JP2521216B2 - Roll stamper for molding information recording medium substrate sheet and apparatus for manufacturing information recording medium substrate using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a roll stamper used when continuously manufacturing a substrate for a high density information recording medium such as an optical disc or an optical card by transferring a concavo-convex preformat pattern on the surface and the roll stamper. The present invention relates to an apparatus for manufacturing an information recording medium substrate.

[0002]

2. Description of the Related Art A substrate for a high density optical information storage medium such as an optical disk and an optical card can be manufactured by injection molding, compression molding or extrusion molding.
By the way, in the injection molding or the compression molding, strict conditions are required for the temperature and pressure of the molten resin, the precision of the mold, etc. in order to prevent the flatness, smoothness, warpage and prevention of air bubbles from entering the substrate. In addition, the molding machine becomes large-scaled, the manufacturing cost is high, and it is difficult to manufacture a thin low birefringence substrate having a thickness of 0.4 mm or less like the substrate of the optical card by the injection molding. Further, since the compression molding is a single-wafer processing, the productivity is poor.

On the other hand, in extrusion molding using an extrusion molding machine, a roll stamper for forming a substrate for an information recording medium provided with a stamper is pressed against the surface of a sheet-shaped resin extruded by the extruder to pre-format. Since a pre-format pattern for giving a signal or a tracking signal can be formed on the substrate, the substrate is excellent in mass productivity, and research has recently been advanced as a method for molding a substrate for an information recording medium.

By the way, a roll stamper for molding a substrate for an information recording medium used in the above-mentioned extrusion molding is conventionally manufactured by the following method. (1) A method of directly forming a preformat pattern on the peripheral surface of a roll base material whose peripheral surface is polished to a mirror surface (hereinafter referred to as a mirror surface roll base material). (2) A method in which a flexible stamper having a pre-formatted pattern formed in advance on its surface is uniformly adhered to the peripheral surface of the mirror roll base material with an adhesive. (3) A method in which a flexible stamper having a pre-format pattern formed in advance on the surface is fixed to the peripheral surface of the mirror roll base material with screws.

However, among the above-mentioned conventional techniques for fixing a stamper, (1) requires replacement of the entire roll stamper even if a defect occurs at one location of the preformat pattern, resulting in poor molding efficiency and In the roll stamper using (2), the adhesive changes with time due to the heat of the resin sheet extruded and the heat of the roll stamper itself, and the adhesive force is reduced, and the stamper is easily peeled off from the mirror-finished roll. There is a problem that the life is very short, and bubbles easily occur in the adhesive, and the unevenness of the stamper generated by these bubbles is unnecessarily transferred to the substrate, making it difficult to transfer the pattern clearly, resulting in poor transfer. There is a problem that occurs.

Further, in the roll stamper using the technique (3), it is difficult to suppress the gap between the flexible stamper and the roll base material, temperature unevenness is likely to occur on the stamper surface, and eventually molding failure occurs. There was a problem.

Therefore, the stamper is mirror-finished so that the flexible stamper is not distorted and the surface (back surface) of the stamper on which the pre-format pattern is not formed is in close contact with the peripheral surface of the mirror-roll base material. As a method for surely fixing to a roll base material, the applicant of the present application filed Japanese Patent Application No. 3-2.
No. 45330, a fixing tool is provided on the back surface of the flexible stamper, and a locking groove into which the fixing tool can be fitted is provided on the peripheral surface of the roll base material, and the fixing tool is fitted into the locking groove and fixed. A method is disclosed.

However, in this fixing method, as shown in FIG.
The roll stamper circumference is provided between the fixture 61-1 and the fixture 61-2 as shown in FIG. 6A or between the fixture 61-3 and the wall 63 of the locking groove 62 as shown in FIG. 6B. A recess 64 is formed on the surface.

Particularly, in the case of a roll stamper in which a tension is applied to a flexible stamper by using a wedge, the distance between the fixing tool and the engaging groove is relatively large as a margin for applying the tension to the flexible stamper. Since it is set, a large recess is formed on the peripheral surface of the roll stamper.

When a substrate for an information recording medium is continuously molded by the apparatus shown in FIG. 7 using the roll stamper having such a concave portion, the roll stamper 71 and a mirror surface roll arranged to face the roll stamper. 7
2, the amount of the molten resin bank in the pressure molding portion 73 of the molten resin sheet formed by 2 and 3 is varied, the thickness of the information recording medium substrate sheet to be molded becomes uneven, and the molten resin is formed in the concave portion. May interfere with smooth separation of the preformat-transferred substrate sheet for information recording medium from the roll stamper, which may adversely affect the optical performance of the substrate sheet for information recording medium. When a convex portion corresponding to the concave portion is formed on the surface on the side where the preformat pattern is transferred, and when the information recording medium is continuously manufactured using the information recording medium substrate sheet, for example, continuous recording is performed. It has been an obstacle when applying layers.

[0011]

The present invention has been made in view of the above problems, and has a uniform thickness, excellent optical performance such as birefringence, and a continuous manufacturing process of an optical recording medium. An object of the present invention is to provide a roll stamper capable of manufacturing a suitable substrate sheet for information recording medium.

Further, the present invention provides a manufacturing apparatus capable of continuously manufacturing an information recording medium substrate sheet having a uniform thickness, excellent optical performance and suitable for a continuous manufacturing process of an optical recording medium. The other purpose is to provide.

[0013]

That is, a roll stamper for forming a substrate sheet for information recording medium of the present invention has a stamper having a pattern corresponding to the preformat pattern of the information recording medium on the surface of the roll base material. A fixed roll stamper is characterized in that a concave portion with respect to the peripheral surface of the roll stamper is filled with a filler so that the peripheral surface of the roll stamper is substantially smoothed.

Further, the roll stamper for molding a substrate sheet for information recording medium of the present invention is fixed to both rear surfaces of both ends of the stamper having a pattern corresponding to the preformat of the information recording medium on the front surface so as to be integrated with the stamper. And a plurality of locking grooves into which the fixtures can be inserted respectively are formed parallel to the axial direction of the mirror roll, and the fixtures are fixed to each other. A roll stamper, which is inserted into each of the stop grooves, and in which the stamper is fixed along the peripheral surface of the mirror-like roll base material, including a gap between the fixture and the locking groove. It is characterized in that a concave portion with respect to the peripheral surface of the stamper is filled with a filler so that the peripheral surface of the roll stamper is substantially smoothed.

Further, the apparatus for producing a substrate sheet for information recording medium of the present invention comprises a means for molding a resin sheet by melting a resin, a roll stamper having a pattern corresponding to a preformat pattern on the surface, and a roll stamper facing the roll stamper. In an apparatus for continuously producing a substrate for information recording medium having a mirror surface roll arranged, as the roll stamper, a concave portion with respect to the peripheral surface of the roll stamper is filled with a filler, and the peripheral surface of the roll stamper is Is characterized by using a roll stamper which is substantially smoothed.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of a roll stamper for molding a substrate sheet for information recording media according to the present invention, and 11 is a fine preformat corresponding to preformat such as track grooves and prepits on the surface. A flexible stamper provided with a pattern, and 12-1 and 12-2 are fixtures fixed to the back surfaces of both ends of the stamper 11. And 13 is the stamper 11
A roll base material whose peripheral surface is covered with
Reference numeral 4 is a locking groove formed so that the fixing tool 12 can be fitted into the peripheral surface of the roll base material. 15 is the fixture 12
Also, it is a filling material that fills the concave portion with respect to the peripheral surface of the roll stamper generated in the gap of the locking groove 14 and substantially smoothes the peripheral surface of the roll stamper 10.

In the present invention, when a material having a thermal expansion coefficient equal to or larger than that of the material forming the roll base material 13 is used as the filler, the roll is used when forming the substrate sheet for information recording medium. When the stamper is heated, thermal expansion of the roll base material does not form a recess between the filler and the roll base material, which is preferable. Further, in order to prevent the roll stamper from protruding from the peripheral surface due to the thermal expansion of the filler when the roll stamper is heated, the coefficient of thermal expansion thereof is 1 × 10 ^-3 / ° C or less, particularly 3 × 10 ^-4 / ° C or less. Is preferred.

As the filler used in the present invention, for example, Pb, Sn, Zn, and solder having a melting point of 500 ° C. or lower and 150 ° C. or higher, particularly 450 ° C. or lower and 200 ° C.
The above-mentioned low melting point metal or low melting point alloy, metal piece or ceramic piece previously molded according to the shape of the recess, or heat resistant resin such as silicone resin, epoxy resin, cyanoacrylate resin, polyimide resin, or fluororesin Among these, in consideration of the material of the roll base material, the heating temperature of the roll stamper, etc., a material having heat resistance within the range of the coefficient of thermal expansion described above and having a heating temperature of the roll stamper is appropriately selected. And use it.

In the present invention, the term "heat resistance" means that melting, deformation, decomposition and other mechanical property changes at the heating temperature of the roll stamper do not occur for at least 2 hours, preferably 50 hours or more.

Further, among the above-mentioned various materials, particularly when used as a roll stamper, a silicone-based resin or a fluorine-based resin can smoothly separate the molded resin sheet from the peripheral surface of the roll stamper, and Silicone resin and epoxy resin are used to fill the recesses by using an uncured material with a relatively low viscosity, so that even minute gaps in the recesses are reliably filled. It is a preferable material because it functions as an anchor for the filler, and the filler does not peel off from the roll stamper when a molten resin sheet is molded using this roll stamper, and also has excellent heat resistance.

In the present invention, as the silicone-based resin, for example, a resin having a structure of the following general formula (1) is polymerized with a curing agent having a structure of the general formula (2) to form a highly crosslinked structure. It is a polymer.

[0022]

Embedded image (However, x and y are integers, R is H, CH ₃ or C ₂ H ₅ )

Alternatively, it has a structure represented by the following general formula (3) and can be formed by polymerizing dimethylsiloxane.

[0024]

Embedded image (However, Z is an integer)

As the filler of the present invention, for example, a silicone resin which is cured by the mechanism represented by the following formulas (4) to (6) can be used, and such resin can be cured by irradiation of ultraviolet rays or electron beams. At the same time, the viscosity at the time of filling the concave portion can be arbitrarily selected by pre-curing, and it is a suitable material in terms of good workability.

[0026]

Embedded image (However, n is an integer)

In the present invention, the roll stamper recess is filled by injecting an uncured silicone resin into the recess and then heating it. At this time, the uncured silicone resin has a viscosity of 100 to 100,000 cps, which can be obtained by a conventional means such as addition of a diluent.
Particularly, when it is set to 1,000 to 10,000 cps, it is preferable that unnecessary flow at the time of injection into the recess can be prevented and the resin can be injected into the fine gap of the recess. Then, the cured silicone resin protruding from the recess is then scraped off so that the peripheral surface of the roll stamper becomes substantially smooth, whereby the roll stamper of the present invention can be obtained.

As the epoxy resin used in the present invention, for example, a cured product of a bisepoxy compound obtained from a polyhydric phenol compound (for example, bisphenol A) and epichlorohydrin is used. An epoxy resin precursor such as an epoxy compound having a viscosity of 100 to 100,000 cps, preferably 1.0
An object of 100 to 10,000 cps can prevent the flow at the time of flowing into the concave portion and also fill the minute gap in the concave portion, so that the epoxy resin filler is prevented from falling off from the roll stamper after curing. Is something that can be done.

Epoxy resin as a filler is one of the preferable materials in that the shrinkage at the time of curing is small, but since the epoxy resin is generally hard, it is difficult to process it when it protrudes from the recess. Therefore, when an epoxy resin is used as the filler in the present invention, as shown in FIG. 8, the covering member 8 processed into a curvature so as to be in close contact with the peripheral surface of the roll stamper.
After coating the concave portion with 1, the mixture of the epoxy resin precursor and the curing agent is injected into the space formed by the concave portion and the covering member 81 from the injection hole portion 82 of the covering member, and the mixture is cured. By applying it, a roll stamper having a smooth peripheral surface can be easily manufactured. This method is also effective when a silicone resin or a low melting point metal is used as the filler.

After the resin is injected into the recess, the recess may be covered with a covering member shown in FIG. 8 to cure the resin.
In the present invention, the concave portion with respect to the peripheral surface of the roll stamper means a concave portion having a depth of more than 100 μm based on the peripheral surface of the flexible stamper when the flexible stamper is fixed to the peripheral surface of the roll base material. It goes without saying that the concave portion of the preformat pattern formed on the stamper surface is not regarded as the concave portion in the present invention.

Further, in the present invention, "substantially smooth" means that the depth of the concave portion or the height of the convex portion with respect to the peripheral surface of the roll stamper is 100 μm or less after filling the filler.
Especially, it means a case of 50 μm or less.

Next, in the present invention, the fixing tools 12-1 and 12
-By setting at least one of the side surfaces 16 and 17 of -2 to have a surface roughness of 10 μm or more, particularly 100 μm or more and 1 mm or less, it is possible to reliably prevent the filler 15 from falling off the roll stamper.

At this time, the fixtures 12-1 and 12-2
Even if a void 18 as shown in FIGS. 2 (a), (b) and (c) is formed on at least one side face of the filler, the filler can be prevented from falling off. -2
The shape of the side surface of the inclined surface 19-1 and 19-2 of FIG.
As shown in FIG. 2, the shape of the recess may be a shape capable of holding the filler, and as shown in FIG.
Even if the recess 2-1 and the wall surface 19-3 of the locking groove 14 have a shape capable of holding the filler, the filler can be prevented from falling off. Further, as shown in FIG. 2 (f), it is also effective to prevent the filler from falling off by providing a gap between the fixture and the roll base material.
The processing of the side surface of the fixture is particularly preferable when a heat resistant resin is used as the filler.

Next, the second roll stamper according to the present invention
The embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a sectional view of a second embodiment of the roll stamper of the present invention, and FIG. 4 is an enlarged plan view of the vicinity of the filling portion of the roll stamper of FIG. In FIG. 3 and FIG. 4, 21-1
Numerals 21-2 are fixing tools which are fixed to the rear surfaces of both ends of the flexible stamper 11 having a pattern 24 corresponding to the preformat of the information recording medium formed on the surface.

The holes 25-1, 25-2, through which the screws 23-1, 23-2 for fixing the fixing members 21-1, 21-2 to the roll base material 13 pass, are the fixing members 21-1, 21-
2 is not completely fixed to the roll base material 14,
The fixing members 21-1 and 21-21 are arranged in the longitudinal direction of the stamper 11.
-2 is formed in a long hole so as to be movable, and the heads of the screws 23-1, 23-2 are countersunk so as not to project to the peripheral surface of the roll stamper. And the taper surfaces 21-1a and 21-2a of each fixture and the wall surface 1 of the locking groove
Wedges 22-1 and 22-2 are arranged between 4a and 14b, and the wedges are screwed to a fixing member 26 fixed to the side surface of the roll base material 13 and contact the wedges 22-1 and 22-2. The central axis c of the roll stamper by the contacting pressing screw
The stamper 11 can be tensioned by advancing toward, and the stamper is configured so as to be surely in close contact with the peripheral surface of the roll base material. Then, after applying a predetermined tension to the stamper, the fixtures 21-1 and 21
The roll stamper of the present invention can be obtained by filling the filling material 15 in the concave portion between −2.

Next, the flexible stamper 11 used in the present invention is manufactured by a usual method, for example, an electroforming method, and as its thickness, sufficient rigidity of the waist is ensured and the roll stamper is prevented from increasing in diameter. Then, from 20 μm
The range of 500 μm is preferable.

As the preformat pattern 24 for the information recording medium formed on the stamper of the present invention, specifically, the width is 0.5 μm to 2 μm and the pitch is 1.0 μm.
m-5 μm, depth 200 Å-5000 Å spiral or concentric circles or parallel optical discs or tracking grooves for optical cards, width 2 μm-5 μm, pitch 8 μm-1
The pattern corresponds to a spiral or concentric circle or parallel optical disc or optical card tracking groove having a depth of about 5 μm and a depth of about 200 Å to 5000 Å.

Further, it is preferable that the back surface of this stamper, particularly the back surface of the region where the preformat pattern 24 is provided on the front surface, is polished to a mirror surface state with a surface roughness of 0.1 μm or less.

Further, as the roll base material 13 used in the present invention, it is preferable that the peripheral surface of the roll base material 13 is polished to have a surface roughness of 0.1 μm or less. , A cemented carbide, a die steel (for example, maraging steel), and the like, which are capable of mirror finishing, are preferable.
Particularly, chrome steel, which can be easily mirror-finished, is preferably used.

Further, this roll base material may have a hollow portion so that a heat medium for heating the roll stamper, such as oil, can be circulated. In this case, the roll base material 1
The thickness of 3 is preferably in the range of 10 cm to 15 cm in consideration of strength of the roll stamper and prevention of enlargement of the diameter.
Furthermore, the locking groove 14 and the like can be formed in the roll base material 13 by a method such as electric discharge machining, bite machining and dressing.

Next, a continuous manufacturing method of the information recording medium substrate using the roll stamper of FIG. 1 will be described with reference to FIG. First, the resin pellets charged into the extruder 53 are heated and melted in the barrel of the extruder 53, pressed by a screw, and molded into a sheet by the T-die 54.

The temperature of the resin at this time is, for example, 260 ° C. to 330 ° C. in the case of polycarbonate resin, preferably 280.
C. to 320.degree. C., and is continuously extruded from the T-die as a transparent and substantially molten resin sheet 55. The T-die is arranged so that this molten resin sheet is extruded between the mirror surface roll 52 and the roll stamper 10.

Next, the molten resin sheet is pinched by the roll stamper 10 and the mirror surface roll 52, and between the roll stamper 10 and the mirror surface roll 51, and the flexible stamper 1 is pressed.
The preformat pattern 24 on the surface of No. 1 is transferred to form the information recording medium substrate sheet 56.

At this time, the roll stamper 10 of the present invention is kept at a temperature at which the molten resin sheet does not solidify on the roll stamper. That is, roll stamper 1
The temperature of 0 is +20 to -20 ° C of the heat distortion temperature of the resin used.
It is preferable that the surface temperature of the roll stamper is heated to 100 ° C. to 160 ° C. when molding a polycarbonate resin, for example. That is, when the temperature is within the above range, the molten resin sheet is not rapidly cooled, so that the resin sheet is less likely to be distorted by shrinkage or the like. Further, it is preferable that the temperature of the mirror-finished rolls 51 and 52 arranged to face the roll stamper is set to be the same as or slightly lower than that of the roll stamper 10. The adjustment of the temperature of these rolls is controlled, for example, by being electrically heated by a heater cast in the roll or by circulating a heat medium in the center of the roll.

As described above, according to the roll stamper of the present invention, in the roll stamper used in the roller grooving method, the filler is filled in the gap generated when the stamper is fixed by using the fixing tool and the fixing groove. Then, by substantially smoothing the peripheral surface of the roll stamper, it is possible to continuously form a substrate sheet for an information recording medium having excellent flatness. Further, according to the present invention, it is possible to obtain a roll stamper having excellent adhesion of the filler to the roll stamper.

[0046]

EXAMPLES Next, the present invention will be described in more detail with reference to examples.

Example 1 A flexible stamper 11 was manufactured according to the following method. First, after mirror-polishing the surface of soda lime glass having a size of length 34 cm x width 30 cm x thickness 10 mm, a photoresist (trade name: Az-1370; Hoechst Japan KK) was spin-coated to a thickness of 3000 Å. Was formed, and then prepaked at 90 ° C. for 30 minutes.

Next, using a laser exposure device, a preformat pattern of light is exposed to light and a developing solution (trade name: Az
By developing with 312 MIF; Hoechst Japan Co., Ltd., a resist pattern was formed and a glass master disk 152 for an optical card was manufactured. The preformat pattern is a pattern corresponding to an optical disk track groove having a width of 0.6 μm, a pitch of 1.6 μm, and a depth of 1000 Å formed in a region of 130 mm in diameter.
A preformat pattern corresponding to two optical disks was formed on one glass master.

Next, as a pretreatment for forming a metal film by electroforming, a nickel film having a film thickness of 1000Å to 2000Å is formed by a sputtering device to form a conductive film on the glass master. . Next, a nickel metal film having a thickness of 250 μm was formed on the glass master having the conductive film by electroforming.

Finally, the conductive film and the metal film are integrally peeled from the glass master at the same time, the photoresist adhering to the surface is removed, trimming is performed, and the back surface is mirror-polished to have a surface roughness of 0.1 μm. Vertically with 2 pre-format patterns for the optical disk finished on the surface
A flexible stamper having a size of 00 mm × width 150 mm and a thickness of 200 μm was manufactured.

Two stampers thus obtained were butted at their end portions and welded with a YAG laser, and then the back surface was mirror-polished to have a surface roughness of 0.1 μm and length 600 mm × width 150.
A flexible stamper 11 used in the present invention having four preformat patterns for an optical disc having a thickness of 200 mm and a thickness of 200 μm was produced.

Further, as the fixing tools 12-1 and 12-2, a stainless steel square bar (SUS304) having a thickness of 6 mm, a width of 13 mm and a length of 250 mm is subjected to R processing in which the thickness of the stamper is added to the curvature of the roll base material 14. 5m from the edge
A pair having a width difference of m and a depth difference of 0.2 mm and two fixing screw holes was prepared.
(See Fig. 1)

Both ends of the flexible stamper 11 having a length of 600 mm were placed on the stepped portions of the fixtures 12-1 and 12-2, and the ends of the stamper were welded by a YAG laser to obtain a stamper with a fixture. YAG laser welding uses ML-2220A (manufactured by Miyaji Laser System Co., Ltd.), charging voltage 350V, pulse width 1.0.
mS, defocus 5 mm (REP-RATE (PP
S): 20), and power was 50 W. Since burrs are generated during welding, the burrs are machined by polishing so as to have irregularities of 10 μm or less, and the side surfaces 16 and 17 of both fixtures are machined to have a surface roughness of 15 μm.

On the other hand, the peripheral surface of a roll material of carbon steel (thermal expansion coefficient: 11 × 10 ⁻⁶ / ° C.) having a diameter of 200 mm and a width of 300 mm was mirror-polished to have a surface roughness of 0.1 μm or less, and then the peripheral surface of the roll material was As shown in FIG. 1, depth 6 mm, width (W ₁₄ ) 15 mm
The locking groove was formed to obtain the roll base material 11.

Next, in the locking groove 14, the fixing members 12-1,
12-2 is inserted and fixed with a screw, and an uncured silicone resin (trade name: KE1204; manufactured by Shin-Etsu Silicone Co., Ltd.) with a viscosity of 5000 cps is injected into the recess formed between the fixtures, and the temperature is 130 ° C. for 30 minutes. After heating the roll stamper to cure the silicone resin, the cured resin protruding from the recess is scraped off with a cutter to obtain a thermal expansion coefficient of 2 × 10 ⁻⁴ / ° C.
As the filling material of (1), a substantially smoothed roll stamper having a maximum step difference of 100 μm or less was produced.

This roll stamper was attached to the molding apparatus shown in FIG. 5 and a polycarbonate resin was extruded from the extruder 53 to produce a 1.2 mm thick optical disk substrate sheet.

The molding conditions were a T-die temperature of 300.
C., the surface temperature of the roll stamper 5 was 145.degree. C., and the resin sheet conveying speed was 3 m / min.
The thickness of the optical disk substrate sheet thus molded is 1.
The stamper surface was accurately transferred with 2 mm. In addition, the portion of the fixture in which the gap was filled was 80 μm or less even at the most convex portion of the substrate sheet, and a continuous sheet with good flatness was obtained.

During molding, the filler did not transfer from the roll stamper to the molded resin sheet. In the present invention, the coefficient of thermal expansion was measured according to ASTM D646. Further, in the present invention, the viscosity of the uncured resin is AS
Performed according to TM D445.

Example 2 As in Example 1, a long stamper 11 with a fixing tool was prepared, and the fixing tool 12-1 and the fixing tool 12 were fixed to the locking groove 14 of the roll base material 13 using screws. About 2 mm between -2
2mm thick, 6mm high, 30c long
m lead plate was inserted, compressed from above to fill the gap, and the convex portion was cut with a cutter, and the step of the peripheral surface of the roll stamper was set to 50 μm or less even at the maximum.

Using the stamper roll thus prepared, an optical disk substrate sheet having a thickness of 1.2 mm was continuously molded in the same manner as in Example 1, and the preformat pattern was transferred with high accuracy. Further, the height of the convex portion of the substrate sheet was 30 μm or less at the maximum, the flatness of the substrate sheet was good, and no problem occurred during continuous coating of the organic dye recording layer with a roll coater. .

Example 3 In Example 1, as a filling material, a stainless steel (SUS4) having a length of 30 cm formed in advance so as to fit the shape of the recess was used.
The filling material of 30) was fitted in the concave portion, and screw holes for fixing were provided at both ends of the filling material and fixed to the roll base material 13. In addition,
The upper surface of the filler was polished to a curvature that was flush with the peripheral surface of the roll stamper, and the roll stamper was formed so that the step difference on the peripheral surface of the roll stamper was 10 μm or less.

When an optical disk substrate sheet was produced in the same manner as in Example 1 using the roll stamper thus produced, the pattern transferability was also good, and the sheet resulted from the fixture and the stamper and the filler. The upper step was also 10 μm or less. Further, the organic dye recording layer was wet-coated on this substrate sheet with a roll coater, but there was no problem due to this step.

Comparative Example 1 A stamper with a fixture was prepared in the same manner as in Example 1,
When the filler was scraped off with a cutter, it was deeply scraped off, and the step on the peripheral surface of the roll stamper was measured, and it was 120 μm. Using the roll stamper thus produced, an optical disk substrate sheet having a thickness of 1.2 mm was prepared in Example 1.
When molded in the same manner as in (1), the resin bite into the groove and the substrate sheet was pulled when it was peeled from the roll stamper, which sometimes caused strain in the sheet.

Comparative Example 2 A stamper with a fixture was prepared in the same manner as in Example 2,
After fixing to the roll base material with screws, the lead plate was pressed in the same way,
The surface was used for forming a substrate sheet while having a convex shape of about 110 μm. As a result, bank unevenness was generated and strain such as flow unevenness was generated on the substrate sheet. In addition, the thickness of the substrate sheet formed in the filler-filled portion of this sheet was about 100 μm thinner than the other portions. A recording layer was applied to this substrate sheet with a roll coater, but the sheet vibrated in the recesses, resulting in uneven thickness.

Example 4 In Example 1, the side surface 16 of the fixtures 12-1 and 12-2 was used.
2 and 17 are provided with small voids as shown in FIG. 2C, and an epoxy resin precursor (trade name: Epicoat 828, manufactured by Shell Co.) having an uncured viscosity of 2500 cps is used as a filler instead of the silicone resin. As shown in FIG. 8, the roll stamper is poured into a concave portion covered with a glass covering member 81 formed into a curvature so as to be in close contact with the peripheral surface of the roll stamper, and then the roll stamper is heated to 120 ° C. to obtain an epoxy resin precursor. As a filler having a coefficient of thermal expansion of 7.2 × 10 ⁻⁵ / ° C., polymerization was performed to prepare a smoothed roll stamper having a maximum step difference of 100 μm or less on the peripheral surface.

When an optical disk substrate sheet was molded using the roll stamper thus obtained in the same manner as in Example 1, the transferability of the preformat pattern was good and the flatness of the substrate sheet was also good. In addition, the filler did not fall off the roll stamper during molding.

Reference Example 1 In Example 1, the side surface 16 of the fixtures 12-1 and 12-2 was used.
A roll stamper was prepared in the same manner as in Example 1 except that the surface roughnesses of Nos. 17 and 17 were processed to 1 μm or less, and a substrate sheet for an optical disk was formed in the same manner as in Example 1 using the roll stamper. Good pattern transferability, and maximum flatness of the substrate sheet is 80μ.
However, the filler fell off from the roll stamper during the molding, and the flatness of the substrate sheet deteriorated.

[0068]

As described above, according to the roll stamper of the present invention, information recording having a uniform thickness, excellent optical performance such as birefringence, and suitable for a continuous manufacturing process of an optical recording medium is carried out. A substrate sheet for media can be manufactured.

According to the apparatus for manufacturing a substrate for an information recording medium of the present invention, a substrate sheet for an information recording medium having a uniform thickness, excellent optical performance and suitable for a continuous manufacturing process of an optical recording medium is provided. It can be manufactured continuously.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a roll stamper of the present invention.

FIG. 2 is a schematic cross-sectional view of a fixture used in the roll stamper of the present invention.

FIG. 3 is a schematic cross-sectional view of another embodiment of the roll stamper of the present invention.

FIG. 4 is a partially enlarged plan view of the roll stamper of FIG.

FIG. 5 is a schematic view of an apparatus for manufacturing a substrate sheet for information recording medium of the present invention.

FIG. 6 is a schematic sectional view of a conventional roll stamper.

FIG. 7 is a schematic cross-sectional view of a conventional apparatus for molding a substrate for information recording medium.

FIG. 8 is an explanatory view of an embodiment of a method for manufacturing a roll stamper of the present invention.

[Explanation of symbols]

 10 Roll Stamper 11 Flexible Stamper 12-1, 12-2 Fixing Tool 13 Roll Base Material 14 Locking Groove 14a, 14b Wall Surface 15 Filling Material 16, 17 Side Surface 18 Void 19-1, 19-2 Inclined Surface 21-1, 21 -2 Fixture 21-1a, 21-2a Tapered surface 22-1, 22-2 Wedge 23-1, 23-2 Screw 24 Preformat pattern 25-1, 25-2 Hole 26 Fixing member 51, 52 Mirror roll 53 Extruder 54 T-die 55 Molten Resin Sheet 56 Substrate Sheet for Information Recording Medium 61-1, 61-2, 61-3 Fixing Tool 62 Locking Groove 63 Wall 64 Recess 71 Roll Stamper 72 Mirror Surface Roll 73 Pressure Forming Section 81 Covering member 82 Injection hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hisanori Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tetsuya Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (17)

(57) [Claims] 1. A roll stamper comprising a stamper having a pattern corresponding to a preformatted pattern of an information recording medium on the surface of a roll base material, the stamper being fixed to the peripheral surface of the roll base material.
A roll stamper for forming a substrate sheet for an information recording medium, characterized in that a recess is formed on the peripheral surface of the roll stamper with a filler to substantially smooth the peripheral surface of the roll stamper. 2. A fixing tool is fixed to the back surface of both ends of a stamper having a pattern corresponding to the preformat of the information recording medium on the front surface so as to be integrated with the stamper, and the fixing tool is fixed to the peripheral surface of the mirror surface roll base material. A plurality of locking grooves into which the tools can be inserted are formed in parallel to the axial direction of the mirror surface roll, the fixing tools are respectively inserted into the locking grooves, and the stamper is formed into the mirror surface roll. In a roll stamper fixed along the peripheral surface of a base material, a filler is filled in a recessed portion with respect to the peripheral surface of the roll stamper including a gap between the fixture and the locking groove, A roll stamper for forming a substrate sheet for an information recording medium, characterized in that a peripheral surface of the stamper is substantially smoothed. 3. The roll stamper according to claim 2, wherein a side surface of the fixture is formed in a shape capable of holding a filler. 4. The roll stamper according to claim 2, wherein a side surface of the fixture has a surface roughness of 10 μm or more. 5. The roll stamper according to claim 2, wherein a concave portion capable of holding a filler is formed on a side surface of the fixture. 6. The roll stamper according to claim 2, wherein the filler has a coefficient of thermal expansion higher than that of the material forming the roll base material. 7. The filler has a coefficient of thermal expansion of 1 × 10 ^−3.
The roll stamper according to claim 2, which is formed of a material having a temperature of / ° C or less. 8. The roll stamper according to claim 2, wherein the filler is a heat resistant resin. 9. The roll stamper according to claim 2, wherein the filler is a low melting point metal. 10. The roll stamper according to claim 8, wherein the filler is a silicone resin. 11. The roll stamper according to claim 8, wherein the filler is an epoxy resin. 12. The viscosity of the filler in the uncured state is 100.
The roll stamper according to claim 10, which is a cured product of a silicone resin of 100,000 cps. 13. The filler in the uncured state is 1,000.
The roll stamper according to claim 12, which is a cured product of a silicone resin having a viscosity of about 10,000 cps. 14. 100 to 1 in the uncured state of the filler.
The roll stamper according to claim 11, which is a cured product of an epoxy resin precursor having a viscosity of 0,000 cps. 15. The filler in the uncured state is 1,000.
The roll stamper according to claim 14, which is a cured product of an epoxy resin precursor having a viscosity of ˜10,000 cps. 16. A substrate for an information recording medium having means for melting a resin to form an extruded resin sheet, a roll stamper having a pattern corresponding to a preformat pattern on its surface, and a mirror surface roll arranged to face the roll stamper. In a device for continuously manufacturing a roll stamper, a roll stamper in which a recessed portion with respect to a peripheral surface of the roll stamper is filled with a filler and the peripheral surface of the roll stamper is substantially smoothed is used. An apparatus for manufacturing a substrate sheet for an information recording medium, which is characterized in that: 17. A stamper having a pattern corresponding to a preformat of an information recording medium on a surface thereof is fixed to a peripheral surface of a roll base material, and a concave portion with respect to the peripheral surface of the roll stamper is filled with a filler to form a peripheral surface. A method for manufacturing a roll stamper in which is substantially smoothed,
A method for manufacturing a roll stamper, comprising: covering the concave portion with a covering member having an injection hole portion formed to have a curvature so as to be in close contact with the peripheral surface, and then injecting a filler into the concave portion.