard coat layer is an ultraviolet curable resin excellent in productivity. The film pressure of the protective layer or the substrate surface hard coat layer is 0.01 to 30 μm, preferably 0.05 to 10 μm.

  In the present invention, the undercoat layer, the protective layer, and the substrate surface hard coat layer are the same as in the recording layer, such as a stabilizer, a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer, and the like. Can be contained.

  A polyion complex obtained from polystyrene sulfonate (weight average molecular weight: 50000) and bishexadecyl-dimethylammonium salt is dissolved in chloroform (400 mg / l), and quartz is obtained at a temperature of 35 ° C. and a humidity of 51% RH. A polymer thin film was formed by casting on a substrate and allowing to stand. As a result of observing the structure of the organic thin film thus obtained using an optical microscope, an atomic force microscope, a laser microscope, etc., a lattice-like polymer network having a pore diameter of about 0.8 μm and a depth of about 0.2 μm can be observed. It was.

  In pure water (40 ml), chloroauric acid (20 mmol) and a polymer content dispersant (5.5 g: Solspearl 27000 / Zeneca) were dissolved, and then dimethylamino alcohol (2.0 ml) was added and heated. Gold ultrafine particles were prepared, and then ethanol (20 ml) and butanol (5 ml) were added to prepare a coating solution.

  The above coating solution was spin-coated on the previously created polymer network to form a metal ultrafine particle layer. From observation with a laser microscope, it was confirmed that an organic-inorganic composite thin film in which a metal ultrafine particle layer was laminated on a polymer network was formed. This state is shown in FIG.

  As the polymer, a chloroform solution (1 g / l) of a long-chain alkyl-substituted acrylamide and a long-chain alkylcarboxylic acid-substituted acrylamide, respectively, is cast onto a mica substrate at a temperature of 35 ° C. and a humidity of 51% RH, and left to stand. Thus, a polymer thin film was formed, and the formation of a polymer network was confirmed in the same manner.

  Nitric acid acidic silver nitrate (60 mmol) and polymer content dispersant (4.5 g: Dispersic 180 / Big Chemie) are dissolved in pure water (40 ml), and then dimethylamino alcohol (2.5 ml) is added and heated. Then, ultrafine silver particles were prepared, and then propanol (30 ml) was added to obtain a coating solution.

  The above coating solution was spin-coated on the previously created polymer network to form a metal ultrafine particle layer. Similarly, from observation with a laser microscope, it was confirmed that an organic-inorganic composite thin film in which a metal ultrafine particle layer was laminated on a polymer network was formed.

  In Example 1, chloroauric acid (15 mmol)) and a polymer content dispersant (4.5 g) were dissolved in pure water (40 ml) on the polymer network, and then dimethylamino alcohol (1.5 ml) was added. The solution was heated and spin-coated with a solution prepared with gold ultrafine particles to form a metal ultrafine particle layer. Similarly, it was confirmed by observation with a laser microscope that an organic-inorganic composite thin film in which a metal ultrafine particle layer was formed in a polymer network was formed.

  The polymer network of Example 2 was formed on a molded substrate, and a metal ultrafine particle layer was formed thereon as in Example 3. From observation with a laser microscope, it was confirmed that an organic-inorganic composite thin film having a metal fine particle layer formed in a polymer network was formed.

  Using the substrate on which the polymer network obtained in Example 1 was formed, a metal ultrafine particle layer was formed by the dip coating method using the coating liquid of Example 1. From observation with a laser microscope, it was confirmed that an organic-inorganic composite thin film in which a metal ultrafine particle layer was formed on a polymer network was formed.

[Comparative Example 1]
On the polymer network of Example 1, a neutral red ethanol solution was spin-coated to form a dye layer to obtain an organic thin film. From observation with a laser microscope, it was confirmed that an organic thin film having a dye layer formed on the polymer network was formed.

[Light resistance test]
The organic-inorganic composite films and organic thin films obtained in Examples 1 to 5 and Comparative Example 1 were left under a xenon lamp (illuminance: 60000 Lux) for 20 hours, and changes in optical density were observed.

(result)
The optical density of the organic-inorganic composite films of Examples 1 to 5 is almost the same as that before irradiation. The optical density of the organic thin film of Comparative Example 1 was less than half that before irradiation. The results are shown in Table 1.

  From the above results, it is clear that the organic-inorganic composite thin film obtained by the method of the present invention has an organic-inorganic composite structure excellent in light resistance composed of a submicron-sized two-dimensional polymer network and ultrafine metal particles therein. It is. With such an organic-inorganic composite thin film having a two-dimensional lattice structure, new electronic properties, conductive properties, optical properties and the like can be expressed.

  The organic-inorganic composite thin film obtained in Example 4 was used as a recording layer to obtain an optical recording medium. On this optical recording medium, a semiconductor laser having an oscillation wavelength of 655 nm and a beam diameter of 0.6 μm was scanned 5 mm in the horizontal and vertical directions at 5 μm intervals. At this time, the irradiated part and the non-irradiated part were observed with an atomic force microscope and an optical microscope, and the transmittance was measured with a microspectroscopic method.

[Comparative Example 2]
The organic thin film of Comparative Example 1 was used as a recording layer and an optical recording medium, and the same evaluation as in Example 6 was performed. The results are shown in Table 2.

  It is clear that the organic-inorganic composite thin film of the present invention can be recorded by laser light in the same manner as the organic thin film. Furthermore, from the above light resistance test results, it is also easily estimated that the optical recording medium using the organic-inorganic composite thin film of the present invention has excellent reproduction stability compared to the optical recording medium using the organic thin film. it can.

It is the top view and sectional drawing of the structural example of the organic inorganic composite thin film of this invention. It is the top view and sectional drawing of the structural example of the organic inorganic composite thin film of this invention. It is sectional drawing which shows the example of the layer structure of the optical recording medium of this invention, (a) is the structural example which has only a board | substrate and a recording layer, (b) is the structural example laminated | stacked in order of the board | substrate, the recording layer, and the reflective layer, (C) shows the structural example which laminated | stacked in order of the board | substrate, the reflection layer, and the recording layer. 2 is a photograph taken with a laser microscope of Example 1. FIG.

Explanation of symbols

1 Substrate 2 Recording layer 3 Reflective layer 4 Ultrafine metal particles 5 Polymer

Claims (12)

Having a polymer with a regular two-dimensional lattice pattern on the substrate;
An organic-inorganic composite thin film characterized by containing ultrafine metal particles in the holes of the lattice. The polymer comprises a polyion complex,
2. The organic-inorganic composite thin film according to claim 1, wherein ultrafine metal particles are contained in the holes of the lattice. The polymer is regularly arranged in a self-organized manner to form a lattice pattern,
3. The organic-inorganic composite thin film according to claim 1 or 2, wherein ultrafine metal particles are contained in the holes of the lattice. The polymer is soluble in a hydrophobic organic solvent;
The organic-inorganic composite thin film according to any one of claims 1 to 3, wherein ultrafine metal particles are contained in the holes of the lattice.   The organic-inorganic composite thin film according to any one of claims 1 to 4, wherein the ultrafine metal particles on the substrate are hydrophilic.   The organic-inorganic composite thin film according to any one of claims 1 to 5, wherein the first substrate is hydrophilic. In the manufacturing method of the organic inorganic composite thin film of any one of Claim 1 to 6,
A manufacturing method comprising forming a film by forming a lattice-like pattern by casting a hydrophobic organic solvent solution of a polymer on the substrate, and further casting a metal ultrafine particle dispersion from thereover. In the manufacturing method of the organic inorganic composite thin film of any one of Claim 1 to 6,
A method of forming a film by forming a lattice-like pattern by casting a hydrophobic organic solvent solution of a polymer on the substrate, and then immersing the whole substrate in a metal ultrafine particle dispersion to form a film.   An optical recording medium comprising the organic-inorganic composite thin film according to any one of claims 1 to 6 as a recording layer.   10. The optical recording medium according to claim 9, wherein the maximum absorption wavelength of plasmon absorption of the organic-inorganic composite thin film is in the vicinity of the wavelength of a recording / reproducing laser.   10. The optical recording medium according to claim 9, wherein the maximum refractive index of the organic-inorganic composite thin film is in the vicinity of the wavelength of a recording / reproducing laser.   The optical recording medium according to any one of claims 9 to 11, wherein the ultrafine metal particles of the organic-inorganic composite thin film are gold, silver, or platinum.