JPS6349492A - Optical information recording medium and recording method using the same - Google Patents

Abstract

PURPOSE:To obtain an optical information recording medium having excellent mass-producibility, high recording sensitivity and excellent preservability and a recording method using the same, by composing a recording layer of a metallic layer providing at the surface of a heat-sensitive layer comprising an organometallic complex by heating the heat-sensitive layer. CONSTITUTION:In an optical information recording medium in which a recording layer enabling writing of information by high energy rays is provided on a base, the recording layer comprises a metallic layer provided at the surface of a heat-sensitive layer comprising an organometallic complex by heating the heat-sensitive layer. Recording of information in the optical information recording medium can be performed by irradiating the recording layer (metallic layer) of the medium with a beam of high energy rays, or by irradiating the recording layer with high energy rays through a photomask. The optical information recording medium has high sensitivity and mass-producibility and excellent preservability. Preferable examples of the organometallic complex include di-mu- chlorobis(eta-2-methylallyl)-dipalladium(II) and di-mu-chlorotetracarbonyldirhodium(I).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an optical information recording medium on which information can be written using high-energy rays, and a recording method thereof.

[Technical background of the invention] In recent years, high-energy beams have been used to write and/or write information.
Alternatively, readable optical information recording media have been developed and put into practical use. Such optical information recording media include, for example, optical discs such as video discs and audio discs, as well as large-capacity still image files, Daikichi! It is applied to computer disk memories, micro image recording media, ultra-micro image recording media, micro facsimiles, optical cards, original plates for phototypesetting, etc.

These conventional optical information recording media have a basic structure of a transparent substrate made of plastic, glass, etc., and a recording layer made of metal or semimetal such as Bi, Sn, In, Te, etc. provided thereon. Note that an undercoat layer made of a polymeric material is usually applied to the surface of the substrate on the side where the recording layer is provided, from the viewpoint of improving the flatness of the substrate, improving the adhesive force with the recording layer, or improving the sensitivity of the optical disc. Or an intermediate layer is provided. Information is written on a recording medium by, for example, irradiating the recording medium with a laser beam, and the irradiated portion of the recording layer absorbs the light and locally increases in temperature, causing physical or chemical damage. Information is recorded by causing changes in the optical properties of the optical fiber. Reading information from a recording medium is also performed by irradiating the recording medium with a laser beam, and the information is reproduced by detecting reflected or transmitted light according to changes in the optical characteristics of the recording layer. .

Recently, as a disk structure for protecting the recording layer, a recording layer is provided on at least one of the two disk-shaped substrates, and the recording layer is located inside the two disk-shaped substrates. Also, an air sandwich structure has been proposed in which a ring-shaped inner spacer and a ring-shaped outer spacer are joined to form a space. In a recording medium with such a structure, the recording layer is not in direct contact with the outside air, and information is recorded and reproduced using laser light that passes through the substrate. Therefore, the recording layer is generally susceptible to physical or chemical damage. There is no possibility that the recording or reproducing of information will be hindered by dust or dirt adhering to its surface.

The recording layer made of metal or semimetal of the optical information recording medium as described above is generally provided on a substrate made of plastic, glass, or the like by a method such as vapor deposition or sputtering.

Vapor deposition is an excellent method for forming a recording layer, but
Materials that can be formed into films by vapor deposition and have high laser sensitivity, such as Te, have storage problems, and require expensive vacuum equipment and advanced vacuum technology, resulting in slow production speeds. There is.

Although the spar two-talling method is superior to the vapor deposition method as a method for forming a recording layer, there are problems in that it is difficult to accurately control the film thickness and that it requires expensive manufacturing equipment.

Optical information recording media that use dyes as recording materials are also known, and in this case, the dye is generally dissolved or dispersed in a suitable solvent, and then this coating liquid is applied onto the substrate to form a recording layer. It is formed. The coating method of coating this dye to form a recording layer has the advantage of being excellent in mass production and being able to provide inexpensive recording media, but compared to the aforementioned recording layer made of metal or metalloid. However, there is a problem of poor light resistance and heat resistance.

Therefore, optical information recording media having conventional recording layers formed by vapor deposition, sputtering, or coating methods are desired to be improved in terms of durability, mass productivity, recording sensitivity, and the like.

[Object of the Invention] An object of the present invention is to provide a novel optical information recording medium that is excellent in mass productivity, high recording sensitivity, and excellent storage stability, and a recording method thereof.

[Summary of the Invention] The present invention provides an optical information recording medium in which a recording layer in which information can be written by a high-energy beam is provided on a substrate, wherein the recording layer includes a heat-sensitive layer containing an organometallic complex. An optical information recording medium comprising a metal layer formed on the surface of the heat-sensitive layer by heating.

Note that the organometallic complex in the heat-sensitive layer is preferably present in a dispersed state in the polymer.

Information recording on such an optical information recording medium is carried out by irradiating the recording layer (metal layer) of two optical information recording media with a beam of high-energy rays, or by irradiating the recording layer (metal layer) of the optical information recording medium with two legs. This can be done by irradiating high-energy radiation through a photomask.

[Effects of the Invention] The optical information recording medium of the present invention is an optical information recording medium in which a recording layer made of a metal layer is formed on the surface of the heat-sensitive layer by heating a heat-sensitive layer containing an organometallic complex provided on a substrate. It is an information recording medium that is highly sensitive and has excellent mass productivity and storage stability.

[Detailed Description of the Invention] The optical information recording medium of the present invention can be manufactured, for example, by the following method.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information recording media. Optical properties, flatness, processability of the substrate,
In terms of ease of handling, stability over time, and manufacturing cost,
Examples of substrate materials include glass such as soda lime glass; acrylic resins such as cell cast polymethyl methacrylate and injection molded polymethyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; epoxy resins; and polycarbonate. can be mentioned.

The thickness of the substrate is not particularly limited;
For example, within a thickness range of 10 gm to several mm,
Thicknesses ranging from flexible to highly rigid can be used depending on the purpose.

The surface of the substrate on which the recording layer is provided has improved flatness,
An undercoat layer (and/or intermediate layer) may be provided for the purpose of improving adhesive strength and preventing deterioration of the recording layer.

Examples of materials for the undercoat layer (and/or intermediate layer) include polymeric substances such as polymethyl methacrylate, acrylic acid/methacrylic acid copolymers, nitrocellulose, polyethylene, polypropylene, and polycarbonate; silane coupling agents, etc. organic substances, and inorganic oxides (
Examples include inorganic substances such as SiO2, A or 203), and inorganic fluorides (MgF2).

The subbing layer (and/or intermediate layer) can be formed, for example, after the above-mentioned substances have been dissolved or dispersed in a suitable solvent.

It can be formed by applying this coating liquid onto the surface of the substrate using a coating method such as spin code, dip coating, or extrusion coating.

The recording layer is provided on the substrate (or subbing layer or intermediate layer).

In the recording layer of the present invention, a heat-sensitive layer containing an organometallic complex is coated on the substrate (or undercoat layer or intermediate P:!j), and the heat-sensitive layer is heated to form a surface of the heat-sensitive layer. It is obtained by selectively depositing metals in an organometallic complex in a layered manner.

The organic gold complex used in the present invention decomposes upon heating and precipitates metal.

Preferably, this organometallic complex is soluble in an organic solvent.

Such an organometallic complex has the general formula (1)=M m L
n (I) (where M is a metal atom, L is a ligand, and 1m is an integer from 1 to 4, n
is an integer from 2 to 12).

In the above organometallic complex, the metal atom (M) is a metal in the periodic table Ib, rVb, vb, v'tb, vnb, VW, such as titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese,
Mention may be made of rhenium, iron, cobalt, nickel, ruthenium, osmium, rhodium, palladium, iridium, platinum, copper and gold.

There are no particular limitations on the ligand (L), but examples include:
Examples include tertiary phosphites, -carbon oxides, linear or cyclic olefins, conjugated olefins, aryl compounds, heterocyclic compounds, organic cyano compounds, organic innitrile compounds, and organic mercapto compounds. Further, it may be a compound containing one or more groups such as an alkyl group, a vinyl group, an allyl group, an ethylidene group, an acyl group, or the like.

Alternatively, the ligand (L) may be an atom such as halogen, oxygen, water, or nitrogen.

A specific example of a preferable organometallic complex is diluglolobis(η-2-methylallyl)nipalladium(II).
), Ji-Chlorotetratonylnirhodium (
I), tetrakis(triphenylphosphine)palladium(O), and di-chlorobis(1,5-cyclooctadiene)niiridium(II).

Note that organometallic complexes capable of precipitating metals by such heating are described in detail in, for example, JP-A-59-207938 and JP-A-60-208891. In this case, it is preferable to use a polymer and an organic solvent for dispersing or dissolving the polymer.

The polymer is preferably one that is soluble in an organic solvent. Specific examples of such polymers include polystyrene, polyvinyl chloride, polyacrylate, polycarbonate, polysulfone, polyvinylidene fluoride, polyurethane, polyamide, polyimide, silicone resin, saturated or unsaturated polyester, epoxy resin, diallyl phthalate resin, etc. can be mentioned.

In the present invention, the heat-sensitive layer is generally prepared by preparing a coating solution by dissolving or dispersing an organometallic complex and a polymer in a solvent, and then applying this coating solution to the substrate surface (or the surface of the undercoat layer or intermediate layer). It can be formed on the substrate by drying.

Solvents for dissolving or dispersing organometallic complexes and polymers include benzene, toluene, xylene,
Acetone, ethyl acetate, butyl acetate, dimethylformamide, dimethyl sulfoxide, chloroform, methylene chloride, trichlene, tetrachloroethane, cellosolve acetate, methyl ethyl ketone, 1,2-dichloroethane, methyl isobutyl ketone, cyclohexane, tetrahydrofuran, ethyl ether and dioxane. Examples include Sun.

In addition, it is also possible to further add various additives such as a plasticizer and a lubricant to the coating liquid for forming a heat-sensitive layer depending on the purpose.

Examples of the coating method include a doctor knife method, a spray method, a spin code method, a dip method, a roll coating method, and a screen printing method.

The recording layer of the present invention is obtained by heating the heat-sensitive layer to decompose the organometallic complex and forming a metal layer on the surface of the heat-sensitive layer.

The heating means is not particularly limited as long as it can heat the surface of the heat-sensitive layer and apply thermal energy to decompose the organometallic complex, and examples include an electric oven.

In the present invention, the decomposition of an organometallic complex refers to the phenomenon in which metal atoms are precipitated from the organometallic complex, and does not particularly mean the decomposition of the ligand of the organometallic complex.

The heating temperature is generally within the range of 40 to 400°C,
Preferably it is within the range of 60 to 350°C.

The heating operation may be carried out under any atmosphere such as the air or an inert gas atmosphere, but is usually carried out in the air.

The heating time can be freely selected depending on the purpose, but is generally within the range of several tens of seconds to several tens of minutes.

In order to efficiently decompose the organometallic complex and form a metal layer on the heat-sensitive layer, the surface of the heat-sensitive layer should be coated with a metallization promoting substance (a substance that can promote the decomposition of the organo-gold l1jS complex).
It is preferable to heat it by contacting with.

As a substance for promoting metallization, it is necessary to have heat resistance that can withstand heating and humidity, and good peelability from the metal layer surface.
Examples include copper, copper alloys, and aluminum.

The metallization promoting substance may be made of a plate-like material such as a copper plate or an aluminum plate, or may be in the form of a powder.

When the metallization promoting substance is a plate-like material, the plate-like material is brought into contact with the surface of the heat-sensitive layer containing the organometallic complex and heated.

When the metallization-promoting substance is in powder form, the powder-like substance is dispersed in a solution of a polymer such as polyvinyl alcohol, and a coating solution obtained is applied to a base ball such as polyethylene terephragm to remove the metallization-promoting substance. A containing sheet is prepared, and the coating surface of this sheet (layer containing a metallization promoting substance)
A method can be used in which heating is performed while the organic gold G5 complex is in contact with the surface of the heat-sensitive layer containing the organic gold G5 complex.

Regarding substances for promoting metallization that are effective in the operation of precipitating the metal in the organometallic complex in the heat-sensitive layer to form a metal layer, see, for example, JP-A-59-207938 and JP-A-60-208891. Detailed information is provided in official bulletins, etc.

In this way, it is possible to manufacture an optical information recording medium having the basic structure in which the substrate and the recording layer are laminated in this order.

The optical information recording medium of the present invention may be made of a single plate having the above structure, or may be of a bonding type in which two substrates having the above structure are bonded together using an adhesive or the like.

Alternatively, an air sandwich type may be used in which at least one of two disk-shaped substrates has the above structure and is joined via a ring-shaped outer spacer and an inner spacer.

Further, the optical information recording medium of the present invention is not limited to a disk shape, but can be freely selected from tape, card, etc. depending on the purpose.

Information can be recorded on the optical information recording medium of the present invention by irradiating the metal layer of the optical information recording medium with a beam of high energy rays.

Examples of high-energy rays include laser beams.

Information recording using a laser beam can be performed using, for example, an argon ion laser beam, a semiconductor laser beam, or a YA laser beam.
This can be done by irradiating the recording layer with a G laser beam or the like.

Furthermore, information recording on the optical information recording medium of the present invention can be performed by beam irradiation or full-surface irradiation with high-energy rays through a photomask onto the recording layer (metal layer) of the optical information recording medium. .

Photomask materials include chromium, chromium oxide, silicon oxide, and iron oxide.

Examples of the high-energy beam used in the recording method using the photomask described above include xenon flash light and various laser beams.

Next, examples of the present invention will be described.

[Example 1] 2.3 g of rolobis(η-2-methylallyl)nipalladium (II) and 5.0 g of polysulfone (Needel Polysulfone P-1700, manufactured by Nissan Chemical Industry Co., Ltd.) were mixed with 66.4 g of chloroform. A coating solution was prepared by dissolving it in

The above coating solution was cast onto a copper plate using a doctor knife so that the thickness of 1M was 40 JLm, and then dried at room temperature to remove chloroform to form a heat-sensitive layer on the copper plate.

The heat-sensitive layer on the copper plate was heated in an electric oven at a temperature of 175°C for 5 minutes in the air, and then the heat-sensitive layer was peeled off from the copper plate. was gotten.

The heat-sensitive layer having the metal layer formed on its surface is laminated on a polyethylene terephthalate sheet so that the surface of the metal layer is exposed, and a focused argon ion laser is applied to the metal layer.
Light (wavelength 5145, beam diameter 6u on metallic shiny surface)
Lm) was modulated to a pulse length of 10 seconds using an AO modulator, and irradiation was performed while changing the laser power on the film surface continuously or stepwise. When the metal surface irradiated with laser light was observed using the reflection method using an optical microscope, it was found that clear recording pits with a significantly lower reflectance than the non-irradiated area were formed by irradiation with laser light with a film surface power of 30 mW. was confirmed.

[Example 2] A coating liquid having the same composition as that used in Example 1 was applied onto a 1.2 mm thick soda-lime glass substrate in the same manner as in Example 1, and dried to form a soda-lime glass substrate. A thermosensitive layer was formed on a lime glass substrate.

Next, a copper plate was pressure-bonded onto the heat-sensitive layer formed on the soda-lime glass substrate, and the copper plate was heated in an electric oven under an atmospheric atmosphere.
After heating at a temperature of 75° C. for 5 minutes, the copper plate was peeled off from the heat-sensitive layer, and a metal layer with metallic luster was obtained on the surface of the heat-sensitive layer that was in contact with the copper plate.

Next, line width 2JL created with chrome hard mask
After bringing the chromium surface of a photomask with a resolution cover turn of m into close contact with the metal layer on the surface of the heat-sensitive layer, xenon flash light (irradiation conditions: Canon flash lamp power IKW, lamp and sample 15 cm) was irradiated.

After irradiation with xenon flash light, the irradiated surface was observed using a reflection method using an optical microscope, and it was found that a pattern with a line width of 2 pm was well formed, indicating that it had good performance as a high-density optical memory. .

[Example 3] A metal layer was formed on the surface of a heat-sensitive layer formed on a soda-lime glass substrate by operating in the same manner as in Example 2.

Next, a photomask having the same resolution cover turn as in Example 2 (however, line width: 1.2 pm) was brought into close contact with the metal layer on the surface of the heat-sensitive layer, and then an argon ion laser was applied to the surface of the metal layer through the photomask. Light (wavelength: 5145, beam diameter: 25 uLm on a metallic shiny surface) at a linear speed of 18.8 m/
The entire surface was uniformly irradiated with a film surface power of 350 mW.

When the metal surface after irradiation was observed using an optical microscope using the reflection method, a pattern with a line width of 1 to 2 gm was well formed, indicating that it has good performance as an optical ROM card, etc. Understood.

Claims (1)

[Claims] 1. In an optical information recording medium comprising a recording layer on a substrate on which information can be written using high-energy rays, the recording layer heats a heat-sensitive layer containing an organometallic complex. An optical information recording medium comprising a metal layer formed on the surface of the heat-sensitive layer by. 2. The organometallic complex is di-μ-chloro-bis(η-2-
methylallyl) dipalladium(II), di-μ-chloro-
Tetracarbonyl dirhodium (I), tetrakis(triphenylphosphine)palladium (O), and di-
Optical information recording according to claim 1, characterized in that it is at least one organometallic complex selected from the group consisting of μ-chloro-bis(1,5-cyclooctadiene)diiridium(II). Medium. 3. The optical information recording medium according to claim 1, wherein the heat-sensitive layer contains a polymer. 4. The heat-sensitive layer contains a polymer, and the polymer is polystyrene, polyvinyl chloride, polyacrylate, polycarbonate, polysulfone, polyvinylidene fluoride, polyurethane, polyamide, polyimide, silicone resin, saturated polyester, unsaturated polyester, epoxy resin, and The optical information recording medium according to claim 1, wherein the optical information recording medium is at least one kind of polymer selected from the group consisting of diallyl phthalate resins. 5. High-energy radiation is applied to the recording layer of an optical information recording medium in which a recording layer consisting of a metal layer is formed on the surface of the heat-sensitive layer by heating the heat-sensitive layer containing an organometallic complex and is provided on a substrate. A recording method for an optical information recording medium, characterized in that information is written by irradiating a beam. 6. The method for recording an optical information recording medium according to claim 5, wherein the heat-sensitive layer contains a polymer. 7. The method for recording an optical information recording medium according to claim 5, wherein the high-energy ray is a laser beam. 8. A recording layer of an optical information recording medium in which a recording layer consisting of a metal layer formed on the surface of the heat-sensitive layer by heating a heat-sensitive layer containing an organometallic complex is provided on a substrate through a photomask. 1. A recording method for an optical information recording medium, characterized in that information is written by irradiating high-energy rays. 9. The method for recording an optical information recording medium according to claim 8, wherein the heat-sensitive layer contains a polymer. 10. The method for recording an optical information recording medium according to claim 8, wherein the high-energy ray is a xenon flash light or a laser beam.