JPH03219443A - Manufacture of roller for molding and substrate for optical recording medium using the same - Google Patents

Abstract

PURPOSE:To improve patterning accuracy and flatness by molding a substrate for optical recording medium by fixing a long-sized pattern in which a pre- format pattern is directly provided on a flexible sheet on the entire plane of the outer periphery of a roller with a joint without generating a step. CONSTITUTION:In a roller 4 for molding, the long-sized stamper 2 is installed on the outer peripheral surface of the roller 1 with the joint 5 without generating the step. The long-sized stamper 2 is formed by directly providing plural pre-format patterns 3 on the flexible sheet. The manufacture of this substrate for optical recording medium is performed in such a manner that it can be performed successively by heating and pressurizing resin pushed out from the T die 13 of a manufacturing device by using the roller 4 for molding, and transferring the pre-format pattern 3, thereby, the patterning accuracy and the flatness can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an optical recording medium, and more specifically, the present invention relates to a method for manufacturing an optical recording medium, and more specifically, information is produced by changing optical properties such as reflectance and transmittance by irradiation with a light beam such as a laser beam. The present invention relates to a method of manufacturing a transparent substrate for an optical recording medium for recording and reproducing information.

[Prior Art] Conventionally, magnetic materials such as magnetic tapes and magnetic disks, various semiconductor memories, and the like have been mainly used to record various types of information. Such magnetic memories and semiconductor memories have the advantage that information can be easily written and read, but on the other hand, they have the problem that the information content can be easily tampered with and that high-density recording is not possible. Ta. In order to solve these problems, an optical information recording method using an optical recording medium has been proposed as a means to efficiently handle a wide variety of information, and an optical information recording carrier, a recording/reproducing method, and a recording/reproducing device for this purpose have been proposed. has been done. Optical recording media as information recording carriers are generally manufactured by using laser light to evaporate a part of the optical recording layer on the information recording carrier, to cause a change in reflectance, or to cause deformation. Information is recorded or reproduced based on differences in reflectance and transmittance. In this case, the optical recording layer does not require any development treatment after information is written, and can be read directly after writing, so-called DRAW (
It is a media (read-after-write),
Since high-density recording is possible and additional writing is also possible, it is effective as an information recording/storage medium.

FIG. 6 is a schematic cross-sectional view of a conventional optical recording medium. In the figure, 31 is a transparent substrate, 32 is a track groove portion, and 3
3 is an optical recording layer, 34 is a spacer/adhesive layer, and 35 is a protective substrate. In FIG. 6, information is recorded and read out optically through a transparent substrate 31 and track grooves 32. At this time, tracking can be performed using the phase difference of the laser beam by utilizing the fine irregularities of the track groove. With the configuration described above,
With conventional video discs, audio discs, etc.
A method of continuously molding a substrate by heating and pressing a thermoplastic resin such as polyvinyl chloride resin (PVC) or polycarbonate resin (PC) with a molding roll on which information is recorded to transfer information or a preformat pattern (special method). Kaisho 5
6-86721) is known. Alternatively, as another method, there is also a method of molding in single sheets using an injection molding method. There are two ways to manufacture molding rolls for continuous molding: one is to form a pattern directly on the roll, and the other is to create a stamper (frame) with a sheet pattern formed on it and adhere it to the roll using an adhesive. (Japanese Patent Publication No. 5O-11518), and a method of fixing a sheet stamper to a roll using magnetic force, adsorption, or mechanical methods (
Utility Publication No. 53-15825, Utility Publication No. 50-9568, No. 5
7-164839) is known.

[Problems to be Solved by the Invention] However, unlike the above-mentioned conventional manufacturing methods for video discs, audio discs, etc., optical recording media such as optical discs, optical cards, and optical tapes require more patterns than audio discs. Because of the fine precision, it is necessary to use equipment related to photolithography technology, such as a laser writing equipment. In the method of directly forming a pattern on a roll, the surface of the roll can be processed with high precision, but there is a problem in that it is difficult to accurately draw or transfer a pattern on the surface of a cylindrical roll. On the other hand, in the method of making a single stamper and fixing it to a roll using a method such as adhesive, the stamper is attached to each stamper individually.
Therefore, it is possible to fabricate flat scumburrs using photolithography technology, and it is possible to fabricate patterns with good pattern accuracy. A fixing method is used to fix the stamp to the surface of the roll, but since a normal sheet stamper forms one pattern on one stamper, it is not possible to form a very large stamper. Since a plurality of stampers are fixed to a book roll, there is a problem in that a level difference occurs at the end of the stamper, and the surface accuracy of the roll deteriorates. There is also the problem that the surface accuracy of the roll cannot be improved depending on the fixing method. If the surface precision of the roll stamper used for forming is poor or uneven,
Because the extruded resin is not sufficiently pressurized during molding, problems arise such as fine patterns not being transferred with high precision and the thickness of the substrate becoming uneven within the surface of the disk. In addition, uneven pressure during molding becomes uneven in birefringence when polycarbonate or the like is used as the resin, resulting in a problem in that quality deteriorates. For this reason, the stamper that molds the resin is required to have good flatness.

The present invention has been made to solve the problems of the prior art described above, and provides a method for manufacturing an optical recording medium with good pattern accuracy and flatness.

[Means for Solving the Problems 1] The present invention relates to a molding roller used for molding a substrate for an optical recording medium, which is a long stamper having a preformat pattern directly formed on a flexible sheet. The above-mentioned molding roller is characterized in that it is fixed so that no steps are formed at the joints, and the substrate for optical recording media is extruded by melting resin and molded using a roller-shaped mold. This is a method for manufacturing an optical recording medium substrate, which is characterized in that, in manufacturing an optical recording medium substrate that is continuously formed with a preformat, the molding with the roller-shaped mold is performed using the above-mentioned molding roller. According to the present invention, it is possible to create a substrate for an optical recording medium with good pattern accuracy and flatness.Furthermore, the molding roller with no step at the seam is a long piece having a length of at least one circumference of the roller. The present invention can also be preferably produced by attaching a stamper to the outer peripheral surface of a roller, trimming the overlapping portion of the long stamper at the seam as necessary, and then fixing the long stamper to the outer peripheral surface of the roller. It is a characteristic of

Note that the optical recording medium refers to a general optical recording medium in which optical properties such as reflectance and transmittance are changed by irradiation with a light beam such as a laser beam to record and reproduce information.

Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the molding roller of the present invention, and FIG. 2 is a schematic diagram showing the configuration of a substrate molding apparatus incorporating the roller. In FIG. 1, the molding roller of the present invention comprises a long stamper installed on the outer peripheral surface of a roller 1 without any difference in level at a seam 5, and a preformat pattern 3 is formed on the surface of the long stamper. Multiple pieces are directly formed. Here, what is meant by a preformat pattern being provided directly on the surface of a long stamper? Since the stamper is a preformat pattern, the stamper can be formed on the sheet using the sheet material itself, or the stamper can be formed on the sheet without using an adhesive or the like. The stamper material is formed as is.

This makes it possible to create a long stamper without causing discontinuities such as misalignment between the stamper and the base sheet. Further, in the present invention, since there are no discontinuous points such as steps on the forming roller, the substrate obtained using the long stamper has excellent pattern accuracy. The method for forming the stamper will be described later.

To mold a substrate using the molding roller, the resin extruded from the T-guidry 13 of the device shown in FIG. 2 is heated and pressed using the molding roller 4 to form information such as a preformat pattern. By transferring, transparent substrates for optical recording media can be manufactured continuously.

FIGS. 3 and 4 are schematic diagrams showing embodiments of the long stamper and the manufacturing method thereof according to the present invention. The long stamper of the present invention usually has a plurality of preformat patterns (hereinafter simply referred to as patterns) 22 formed on a base sheet 21 made of a flexible material.

The base sheet 21 that can be used in the present invention may be made of any material as long as it is flexible enough to be attached to the outer peripheral surface of the roller and has sufficient heat resistance and mechanical strength for resin molding. 0 Can be used. For example, resins such as polyethylene terephthalic acid and polyimide, metals or metal compounds such as nickel and chromium, metal alloys, glass, and ceramics can be used. Here, it is necessary that the length of the base sheet is such that the long scooper can be fixed to the outer periphery of the roller without forming a step at the seam, as shown in FIG. That is, a long stamper
If the length is longer than one circumference of the forming roller, it is possible to avoid creating a step at the seam by aligning the ends tightly at the seam when fixing to the roller.

Here, when the length of the long stamper is longer than one circumference of the outer circumferential surface of the roller, the length of the portion corresponding to the outer circumference of the roller is the length of the roller before the long stamper is attached to the roller. It is longer than the length of the outer circumference - the circumference of. That is, when the stamper is mounted on a roller, the length is such that the ends of the stamper overlap at the seam. How much longer it needs to be than the length of the outer circumference of the roller varies depending on the method of fixing the elongated stamper to the roller, the type of adhesive used in that method, etc. For example, if the adhesive used is a cure-shrink type, the overlap of the seam will be reduced after fixing, compared to applying the adhesive on a roller and placing a long stamper on top of it. This reduction must be taken into consideration. Furthermore, if the adhesive to be applied is thick, the length of the elongated stamper must be longer than the outer circumference of the roller. If the long stamper is too long, it can be trimmed before fixing it to the roller, so there is no particular problem, and the stamper can be adjusted as appropriate depending on the ease of work. In any case, after fixing the long stamper to the roller, it is sufficient to make sure that there are no steps in the seam. Usually long stamper
The length may be about 5 to 20% longer than the roller outer circumference-peripheral length.

Further, the thickness of the base sheet may be approximately 5 to 500 μl, but this may be adjusted as appropriate depending on the size of the roller used, the means for fixing the roller to the long stamper, the method of making the stamper, etc.

In the present invention, it is preferable that the elongated stamper is fixed to a roller and used in the substrate molding method, but since the elongated stamper has flexibility, it is not necessarily limited to a roller, and can be a caterpillar-shaped sheet or a continuous stamper. It can also be used by being fixed to a sheet. Also in this case, the length of the long stamper may be made longer than the entire circumference of the molded sheet, and the stamper may be fixed so as not to form a step at the seam.

Any method can be used to form the pattern 22 directly on the base sheet 21 as long as it can form a pattern with the required accuracy. For example, known methods such as embossing with a press, embossing (FIG. 4), and ultraviolet curing resin (FIG. 5) can be used. Whichever method is used, the pattern is formed on the base sheet using a mold having one or more desired patterns. Patterns are repeatedly formed until patterns are formed on all required portions of the base sheet, and usually a long stamper with a large number of patterns is produced.

Note that the patterned mold 23 can be produced by a manufacturing method generally used for CDs (compact discs) and the like. Specifically, a resist is applied to a glass master disk, a pattern is exposed and developed, a nickel film is formed by sputtering, and nickel is deposited to a predetermined thickness by electroforming.

A third master (mother) and a grandchild stamper may be created using the second master thus obtained as a father. Another method is to form a pattern on a rigid substrate using a method such as photolithography, and use that pattern as a resist to form grooves in the pattern to the required depth using wet or dry etching on the rigid substrate. A method can also be used. The thickness of the patterned mold 23 is such that the mechanical strength and durability required for the processing method used is determined because the patterned mold 23 is used to process the pattern on the base sheet in the present invention. Make it. The preferred range is 10 μm to 20 mm.

In the present invention, the elongated stamper may have a cured film/protective film formed on the pattern surface as necessary. It is also possible to form a protective layer on the opposite side of the patterned side of the base sheet or to bond a backing material to the base sheet.

The roller 1 can be made of any material as long as it has high hardness and good thermal conductivity; for example, metals such as iron and chrome steel, metal alloys, metal compounds, etc. can be used. .

Processing of the roller surface involves derusting, degreasing, removing moisture, and polishing. The surface accuracy must be approximately the same as or better than the surface accuracy of the optical recording medium to be molded. Further, if necessary, a hardened film such as titanium nitride or a protective layer such as silicon may be formed on the surface, or plating such as chrome plating may be applied.

Any method of fixing the long stamper 2 to the roller 1 can be used as long as it can obtain the surface accuracy necessary for molding the resin and does not cause positional deviation during fixation or molding. be able to.

For example, methods such as mechanical fixing such as screwing, adhesion using adhesive or pressure-sensitive adhesive, and fitting/caulking can be used. Further, a sheet of metal or the like may be sandwiched between the long stamper 2 and the roller 1 if necessary.

Furthermore, a roller or the like may be provided with a notch or an uneven portion for positioning. As mentioned above, at the seam of a long stamper, it is necessary to edge both ends together to avoid the formation of a step. When using adhesive,
It is necessary to ensure that there are no gaps between the joints of the long stampers and no adhesive protrusion due to curing shrinkage of the adhesive.

The coating amount of the adhesive may be about 1 to 100 ul thick.

A specific method for fixing a long stamper to a roller without a step difference at the seam is to attach a long stamper that is longer than the outer circumference of the roller to the roller using a fixing means such as adhesive. Trim the area taking into consideration curing shrinkage of the adhesive, etc. The amount of trimming is empirically set for each of the six cases. Trimming can be performed by cutting off the ends using a single-turn punching blade or the like.

The substrate manufactured by the method of the present invention becomes an optical recording medium by adding an optical recording layer, a reflective layer, and other protective layers as necessary. Note that the methods and materials described above can be freely selected from those commonly used in optical recording media. Further, the long stamper according to the present invention is
For example, it can be used to manufacture all kinds of optical recording media such as optical discs, optical cards, optical tapes, and optical coins.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 As shown in Fig. 3, the thickness was 10 μm, the length was 1000 mm,
A 2 mm diameter 86 mm nickel stamper (thickness: 300 μm) with continuous grooves of 1.6 μm pitch, 0.6 μm width, and 700 A depth formed on a 300 mm wide polyester (Lumiror, manufactured by Toshi) base sheet. The pattern was transferred by heating and pressing for 2 minutes at 200℃ and applying a pressure of 10 kg/cm between the same 2 mm chrome steel sheets.The transfer was repeated and the pattern was transferred to the base. Thirty (3X10) patterns were formed on the sheet.The pattern transfer was 95% in depth (measured by Taylor Hobson Co., Ltd., Talystep), and the line width and track pitch transfer was 100% ( The pattern transfer rate was good (measured using a surface profile measuring device manufactured by Elionix Co., Ltd.), and no wrinkles were observed on the surface of the base sheet due to pattern transfer.

Roll diameter 30 with chrome plating on the surface to a thickness of 1 μm
A small amount of epoxy resin (Diabond 200O8, manufactured by Nozawa Chemical Co., Ltd.) and diethylene triamine (Kishida Chemical Co., Ltd.) as a hardening agent were added to a 0 mmφ iron roll, mixed uniformly, and coated uniformly to a thickness of 20 μm using a roller. From above, the long stamper described in 8 above was applied in order from one end to the outer circumferential direction of the roll. The ends of the long stampers were overlapped and adhered, and before curing, the overlapping portion was cut off using a punching blade. The length of the seam gap was 5 μm or less. Furthermore, the maximum level difference at the seam was 10 μm. The maximum unevenness (p-p) of the surface was 3 μm, and the surface accuracy was good.

This roll was molded using an extrusion molding machine (Hitachi Zosen, 5HT90-
At a speed of 2.3 m/min, with a die temperature of 250°C and a roller temperature of 150°C, 1.2 m of polycarbonate (Ondai Kasei, K-1285) was attached to
It was extruded to a thickness of m.

When the extruded substrate was measured, the maximum thickness unevenness was 50 μm, which was sufficiently small.

The value of birefringence is 20 nm in a single pass, with little variation (Japan Denshi Kogaku Co., Ltd., birefringence measuring machine, λ = 830 nm)
The light transmittance was 89% and was sufficiently transparent (measurement results using Hitachi U-3400, λ = 830 nm).
The amount of surface runout was sufficiently small at 20 μm in pp (9 measurements made using a three-dimensional measuring machine by Carl Zeiss), and the transfer rate of the briformat vacuum formed on the long stamper was 96 to 98% in depth. Yes (Taylor Hobson Co., Ltd., measurement results at Christetsub),
Furthermore, the transfer of line width and track pitch is 100 to 1
01% (measured using a surface profile measuring machine manufactured by Elionix Co., Ltd.), which was good in all cases.

This substrate was cut to a size of 86 mm, and an optical recording material represented by the following structural formula El was coated with a solvent.

For the protection board, cut 0.3 mm thick polycarbonate (Banjin Kasei, Panlite 251) into 86 mm diameter.
．． It was glued so that there was an air gap of 3 mm. When I tried recording and playing back, the rotation speed of the disc was 180 Orp.
m, writing frequency 3MH2, writing power 6mW,
At a readout power of 0.5 mW, the Cl2O N ratio was 50 dB (Nakamichi Co., Ltd., 0MS-1000II
(Measurement results) were excellent with no problems at all.

Example 2 The same polyester sheet as in Example 1 was coated with ultraviolet curing resin (Nippon Kayaku Co., Ltd., lNC118) to a thickness of 10 μm, and the same polyester sheet as in Example 1 was heated at 5KW using the same Tsukeru stamper as the master. An ultraviolet curing resin (Nippon Kayaku Co., Ltd., INC118) was completely cured using an ultraviolet lamp (Ushio Electric Co., Ltd.), and the same number of patterns as in Example 1 were transferred to produce a long stamper. When the pattern transfer rate was measured in the same manner as in Example 1, the pattern transfer was 99% in depth, and the line width and track pitch transfer was 10%.
It was good at 0%. Further, as in Example 1, no wrinkles were observed on the surface of the base sheet due to pattern transfer.

Chrome plated roll diameter 300mmφ same as Example 1
It was fixed to an iron roll in the same manner as in Example 1. The maximum level difference at the seam was 10 μm. The maximum unevenness (p-p) of the surface was 3 μm, and the surface accuracy was as good as in Example 1.

This roll was attached to the same extrusion device as in Example 1, and the same resin as in Example 1 was extruded under the same conditions. When the extruded resin was measured in the same manner as in Example 1, the results were as shown in Table 1. A similarly good substrate was obtained.

This substrate was cut into 86 mmφ in the same way as in Example 1.
After forming the optical recording layer, a protective substrate was attached to complete the optical disc. When I tried recording and playing back, the disc rotation speed was 1800 rpm, and the writing frequency was 3MH.
z, write power 6 mW, read power 0.5 m
W, the C/N ratio was 53 dB, which was good.

Example 3 An aluminum sheet of the same thickness and size as Example 1 was coated with ultraviolet curable resin (Nippon Kayaku Co., Ltd., lNC118) to a thickness of 10 μm, with a pitch of 12 μm, a width of 2.5 μm, and a depth of 2.5 μm. 9 9 with a 3000A card pattern groove formed
Using a 71 mm x 71 mm glass stub bar (2 mm thick) as a master, the ultraviolet curing resin was completely cured using a 5 KW ultraviolet lamp (Ushio Electric Co., Ltd.), and the same number of patterns as in Example 1 were transferred. A long stamper was produced. The pattern transfer rate was good, with the depth being 99%, and the line width and track pitch transfer being 100%. As in Example 1, no wrinkles were observed on the surface of the base sheet due to pattern transfer.

Chrome plated roll diameter 300mmφ same as Example 1
It was fixed to an iron roll in the same manner as in Example 1. The maximum level difference at the seam was 10 μm. The maximum unevenness (p-p) of the surface was 3 μm, and the surface accuracy was as good as in Example 1.

This roll was attached to the same extrusion device as in Example 1, and the same resin as in Example 1 was extruded and molded under the same conditions. When the extruded resin was measured, as shown in Table 1, a good substrate was obtained as in Example 1.

After coating this substrate with the same optical recording material as in Example 1 using a solvent, a backing material of 0.25 mm thick polycarbonate (manufactured by Ondai Kasei, Panlite 251) was attached with a hot melt adhesive (manufactured by Hirodyne, Evaflex). EXP80) was used for adhesion. Then, it was cut into a card size of 86 x 54 mm to produce an optical card.

When I recorded and played back under the following conditions, the C/N ratio was 50.
dB, which was excellent.

・Card feed speed: 160 mm/sec, playback 400
mm7 seconds・Recording frequency: 7.65 k) Iz・Laser power: Writing 3.5mW, reading 0.
2 mW, spot diameter 3 microns Comparative Example 1 The same nickel stamper as in Example 1 was placed on the same polyester sheet as in Example 1, using the same adhesive used to fix the long stamper to the roller in Example 1. 30
A long stamper (3×10) was pasted onto the polyester sheet to produce a long stamper. A long stamper was attached to the same roller as in Example 1 in the same manner as in Example 1. 4 Transfer of the pattern was 96% in depth, and transfer of line width and track pitch was 100%, indicating a good pattern transfer rate. As in Example 1, long stampers were sequentially pasted from one end to the outer circumferential direction of the roll. long stamper
The length of the gap between the seams was 5 μm or less, and the accuracy was sufficient. However, the maximum level difference at the edge or seam of each stamper is 100 to 300 μm, and the gap is about 300 to 500 μm in length. The steps and gaps at the ends and joints of each stamper were transferred to the resin, and the amount of surface runout was too large, making it unsuitable for use as a resin substrate. In addition, since the pressing force during molding of the resin is uneven in these steps and gaps, the birefringence of the resin substrate was measured using the same method as in Example 1 and was approximately 400 nm, making it unsuitable as a substrate. In addition, during molding, the ends of each stamper attached to the long stamper came off, and it became clear that this method of resin molding was inappropriate.

5 Comparative Example 2 Thirty (3 x 10) nickel stampers, the same as in Example 1, were directly attached to the same roller as in Example 1 using the same adhesive used to fix the long stamper to the roller in Example 1. I attached it. As in Comparative Example 1, the maximum level difference at the edge or seam of each stamper is 100 to 300 L.
1 m, the gap is about 300 to 500 μm in length, and when a resin substrate is molded using this roller under the same conditions as in Example 1, the steps and gaps at the edges and seams of each stamper are The amount of surface runout was too large, making it unsuitable for use as a resin substrate. In addition, since the pressing force during molding of the resin is uneven in the steps and gaps, the birefringence of the resin substrate was about 400 nm when measured using the same method as in Example 1, making it unsuitable as a substrate.

As in [Comparative Example], the edges of each stamper attached to the roller came off during molding, and it became clear that this method of resin molding was inappropriate.

6 Table Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 020 020 010 00 00 9 9 0 0 0 0 97-98 100-101 97-98 100-101 97-98 100-101 [Effects of the invention ] According to the present invention, a long stamper is made of a flexible material, has a pattern directly formed on at least one surface thereof, and has a length longer than one circumference of the molding roller. By making the long stand bar 7 go around the outer peripheral surface and fixing it to the outer peripheral surface of the roller without creating a step at the seam, it is possible to mold a substrate for an optical recording medium with good pattern accuracy and flatness. A roller can be created, and a substrate molded using this molding roller has a preformat pattern accurately transferred and has excellent flatness.

The long stamper of the present invention is not limited to the above-mentioned roller, but can also be applied to caterpillar-shaped sheets, etc., and similar effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of the molding roller of the present invention, FIG. 2 is a schematic diagram showing an example of the configuration of a substrate molding apparatus for molding a substrate using the molding roller of the present invention, and FIG. The figure is a schematic sectional view showing an aspect of the long stamper according to the present invention, FIGS. 1 is a general schematic cross-sectional view of a conventional optical recording medium. 1. Roller 2. Long stamper 3, uneven pattern 4. Forming roller 5 Seam 11. Substrate resin 8 12° 4 16° 21° 23° 24° 26° 32° 34° Pressure roller 13° Ruder - 15° Take-up roller base sheet 22° Patterned pressure mold 25° Ultraviolet lamp 31 Track groove 33゜Spacer 35゜T tie hopper - Two patterns Ultraviolet curing resin transparent substrate Optical recording medium protection substrate

Claims (1)

[Scope of Claims] 1. A molding roller used for molding a substrate for an optical recording medium, in which a long stamper in which a preformat pattern is directly provided on a flexible sheet is provided with a step on the entire outer periphery of the roller. The above-mentioned molding roller is characterized in that it is fixed without forming. 2. The molding roller according to claim 1, wherein the elongated stamper is obtained by forming one or more preformat patterns on a flexible sheet. 3. The long stamper is obtained by stamping a flexible sheet and/or forming a preformat pattern using an ultraviolet curing resin. The molding roller described. 4. In manufacturing a substrate for an optical recording medium, the substrate for an optical recording medium is continuously formed with a preformat by melting a resin, extruding it, and molding it using a roller-shaped mold,
A method for manufacturing a substrate for an optical recording medium, characterized in that the molding with the roller-shaped mold is performed using the molding roller according to claim 1. 5. A method for producing a molding roller according to claim 1, comprising: attaching a long stamper having a length of at least one circumference of the roller to the outer circumferential surface of the roller; The method for making a molding roller as described above, characterized in that, after trimming if necessary, the long stamper is fixed to the outer peripheral surface of the roller to create a molding roller with no step at the seam.