JP2001319386A - Method for forming convex resin film and optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a convex resin film consisting of a resin. SOLUTION: A mask film 17 (a pattern film) having a desired shape is attached onto a substrate 11 being a subject to be processed, a resin film 18 is formed to cover the film 17 and such a recessed part 19 that a pattern of the film 17 is transferred to the film 18 is formed on the film 18 when the film 17 is peeled off together with the film 18. When a convex part forming composition containing a photo-polymerizable/curable resin is injected into the part 19, a convex part forming composition-applied layer swollen from the surface of the film 18 is formed in the part 19 by surface tension. When the convex part forming composition-applied layer is irradiated with ultraviolet rays, the convex resin film (a projecting part 20) having the desired pattern can be obtained. By using this method an elevation film can be formed on the substrate of an optical recording medium without using a metallic mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of manufacturing an optical recording medium, and more particularly to a technique for forming a convex portion having a desired shape made of resin on a substrate of an optical disk.

[0002]

2. Description of the Related Art Conventionally, optical disks and magneto-optical disks have been used as recording media for computers and the like and media for recording music. Reference numeral 110 in FIG. 3 indicates an optical disk among them.

This optical disk 110 has a disk-shaped substrate 111 made of a transparent resin, and a circular hole 113 is provided at the center of the substrate 111.

A recording film made of a metal thin film and a protective film for protecting the recording film are formed on the surface of the substrate 111, and an elevation film made of a ridge is formed around the hole 113 on the back surface of the substrate 111. 120 are provided. Therefore, the elevation film 120 has a ring shape as a whole, and its center coincides with the hole 113 and the center of the substrate 111.

The elevation film 120 and the substrate 11
1 is formed by an injection molding method in which a resin is injected into a cavity of a mold, and therefore, the elevation film 120 and the substrate 111 are integrated.

[0006] The recording film is disposed on the outer peripheral portion of the ridge. An area outside the ridge is defined as an information recording area 118, and irregularities and grooves are formed on the recording film in the information recording area 118. With this, information can be recorded.

When information is read from the optical disk 110, laser light is irradiated from the side opposite to the surface on which the recording film is formed, and the laser light reflected by the recording film is detected. . The laser beam emitting device is usually disposed inside the reading device, and when the optical disk 110 is mounted on the reading device, the elevation film 120 is placed with the elevation film 120 facing downward.

In this case, since the elevation film 120 is placed on the mounting table of the reading device, the information recording area 118 does not contact the surface of the mounting table and is not damaged. Also,
Since the surface of the optical disk 110 does not adhere to the mounting table, the optical disk 110 can be easily taken out.

However, when the elevation film 120 is formed by the injection molding method as described above,
A mold is required, which increases the manufacturing cost.

Further, since the substrates 111 are formed one by one, the manufacturing cost of the entire substrate 111 increases.

On the other hand, the elevation film 1 is used without using a mold.
When forming 20, a UV-curable resin solution is applied on the substrate in a ring shape, and cured by irradiating UV rays,
A method of forming a ring-shaped resin film is conceivable. However, if the viscosity of the resin solution is high, the line of the resin solution becomes thick, and if the viscosity is low, the resin solution flows on the substrate surface, so that it is difficult to form an elevation film having an accurate width and height. is there.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and has as its object the object of forming a fine pattern of projections on the surface of a workpiece without using a mold. It is an object of the present invention to provide a technology for forming

[0013]

According to an aspect of the present invention, there is provided a method for forming a convex resin film, comprising: forming a pattern film having a desired shape on an object to be processed; A step of supplying a resin film composition containing a photopolymerizable curable resin to the side on which the pattern film of the object is formed, and irradiating at least the resin film composition on the object with ultraviolet light, Curing the resin film composition to form a resin film; removing the pattern film together with the resin film on the pattern film to form a concave portion in the resin film; Supplying a convex composition containing a resin, forming a coating layer of the convex composition in a state of being raised from the surface of the resin film, and applying ultraviolet rays to the convex composition supplied to the concave portion. Irradiate to cure the convex composition And a step. The invention according to claim 2 is the method for forming a convex resin film according to claim 1,
The resin film composition has a first lubricant that is compatible with the photopolymerizable cured resin, and a second lubricant that is incompatible with the photopolymerizable cured resin; The composition is characterized in that the photopolymerizable cured resin is incompatible with at least the second lubricant. The invention according to claim 3 is the method for forming a convex resin film according to claim 2, wherein the first lubricant and the second lubricant are silicone-based lubricants. The invention according to claim 4 is the method for forming a convex resin film according to any one of claims 1 to 3, wherein the viscosity of the convex composition is 10 mPa · s or more.
It is not more than 00 mPa · s. Claim 5
According to a fourth aspect of the present invention, there is provided the method of forming a convex resin film according to the fourth aspect, wherein a height from a bottom surface of the concave portion to a surface of the resin film is 3 μm or more. The invention according to claim 6 is an optical recording medium, wherein a disc-shaped laminated substrate having a recording film, a resin film formed on the laminated substrate,
A ring-shaped concave portion provided in the resin film and having the same center as the center of the laminated substrate, and a convex portion formed in the concave portion so as to rise from the resin film.

The present invention is configured as described above. When a concave portion is formed in a resin film on the surface of an object to be processed and a liquid convex composition is injected into the concave portion, the injected convex composition is provided. Is raised on the opening surface of the concave portion due to surface tension, and when this is irradiated with ultraviolet rays and cured, a convex portion whose front end surface is raised higher than the resin film can be formed.

Also, the first lubricant which is compatible with the photopolymerizable cured resin of the resin film composition and the photopolymerizable cured resin are incompatible, but are compatible with the first lubricant. Is added to the resin film, the second lubricant oozes on the surface of the resin film to such an extent that the second lubricant does not precipitate. On the other hand, when the photopolymerizable cured resin of the convex composition is incompatible with the second lubricant, the convex composition injected into the concave portion of the resin film repels the second lubricant on the surface of the resin film. Do not protrude from the recess.

At this time, the viscosity of the convex composition is 10 m
When it is not less than Pa · s and not more than 1000 mPa · s, and the height from the bottom surface of the concave portion to the surface of the resin film is not less than 3 μm, it is possible to obtain a convex resin film having a better molded state.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical recording medium of the present invention and a method for forming a convex resin film on the substrate surface thereof will be described with reference to the drawings.

Reference numeral 11 in FIG. 2A denotes an object to be processed which can be used in the present invention, and indicates a disk-shaped substrate constituting an optical recording medium.

The substrate 11 is made of polycarbonate, and has a metal thin film 13 formed on its surface by sputtering.
Are formed. A protective film 15 made of a resin is formed on the metal thin film 13.

In order to form a convex resin film on the substrate 11, first, the center of the ring-shaped mask film 17 (pattern film) is made to coincide with the center of the substrate 11, and the mask film 17 is Affix to the surface (FIG. 2 (b)).

FIG. 1A is an enlarged sectional view of a portion near the center of the substrate 11 indicated by reference numeral 30 in FIG. 2B, and shows a partial cross section of the mask film 17.

Next, a photopolymerizable cured resin, a trace amount of a photopolymerization initiator, and a first polymer having compatibility with the photopolymerizable cured resin.
A resin film composition is prepared which comprises a second lubricant which is incompatible with the first lubricant and is incompatible with the photopolymerizable cured resin, but which is compatible with the first lubricant. Next, the substrate 11 is disposed horizontally, and the resin film composition is dropped near the center of the surface. When the substrate 11 is rotated in a horizontal plane about the center of rotation, the dropped resin film composition spreads on the surface of the substrate 11 and a coating layer of the resin film composition is formed so as to cover the mask film 17 ( Spin coating method).

Next, when the surface on which the coating layer of the resin film composition is formed is irradiated with ultraviolet rays, the resin film composition is cured and a resin film 18 is formed (FIG. 1B).

Next, when the mask film 17 is peeled off,
The resin film 18 on the mask film 17 is also peeled off, and a concave portion 19 on which the pattern of the mask film 17 is transferred is formed on the resin film 18 (FIG. 1C).

Next, the substrate 11 is rotated in a horizontal plane while the same resin film composition (convex composition) as that used for the resin film 18 is injected into the concave portion 19, and the resin film composition is injected into the entire concave portion 19. I do. At this time, since the second lubricant of the resin film composition is seeping out on the surface of the resin film 18, the resin film composition injected into the concave portion 19 repels the second lubricant, and 19 Do not protrude outside, and due to surface tension,
This resin film composition rises higher than the surface of the resin film 18.

Next, when the surface of the substrate 11 on which the resin film 18 is formed is irradiated with ultraviolet rays to cure the resin film composition disposed in the concave portion 19, the pattern follows the pattern of the mask film 17. A convex portion 20 (a convex resin film) is formed (FIG. 1D).

FIG. 2C shows the optical recording medium 10 of the present invention in a state in which the convex portions 20 are formed. A resin film 18 is formed on the substrate 11 of the optical recording medium 10, and a ring-shaped recess 19 having the same center as the substrate 11 is formed on the resin film 18. In the concave portion 19, a convex portion 20 is formed so as to rise from the surface of the resin film 18. The metal thin film 13 described above is disposed on the outer peripheral portion of the convex portion 20, and a region on the outer peripheral side of the convex portion 20 becomes an information recording region 38. The convex portion 20 is provided on the optical recording medium 10.
Function as an elevation film.

Test pieces (Examples 1 to 3) were prepared in the same process as the above-described method for forming the resin film (convex portion 20), and the convex portion 20 was observed to evaluate its shape.

Here, a polyfunctional oligomer (Aronix M6250, Toagosei Co., Ltd.) is used as the photopolymerizable curing resin.
To 30 parts by weight of a bifunctional monomer (NPGD)
A, Nippon Kayaku Co., Ltd.) 80 parts by weight were mixed, and as a photopolymerization initiator, irkaguer 184, Ciba Specialty Chemicals Co., Ltd.) Ethylene dimethylsiloxane (KF96, Shin-Etsu Chemical Co., Ltd.) as the first lubricant, a second lubricant which is incompatible with the above-mentioned photopolymerizable cured resin but compatible with the first lubricant Ethylene oxide-modified silicone oil (TSF4441, Toshiba Silicone)
The above compositions were homogenized using a homogenizer to prepare a liquid resin film composition. When curing the resin film composition, ultraviolet rays of 300 mJ / cm ² were irradiated.

Examples 1 to 3 are cases where the total content (% by weight) of the first lubricant and the second lubricant in the resin film composition is different. The results of the evaluation test are shown in Table 1 below.

[0031]

[Table 1]

Comparative Example 1 is a case where the resin film composition was applied directly on the substrate 11 without forming the resin film 18 to form the projections. In Comparative Example 2, similarly to Comparative Example 1, a mixture of the first lubricant and the second lubricant was applied onto the substrate 11 without forming the resin film 18, and the protrusions 20 were formed thereon. Is formed.

As compared with Comparative Examples 1 and 2, in Examples 1 to 3, liquid dripping and bleeding of the resin composition injected into the recess did not occur.
The projection 20 having a good shape was obtained. In particular, Examples 2 and 3
Then, the resin solution that had protruded out of the concave portion 19 was returned into the concave portion 19 by the lubricant, and the convex portion 20 in a particularly favorable state could be obtained.

In the first to third embodiments, the case where the resin film 18 and the projection 20 are formed by using the same resin film composition has been described, but the present invention is not limited to this. Although different resin film compositions can be used for each, it is desirable to use the photopolymerizable cured resin as the binder. Further, the resin film 18 includes one or more first lubricants which are compatible with the binder used in the resin film composition, and the first lubricant which is incompatible with the binder but is incompatible with the binder. Desirably contains a second lubricant having compatibility. At this time, the binder of the resin film composition (projection composition) constituting the projections 20 includes:
It is desirable to use one that is incompatible with the second lubricant.

In the above embodiment, when the resin film 18 is formed,
Although the resin film composition was applied by a spin coating method, other methods can be used. For example, the resin film composition may be applied using a foil coater.

In molding the convex portion 20, if the resin film composition does not inhibit the photopolymerization reaction, for example, a coloring agent or the like can be added. It is also possible to form the raised protrusion 20.

After the projection 20 is formed, the resin film 18 may be peeled off. When the resin film 18 is left on the substrate 11, a transparent resin that does not disturb the reading of information on the optical recording medium may be used for the resin film composition forming the resin film 18.

In the above-described method of forming a convex portion, a case has been described in which a convex portion (elevation film) is formed on an optical recording medium. It can also be used for decoration.

[0039]

According to the present invention, a convex resin film having a fine pattern can be formed on the surface of an object to be processed.

[Brief description of the drawings]

FIGS. 1A to 1D are diagrams for explaining an example of an optical recording medium and a resin film forming method of the present invention.

FIGS. 2A to 2C are cross-sectional views for explaining an optical recording medium of the present invention together with a step of forming a resin film.

FIG. 3 is a sectional view for explaining a conventional optical recording medium.

[Explanation of symbols]

 Reference Signs List 10 optical recording medium 11 processing object (substrate) 13 recording film (metal thin film) 17 pattern film (mask film) 18 resin film 19 concave portion 20 convex portion (convex) Resin film)

Claims (6)

[Claims] 1. A step of forming a pattern film of a desired shape on an object to be processed, and supplying a resin film composition containing a photopolymerizable cured resin to a side of the object to be processed on which the pattern film is formed. A step of irradiating at least a resin film composition on the object to be processed with ultraviolet rays to cure the resin film composition and form a resin film; and forming the pattern film together with the resin film on the pattern film. Peeling and forming a concave portion in the resin film, supplying a convex portion composition containing a photopolymerizable curable resin to the concave portion, and applying the convex portion composition in a state of being raised from the resin film surface A method of forming a convex resin film, comprising: a step of forming a layer; and a step of irradiating ultraviolet rays to an application layer of the convex composition to cure the convex composition. 2. The resin film composition has a first lubricant compatible with the photopolymerizable cured resin and a second lubricant compatible with the photopolymerizable cured resin. The method according to claim 1, wherein the photopolymerizable cured resin of the convex composition has at least incompatibility with the second lubricant. 3. A method according to claim 2, wherein said first lubricant and said second lubricant are silicone-based lubricants. 4. The method for forming a convex resin film according to claim 1, wherein the viscosity of the convex composition is 10 mPa · s or more and 1000 mPa · s or less. 5. The method according to claim 4, wherein the height from the bottom surface of the concave portion to the surface of the resin film is 3 μm or more. 6. A disk-shaped laminated substrate having a recording film, a resin film formed on the laminated substrate, and a ring-shaped recess provided on the resin film and having the center coincident with the center of the laminated substrate. An optical recording medium having a ring-shaped convex portion which is disposed in the concave portion and whose surface is raised from the surface of the resin film.