JPH0822642A - Optical recording medium and its production - Google Patents

Abstract

PURPOSE:To prevent recording and reproducing performance of an optical recording medium from being deteriorated. CONSTITUTION:The objective optical recording medium is produced through at least one process selected from a process for coating the top of a substrate with a resin for forming a groove, a process for coating with an org. protective film and a process for bonding a 1st optical recording medium to a 2nd optical recording medium or a protective plate. After the process, the edge of the substrate is polished by a polishing means so as to remove a resin overflowing the edge of the resultant disk from the substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical recording medium having at least a recording layer, and is particularly characterized by a method for treating an end surface of a disc.

[0002]

2. Description of the Related Art Conventional optical recording media are manufactured by injection molding or 2P (Photo Polymer) molding to produce a flat substrate having tracking grooves or pits on one side, and an optical recording medium layer is formed on the surface of the flat substrate. It is formed by vacuum evaporation, sputtering, and spin coating, and a recording film protection measure such as an organic protective film is applied on top of this. The optical recording media manufactured in this way are of a type for single-sided recording which is used as it is or used by adhering a protective substrate, and for double-sided recording which is adhered so that the surfaces on which optical recording medium layers are formed face each other. . A reactive adhesive such as a photo-curable adhesive or a thermosetting adhesive, a hot-melt adhesive, or the like is used for bonding the substrates.

[0003]

When the optical recording medium manufactured by the conventional manufacturing method is incorporated into a cartridge and recording / reproducing is performed, a recording / reproducing defect accident may occur. As a result of research to find out the cause, the inventor of the present application found out that there is a problem in the method of manufacturing an optical recording medium. In the conventional method for manufacturing an optical recording medium, it is unavoidable that a part of the 2P material, the organic protective film, or the bonding adhesive sticks out from the end surface of the substrate during manufacturing from the end surface of the inner and outer peripheral portions of the substrate. As a result, some of the resin peels off inside the disk cartridge during use and adheres to the substrate surface,
There was a risk of causing a recording / reproduction failure accident. Therefore, in the case of an optical recording medium using a plastic substrate, after the organic protective film is formed on the end plate disk and after the bonding is completed on the bonded disc, the organic material or resin or Measures have been taken to cut off the adhesive together with the substrate.

However, when a glass substrate is used as the substrate, it is not possible to cut the substrate end face with a laser. Further, even when the resin on the end surface of the substrate is scraped off with a cutting tool or the like, there is a high possibility that the substrate will be scratched or destroyed, and there is no suitable processing method.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for peeling resin that has run off without damaging the substrate. That is, in an optical recording medium using at least one of a groove-forming resin, an organic protective film, and a bonding means for bonding as a constituent member, the resin protruding from the end face of the substrate is coated with abrasive particles on a resin film. It is a method for manufacturing an optical recording medium, characterized in that it is peeled off with the polishing tape. Further, the base film of the polishing tape to be used is made of polyester or polyurethane in order to scrape off only the protruding resin without damaging the substrate. Further, it is characterized in that an abrasive tape having an average particle size of 50 to 10 microns is used.

Therefore, the first aspect of the present invention is the "process of applying a resin for forming a groove on a substrate, a process of applying an organic protective film, or a process of adhering optical recording media having protective plates or recording layers to each other by an adhering means. In the method for producing an optical recording medium having at least any one step, the end face of the substrate is polished by a polishing means after each of the steps, the method for producing an optical recording medium (claim 1) ". provide.

[0007]

FIG. 1 is a schematic diagram showing the structure of an optical recording medium using a double-sided recording type glass substrate. A 2P layer 2 in which guide grooves and prepits of a stamper are transferred by a photocurable resin is formed on a substrate 1 which has been mirror-polished. At this time, the resin often squeezes out at a part of the outer peripheral portion. 2P
The recording layer 3 is formed on the surface of the layer by vacuum deposition or sputtering. Next, a photocurable organic protective film 4 is formed to protect the recording layer. Usually, after forming a coating film by the spin coating method, it is cured by irradiation with ultraviolet rays. In the case of spin coating, it is unavoidable that the resin adheres to the end surface of the substrate when the resin is spread over the periphery. A hot melt type adhesive 5 is often used for adhering a single plate disk. The adhesive is roll-coated, but a part of the applied adhesive may protrude from the end surface of the disc.

FIG. 2 shows the general structure of the polishing tape used in the present invention. Abrasive particles 13 are applied together with a binder 12 on a base film 11. A polyester resin is used as the binder.
The tape needs to have a structure suitable for scraping off only the resin protruding to the end face without damaging the substrate. It is necessary to use polyester or polyurethane resin for the base film. When a harder film is used as a base, polishing streaks are likely to remain on the substrate surface. Further, it is necessary to select an abrasive having a particle size of 10 μm or more and 50 μm or less. If the particle size exceeds 50 μm, scratch marks are left on the surface of the substrate, and if it is 10 μm or less, the peeling efficiency of the protruding resin deteriorates. For example, when glass is used for the substrate, if a soft polyester resin is used for the base film, even if the abrasive is a hard alumina-based material, the surface of the substrate is hardly damaged.

FIG. 3 shows an example of a processing device for realizing the present invention. Mount the disk 22 on the spindle 21,
Fix with the tightening part 23. On the other hand, the polishing tape is wound around the reel 24, and the winding reel 25 is placed on the side opposite to the disc. In addition, the members 26 and 2 that regulate the pressing pressure
7 is provided. At the time of peeling off the protruding resin, the end face is pressed against the surface of the running polishing tape while rotating the spindle on which the disc is mounted at a constant speed. The optimum polishing conditions are determined by adjusting the tension of the polishing tape and the pressing strength of the substrate. As described above, the present invention provides a method of peeling the protruding resin without damaging the substrate. That is, in an optical recording medium using at least one of a groove forming resin, an organic protective film, and an adhesive for bonding as a constituent member, the resin protruding from the end face of the substrate is coated with abrasive particles on a resin film. It is a method for manufacturing an optical recording medium, characterized in that it is peeled off with the polishing tape. In addition, in order to scrape off only the protruding resin without damaging the substrate, the material of the base film of the polishing tape used is polyethylene or polyurethane resin. Further, the size of the abrasive particles is characterized by using an abrasive tape having an average particle diameter of 10 μm to 50 μm. According to the present invention, the resin protruding to the end surface of the disk can be peeled off without damaging the substrate.

[0010]

Example: Outer diameter 130 mm, inner diameter 10 mm, thickness 1.1
A photocurable resin layer (2P layer) having grooves transferred from a stamper was formed on a 5 mm glass substrate. The 2P layer has an average thickness of 30 μm and is formed from a radius of 20 mm to 65 mm,
A part of the outer peripheral portion protruded from the end face of the substrate.

A sputtered film was formed on this substrate in the order of the electroconductive film, the magneto-optical recording layer, and the electroconductive film. Next, a photocurable organic protective film was applied with a spin coater and cured with an ultraviolet irradiation device. The organic protective film has an average thickness of 5 μm and a radius of 15 m.
It is formed from m to the outermost circumference. The protruding organic protective film was adhered to the outer peripheral edge surface of the substrate over substantially the entire circumference. The hot melt adhesive was applied to the substrate using a roll coater. The adhesive was applied to the entire surface to be bonded with an average thickness of 30 μm. Also, when roll-coating, squeeze-out of the adhesive was seen at the first and last parts.

The adhesive-coated surfaces of the two veneer disks were put together and pressure-bonded. The disk thus manufactured was attached to a spindle, and the substrate was fixed with a screw. Further, a polishing tape in which alumina having an average particle diameter of 50 μm was applied on a polyester base film having a width of 12.7 mm and a thickness of 0.1 mm was set on a reel, and when the disk substrate end face was pressed against this tape, 5 k was applied to the substrate end face.
The tape tension was adjusted so that a force of g / cm ² was applied.
When operated at a disk rotation speed of 1 rotation / minute and a tape running speed of 5 cm / minute, all the resin adhering to the entire circumference was peeled off in 5 minutes and the glass surface was exposed.

[0013]

[Comparative Example 1] A glass substrate disk having a diameter of 130 mm with resin protrusion to the same extent as in the example was set in the same polishing apparatus as in the example, and the width and thickness of the base film were the same as in the example and the material was vinyl acetate. Using a polishing tape made of a resin and having an average particle diameter of 50 μm, polishing was performed at the same disk rotation speed, tape traveling speed, and substrate pressing pressure.
When the edge surface of the substrate after polishing was observed with a microscope, numerous scratches were observed on the substrate in the running direction of the polishing tape.

[0014]

[Comparative Example 2] The base film of the polishing tape had a thickness of 0.1.
2mm average particle size is used for abrasive
Disk end surface polishing was performed for 5 minutes under the same conditions as in Comparative Example 1 except that the alumina coated with m was used. When the edge surface of the substrate was observed after polishing, a large number of resins remained.

[0015]

According to the present invention, the resin protruding to the end surface of the disk can be efficiently peeled off without damaging the substrate, and even when the optical recording medium is manufactured using the glass substrate, the end surface of the substrate efficiently protrudes. The resin and adhesive can be removed. Further, the cured resin does not scatter in the cartridge, and the recording / reproducing performance is not deteriorated.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the structure of a double-sided recording type magneto-optical disk according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the structure of the polishing tape of one example according to the present invention.

FIG. 3 is a schematic view of a polishing apparatus according to an embodiment of the present invention.

[Explanation of Codes] 1 ... Glass substrate 2 ... 2P layer 3 ... Recording layer 4 ... Organic protective film layer 5 ... Adhesive layer 11 ... Abrasive tape, base film 12 ...・ Binder 13 ・ ・ ・ Abrasive material 21 ・ ・ ・ Spindle 22 ・ ・ ・ Disk 23 ・ ・ ・ Tightening parts 24 ・ ・ ・ Supply reel 25 ・ ・ ・ Winding reels 26, 27 ・ ・ ・ Tension adjusting parts

Claims (7)

[Claims] 1. At least one step of applying a groove-forming resin on a substrate, applying an organic protective film, or adhering optical recording media having protective plates or recording layers to each other by an adhering means. In the method for producing an optical recording medium having the above step, the end face of the substrate is polished by a polishing means after each of the steps. 2. A manufacturing method, wherein the polishing means according to claim 1 is one in which an abrasive is provided on a film-shaped member. 3. A manufacturing method, wherein the film-shaped member according to claim 2 is made of polyester or polyurethane resin. 4. A manufacturing method, wherein the abrasive according to claim 1 or 2 contains at least one of aluminum oxide, silicon carbide and chromium oxide. 5. The average particle size of the abrasive according to claim 4 is 5.
Manufacturing method characterized by being 0 μm to 10 μm 6. A method according to claim 1, wherein the substrate is made of polycarbonate, polyolefin, acrylic, epoxy resin, tempered glass or soda lime glass. 7. An optical recording medium manufactured by the manufacturing method according to claim 1 and having an end surface polished.