JP2515513B2 - Method for producing optical organic recording medium - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an optical organic recording medium such as an optical disk and an optical card having an organic recording layer.

[Prior Art] Conventionally, an optical organic recording medium used in an optical disk or optical card technology is formed by providing a recording layer containing an organic dye as a main component on a transparent substrate such as glass or plastics.
It is used as a recording medium for scanning information with high density by scanning focused laser light on the surface of the recording layer and forming pits only on the surface irradiated with the laser light. The recorded information is read by scanning a weak laser beam and detecting optical changes such as reflectance and transmittance of a portion where pits are formed and a portion where pits are not formed.

As a method for forming the recording layer on the above-mentioned optical organic recording medium, there are, for example, a sputtering method, a vacuum vapor deposition method or a coating method, among which the coating method is productivity, cost,
It is advantageous in terms of yield and the like.

Spin coating, dipping method, roll coating,
There are methods such as bar coating, blade coating, spray coating, letterpress printing, offset printing, gravure printing, intaglio printing, screen printing and tampo printing.

However, for example, when the substrate is dipped in the coating liquid by the dip coating method and then pulled up at a constant speed for coating, all the dipped portions are coated with the coating liquid. On the other hand, in recording / reproduction of an optical organic recording medium, since a laser beam is generally applied to a recording layer through a transparent substrate, a recording layer having absorptivity for the laser beam is attached to the back surface side of the recording layer surface of the substrate. This is not preferable because the light absorption efficiency of the recording layer at the time of recording is reduced and the intensity of the reproduction reflected light is uneven or the reproduction signal intensity is decreased during reproduction.

Further, particularly when the optical organic recording medium is an optical disk, it is usually provided on the substrate as a guide groove for laser beam scanning in a groove form having a width of about 0.5 to 2 μm. Since the spiral groove and the center hole of the disk must be in a state of good eccentricity, it is not preferable to apply the recording layer to the end surface of the center hole.

On the other hand, in order to expose the substrate of the portion other than the recording layer of the optical organic recording medium, in the coating step, that portion may not be immersed in the coating liquid or may not be brought into contact with the coating liquid. It is not easy to use any of the above application methods.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional techniques, and a substrate on which a recording layer is formed by applying a coating liquid is bonded and mounted. The optical organic recording medium is manufactured by a very simple process of removing unnecessary portions of the recording layer exposed on the surface of the medium by continuously performing the step of wiping after the step of applying. It is to provide a method that can.

[Means for Solving Problems] and [Operation] That is, the first invention of the present invention is a method for manufacturing an optical recording body having an organic recording layer, wherein each of the first substrate and the second substrate is used. A coating step of applying a coating liquid to at least one surface of the recording layer to form a recording layer, and the first substrate and the second substrate on which the recording layer is formed need an adhesive so that the recording layer surfaces face each other. In the method of manufacturing an optical organic recording medium, a mounting step for adhering and then a wiping step for wiping off unnecessary portions of the recording layer exposed on the surface of the medium are continuously performed.

The second invention is a method for producing an optical recording medium having an organic recording layer, in which a coating liquid is applied to at least one surface of the first substrate to form a recording layer, and the recording layer is formed. And a mounting step of adhering the second substrate with an adhesive so as to face the required recording layer surface of the first substrate, and then a wiping step of wiping off unnecessary portions of the recording layer exposed on the medium surface and applied. It is a method for producing an optical organic recording medium, which is characterized in that it is continuously performed.

Further, the third invention is a method for producing an optical recording medium having an organic recording layer, in which a coating liquid is applied to at least one surface of the substrate to form a recording layer, and a substrate having the recording layer is formed. An optical system characterized by continuously performing a mounting step of providing a protective layer on the surface of a required recording layer to conceal it, and then a wiping step of wiping off unnecessary portions of the recording layer exposed on the medium surface and applied. It is a method of manufacturing an organic recording medium.

 Hereinafter, the present invention will be described in detail.

The method for producing an optical organic recording medium having an organic recording layer according to the present invention includes a coating step of forming a recording layer by a solvent coating method in which a coating liquid is applied to at least one surface of a substrate, that is, both surfaces or one surface of the substrate, A step of laminating the first substrate having the recording layer formed thereon and the second substrate having the recording layer formed by the same means, or another substrate so that the recording layer surfaces facing each other, or on the recording layer A mounting step consisting of a step of providing a protective film on the surface of the medium to conceal it, and then a wiping step of removing the unnecessary portion of the recording layer exposed on the surface of the medium by rubbing a flexible member by wiping. It is characterized by carrying out.

In the coating step for forming the recording layer of the optical organic recording medium produced by the method of the present invention, the coating liquid applied to the substrate requires a dye compound and a solvent which have an absorption maximum in the vicinity of the wavelength of the recording laser light, and others. It is composed of a binder, a dispersant and the like.

The dye compound needs to be appropriately selected depending on the wavelength of the laser light used, and examples thereof include cyanine, merocyanine, triphenylmethane, naphthoquinone, xanthene, squarylium, azulene, methine and pyrylium, and azo and stilbene. , Phthalocyanine direct dye, azo, anthraquinone, triphenylmethane, xanthene, asine acid dye, cyanine, azo, asine, triphenylmethane, azulene,
Methine, pyrylium-based basic dye, azo, anthraquinone, xanthene, triphenylmethane mordant, acid mordant dye, anthraquinone, indigoid vat dye, azo, anthraquinone, phthalocyanine, triphenylmethane oil-soluble dye, A sulfur dye, a dithiol-based metal complex, etc. may be used alone or in combination of two or more, as appropriate.

Next, the solvent used in the present invention is preferably an organic solvent, and it is generally methanol, ethanol, isopropanol, diacetone alcohol, methyl, although it varies depending on whether the dye compound is in a dispersed state or in a dissolved state. Alcohols such as cellosolve, ketones such as acetone, methyl ethyl ketone and cyclohexanone, amides such as N, N-dimethylformamide and N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, etc. Ethers, esters such as methyl acetate, ethyl acetate and butyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, dichloroethylene, carbon tetrachloride and trichloroethylene Kind, benzene, toluene,
Aromatic compounds such as xylene, monochlorobenzene and dichlorobenzene, and aliphatic hydrocarbons such as n-hexane and ligroin can be used.

Further, in the present invention, a binder may be mixed as necessary in consideration of film-forming property and coating film stability.

Suitable binders can be selected from a wide range of resins. Specifically, nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose myristate, cellulose palmitate, cellulose acetate / propionate, cellulose acetate such as cellulose acetate / butyrate, methyl cellulose, Cellulose ethers such as ethyl cellulose, propyl cellulose, butyl cellulose, polystyrene, polyvinyl chloride, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyvinyl resins such as polyvinylpyrrolidone, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, Copolymer resins such as styrene-butadiene-acrylonitrile copolymer and vinyl chloride-vinyl acetate copolymer Acrylic resins such as polymethylmethacrylate, polymethylacrylate, polybutylacrylate, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyacrylonitrile, polyesters such as polyethylene terephthalate, poly (4,4'-isopropylidenediphenylene- Co-1,4-0 cyclohexylene dimethylene carbonate), poly (ethylenedioxy-3,3'-phenylene thiocarbonate), poly (4,4'-isopropylidene diphenylene carbonate-co-terephthalate), poly ( Polyarylates such as 4,4'-isopropylidenediphenylene carbonate), poly (4,4'-sec-butylidene diphenylene carbonate), poly (4,4'-isopropylidenediphenylene carbonate-block-oxyethylene) Resins , Or polyamides, polyimides, polyurethanes, epoxy resins, phenol resins, polyethylene, polypropylene, chlorinated polyethylene, polyolefins such as polybutene and polyisobutylene, elastomers such as natural rubber, isoprene rubber, chloroprene rubber, etc. Can be used.

In addition, natural waxes other than resins, such as whale wax, beeswax, lanolin, carnauba wax, candelilla wax, montan wax, ceresin wax, petroleum waxes such as paraffin wax and microcrystalline wax, oxidation waxes, ester waxes, etc. Synthetic waxes such as Fischer-Tropsch wax, higher resin acids such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, higher alcohols such as stearyl alcohol and behenyl alcohol, fatty acid esters of sucrose, fatty acid esters of sorbitan sugar esters And amides such as oleylamide can be appropriately mixed.

Plasticizer such as dioctyl phthalate, dibutyl phthalate, tricresyl phosphate in the above binder,
An oil agent such as mineral oil or vegetable oil, a dispersant such as sodium alkylene sulfonate, and polyoxyethylene alkylphenyl ether, and other additives may be appropriately mixed to enhance the film-forming property and coating film stability of the recording layer. it can. Further, in order to improve the stability and / or the adhesiveness of the coating film, a protective layer and an undercoat layer may be provided as a recording layer above and below the layer containing the dye compound.

As the substrate used in the present invention, a conventionally known film or plate-shaped substrate can be used, and for example, glass, metal, ceramics, paper and polymethylmethacrylate, polycarbonate, synthetic resin such as polyethylene terephthalate are suitable. Can be used for Further, a support material or the like which has not been used as a substrate in the past can be used.

In the coating step in the present invention, as a method for applying the coating liquid to the substrate, a usual method can be used without particular limitation, and specific examples thereof include a dipping method, spin coating, roll coating, Coating methods such as bar code, blade coating, spray coating, letterpress printing, offset printing, gravure printing, intaglio printing, screen printing and tampo printing can be used.

Next, in the mounting process, the first substrate on which the recording layer is formed by the above-mentioned coating process and the second substrate on which the recording layer is formed by the same means are required so that the recording layer surfaces face each other. Or a method of adhering another second substrate having no recording layer facing the recording layer surface of the first substrate on which the recording layer is formed with an adhesive, or a recording layer is formed. A medium is formed by a method of providing a protective layer on the required recording layer surface of the formed substrate and concealing and protecting it.

As the adhesive, generally used thermoplastic adhesives, thermosetting adhesives, rubber adhesives, pressure-sensitive adhesives, hot-melt adhesives, as long as they do not damage the recording layer.
Any adhesive such as a Shimano acrylate adhesive, an emulsion adhesive, an ultraviolet curable adhesive, a natural product adhesive, and a heat resistant adhesive can be used.

Next, in the wiping step, the unnecessary portion of the recording layer that is exposed and applied to the surface of the medium formed in the above mounting step is wiped and removed. As a wiping method, a flexible wiping member is recorded. This can be performed by bringing the unnecessary portion of the layer into contact with a predetermined pressure, and rotating or moving the substrate or the wiping member to rub it. In this case, if the wiping member is impregnated with a solvent, the solvent dissolves the recording layer,
The cleaning effect can be increased due to washing.

The flexible wiping member, polyethylene, polypropylene, polyolefin resin such as polytetrafluoroethylene, polyester resin, polyamide resin, epoxy resin, polyurethane resin, polyacrylic resin, polyvinyl chloride resin, Elastomers such as polystyrene-based resin, phenol-based resin, natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, and silicone rubber can be used.

In the present invention, it is preferable to continuously perform the coating step of forming the recording layer on at least one surface of the substrate, the mounting step of attaching the substrate, and the wiping step of wiping unnecessary portions of the recording layer. By performing continuously, the recording layer formed on the substrate is wiped before being dried or cured, so that unnecessary portions of the recording layer can be completely removed.

[Examples] The present invention will be described more specifically below based on examples shown in the drawings.

FIG. 1 shows an embodiment of the present invention, and FIG.
(C) is an explanatory view showing an example of each coating process, FIG. 2 (a)
3A to 3D are cross-sectional views showing an example of the mounting process, and FIGS. 3A to 3C are explanatory views showing an example of the wiping process.

In the method for producing an optical organic recording medium of the present invention, first, in the coating step, as a coating method, the substrate 2 is dipped in the coating liquid 1 as shown in FIG. In the dipping method for forming the substrate 2, as shown in FIG. 1 (b), the substrate 2 is rotated and the coating liquid 1 is caused to flow out from the nozzle so as to be applied in the vicinity of the center.
The coating solution 1 applied to the substrate is spun by centrifugal force to make the thickness uniform, and as shown in FIG. 1 (c), the coating solution 1 is applied between the fan roller and the transfer roller. To the composition roller, the coating amount is adjusted, and the composition is transferred to the composition roller. The substrate 2 is provided between the composition roller and the impression roller positioned below the composition roller and serving as a pressing member.
The recording layer 3 by roll coating or the like to form a coating film.
To form.

Next, in a mounting process, the substrates are attached to each other or a protective layer is provided to shield the required recording element surface of the recording layer from the outside.

 A cross-sectional view of an example of the mounting process is shown in FIG.

FIG. 2 (a) shows an adhesive layer formed by interposing a spacer 4 between two substrates 2 and 2'on which a recording layer 3 is formed in a coating process so that their required recording layer surfaces 3a face each other inside. An example in which they are bonded to each other by 5 to form a central structure is shown.
With this configuration, the recording layer 3 is shielded from the outside air without impairing the sensitivity, and can be protected from dust adhesion, scratch generation, contact with harmful gas, etc., so that the storage stability is improved. Furthermore, it can record on both sides and is highly practical.

2B shows an example in which the substrate 2 on which the recording layer 3 is formed in the coating step and the substrate 2a on which the recording layer is not formed are formed in a hollow structure as in FIG. 2A.

FIG. 2C shows an example in which the adhesive layer 5 is further formed on the substrate 2 on which the recording layer 3 is formed and another substrate or the film 2a is attached. This structure is highly practical because it is easy to manufacture and has improved storage stability.

FIG. 2D shows an example in which the protective layer 6 is further formed on the substrate 2 on which the recording layer 3 is formed. This structure is also shown in FIG. 2 (c).
Similarly to the above, there is an advantage that the practicability is high because the production is simple and the storage stability is improved.

The spacer 4 may be made of any material that can keep the distance between the two substrates parallel and constant, such as resin, metal,
All of ceramics and glass can be used.

Further, the protective layer 6 can be formed by applying a resin to obtain an optical organic recording medium for single-sided recording / reproduction.

Next, since the optical recording medium obtained as described above is exposed on the medium surface and the recording layer is still applied, the process proceeds to the wiping step to remove the unnecessary recording film.

The wiping process is shown in FIGS. 3 (a) to (c). In the figure, reference numeral 7 denotes a flexible wiping member, which is brought into contact with an unnecessary portion 9 of the recording layer exposed on the medium surface by a holding portion with a constant pressure to rotate or move the medium or rotate the wiping member 9. Alternatively, if it is moved, the unnecessary portion 9 of the recording layer can be removed over the entire surface of the medium.

FIG. 3A shows an example in which the unnecessary portion 9 of the recording layer is on the surface of the medium.

FIG. 3B shows an example in which the unnecessary portion 9 of the recording layer is located on the end face of the inner and / or outer periphery of the medium.

This method is particularly easy to remove the edges of the coating, and the apparatus can also be simple in structure.

In addition, when the wiping member 7 is rubbed with the solvent that dissolves the coating film, the solvent also has the effect of washing the coating film, so that unnecessary portions of the recording layer can be removed cleanly. As a method of rubbing with the solvent, there is a method of dropping the solvent on the rubbing portion or a method of rubbing in the solvent. An example is shown in FIG. 3 (c).

Put the solvent 8 in the container up to the height to be removed,
The medium may be soaked in this and the medium may be rotated while the wiping member 7 is in contact therewith.

The method of removing the coating film by rubbing a flexible member like the wiping step of the present invention is more effective than the method of scraping the coating film with a brush or a brush, and is not scattered and is removed cleanly without scratches on the medium. can do.

[Effects of the Invention] As described above, according to the present invention, a coating step of coating a recording layer on a substrate, and then a mounting step of mounting the substrate,
Furthermore, by continuously performing the wiping step of wiping the unnecessary portion of the recording layer, it is possible to provide a method for manufacturing an optical organic recording medium capable of easily removing the unnecessary portion of the recording layer.

Furthermore, the present invention is an excellent manufacturing method suitable for automation of the manufacturing apparatus.

[Brief description of drawings]

1 (a) to 1 (c) are explanatory views showing an example of a coating process, FIGS. 2 (a) to 2 (d) are sectional views showing an example of a mounting process, and FIGS. 3 (a) to 3 (a). c) is an explanatory diagram showing an example of a wiping step. 1 coating liquid 2,2 ', 2a substrate 3 recording layer 3a required recording layer surface 4 spacer 5 adhesive layer 6 protective layer 7 wiping member 8 … Solvent 9 …… Unnecessary part of recording layer

Claims (4)

(57) [Claims] 1. A method of manufacturing an optical recording medium having an organic recording layer, wherein a coating liquid is applied to at least one surface of each of a first substrate and a second substrate to form a recording layer, A mounting step of adhering the first substrate having the recording layer formed thereon and the second substrate with an adhesive so that the recording layer surfaces facing each other, and then the recording layer exposed and applied to the medium surface. A method for manufacturing an optical organic recording medium, which comprises continuously performing a wiping step of wiping an unnecessary portion. 2. A method of manufacturing an optical recording medium having an organic recording layer, the coating step of coating a coating liquid on at least one surface of a first substrate to form a recording layer; The mounting process of adhering the second substrate with an adhesive so as to face the required recording layer surface of one substrate, and then the wiping process of wiping off unnecessary portions of the recording layer exposed on the medium surface and applied continuously A method of manufacturing an optical organic recording medium, which is characterized in that 3. The method for producing an optical organic recording medium according to claim 2, wherein the second substrate has no recording layer. 4. A method of manufacturing an optical recording medium having an organic recording layer, which comprises a step of applying a coating liquid to at least one surface of the substrate to form a recording layer, and the necessity of the substrate having the recording layer formed thereon. The optical organic recording is characterized in that the mounting step of providing a protective layer on the surface of the recording layer and hiding it, and the wiping step of wiping off unnecessary portions of the recording layer exposed on the surface of the medium are successively performed. Medium manufacturing method.