JP2670865B2 - Method and apparatus for continuously producing substrate for optical recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for continuously manufacturing a substrate for an optical recording medium suitable for optical writing and recording with a laser or the like.

2. Description of the Related Art Conventionally, in an optical information recording medium such as an optical disk or an optical card, minute pits of about several μm that can be optically detected are formed in a track shape on a thin recording layer provided on a base. Thereby, high-density recording of information can be performed.
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 provided with a guide groove for tracking is generally used.

As a method for producing such a guide groove or a substrate having a guide groove, 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) that transfers guide grooves from a stamper using the ld) method or an ultraviolet curable resin (Photo Polymer)
Although the n) method is known, the 2P method is the most excellent in terms of the transferability of the guide groove and the solvent resistance of the substrate.
The excellent solvent resistance of the substrate is particularly advantageous when a recording layer is formed by application using an organic material as a recording material. In this case, since a solvent that cannot be used can be used because it damages the substrate, it is possible to greatly extend 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, WO88 / 03311 (Japanese Patent Application No. 62-506504)
No.), a stamper having a concavo-convex pattern formed thereon is used to transfer the concavo-convex pattern of the stamper to a film base material to continuously form a film-like substrate for optical information recording media. Have been proposed. Specifically, for example, after applying an ultraviolet curable resin to a roll-shaped stamper on which a concavo-convex pattern has been formed, if necessary, overlap the film with a film base material provided with an anchor material layer, and irradiate ultraviolet light to cure the ultraviolet curable resin. A technique has been proposed in which a resin is cured, and then a film substrate and an ultraviolet curable resin cured thereon are separated from a stamper.

[Problems to be Solved by the Invention] However, when the ultraviolet curable resin and the base material are superposed by the above method, the contact between the resin-coated surface and the base material becomes the contact between the liquid surface and the solid surface. There was a problem that air bubbles were easily mixed.

Furthermore, the guide grooves of the roll-shaped stamper and the irregularities corresponding to the information require submicron accuracy, but it is not possible to eliminate the rotation unevenness of the DC motor that drives the roll-shaped stamper and the rotation unevenness due to the gear with higher accuracy. It wasn't that easy. This is due to the eccentricity of the recording medium,
It was one of the causes of defects and recording errors.

The present invention is made in view of the above problems,
An optical recording medium that uses a roll-shaped stamper that elastically deforms as a roll-shaped stamper to prevent air bubbles from being mixed into the ultraviolet curable resin and to improve the follow-up between the roll-shaped stamper and the sheet substrate to improve the eralate rate. It is an object of the present invention to provide a method and an apparatus for continuously manufacturing a substrate for manufacturing with high productivity.

[Means for Solving the Problem] That is, the present invention uses a roll-shaped stamper having a guide groove and / or a fine concave-convex pattern corresponding to information, and the concave-convex pattern of the stamper is coated with an ultraviolet curable resin on a sheet substrate. In a method for continuously manufacturing a substrate for an optical recording medium by transferring and forming by using a roll-shaped stamper that elastically deforms, an uneven pattern of the stamper is transferred onto a sheet substrate. It is a continuous manufacturing method of a substrate for a recording medium.

Further, according to the present invention, a roll-shaped stamper having a guide groove and / or a fine uneven pattern corresponding to information is used, and the uneven pattern of the stamper is optically transferred onto a sheet substrate by using an ultraviolet curable resin to optically form. An apparatus for continuously producing a substrate for a recording medium, wherein the roll stamper is composed of a roll stamper that is elastically deformed.

 Hereinafter, the present invention will be described in detail.

The present invention enhances the contact between the sheet substrate and the roll-shaped stamper by using an elastically deformable roll-shaped stamper as the roll-shaped stamper, and prevents air bubbles from being mixed into the ultraviolet curable resin sandwiched therebetween. Is made easy. Further, the medium error can be easily reduced by improving the followability of the sheet substrate against the irregular rotation of the roll stamper and the electric power.

FIG. 1 is a structural diagram showing an example of an apparatus used in the method for continuously producing a substrate for an optical recording medium of the present invention. In FIG. 1, the sheet substrate 1 is configured to be fed out by the feeding roller 2. The sheet substrate 1 is not limited as long as it is flexible, and for example, a plastic sheet such as polycarbonate, acrylic resin, polyolefin resin, polyester resin, or epoxy resin can be preferably used. Note that a primer layer may be formed on the surface of the sheet substrate 1 in order to enhance the adhesion with the ultraviolet curable resin 5.

A guide groove and irregularities corresponding to information are formed on the surface of the roll stamper 3, and the sheet substrate 1 sent from the feeding roller 2 is conveyed along the circumference of the roll stamper 3. Although the diameter of the roll stamper 3 varies depending on the thickness and material of the sheet substrate 1, for example, φ300 mm or more is preferable in consideration of an optical disk using 1.2 mm thick polycarbonate. Also, φ150 mm or more is preferable even when considering a 0.4 mm thick polycarbonate optical card.

Such a roll stamper 3 is, as shown in FIG.
An elastic roll is formed by providing an elastomer 5 such as polyurethane, natural rubber, isoprene rubber, chloroprene rubber, or silicone rubber on the outer peripheral surface of the metal core 4, and further has a thickness of 0.1 to 0.3 mm on the outer peripheral surface of the elastic roll. The Ni flat plate stamper 6 can be prepared by a method of adhering the Ni flat plate stamper 6 along the roll surface with an adhesive or the like, or a method of mechanically fixing it with a screw or the like.

FIG. 2 is a structural diagram showing another apparatus used in the continuous method for producing a substrate for an optical recording medium of the present invention. In FIG. 2, the roll-shaped stamper 3 has a metallic core 4 and an elastic resin stamper 7 such as a silicone resin or a fluororesin bonded around the metallic core 4 along the outer peripheral surface of the roll or directly on the roll. It can be produced by solidification molding.

The nip roller 8 transfers the sheet substrate 1 to the roll stamper 3
Has the function of pressing against the surface of. Below the roll stamper 3, a resin tank 10 containing a liquid ultraviolet curable resin 9 which is cured by ultraviolet irradiation is arranged. In the resin tank 10, a liquid ultraviolet curable resin 9 is applied by a coating roller 11 which rotates while being pressed against the surface of the roll stamper 3.
Is applied to the surface of the roll stamper 3. The resin liquid thus applied is adjusted to have a uniform thickness by the blade 12 and then filled between the sheet substrate 1 and the roll stamper 3 by the nip roller 8. The coating thickness is 0.
Adjust so that bubbles do not get mixed between 1 μm and 50 μm.

As the ultraviolet curable resin 9, a prepolymer, an oligomer, a monomer or the like having an unsaturated bond in the 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. Photopolymerizable monomers having a bond, for example, a mixture of functional monomers such as dicyclopentenyl acrylate, 1,3-butanediol acrylate, polyethylene glycol diacrylate, and pentaerythritol triacrylate, and halogenated acetophenones as a polymerization initiator , Benzophenone, benzoin, benzoin ether, Michler's ketone, benzyl, benzyl dimethyl ketal, tetramethyl thiuram mono A radical-generating compound such as sulfide or thioxanthone is used, and it is sufficient if it can be easily peeled from the stamper in the cured state and has good matching with the recording layer. The application of the liquid UV-curable resin 9 to the roll-shaped stamper 3 is not particularly limited, and may be performed by using a dispenser nozzle or other known coating methods used in printing instead of the application roller 11. It can be selected according to the coating film thickness. Further, the ultraviolet curable resin 9 may be directly applied to the sheet substrate by the application roll 11 '.

The ultraviolet light is applied to the sheet substrate 1 passing through the nip roller 8 by an ultraviolet lamp 13 provided above the roll stamper 3 over the entire width of the ultraviolet curing resin liquid filled between the sheet substrate 1 and the roll stamper 3. Is irradiated to cure the ultraviolet curable resin 9. The delivery roller 14 has a function of separating the sheet substrate 1 and the layer of the ultraviolet curable resin 9 which is cured in a state of being fixed to the sheet substrate 1 from the roll stamper 3.

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 further irradiating with ultraviolet light may be provided after peeling off the layer of the ultraviolet curable resin 9.

Further, it is desirable that the feeding speed of the sheet substrate 1 is in the range of 0.05 to 5 m / min, preferably 0.05 to 2.5 m / min. 0.
If the speed is less than 05m / min, productivity cannot be increased, and 5m / mi
At a speed exceeding n, bubbles tend to be mixed.

[Example] 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 Ni flat plate stamper for a 3.5-inch optical disc having a spiral-shaped concavo-convex pattern of 1.6 μm and a groove depth of 900Å was obtained.

The resulting Ni flat plate stamper was wrapped around a stainless steel core roll with an outer diameter of 350 mm and a width of 150 mm with a 50 mm thick chloroprene rubber so that the outer diameter was 400 mm. : EP-17C, manufactured by Cemedine Co., Ltd.) were used to adhere 12 pieces in a row to form a roll stamper.

A 1.2 mm thick and 130 mm wide polycarbonate sheet substrate is used as the substrate, and an epoxy acrylate UV curable resin (MRA-5, manufactured by Mitsubishi Rayon Co., Ltd.) is used on the uneven surface of the roll stamper.
000) is applied to a thickness of 25 μm and the speed of the sheet substrate is 2.5 m / mi
n, the roll-shaped stamper and the sheet substrate are brought into close contact with each other by a nip roll, and then the spread ultraviolet curing resin is irradiated with ultraviolet rays (4 Kw high-pressure mercury lamp, 300 mW / cm ² ) over the entire surface of the substrate, The UV curable resin was cured.

Next, the sheet substrate and the ultraviolet curable resin cured thereon were peeled off from the roll stamper to obtain a sheet substrate having a concavo-convex pattern with a groove width of 0.6 μm, a pitch of 1.6 μm and a groove depth of 900Å. No defects due to air bubbles were observed in the substrate thus obtained, and the disk substrate was cut with a CO ₂ laser cutting machine after masking from this sheet substrate, and the error rate of the substrate was measured, The average value of 10 sheets was 5 × 10 ⁻⁶ .

Comparative Example 1 The same operation as in Example 1 was performed except that a Ni flat stamper was attached to the side surface of a stainless steel roll having an outer diameter of 400 mm with an epoxy-based adhesive as a roll-shaped stamper. A disk substrate having the above was obtained. In the thus obtained substrate, some defects due to bubbles were recognized, and the average value of 10 elalates was 6 × 10 ^−5.
Met.

Example 2 After forming a photoresist (trade name: AZ1300, manufactured by Hoechst) film having a film thickness of 3000 Å on a glass master, it was exposed using a laser cutting device and then developed to form an uneven pattern. Next, apply a silicone resin (product name: KE10, made by Shin-Etsu Silicone) 5 on the formed uneven pattern.
After coating at a thickness of 3 mm and curing at 60 ° C. for 3 hours, it was peeled off from the glass master to obtain a silicone resin stamper for optical cards having a stripe-shaped uneven pattern with a groove surface of 3 μm, a pitch of 12 μm and a groove depth of 3000 mm. It was made.

Attach this stamper to the side surface of a stainless steel core roll with an outer diameter of 200 mm and a width of 130 mm, using a silicone adhesive (trade name: KE4
1) made by Shin-Etsu Silicone)
A roll stamper was produced.

A polycarbonate sheet substrate having a thickness of 0.4 mm and a width of 120 mm was used as the substrate, and the sheet substrate was supplied at a speed of 3 m / min. The same operation as in Example 1 was performed to obtain a groove width of 3 μm, a pitch of 12 μm, and a groove depth of 3000 mm. An optical card substrate having a concavo-convex pattern was obtained. No defects due to air bubbles were observed in the thus obtained substrate, and the average error rate of 10 card substrates was 7 × 10 ⁻⁶ .

[Effects of the Invention] As described above, according to the present invention, by using a roll-shaped stamper that elastically deforms as the roll-shaped stamper, it is possible to prevent air bubbles from being mixed into the ultraviolet curable resin and to form a roll-shaped stamper. It is possible to continuously manufacture the substrate for an optical recording medium in which the followability of the sheet substrate is improved and the elalate is improved with high productivity.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing an example of an apparatus used in the method for continuously producing a substrate for an optical recording medium of the present invention, and FIG. 2 is a structural diagram showing another example of the apparatus of the present invention. DESCRIPTION OF SYMBOLS 1 ... Sheet board, 2 ... Feed roller 3 ... Roll stamper 4, ... Metal core 5 ... Elastomer, 6 ... Ni stamper 7 ... Elastic resin stamper 8 ... Nip roller 9 ... … UV curing resin, 10 …… Resin tank 11 …… Coating roller, 12 …… Blade 13 …… UV lamp, 14 …… Sending roller

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Osamu Kaname 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masataka Yashima 3-30-2 Shimomaruko, Ota-ku, Tokyo Ki Within Canon Inc. (56) Reference Japanese Patent Laid-Open No. 1-152044 (JP, A)

Claims (4)

(57) [Claims] 1. Optical recording by using a roll stamper having a guide groove and / or a fine concavo-convex pattern corresponding to information, and transferring the concavo-convex pattern of the stamper onto a sheet substrate using an ultraviolet curable resin. A method for continuously manufacturing a substrate for an optical recording medium, which comprises: using a roll-shaped stamper that elastically deforms and transferring the uneven pattern of the stamper onto a sheet substrate. 2. Optical recording by using a roll-shaped stamper having a guide groove and / or a fine concave-convex pattern corresponding to information, and transferring the concave-convex pattern of the stamper onto a sheet substrate using an ultraviolet curable resin. An apparatus for continuously producing a medium substrate, wherein the roller stamper is composed of a roll stamper that is elastically deformed. 3. An apparatus for continuously producing a substrate for an optical recording medium according to claim 2, wherein the elastically deformable roll-shaped stamper comprises a metal stamper formed on an elastic roll. 4. An apparatus for continuously manufacturing a substrate for an optical recording medium according to claim 2, wherein the elastically deformable roll-shaped stamper is formed by forming a resin stamper on a metal roll.