JP2665264B2 - Continuous manufacturing method of substrate for optical recording medium - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method for continuously manufacturing a substrate for an optical information recording medium suitable for optical writing and recording using a laser or the like.

[Conventional technology]

An optical information recording medium such as an optical disk or an optical card records information at a high density by forming microscopic pits of several μm, which can be detected optically, on a thin recording layer provided on a base in a track shape. be able to. In such an optical information recording medium, when recording and reproducing information, it is necessary to scan a laser beam along a track. Therefore, a substrate having a guide groove for tracking is generally used.

The method of manufacturing the guide groove or the substrate with the guide groove is a compression molding method in which the softened plastic material is pressed with a stamper and then solidified, or the plastic material melted in a mold provided with the stamper Injection molding method to inject and solidify
The 2P (Photo Polymerization) method of transferring guide grooves from a stamper using an ultraviolet curable resin (Photo Polymer) is known. However, the 2P method is difficult in terms of transferability of guide grooves and solvent resistance of substrates. Is the best.
That the solvent resistance of the substrate is excellent is particularly advantageous when an organic material is used as a recording material and a recording layer is formed by coating.In this case, general plastic substrates such as acrylic and polycarbonate are used. Since it is possible to use a solvent that cannot be used because it erodes the substrate, it is possible to greatly expand the range of selection of the recording material. In addition, the 2P method has a great advantage that the capital investment is very small compared to other methods.

However, the 2P method has a problem that the manufacturing time per substrate is longer than other methods, and it is not suitable for mass production. Therefore, for example, as disclosed in Japanese Patent Application No. 62-506504, using a stamper having an uneven pattern formed thereon, and transferring the uneven pattern of the stamper to a film substrate, thereby forming a film-shaped optical information recording medium. Techniques for continuously producing a medium have been proposed. Here, for example, after applying an ultraviolet curable resin to a roll-shaped stamper on which a concavo-convex pattern is formed, superimposing the film on a film substrate, irradiating ultraviolet rays to cure the ultraviolet curable resin,
A technique has been proposed in which a film substrate and an ultraviolet curable resin cured thereon are peeled off from a stamper.

This technique will be described with reference to FIG. As shown in FIG. 2A, the substrate 1 sent out from the feed roller 2 is conveyed along the circumference of a roll-shaped stamper 10 having guide grooves and irregularities formed according to information. Nip roller 9
Has a function of pressing the substrate 1 against the surface of the roll-shaped stamper. A resin tank containing a resin liquid 6 that is cured by irradiation with ultraviolet light is provided below the roll-shaped stamper. An application roller 7 that rotates while being pressed against the roll-shaped stamper 10 is provided in the resin tank, and the resin liquid 6 is applied to the surface of the roll-shaped stamper 10 by the application roller 7. The resin liquid 6 applied in this manner is applied to the substrate 1 and the roll-shaped stamper 10 by a nip roller 9.
Is filled in between. An ultraviolet lamp 11 is provided above the roll-shaped stamper 10, and irradiates the resin liquid 6 filled between the substrate 1 and the roll-shaped stamper 10 with ultraviolet rays to cure the resin liquid 6. The delivery roller 12 has a function of peeling off the substrate 1 and the layer of the ultraviolet curable resin 6 which is cured while being fixed to the substrate 1 from the roll-shaped stamper 10. Thus, the concavo-convex pattern of the optical disk is transferred onto the substrate.
FIG. 2b shows the roll stamper viewed from the ultraviolet lamp 11 side (upper side).

[Problems to be solved by the invention]

However, while such an operation is repeated, the ultraviolet curable resin 6 has fluidity before curing, although the width of the ultraviolet curable resin application roller 7 is smaller than the width of the substrate 1. The resin 6 which has protruded from the end of the roll-shaped stamper 10 is hardened and accumulated by the light irradiation on the portion A on the roll-shaped stamper 10 and the transfer remains, so that it is necessary to frequently replace and clean the stamper. . Alternatively, the resin which has hardened by protruding from the end of the substrate 1 is in close contact with the stamper 10 and tends to be chipped from the end of the substrate, and the burr B having a pointed shape is often present at the end of the substrate.
When the substrate with the guide groove is released from the roll-shaped stamper 10, these chipped burrs adhere as dust to the substrate 1, which has been peeled and charged, which is one of the causes of defects in the recording medium and recording errors.

The present invention has been made in view of the above problems, its purpose is to use a roll-shaped stamper, when continuously forming a substrate with a guide groove of an ultraviolet curable resin, significantly reduce the cleaning and replacement of the roll-shaped stamper, Another object of the present invention is to provide a method for continuously manufacturing a substrate for an optical recording medium, which can prevent dust from adhering to the substrate surface due to the generation of burrs.

[Means for solving the problem]

The present invention uses a roll-shaped stamper having a guide groove and / or a fine concavo-convex pattern corresponding to information, and transfers and forms the concavo-convex pattern of the stamper on a sheet substrate by using an ultraviolet curable resin to form an optical recording medium. In the continuous manufacturing method, a step of applying a release agent to an outer edge portion of the sheet substrate, a step of applying an ultraviolet curing resin to the sheet substrate, and a step of closely attaching the sheet substrate coated with the resin to the roll-shaped stamper After that, a step of irradiating ultraviolet rays through the sheet substrate to cure the resin, and then a step of peeling the sheet substrate and the resin cured thereon from the roll-shaped stamper as a series of steps are performed. This is a method for continuously producing an optical recording medium.

Hereinafter, the present invention will be described in more detail. FIG. 1 conceptually shows an example of an apparatus for carrying out the manufacturing method of the present invention,
a is a front view and b is a plan view.

The substrate 1 is fed by a feed roller 2. The substrate 1 is not particularly limited as long as it is flexible, and for example, a plastic sheet such as polycarbonate, acrylic resin, polyolefin resin, polyester resin, and epoxy resin can be suitably used. Note that a primer layer may be formed on the surface of the substrate 1 in order to increase the adhesion to the ultraviolet curing resin 6.

As shown in FIG. 1B, the ultraviolet curable resin 6 is not adhered by the two application rollers 3 to the outer edges of both ends of the sheet substrate, on which the guide groove is not formed by the ultraviolet curable resin, of the substrate 1 sent out from the feed roller 2. An oil-based release agent 4 is applied. Next, the release layer 4 is formed at the outer edges of both ends of the sheet substrate through the heat treatment device 5.

The thickness of the release layer 4 is preferably 10 μm or less, and more preferably 0.01 μm to 5 μm, because the thickness of the release layer 4 affects the thickness of the ultraviolet curable resin 6 adhered to the substrate 1. The release layer 4 may be made of any material having an oil-repellent effect, but is preferably made of a silicone resin or a fluorine-based resin.

Examples of the silicone resin include dimethyl silicone, methyl phenyl silicone, methyl hydrogen silicone, polydiorganosiloxane diol, chlorophenyl silicone, fluorosilicone, silicone polyether copolymer, alkyl-modified silicone, higher fatty acid-modified silicone, amino-modified silicone, epoxy All compounds such as silicone oils such as modified silicones, resins and cross-linked products can be used, or mixtures thereof can also be used.

As the fluorine-based resin, polytetrafluoroethylene, ethylene tetrafluoride-propylene hexafluoride copolymer, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer,
Resins containing fluoroolefins in the base skeleton, such as ethylene tetrafluoride-ethylene copolymer, poly (ethylene trifluoride), polyvinylidene fluoride, polyvinyl fluoride, and ethylene trifluoride-ethylene copolymer, or mixtures thereof. All can be used.

Next, the resin liquid 6 is applied by an application roller 7 disposed in a resin tank containing the resin liquid 6 which is cured by ultraviolet irradiation.
Is applied to the center of the surface of the sheet substrate 1. It is preferable to apply the resin liquid after adjusting the thickness uniformly with a plate 8. Next, the space between the substrate 1 and the roll-shaped stamper 10 is filled by the nip roller 9. Since the outer edge portion of the substrate 1 has oil repellency by the release treatment, the protrusion of the ultraviolet curable resin 6 is suppressed. The coating thickness is preferably from 0.1 μm to 50 μm, and is adjusted so as to reduce air bubbles.

As the ultraviolet curing resin 6, a prepolymer, oligomer, or monomer having an unsaturated bond in a molecule can be used. For example, unsaturated polyesters, epoxy acrylate, urethane acrylate, acrylates such as polyether acrylate, epoxy methacrylate, urethane methacrylate, polyether methacrylate,
Methacrylates such as polyester methacrylate
A kind or two or more kinds, and a photopolymerizable monomer having an unsaturated bond in a molecule such as dicyclopentenyl acrylate;
A mixture of polyfunctional monomers such as 1,3-butanediol acrylate, polyethylene glycol diacrylate and pentaerythritol triacrylate can be used, and further, as a polymerization initiator, halogenated acetophenones, benzophenone, benzoin, benzoin ether A radical generating compound such as Michler's ketone, benzyl, benzyldimethyl ketal, tetramethylthiuram monosulfide, thioxanthone, or the like may be used as long as it is easily peeled from the stamper in a cured state and has good matching with the recording layer. The application of the ultraviolet curable resin 6 to the substrate 1 is not particularly limited, and a dispenser nozzle or other known ink supply method used in printing can be used instead of the application roller 7.

The surface of the roll-shaped stamper 10 is formed with guide grooves and irregularities corresponding to information, and the substrate 1 coated with the ultraviolet curable resin 6 is conveyed along the circumference of the roll-shaped stamper 10. The diameter of the roll-shaped stamper 10 varies depending on the thickness and the material of the substrate 1, but is preferably 300 mm or more in consideration of, for example, a 1.2 mm thick polycarbonate optical disk. 0.4
150mm diameter even for an optical card made of mm thick polycarbonate
The above is preferred.

Such a roll-shaped stamper is a method of bonding a flat stamper having a thickness of 0.1 mm to 0.3 mm along the roll surface with an adhesive, or a method of mechanically fixing with a screw or the like, or a method of directly imprinting irregularities on a roll. And the like.

The substrate 1 having passed through the nip roller 9 is irradiated with an ultraviolet lamp 11 provided above a roll-shaped stamper 10.
The resin liquid 6 is cured by irradiating ultraviolet rays over the entire width of the resin liquid filled between the resin liquid and the roll-shaped stamper 10. The delivery roller 12 has a function of peeling off the substrate 1 and the layer of the ultraviolet curing resin 6 which is cured while being fixed to the substrate 1 from the roll-shaped stamper 10.

In this way, the concavo-convex pattern corresponding to the information on the optical disk is transferred onto the substrate, and the substrate for the optical information recording medium can be manufactured continuously. If necessary, a step of irradiating ultraviolet rays after peeling may be provided. The feed speed of the sheet substrate 1 is preferably in the range of 0.05 m / min to 5 m / min. At a speed of 0.05 m / min or less, productivity is not improved, and at a speed of 5 m / min or more, air bubbles are easily mixed.

Further, if necessary, the ultraviolet curable resin 6 may be supplied to the roll-shaped stamper by a coating roller 7 'which rotates while being pressed against the surface near the center of the roll-shaped stamper 10.

〔Example〕

Example 1 After forming a photoresist film (commercial surface: AZ1300, manufactured by Hoechst) with a thickness of 1000 mm on a glass master, exposure and development were performed using a laser cutting device to form a concavo-convex pattern. Next, a Ni thin film was formed on the formed concavo-convex pattern by sputtering to make the surface conductive, and then a Ni body having a thickness of 0.1 mm was applied by electroforming. Next, the glass master was peeled off to obtain a Ni flat stamper for a 3.5-inch optical disk having a spiral uneven pattern with a groove width of 0.6 μm, a pitch of 1.6 μm, and a groove depth of 900 °.

The obtained Ni flat stamper was coated with an epoxy-based adhesive (trade name: EP-170, manufactured by Cemedine Co., Ltd.) and had an outer diameter of 400 mm and a width of 1 mm.
A roll-shaped stamper having 12 pieces adhered in one row to the side of a 50 mm roller was prepared.

A polycarbonate sheet substrate with a thickness of 1.2 mm and a width of 130 mm was used as the substrate, and the sheet substrate was supplied at a speed of 2 m / min.
022, Toshiba Silicone) and a catalyst (YC6831, Toshiba Silicone) in isopropyl alcohol
The composition was thermally cured through a drying furnace (heat treatment apparatus) adjusted to a temperature of 0 ° C. to provide a release layer having a thickness of 0.2 μm.

25 mm of epoxy acrylate UV curable resin (MRA-5000, manufactured by Mitsubishi Rayon Co., Ltd.) with a width of 80 mm
After applying a μm coating, the roll-shaped stamper and the sheet substrate are brought into close contact with each other with a nip roll, and then the ultraviolet curable resin expanded to a width of 110 mm is irradiated with ultraviolet rays (4 KW high-pressure mercury lamp, 300 mW / cm ² ) over the entire width of the substrate. The cured resin was cured. Next, the sheet substrate and the ultraviolet-cured resin cured thereon are peeled off from the roll-shaped stamper, and the groove width is 0.6 μm.
m, a pitch of 1.6 μm, and a groove depth of 900 °, a sheet substrate having a flash-free uneven pattern was obtained. This operation was repeated to form a substrate for 1,000 disks, but no burrs on the outer edge of the substrate and no residual UV-curable resin in a roll-shaped stamper were generated.

Example 2 In the same manner as in Example 1, the groove width was 3 μm and the pitch was 12 μm.
m, an optical card Ni flat stamper with a stripe-shaped uneven pattern with a groove depth of 3000 mm was manufactured with an outer diameter of 200 mm and a width of 130 m.
A roll stamper was prepared by adhering 10 rollers in a row to the side surface of the m roller.

A polycarbonate sheet substrate with a thickness of 0.4 mm and a width of 120 mm is used as the substrate, and the sheet substrate is supplied at a speed of 2.5 m / min, and a solution type fluororesin (Lummicron LF300, manufactured by Asahi Glass Co., Ltd.) with a width of 10 mm at each outer edge of the substrate. And a solution of tolylene diisocyanate in ethanol and heat-treated at 80 ° C to achieve a film thickness of 0.
A release layer of 3 μm was provided.

Next, the same operation as in Example 1 was performed, and the groove width was 3 μm,
A sheet substrate having a pitch of 12 μm and a groove depth of 3000 ° and having a flash-free uneven pattern was obtained. Repeat this operation for the card
Although 1,000 substrates were formed, no burrs on the outer edge of the substrate and no residual ultraviolet-curable resin remained on the roll-shaped stamper.

Comparative Example A sheet substrate having a concavo-convex pattern was produced by performing the same operation as in Example 1 without providing a release layer at the end of the sheet substrate. Adjustment of the coating width, coating thickness and nip roll becomes very complicated to prevent the UV curable resin from protruding from the end face of the substrate, and burrs and transfer residue to the roll-shaped stamper occur immediately, and the roll-shaped stamper is replaced. Cleaning was required.

〔The invention's effect〕

According to the present invention, when continuously forming a substrate with a guide groove made of an ultraviolet-curable resin using a roll-shaped stamper, the application accuracy of the ultraviolet-curable resin is increased, and dust is prevented from adhering to the substrate surface by burrs due to protrusion. Replacement of the roll stamper can be significantly reduced.

[Brief description of the drawings]

FIG. 1 conceptually shows an apparatus for carrying out the present invention,
a is a front view thereof, and b is a plan view thereof. FIG. 2 is a conceptual view of an apparatus conventionally used for manufacturing an optical recording medium, in which a is a front view and b is a plan view. 1: Substrate, 2: Feeding roller 3: Release agent application roller 4: Release agent, 5: Heat treatment device 6: UV curable resin 7: UV curable resin application roller 8: Blade, 9: Nip roller 10: Roll shape Stamper 11: UV lamp 12: Delivery roller

Claims (3)

(57) [Claims] 1. Optical recording by using a roll-shaped stamper having a guide groove and / or a fine concavo-convex pattern corresponding to information, and transferring and forming the concavo-convex pattern of the stamper on a sheet substrate using an ultraviolet curing resin. In a method for continuously producing a medium, a step of applying a release agent to an outer edge portion of the sheet substrate, a step of applying an ultraviolet curing agent resin to the sheet substrate, a sheet substrate coated with the resin and the roll stamper, And then curing the resin by irradiating ultraviolet rays through the sheet substrate, and then removing the sheet substrate and the resin cured thereon from the roll-shaped stamper as a series of steps. A method for continuously manufacturing a substrate for an optical recording medium. 2. The method according to claim 1, wherein said release agent comprises a silicone resin. 3. The method according to claim 1, wherein said release agent comprises a fluororesin.