JP2533379B2 - Method and apparatus for continuously producing substrate for optical recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for continuously producing a substrate for an optical information recording medium suitable for optical writing / recording by a laser or the like, and an apparatus therefor.

[Prior Art] Conventionally, in an optical information recording medium such as an optical disk or an optical card, fine pits of about several μm that can be optically detected are formed in a track shape on a thin recording layer provided on a substrate. Thus, it is possible to record information at a high density.
In such an optical information recording medium, it is necessary to scan a laser beam along a track when recording and reproducing information, and therefore, a substrate having a guide groove for tracking is generally used.

Such a guide groove or a substrate with a guide groove is manufactured by compression molding (Compression Mol) in which a softened plastic material is pressed with a stamper and then solidified.
d) method, injection molding in which molten plastic material is injected and solidified in a mold equipped with a stamper (Injection Mo
2P (Photo Polymerizatio) in which the guide groove is transferred from the stamper using the ld) method or UV curable resin (Photo Polymer)
n) method etc. are known, but in terms of the transferability of the guide groove, the solvent resistance of the substrate and the optical distortion of the substrate can be reduced.
The 2P method is the best. The excellent solvent resistance of the substrate is particularly advantageous when an organic material is used as a recording material and a recording layer is formed by coating. In this case, acrylic, because it will attack the substrate,
Since a solvent that cannot be used for general plastic substrates such as polycarbonate can be used, it is possible to broaden the range of selection of recording materials. In addition, the 2P method has a great advantage that the capital investment is much smaller than other methods.

However, the 2P method has a problem that the manufacturing time per substrate is longer than that of other methods and is not suitable for mass production. Therefore, as disclosed in WO88 / 0311 Japanese Patent Application No. 62-506504, a master having a concavo-convex pattern is used, and the concavo-convex pattern of the master is transferred to a film substrate to form a film. A technique for continuously manufacturing a substrate for an optical information recording medium is proposed. Specifically, after applying the ultraviolet curable resin to the roll-shaped stamper having the concavo-convex pattern formed thereon, it is superposed on the film substrate and irradiated with ultraviolet rays to cure the ultraviolet curable resin,
Then, the film substrate and the ultraviolet curable resin cured thereon are separated from the stamper.

[Problems to be Solved by the Invention] However, in such a method, the following problems remain unsolved. Fig. 2 (a)
Is a structural view showing an apparatus used in a method for forming a guide groove in a substrate by the above conventional method, and FIG. 2 (b) is a partial explanatory view thereof. In FIG. 1, a sheet-like substrate 1 sent from a feed roller 2 is conveyed along the circumference of a roll-shaped stamper 3 on which guide grooves and irregularities corresponding to information are formed. The nip roller 4 has a function of pressing the substrate 1 against the surface of the roll-shaped stamper 3. Below the roll-shaped stamper 3, a resin tank 6 containing a liquid ultraviolet curing resin 5 which is cured by irradiation with ultraviolet light is provided. A coating roller 7 that rotates while being pressed against the roll stamper 3 is provided in the resin tank 6.
The liquid UV-curable resin 5 is rolled into a roll-shaped stamper 3
Applied to the surface of The ultraviolet curable resin 5 applied in this manner is filled between the substrate 1 and the roll-shaped stamper 3 by the nip roller 4. Roll stamper 3
Above the substrate, an ultraviolet lamp 10 is provided, which irradiates the ultraviolet curing resin 5 filled between the substrate 1 and the roll-shaped stamper 3 with ultraviolet rays to cure the ultraviolet curing resin 5. The delivery roller 11 has a function of separating the substrate 1 and the layer of the ultraviolet curable resin 5 which is cured while being fixed to the substrate 1 from the roll stamper 3. Thus, the concavo-convex pattern of the optical disk is transferred onto the substrate. FIG. 2B shows the roll stamper 3 as seen from the ultraviolet lamp 10 side (upper side).

However, during the repetition of such operations, even though the width of the coating roller 7 for the liquid ultraviolet curable resin 5 is made smaller than the width of the substrate 1, the ultraviolet curable resin 5 has a fluidity before curing. Therefore, it may be protruded from the end portion of the substrate 1, and the protruding ultraviolet curable resin 5
However, since the C portion of the roll-shaped stamper 3 is cured by light irradiation and accumulated, it is necessary to frequently replace the roll-shaped stamper 3 for cleaning. Alternatively, the ultraviolet curable resin 5 that sticks out from the end portion of the substrate 1 and is cured adheres to the roll stamper 3 and is more likely to be chipped than the resin at the end portion of the substrate.
It was not uncommon for sharp burrs to form on the edge of the substrate.
When the substrate with the guide groove was released from the roll stamper 3, these chipped burrs adhered as dust to the substrate 1 that was peeled off and charged, which was 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,
The purpose is to significantly reduce cleaning and replacement of the roll stamper when continuously molding a guide grooved substrate made of a UV curable resin using the roll stamper, and to easily remove the resin after transfer. An object of the present invention is to provide a continuous manufacturing method of an optical recording medium substrate and an apparatus thereof capable of preventing dust from adhering to the substrate surface due to burr generation.

[Means for Solving the Problems] That is, according to the present invention, an ultraviolet curable resin is applied to a roll stamper having a guide groove and / or a fine concavo-convex pattern corresponding to information, and then the roll stamper is applied with the ultraviolet curable resin. Contact the sheet-shaped substrate via the, and then irradiate ultraviolet rays to cure the ultraviolet curable resin, peel the cured ultraviolet curable resin from the roll stamper and transfer the uneven pattern of the stamper to the ultraviolet curable resin on the substrate In the continuous method for producing a substrate for an optical recording medium, a roll-shaped stamper provided with a release layer on a portion outside the effective area where a fine uneven pattern is provided is used to form the uneven pattern of the stamper on the substrate. It is a continuous manufacturing method of a substrate for an optical recording medium, which is characterized in that it is transferred to an ultraviolet curable resin.

Further, according to the present invention, a roll stamper having a guide groove and / or a fine concavo-convex pattern corresponding to information, and an ultraviolet curable resin applied to the roll stamper are brought into contact with a sheet-like substrate and irradiated with ultraviolet rays. Continuous production of a substrate for an optical recording medium provided with means for curing the ultraviolet curable resin and means for separating the cured ultraviolet curable resin from the roll stamper and transferring the uneven pattern of the stamper to the ultraviolet curable resin on the substrate. In the apparatus, a release layer is provided on a portion outside an effective area in which a fine uneven pattern of a roll stamper is provided, which is an apparatus for continuously manufacturing a substrate for an optical recording medium.

 Hereinafter, the present invention will be described in detail.

The present invention uses a roll stamper having a guide groove and / or a concave / convex pattern corresponding to information, and applies an ultraviolet curable resin on the concave / convex pattern of the roll stamper, and superimposes it on a sheet-shaped substrate for ultraviolet curing. After that, the cured ultraviolet curing resin is peeled from the roll stamper together with the substrate to transfer and form the uneven pattern on the substrate. It can be constituted by providing a release layer on the portion outside the region.

FIG. 1 (a) is a structural view showing an apparatus used in the continuous manufacturing method of an optical recording medium substrate of the present invention, and FIG. 1 (b) is a partial explanatory view of the apparatus, in which a roll stamper 3 is viewed from above. FIG. In the figure, the light-transmissive substrate 1 is configured to be fed by a feeding roller 2. The substrate 1 is not particularly limited as long as it is flexible. For example, a plastic sheet such as a polycarbonate, an acrylic resin, a polyolefin resin, a polyester resin, and an epoxy resin can be suitably used.
In addition, a primer layer may be formed on the surface of the substrate 1 in order to enhance the adhesion with the ultraviolet curing resin 5.

The surface of the roll-shaped stamper 3 is formed with guide grooves and irregularities corresponding to information. Although the diameter of the roll stamper 3 varies depending on the thickness and material of the substrate 1, for example, φ300 or more is preferable in consideration of an optical disk using 1.2 mm thick polycarbonate.
Such a roll stamper 3 is a method of adhering a flat plate stamper having a thickness of 0.1 to 0.3 mm along the roll surface with an adhesive,
Alternatively, it can be prepared by a method of mechanically fixing with a screw or the like or a method of directly engraving on the roll surface.

As shown in FIG. 1 (b), an uneven pattern corresponding to the information on the optical disc is engraved on the roll stamper 3. An oil-repellent release layer 9 to which the ultraviolet curable resin 5 does not adhere is provided in a portion A outside the effective area. Since the thickness of the release layer 9 affects the thickness of the ultraviolet curable resin 5 adhered to the substrate 1, it is 50 μm or less, preferably 0.01 to
10 μm is desirable. The release layer 9 may be made of any material that exhibits an oil repellency effect, but a silicone resin or a fluorine-based resin is preferably used.

Examples of the silicone resin include dimethyl silicone, methylphenyl silicone, methylhydrogen silicone, polydiorganosiloxane diol, chlorophenyl silicone, fluorosilicone, silicone polyether copolymer, alkyl modified silicone, higher fatty acid modified silicone, amino modified silicone, epoxy. Compounds such as silicone oils such as modified silicones, resins, and crosslinked products can all be used. Alternatively, any mixture thereof can be used.

Examples of the fluorine resin include polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, and polytrifluoroethylene. Resins containing fluoroolefins in the basic skeleton such as fluorinated ethylene chloride, polyvinylidene fluoride, polyvinyl fluoride, ethylene trifluoride chloride-ethylene copolymer, and mixtures thereof can all be used.

The nip roller 4 has a function of pressing the substrate 1 against the surface of the roll-shaped stamper 3. Below the roll-shaped stamper 3, there is provided a resin tank 6 containing a liquid ultraviolet curing resin 5 which is cured by ultraviolet irradiation. In the resin tank 6, a liquid ultraviolet curable resin 5 is applied to the surface of the roll stamper 3 by an application roller 7 that rotates while being pressed against the surface of the roll stamper 3. After the resin liquid applied in this manner is uniformly adjusted in thickness by the blade 8, the resin liquid is filled between the substrate 1 and the roll-shaped stamper 3 by the nip roller 4. The thickness of the coating is 0.1μm ~ 50μ
Adjust so as to reduce the mixing of bubbles between m.

As the ultraviolet curing resin 5, a prepolymer, oligomer, monomer, or the like having an unsaturated bond in a molecule can be used. For example, unsaturated polyesters, acrylates such as epoxy acrylate, urethane acrylate, and polyether acrylate, and one or more methacrylates such as epoxy methacrylate, urethane methacrylate, polyether methacrylate, and polyester methacrylate, which are unsaturated in the molecule. A mixture of a monomer having a bond or a functional compound, and radicals such as halogenated acetophenones, benzophenone, benzoin, benzoin ether, Michler's ketone, benzyl, benzyldimethylketal, tetramethylthiuram monosulfide, and thioxanthones as a polymerization initiator. It is sufficient if the generating compound is used, it can be easily peeled from the stamper in the cured state, and has good matching with the recording layer. In addition, in order to apply the liquid ultraviolet curable resin 5 to the roll stamper 3, instead of the application roller 7, a dispenser nozzle or other known ink supply method used in printing can be used.

The substrate 1 which has passed through the nip roller 4 is irradiated with ultraviolet rays by the ultraviolet lamp 10 provided above the roll stamper 3 over the entire width of the ultraviolet curable resin liquid filled between the substrate 1 and the roll stamper 3. And UV curable resin 5
Cure. The delivery roller 11 has a function of separating the substrate 1 and the layer of the ultraviolet curable resin 5 that is cured in a state of being fixed to the substrate 1 from the roll stamper 3.

FIG. 1 (c) shows a cross-sectional explanatory view taken along the line BB of FIG. 1 (a). On the roll stamper 3, the width of the portion (effective area) where the release layer 9 is not provided is made smaller than the width of the substrate 1 so that the ultraviolet curable resin 5 at the end portion of the substrate can be easily peeled off. Is preferred.

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. It should be noted that, if necessary, a step of irradiating with ultraviolet rays after peeling off the ultraviolet-curable resin 5 may be provided.

The feed speed of the sheet-like substrate 1 is 0.05 to 5 m / mi.
It is desirable that it is in the range of n, preferably 0.05 to 2.5 m / min. At a speed of less than 0.05 m / min, productivity cannot be increased, and at a speed of more than 5 m / min, air bubbles tend to be mixed.

Further, if necessary, after peeling, the roll-shaped stamper 3
A blade 12 or the like may be brought into contact with the upper release layer 9 to scrape off the ultraviolet curable resin 5 remaining without being transferred to the substrate 1.

Immediately after passing through the nip roller 4, the ultraviolet curing resin 5 before curing, which protrudes from the edge of the substrate, may be sucked and removed by a vacuum tube (not shown).

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 After forming a photoresist film (trade name, manufactured by AZ-1300 Hoechst Co.) with a thickness of 1000 mm on a glass master disk, exposure was performed using a laser cutting device, followed by development to form a concavo-convex pattern. Next, after a Ni thin film was formed on the formed concavo-convex pattern by sputtering to make the surface conductive, a Ni body having a thickness of 0.1 mm was applied by electroforming.
Then, peel off from the glass master, groove width 0.6μm, pitch
A 3.5-inch Ni flat plate stamper having a spiral-shaped concavo-convex pattern of 1.6 μm and a groove depth of 900Å was obtained.

Using an epoxy adhesive (trade name, EP-170, manufactured by Cemedine), the obtained Ni flat plate stamper was used to obtain an outer diameter of 400 mm.
Twelve rollers were bonded in a line to the side surface of a roller having a width of 150 mm to produce a roll stamper.

On both ends of this roll stamper, an isopropyl alcohol solution in which 97 parts by weight of solution type silicone (made by YSR 3022 Toshiba Silicone) and 3 parts by weight of catalyst (made by YC 6831 Toshiba Silicone) were dissolved was coated at 60 mm, After heat-curing for 10 minutes, a release layer having a thickness of 0.2 μm was provided.

A polycarbonate sheet substrate with a thickness of 1.2 mm and a width of 140 mm was used as the substrate, and an epoxy acrylate UV curable resin (MRA-5, manufactured by Mitsubishi Rayon) was used on the uneven surface of the roll-shaped stamper.
000) to a thickness of 25 μm and the sheet substrate at a speed of 2 m / min.
, The roll stamper and the sheet substrate are brought into close contact with each other by a nip roll, and then the UV curable resin that has been spread is spread over the entire surface of the substrate with ultraviolet light (4Kw high pressure mercury lamp, 3
It was irradiated with 00 mW / cm ² ) to cure the ultraviolet curable resin.

Next, the sheet substrate and the ultraviolet-curable resin cured thereon were peeled off from the roll-shaped stamper to obtain a sheet substrate having a groove width of 0.6 μm, a pitch of 1.6 μm, and a groove depth of 900 mm and having a flash-free uneven pattern. Repeat this operation to disc
Although 500 substrates were molded, no UV curable resin remained on the roll stamper.

Example 2 Instead of the silicone release layer of Example 1, a solution type fluororesin (Lumiflon LF3 with a width of 20 mm was provided on both ends of a roll stamper.
00 Asahi Glass) 70 parts by weight of tolylene diisocyanate
An ethanol solution in which 30 parts by weight was dissolved was applied and heat-cured at 80 ° C. for 3 hours to form a release layer having a film thickness of 0.2 μm.

Then, the same operation as in Example 1 is performed, 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 500 disks, but no UV curable resin remained on the roll stamper.

Comparative Example 1 The same operation as in Example 1 was performed without providing a release layer at the end of the roll-shaped stamper to obtain a sheet substrate having an uneven pattern. In order to prevent the UV curable resin from sticking out from the edge of the substrate, the adjustment of the coating width, coating thickness, and nip roll becomes very complicated, and burrs and transfer residue on the roll stamper immediately occur. Need to be replaced and washed.

[Effects of the Invention] As described above, according to the present invention, the roll-shaped stamper is used to guide the guide groove and / or the guide groove made of the ultraviolet curing resin.
Alternatively, when continuously molding a substrate having a fine uneven pattern corresponding to information, it is possible to remarkably reduce the replacement of the roll stamper and prevent dust from adhering to the substrate surface due to burrs.

[Brief description of drawings]

FIG. 1 (a) is a structural view showing an apparatus used in a continuous method for producing an optical recording medium substrate of the present invention, FIG. 1 (b) is a partial explanatory view thereof, and FIG. 1 (c) is a first drawing. FIG. 2A is a cross-sectional view taken along line BB, FIG. 2A is a structural view showing an apparatus used for forming a guide groove in a substrate by a conventional method, and FIG. 2B is a partial explanatory view thereof. is there. DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Feeding roller 3 ... Roll stamper, 4 ... Nip roller 5 ... UV curable resin, 6 ... Resin tank 7 ... Coating roller, 8, 12 ... Blade 9 ... Release layer, 10 ... UV lamp 11 ... Sending roller

Claims (5)

(57) [Claims] 1. A roll-shaped stamper having a guide groove and / or a fine uneven pattern corresponding to information is coated with a UV-curable resin, and the roll-shaped stamper is brought into contact with a sheet-shaped substrate through the UV-curable resin. Then, UV irradiation is applied to cure the UV curable resin, the cured UV curable resin is peeled from the roll stamper, and the uneven pattern of the stamper is transferred to the UV curable resin on the substrate. In the method, a roll-shaped stamper provided with a release layer on a portion outside the effective area where a fine uneven pattern is provided is used to transfer the uneven pattern of the stamper to the ultraviolet curable resin on the substrate. A method for continuously manufacturing a substrate for an optical recording medium. 2. A roll-shaped stamper having a guide groove and / or a fine concave-convex pattern corresponding to information, and an ultraviolet-curing resin applied to the roll-shaped stamper are brought into contact with a sheet-shaped substrate and irradiated with ultraviolet rays to emit ultraviolet rays. Continuous production apparatus for substrates for optical recording medium, including means for curing the curable resin and means for peeling the cured ultraviolet curable resin from the roll stamper and transferring the uneven pattern of the stamper to the ultraviolet curable resin on the substrate 2. A continuous manufacturing apparatus for a substrate for an optical recording medium, characterized in that a release layer is provided on a portion outside the effective region where the fine uneven pattern of the roll stamper is provided. 3. The optical element according to claim 2, wherein the distance between the release layers provided at both ends outside the effective area of the roll-shaped stamper without the release layer is smaller than the width of the sheet-shaped substrate. Device for continuous production of substrates for recording media. 4. The continuous production apparatus for an optical recording medium substrate according to claim 2, wherein the release layer is made of a silicone resin. 5. The release layer is made of a fluororesin.
An apparatus for continuously manufacturing a substrate for an optical information recording medium as described above.