JPH03219445A - Production of optical information recording medium - Google Patents

Abstract

PURPOSE:To wash a substrate simultaneously with formation of a protective layer by supplying a coating liquid for forming the protective layer onto a reflecting layer formed on a recording layer under the rotation of the substrate and simultaneously supplying a liquid contg. a specified org. solvent on the rear side of the substrate from below. CONSTITUTION:The recording layer 12 is formed by supplying the coating liquid for forming the recording layer onto the substrate surface from above the disk-shaped substrate 11 and applying the liquid on the substrate while rotating the substrate 11. The reflecting layer 14 consisting of a metal is formed by vapor deposition on the recording layer 12. The material of the recording layer 12 and the material of the protective layer can be dissolved at the treating temp. on the rear surface of the substrate 11 on the side where the recording layer 12 is not provided simultaneously while the coating liquid for forming the protective layer is supplied and applied onto the reflecting layer 14 from a liquid material supplying pipe 17 under the rotation of the substrate 11 which is formed the recording layer 12 and the reflecting layer 14. In addition, the protective layer 15 is formed by supplying the liquid contg. the volatile org. solvent which does not dissolve or swell the substrate 11 material at the treating concn. from a liquid material supplying pipe 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for manufacturing an optical information recording medium on which information can be recorded using light.

[Technical Background of the Invention] The basic structure of an optical disc on which information can be recorded is a disk-shaped substrate made of glass, synthetic resin, etc., and a metal such as Bi, Sn, In, Te, etc. It has a recording layer made of a semimetal; or a cyanine-based, metal complex-based, or quinone-based dye. Incidentally, the surface of the substrate on which the recording layer is provided usually has an undercoat layer made of a polymeric substance in order to improve the flatness of the substrate, the adhesion to the recording layer, and the sensitivity of the optical disc. Often provided.

Writing and reading information to and from an optical disc is usually performed by the following method.

Information is written by irradiating this optical disc with a laser beam, and the irradiated portion of the recording layer absorbs the light, causing a local temperature rise, causing physical or chemical changes (for example, the formation of pits). information is recorded by changing its optical properties. Information is also read by irradiating the optical disk with a laser beam, and the information is reproduced by detecting reflected or transmitted light depending on changes in the optical characteristics of the recording layer.

As mentioned above, the manufacturing method for such optical discs includes:
It includes a step of providing layers such as a recording layer, an undercoat layer, and a protective layer on the surface of the disc-shaped substrate. One of the most commonly used methods for forming each layer is a spin code method. In the spin code method, as shown in the attached Figure 1-A, the substrate 11 is held horizontally and attached to the spindle 6 of the spinner, and the spinner is
While rotating at a rotational speed of 000 r, p, m, a liquid material for forming a film to be each layer is supplied from the liquid material supply pipe 7 onto the substrate by dropping, spraying, etc.
This method uses centrifugal force due to the rotation of the substrate to scatter liquid material and form a film on the substrate surface.

The recording layer and other materials coated by this method adhere not only to the coated surface of the substrate, but also to the back surface of the substrate, which is the non-coated surface that should not be coated, and to the outer peripheral side wall. . That is, a part of the liquid material scattered by the centrifugal force caused by the rotation of the substrate flows around from the outer periphery of the substrate to the back side of the substrate and adheres to the non-coated surface of the substrate. Such substances adhering to the back side of the substrate, etc., must be removed because they may interfere with the recording and reproducing of information, or the resulting optical disc may have a poor appearance. For this reason, conventionally, after forming all the layers or between intermediate steps, the substrate was turned over and the non-coated surface of the substrate was cleaned.

However, it is necessary to add a cleaning process in addition to the process of forming each layer, which increases the number of manufacturing steps, so it is desired to shorten the process.

On the other hand, as a coating method to prevent the coating solution from turning over,
Using a coating method using a spinner, when the coating liquid is sprayed onto the object from above, the coating liquid that flows around the object is sucked and water is sprayed onto the back side of the rotating object. A technique for forming a film by coating from above while preventing the coating from rotating is disclosed in Japanese Utility Model Application Publication No. 58-81932. When a dye coating liquid, which is a recording layer material, is applied using such a method, the liquid sprayed from the back side is water, so the dye attached to the substrate cannot be washed away. There is a problem in that the droplets adhere to the pigment coating layer and cause defects in the coating film.

[Objective of the Invention] The present invention is a simple method that can remove organic stains on the substrate of an optical information recording medium generated by spin-coating the recording layer, etc., to the same extent as the conventional method. As described above, it is an object of the present invention to provide a method for manufacturing an optical information recording medium that can clean the substrate of the optical information recording medium.

[Summary of the Invention] The present invention provides a step of forming a recording layer by supplying and coating a recording layer forming coating liquid onto the surface of the substrate from above the substrate while rotating the disk-shaped substrate; A step of forming a reflective layer made of metal on the layer by vapor deposition, and while the substrate is being rotated, a coating liquid for forming a protective layer is supplied from above the substrate to be coated on the reflective layer, and at the same time, the recording is performed. A volatile material that can dissolve at least the material of the recording layer and the material of the protective layer at the processing temperature and does not cause the substrate material to dissolve or swell at the processing temperature is added to the surface of the back side of the substrate on the side where no layer is provided. The method (A) for manufacturing an optical information recording medium includes the step of forming a protective layer by supplying a liquid containing an organic solvent from below the substrate.

The present invention also provides a step of forming an undercoat layer by supplying and applying a coating solution for forming an undercoat layer onto the surface of the substrate from above the substrate while rotating the disc-shaped substrate; A step of forming a recording layer made of metal on the layer by vapor deposition, and while the substrate is being rotated, a coating liquid for forming a protective layer is supplied and applied from above the substrate onto the recording layer, and at the same time, the recording layer is coated on the recording layer. On the surface of the back side of the substrate on the side where no layer is provided, at least the material of the undercoat layer and the material of the protective layer can be dissolved at the processing temperature, and the substrate material does not dissolve or swell at the processing temperature. There is also a method (B) for manufacturing an optical information recording medium that includes a step of forming a protective layer by supplying a liquid containing a volatile organic solvent from below the substrate.

Preferred embodiments of the method for manufacturing the optical information recording medium of the present invention are as follows.

1) The above-mentioned method for producing an optical information recording medium, wherein the organic solvent is a liquid having a boiling point of 50 to 150°C.

2) The solution containing the organic solvent consists only of a volatile organic solvent, and the organic solvent is supplied at a position on the substrate in a range on the outer circumferential side of a circle with a radius of 1/2 of the radius of the substrate. The method for manufacturing an optical information recording medium as described above, characterized in that the method is carried out within a company.

3) The optical information as described above, wherein the liquid containing the organic solvent contains a functional layer forming material, and the solution is supplied at a position on the substrate near the rotation center of the substrate. A method for manufacturing a recording medium.

4) The method for producing an optical information recording medium according to 4) above, wherein the functional layer forming material is a protective layer forming material, an antireflection layer forming material, or an antistatic layer forming material.

5) The above method (A) for producing an optical information recording medium, wherein the recording layer material of the coating liquid for forming a recording layer is a dye that can be recorded by laser irradiation.

Note that the above vapor deposition means vacuum vapor deposition, sputtering, or ion blating.

Furthermore, dissolving the materials forming the recording layer, undercoat layer, or protective layer means that 0.01 part by weight or more of any of the above materials is dissolved in 100 parts by weight of the organic solvent used at 25°C. means.

Furthermore, not dissolving the material forming the substrate means that the substrate material is 0.0% per 100 parts by weight of the organic solvent used at 25°C.
This means that less than 0.01 parts by weight is dissolved. By non-swelling of the substrate is meant that at 25° C., 100 parts by weight of the substrate material absorbs less than 0.1 part by weight of the organic solvent used.

[Detailed Description of the Invention] The optical information recording medium obtained by the manufacturing method of the present invention has a coated recording layer, a reflective layer and a coated protective layer on a substrate, or a coated undercoat layer, a metal coated layer on a substrate, etc. It has a basic configuration in which a recording layer and a coated protective layer are laminated in this order. The back surface and outer side wall of the substrate, on which the recording layer and the like are not provided, are extremely clean and are characterized by the fact that there is no adhesion of organic matter such as recording layer material.

The material of the substrate can be arbitrarily selected from various materials. In terms of substrate optical properties, flatness, workability, handling, stability over time, and manufacturing costs, examples of substrate materials include glass; acrylic resins such as polymethyl methacrylate; and polyvinyl chloride and vinyl chloride. Examples include vinyl chloride resins such as polymers; epoxy resins; polycarbonate resins, amorphous polyolefins, and polyesters. Preferably, mention may be made of polycarbonate, polyolefin and polymethyl methacrylate.

A pre-pit layer and/or a pre-groove layer are provided on the substrate, in which tracking grooves or fine irregularities representing information such as address signals are formed. As the material for the pre-pit layer and/or the pre-groove layer, a mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester, and tetraester and a photopolymerization initiator can be used. .

To form a pre-pit layer and/or a pre-groove layer, first, a mixed solution consisting of the above acrylic ester and a polymerization initiator is applied onto a precisely made matrix (stambar),
Furthermore, after placing a substrate on this coating liquid layer, the liquid layer is cured by irradiation with ultraviolet rays through the substrate or the matrix, thereby fixing the substrate and the liquid phase. Next, by peeling the substrate from the mother mold, a substrate provided with a pre-pit layer and/or a pre-groove layer is obtained. The thickness of the pre-pit layer and/or pre-groove layer is generally in the range of 0.05 to 100 μm, preferably in the range of 0.1 to 50 μm.

When the substrate material is plastic, pre-pits and/or pre-grooves may be provided directly on the substrate by injection molding, extrusion molding, or the like.

The film formed on the substrate surface as described above includes a recording layer containing a dye that allows information to be written with laser light, improving recording performance, improving playback signal quality, improving flatness, and improving adhesive strength. For the purpose of improving the solvent resistance of the substrate and preventing deterioration of the recording layer, examples thereof include an undercoat layer provided between the substrate and the recording layer, and a protective layer provided on the recording layer. The back surface and the outer peripheral side surface of the substrate of the optical information recording medium obtained by the manufacturing method of the present invention, on which the recording layer etc. are not provided, are covered with the recording layer material formed by the above coating, the undercoat layer material, the protective layer material, etc. Layer material etc. are not attached.

Examples of film-forming materials for the undercoat layer include polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, styrene/maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene/sulfonic acid copolymer, and styrene.・Vinyl toluene copolymer, chlorosulfonated 1 2 polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate/vinyl chloride copolymer, ethylene/vinyl acetate copolymer, polyethylene, polypropylene, Polymer substances such as polycarbonate; organic substances such as silane coupling agents; and inorganic oxides (S i O2, Afi203
etc.), inorganic substances such as inorganic 7y-ride (MgF2),
Examples include coating liquids prepared by dissolving or dispersing them in a suitable solvent. The thickness of the undercoat layer is generally 0.005 to 2
It is in the range of 0 μm, preferably in the range of 0.01 to 10 μm.

As the film-forming material for the recording layer, there may be mentioned a coating liquid prepared by dissolving the above-mentioned dyes in a solvent together with a binder if desired. In addition to dyes, examples include polymeric materials whose phase can be changed by light, and metals (used as a dispersion liquid) which can form bits and the like by light. The above-mentioned dye is not particularly limited, and any dye may be used as long as it is used in manufacturing optical discs. For example, cyanine dyes, phthalocyanine dyes, biryllium/thiopyrylium dyes, azulenium dyes, squarylium dyes, metal complex dyes with Ni, Cr, etc., naphthoquinone/anthraquinone dyes, indophenol dyes, and indoaniline. Examples include triphenylmethane dyes, triallylmethane dyes, aluminum/diimmonium dyes, and nitroso compounds. Preferable examples include cyanine dyes, azulenium dyes, and squarylium dyes.

Among these, semiconductor lasers that emit near-infrared light have been put into practical use as recording and reproducing lasers.
A dye having a high absorption rate for light in the near-infrared region of 700 to 900 nm is preferable.

Note that these dyes may be used alone or as a mixture of two or more. Further, when a cyanine dye is used, it is preferable to use the metal complex dye or the aminium/diimmonium dye as a quencher. In that case, a metal complex dye or the like is used as a quencher in an amount of 0.001 to 0.00% per mole part of the total dye.
It is preferable to contain 1 mole part.

Examples of the solvent for preparing the dye coating solution include esters such as ethyl acetate, butyl acetate, and cellosolve acetate, ketones such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone, halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, and chloroform; Ethers such as tetrahydrofuran, ethyl ether, dioxane, alcohols such as ethanol, n-propanol, isopropanol, and n-butanol, amides such as dimethylformamide, fluorocarbon solvents such as 2.2.3.3, tetrafluoropropanol, etc. etc. can be mentioned. Note that these non-hydrocarbon organic solvents may contain hydrocarbon solvents such as aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, and aromatic hydrocarbon solvents, as long as the amount is within 50% by volume. .

The coating solution also contains antioxidants, UV absorbers, plasticizers,
Various additives such as lubricants may be added depending on the purpose.

When a binder is used, examples of the binder include cellulose derivatives such as gelatin, nitrocellulose, and cellulose acetate; natural organic polymeric substances such as dextran, rosin, and rubber; and carbonized materials such as polyethylene, polypropylene, polystyrene, and polyisobutylene. Hydrogen resins, vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride/polyvinyl acetate copolymers, acrylic resins such as polymethyl acrylate, polymethyl methacrylate,
Examples include synthetic organic polymeric substances such as polyvinyl alcohol, chlorinated polyolefins, epoxy resins, butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol/formaldehyde resins.

When a binder is used as a material for the recording layer, the ratio of dye to binder is generally 0.01 to 99% (weight ratio).
It is preferably in the range of 1.0 to 95% (weight ratio).

5 6 When an undercoat layer is provided on the above substrate by coating using a spin code method, the coating liquid for the undercoat layer will adhere to the back surface of the substrate, etc., as in the case where a recording layer is provided by coating. This deposit remains even after a metal vapor deposition layer is provided as a recording layer. Therefore, even in such cases, the process of cleaning at the same time as applying the protective layer of the present invention is extremely useful.

The material of the recording layer formed by vapor deposition is Te%S.
Low melting point metal compounds such as e, In, Pb%Bi; Ag%A
u, Al1, TIL, Cu, Ga1Sb, Sn, Ti%
Fe, co, Ni, Mn.

Examples include metals with high surface tension such as Nb, Pd, and Zn. In addition, metal compounds such as metal sulfides, metal fluorides, and metal oxides may be contained.

The metal recording layer can be formed on the undercoat layer by, for example, vapor deposition, sputtering, or ion-blating the metal. The layer thickness is generally preferably in the range of 300 to 2000λ.

In addition, in the manufacturing method of the present invention, on the recording layer provided by coating, when cleaning the back side of the substrate at the time of forming the protective layer,
A reflective layer is provided to prevent the recording layer from causing coating defects due to scattering cleaning fluid.

The metal recording layer also plays the same role as this reflective layer. By providing a reflective layer, it is possible to obtain the effect of improving reflectance, improving S/N during information reproduction, and improving sensitivity during recording.

Materials for the reflective layer include Au, Al, 1st base, and Cu%.
In, Sb, Te% Ge, Se, Bi.

Sn, Ti, Fe, Co, Ni, Mo, Ta.

Examples include metals such as PT, semimetals, and alloys thereof.

The reflective layer can be formed on the recording layer by, for example, vapor deposition, sputtering, or ion-blating the above-mentioned light-reflective material.

The thickness of the reflective layer is generally preferably in the range of 100 to 3000X.

A protective layer is provided on the metal recording layer or the reflective layer by coating.

Examples of the film-forming material for the protective layer include coating liquids prepared by dissolving organic substances such as thermoplastic resins, thermosetting resins, and UV curable resins in appropriate solvents. Particularly preferred is one containing a UV curable resin, and in the case of a UV curable resin, it may be used as is. As UV curable resins, urethane (meth)acrylate, epoxy (meth)
Oligomers of (meth)acrylate such as acrylate and polyester (meth)acrylate, monomers such as (meth)acrylic acid ester, etc. Furthermore, ordinary UV curable resins such as photopolymerization initiators can be used. Various additives such as antistatic agents, antioxidants, and UV absorbers may be further added to these coating liquids depending on the purpose.

The thickness of the protective layer is generally in the range of 0.1 to 100 μm.

The protective layer or antireflection layer may be applied by coating to the back surface on which the recording layer is not provided.

Further, on the protective layer, SiO, 5j02, SiN4
, MgF2. A protective layer made of an inorganic material such as SnO2 may be provided.

Next, a method for manufacturing an optical information recording medium according to the present invention will be explained in detail with reference to the accompanying drawings.

In the present invention, coating is carried out by supplying a coating liquid for forming an undercoat layer or a coating liquid for forming a recording layer such as a dye onto the surface of the disk-shaped substrate from above the substrate while rotating the substrate. Next, on the layer formed by such coating, a metal vapor deposition layer (a metal recording layer on the undercoat layer and a reflective layer on the recording layer of dye, etc.) is formed, and the layer formed by the above coating is formed. protect At the time of forming the protective layer, a liquid containing an organic solvent is simultaneously supplied to the back surface of the substrate from below the substrate,
When the coating liquid for forming an undercoat layer or the coating liquid for forming a recording layer is applied, the coating forming material that has adhered to the back side or the like is cleaned. Note that, of course, the undercoat layer may be provided below the dye recording layer.

Although any device can be used to rotate the substrate at high speed and supply various coating liquids or 90 organic solvents, a spin cord method generally used for thin film coating can be conveniently used.

When applying an organic solvent from below while coating a recording layer coating liquid or a protective layer coating liquid from above the substrate, for example, as shown in Fig. It's good to have an exit.

Figure 1-A, Figure 1-B, Figure 1-0, Figure 1-0, and Figure 1-E show the state of each step for explaining one embodiment of the manufacturing method of the present invention. FIG.

In FIG. 1-A, the substrate 11 is placed on the spindle 6 of the spinner.
The recording layer forming dye coating liquid is sprayed from the liquid material supply pipe 7 above the substrate while rotating the inserted substrate. The coating method shown in FIG. 1-A is the same as the conventional spin code method.

In FIG. 1-B, as shown in FIG. 1-A, a dye coating liquid for forming a recording layer is applied onto the surface of a substrate 11 having a hole 13 in the center by a spin code method. The state in which the recording layer 12 consisting of the following is formed is shown. Also shown is a dye layer forming material 12a such as a dye or a polymer in the dye coating liquid that turned around and adhered to the substrate when the dye coating liquid was applied by the spin code method.

FIG. 1-0 shows a state in which a reflective layer 14 made of metal is formed by a conventional method on a recording layer 12 provided on the surface of a substrate 11 having a hole 13 in the center. The reflective layer is formed by sputtering or the like with metal, but since the areas near the inner and outer edges are generally masked and sputtered, metal will not adhere there.

In FIG. 1-D, the substrate 11 on which the recording layer 12 and the reflective layer 14 are formed is inserted into the spindle 16 of a spinner, and while the inserted substrate is rotated, it is protected from the liquid material supply pipe 17 above the substrate. Coating liquid for layer formation is sprayed,
A state in which an organic solvent is being sprayed from the lower liquid material supply pipe 18 is shown.

In order to apply the coating liquid for forming a protective layer on the reflective layer 14 of the substrate 11 to form a film, first, while rotating the substrate 11 as described above with a spinner, the protective layer is removed from the liquid material supply pipe 17 above the substrate. The coating liquid for layer formation is supplied onto the reflective layer 14 by spraying. The coating liquid for forming a protective layer supplied onto the reflective layer 14 is spread over the entire surface of the reflective layer 14 by the centrifugal force and gravity caused by the rotation of the substrate 11, and a coating film having a uniform thickness is formed. Liquid material supply pipe 17 above the substrate
When spraying the coating liquid for forming a protective layer from the substrate, at the same time, an organic solvent is sprayed from the liquid material supply pipe 18 below the substrate onto the back surface of the substrate where the reflective layer 14 is not provided. The organic solvent supplied to the back side of the substrate spreads to the outer circumferential side and the outer circumferential side wall of the back side of the substrate due to the centrifugal force caused by the rotation of the substrate 11, and is transferred to the back side of the substrate and the dye attached by the back side during the formation of the recording layer. All of the coating liquid for forming the protective layer can be removed by washing. The organic solvent needs to be a volatile organic solvent that can dissolve the recording layer material and the protective layer material at the processing temperature and does not dissolve or swell the substrate material at the processing temperature. The coating liquid for the protective layer is, for example, UV
Since curable resins often have a relatively high viscosity and are difficult to cause backing, the organic solvent used for cleaning does not have to have such a large dissolving power that it stiffens the material forming the protective layer. Further, the position on the substrate of the liquid material supply pipe 18 through which the organic solvent is sprayed is not particularly limited, but as shown in the figure, it may be installed on the outer circumferential side of a circle with a radius of 1/2 of the radius of the substrate. When you are there,
Particularly, the outer peripheral portion is preferably cleaned because it is efficiently cleaned.

The protective layer is formed by removing the solvent from the coating film by drying after the coating film has a predetermined thickness.

By controlling the concentration, viscosity and amount of the coating solution of the forming material such as the coating solution for forming the protective layer mentioned above and the coating solution for forming the recording layer, the rotation speed of the substrate, temperature, humidity, etc. These conditions can be easily set by those skilled in the art using the conventionally known spin-coding technique.

Since cleaning and coating by the spin code method are generally carried out at room temperature and pressure, the organic solvent used is 50%
Preferably it is a liquid with a boiling point of ~150°C.

The specific substance of the organic solvent mentioned above can dissolve the target dye and resin, and the material of the substrate used (mainly resin)
It can be appropriately selected so as not to dissolve or swell. For example, if the substrate material is polycarbonate, methanol, ethanol, impropatol,
Alcohols such as n-butanol, 2.2.3, 3.
- From among fluorine-containing alcohols such as tetrafluoro-1-propatol, diketo alcohols such as diacetone alcohol, aliphatic hydrocarbons, and mixtures thereof, the above-mentioned dye, the above-mentioned protective layer material, as described below. It is selected in consideration of the solubility of the undercoat layer material. The organic solvent is preferably filtered and purified using a microfilter before use.

Instead of the organic solvent used for the cleaning, the cleaning and the coating of the functional layer may be performed simultaneously by using a coating liquid containing the organic solvent and a functional layer forming material and spraying as described above. It is possible. At this time, it is necessary to supply the coating liquid near the center of rotation of the substrate. Examples of the functional layer forming material include a protective layer forming material, an antireflection layer forming material, and an antistatic layer forming material.

FIG. 1-E shows a cross-sectional view of the optical disc obtained as described above. The optical disc includes a recording layer 12 formed on the surface of a substrate 11 having a hole 13 in the center;
It consists of a reflective layer 14 formed on the recording layer, and a protective layer 15 coated on the reflective layer while cleaning the back side of the substrate by the method of the present invention described above. Although some dye remained near the outer periphery of the substrate on the side where the recording layer was provided, on which no reflective layer was formed, this was mainly removed by applying the coating liquid for forming a protective layer and centrifugal force.

In this way, optical information can be recorded using a simple method to the same extent or higher than conventional methods, without increasing the process of cleaning organic dirt on the substrate of an optical information recording medium, which is generated by coating the recording layer using the spin code method. Dirt on the substrate of the medium can be cleaned.

In addition, before forming the reflective layer, other layers such as an undercoat layer may be provided in addition to the dye recording layer, and all deposits may be removed at once by cleaning when forming the protective layer. is also possible.

2-A and 2-B are cross-sectional views for explaining another embodiment of the manufacturing method of the present invention.

Another embodiment of the above-mentioned optical disc includes a structure in which an undercoat layer, a metal recording layer, and a protective layer are laminated in this order on a substrate.

1-A-E shows an example in which a dye recording layer, a reflective layer, and a protective layer are sequentially laminated on a substrate, but in the above embodiment, a polymer compound formed by coating on a substrate is shown. An undercoat layer consisting of a metal recording layer formed by vapor deposition, and a protective layer are laminated in this order. However, there is no essential difference in the manufacturing method, except that the coating layer on the substrate has been changed from a dye layer to an undercoat layer, and the metal layer on the coating layer has been changed from a reflective layer to a recording layer.

In FIG. 2-A, a substrate 21 on which an undercoat layer 22 is coated by the above-mentioned spin code method and a recording layer 24 made of metal is formed by vapor deposition thereon is inserted into a spindle 26 of a spinner. , while the inserted substrate is being rotated, a protective layer forming coating liquid is being sprayed from the liquid material supply pipe 27 above the substrate, and an organic solvent is being sprayed from the liquid material supply pipe 28 below. . The undercoat layer is formed on the surface of the substrate by applying a coating liquid of a polymer compound for forming the undercoat layer using a spin code method, so that the undercoat layer forming material 22a (polymer compound) is applied to the back side of the substrate. It is attached backwards.

As the organic solvent sprayed from the lower liquid material supply pipe 28, care must be taken to select an organic solvent that easily dissolves the polymer compound instead of the dye, but in general, the same organic solvent may be used. many.

FIG. 2-B shows a cross-sectional view of the optical disc obtained as described above. The optical disc includes an undercoat layer 21 formed on the surface of a substrate 21 having a hole 23 in the center, a recording layer 24 made of metal formed on the undercoat layer, and the above-mentioned book on the recording layer. It consists of a protective layer 25 that is applied while cleaning the back surface of the substrate by the method of the invention.

In this way, the optical information recording medium having the above-mentioned structure can be easily used without increasing the step of cleaning the substrate of the optical information recording medium from dirt such as polymer compounds generated by spin-coating of the undercoat layer. Dirt on the substrate of the medium can be cleaned.

[Effects of the Invention] The method for producing an optical information recording medium of the present invention includes first forming a coating type layer such as a coating type recording layer such as a dye or a coating type undercoat layer such as a polymer compound on a substrate. A reflective layer or a recording layer made of a metal is formed thereon by vapor deposition, sputtering, etc. to form a layer insoluble in organic solvents to protect the area of the coating layer on the substrate surface necessary for recording and reproduction. When applying the protective layer forming material using the spin code method, at the same time, an organic solvent is sprayed from the back side of the substrate to clean the dye or polymerized metal that has adhered to the back side or side surface of the substrate, and at the same time, to clean the substrate of the protective layer forming material. While also preventing the back of the
The above protective layer is formed. This makes it possible to clean organic stains adhering to the back side of the substrate, etc., at the time of forming the protective layer, which has conventionally been done as a separate process.

Therefore, the present invention provides a simple method for cleaning organic stains on the substrate of an optical information recording medium generated by spin-coating the recording layer, etc., to the same degree or more than the conventional method. The substrate of the information recording medium can be cleaned.

Examples and comparative examples of the present invention are described below. However, each of these aspects does not limit the invention.

[Example 1] A dye having the following structural formula: was dissolved in 2,2,3°3-tetrafluoropropanol to a concentration of 2.75% by weight to prepare a coating liquid for forming a dye recording layer.

Length: 0.8 μm, Width: 0.4 μm, Depth: 800 Disc-shaped polycarbonate substrate (outer diameter: 120 mm, inner diameter : 15mm, thickness: 1.2
mm) on the spinner at a rotation speed of 1000 r, p.
While rotating at a speed of , m, the above coating liquid was spin-coated by spraying from above the substrate to form a recording layer with a layer thickness of 1000.

A reflective layer having a thickness of 1300 mm was formed on the recording layer by sputtering Au.

At that time, a circle with a radius of 20 mm and a radius of 118 m on the board.
This was done by masking the area other than the area surrounded by the circle of m.

In the manner shown in FIG. 1-D, the substrate having the obtained recording layer and reflective layer was attached to a spinner in a spin coater house with an internal temperature of 25° C., and the number of revolutions was 1000 r, p, m.
While rotating at a speed of
25°C), manufactured by Three Bond ■) from the liquid material supply pipe 17 at a liquid delivery rate of 1 cc/sec, while spraying it onto the reflective layer.
Isopropyl alcohol was sprayed upward from the bottom of the substrate from the liquid material supply pipe 18 at a rate of 2 cc/sec onto the back surface of the substrate for cleaning. The coating liquid was sprayed for 5 seconds, the supply of both liquid materials was stopped, and the rotation was maintained for 10 seconds to dry the coating layer. Next, the coating layer was irradiated with ultraviolet rays (for 10 seconds using a 200 w/cm mercury lamp) to form a protective layer with a layer thickness of 2 μm.

In this way, an optical information recording medium consisting of a recording layer made of a dye, a reflective layer, and a protective layer on a substrate was manufactured.

[Example 2] Quantity Chlorinated polyethylene 0.2 parts Methyl ethyl ketone 10 parts 1 2 Cyclohexane 100 parts Length: 0.8 μm, width: 0.4 μm, depth = 800λ bit tracks: 1.6 μm in longitudinal direction A disc-shaped polycarbonate substrate with pre-pits lined up (
Outer diameter: 120mm, inner diameter: 15mm, thickness: 1.2
mm) on the spinner at a rotation speed of 1000 r, p.
While rotating at a speed of , m, the coating liquid for forming an undercoat layer was sprayed from above the substrate by spin-coding to form an undercoat layer with a thickness of 300 layers.

On top of the above undercoat layer, 40% of In and GeS are each applied.
Weight%: co-deposited at a ratio of 60% by weight, with a layer thickness of 1
A recording layer with 300 layers was formed.

At that time, a circle with a radius of 20 mm and a radius of 118 m on the board.
This was done by masking the area other than the area surrounded by the circle of m.

In the manner shown in FIG. 2-A, the substrate having the obtained undercoat layer and recording layer was mounted on a spinner in a spin coater house with an internal temperature of 25° C. at a rotation speed of 1000 r, p, m,
While rotating at a speed of
While spraying isopropyl alcohol upward from below the substrate at a rate of 2 cc/sec from the liquid material supply pipe 28 while spraying a liquid (manufactured by Three Bond ■) from the liquid material supply pipe 27 at a rate of 1 cc/sec onto the reflective layer. Cleaning was performed by spraying onto the back surface of the substrate at a liquid delivery rate. The spraying of the coating liquid was maintained for 5 seconds, the supply of both liquid materials was stopped, and the rotation was maintained for 10 seconds to dry the coating layer. Next, the coating layer was irradiated with ultraviolet light (100 W/cm mercury lamp).
A protective layer with a layer thickness of 2 μm was formed by applying the following steps.

In this way, an optical information recording medium was produced, which consisted of an undercoat layer made of a polymer compound, a metal recording layer, and a protective layer on a substrate.

As a result of visually observing the appearance of the optical information recording media obtained in Example 1 and Example 2 above, it was found that there was no dye adhesion or high density on the back side of the substrate, the outer peripheral side wall surface, the outer peripheral side edge, and near the outer peripheral edge on the front side of the substrate. No attachment of molecular compounds was observed. Furthermore, information could be recorded and reproduced without any errors.

[Brief explanation of drawings]

FIG. 1-A is a cross-sectional view showing a state in which film formation is performed by a conventional spin code method; FIG. 1-B is a cross-sectional view of an optical disk in the process of being manufactured in an embodiment according to the manufacturing method of the present invention; FIG. 1-C is a cross-sectional view of an optical disk in the process of being manufactured in an embodiment according to the manufacturing method of the present invention, and FIG. FIG. 1-E is a cross-sectional view of an optical disc obtained by an embodiment according to the manufacturing method of the present invention. Figure 2-A is a sectional view showing a state in which film formation and cleaning are performed by the spin code method of another embodiment according to the manufacturing method of the present invention, and Figure 2-B is a cross-sectional view according to the manufacturing method of the present invention. FIG. 3 is a cross-sectional view of an optical disc obtained according to another example. 5 11.21: Substrate 12: (dye) recording layer 22: Undercoat layer 13.23: Hole 14: Reflective layer
24: (metal) recording layer 15. 25: protective layer 6. 16. 26: spindle 7. 17. 27: (upper) liquid material supply pipe 18. 28:
(Lower) Liquid material supply pipe 12a: Dye layer forming material 22a: Undercoat layer forming material

Claims (1)

[Claims] 1. A step of forming a recording layer by supplying and coating a coating liquid for forming a recording layer onto the surface of the substrate from above the disk-shaped substrate while rotating the substrate, the recording layer. A step of forming a reflective layer made of metal on top of the substrate by vapor deposition, and while the substrate is being rotated, a coating liquid for forming a protective layer is supplied from above the substrate and applied thereon, and at the same time, the recording layer is coated on the reflective layer. A volatile material that can dissolve at least the material of the recording layer and the material of the protective layer at the processing temperature and does not cause the substrate material to dissolve or swell at the processing temperature is added to the surface of the back side of the substrate on the side where the material is not provided. A method for manufacturing an optical information recording medium, comprising a step of forming a protective layer by supplying a liquid containing an organic solvent from below the substrate. 2. A step of forming an undercoat layer by supplying and applying a coating solution for forming an undercoat layer onto the surface of the substrate from above the substrate while rotating the disc-shaped substrate, and applying metal on the undercoat layer. a step of forming a recording layer by vapor deposition, and while the substrate is being rotated, a coating liquid for forming a protective layer is supplied and applied from above the substrate onto the recording layer, and at the same time the recording layer is provided. A volatile organic solvent that can dissolve at least the material of the undercoat layer and the material of the protective layer at the processing temperature and does not dissolve or swell the substrate material at the processing temperature. 1. A method for manufacturing an optical information recording medium, comprising the step of forming a protective layer by supplying a liquid containing: from below the substrate.