JP2002230853A - Method of manufacturing optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means of stably laminating sheets to plane by using the sheets for light transmission layers and a method capable of easily peeling and supplying the sheet after bonding and making stable manufacture. SOLUTION: The method of manufacturing optical recording media by forming the light transmission layers on one or both surfaces of a substrate and subjecting the media to reproducing and recording of information by irradiation of the media with light from the light transmission layers, in which the light transmission layers are laminated to the substrate by UV curing adhesives in the state that the light transmission layers are corrected to the flat surfaces by UV transmission members having the planes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium and a method for manufacturing the same, and more particularly, to an optical recording medium capable of high-density recording and a method for manufacturing the same.

[0002]

2. Description of the Related Art As an example of a structure in which a light transmitting layer is made of a UV resin or a sheet (film), see JP-A-8-235.
No. 638 discloses that the numerical aperture (NA) of an objective lens of an optical pickup is increased with the improvement of the recording density on an optical information recording medium.
To reduce the diameter of the reproduction light spot (by increasing the NA of the objective lens, the spot diameter decreases, but the allowable amount of disc tilt (tilt) with respect to the optical axis of the optical pickup decreases. (A method of reducing the thickness of the substrate so as to minimize the influence on the tilt). This is one in which a substrate portion serving as a light transmitting layer is made extremely thin using an ultraviolet curing resin or sheet. As an example of a configuration in which a light transmitting layer is made of UV and a groove in which a UV resin is embedded is provided on the substrate, the technology described in Japanese Patent Application Laid-Open No. 9-13447 discloses a substrate (information recording layer A groove for receiving the resin is formed on the (side), and the thickness is made uniform by filling the groove. Further, as an example of a manufacturing method for equalizing the thickness when the light transmitting layer is formed by UV, the technology described in Japanese Patent Application Laid-Open No. H11-31338 discloses a technique in which a flat jig for defining the resin thickness is arranged on the coating surface. The flat jig is used to achieve uniform thickness and flatness.
In each case, an ultraviolet curable resin is formed in the light transmitting layer instead of the sheet. These common challenges include:
The problem is how to obtain the uniformity (flatness) of the thickness. When a sheet is used, the thickness is regulated by the sheet. Is difficult to stick on a flat surface on the substrate side, and productivity is very poor. Therefore, it has been made that the light transmitting layer is formed of an ultraviolet curable resin.

On the other hand, when the ultraviolet-curable resin itself is formed on the light transmitting layer, there are the following problems. Generally, an ultraviolet curable resin undergoes volume shrinkage upon curing. The amount of shrinkage depends on the material, but is generally about 7% to 10%. Therefore, even if the thickness of the UV-curable resin is uniform in a liquid state as in the prior art, the thickness changes due to curing shrinkage, and it is difficult to cure uniformly, and it is a major problem that the resin does not become flat. is there. JP-A-11-31
The method disclosed in Japanese Patent Publication No. 338 has an aim of transferring a flat surface using a flat jig. However, when a jig is set to a desired thickness and the resin is cured, the resin is not partially transferred due to volume shrinkage. There will be parts. further,
Another problem is the problem of peeling after being cured. If the adhesiveness is low, it is easy to peel off, but on the other hand, the adhesiveness to the substrate having the recording layer is also low, resulting in insufficient adhesive strength. This is a major problem for product reliability. In addition, if a highly adhesive material is used to increase reliability, it is difficult to peel off from the flat jig, and the light transmitting layer may be destroyed without interfacial peeling, or the transferred plane may be broken by deformation. become.

[0004]

SUMMARY OF THE INVENTION Accordingly, in view of the above-mentioned prior art, an object of the present invention is to use a sheet for a light transmitting layer, stably bond the sheet to a flat surface, and provide a sheet after the bonding. An object of the present invention is to provide a method capable of easily performing peeling of a sheet and supplying a sheet, and enabling stable production.

[0005]

Means for Solving the Problems The object of the present invention is to provide (1) a light transmitting layer formed on one or both surfaces of a substrate and irradiating light from the light transmitting layer to reproduce and record information. A method of manufacturing an optical recording medium, comprising: bonding a light transmitting layer to a substrate with an ultraviolet curable adhesive in a state where the light transmitting layer is corrected to a flat surface by an ultraviolet transmitting member having a flat surface. (1) The method according to the above (1), wherein the light transmitting layer is formed of a sheet of polycarbonate or amorphous polyolefin, and a quartz plate is used as a flat ultraviolet transmitting member. And (3) that the thickness of the light transmitting layer is 10 μm to 300 μm.
μm, the method for manufacturing an optical recording medium according to the above item (1) ”, (4)“ a plurality of the light transmitting layer sheets are laminated on a flat, ultraviolet transmitting member. (5) The method for manufacturing an optical recording medium according to (1), wherein the optical recording medium is set in a state.
"The method for manufacturing an optical recording medium according to the above mode (1), wherein the correction and lamination of the light transmitting layer sheet using the ultraviolet light transmitting member having the flat surface are performed by an adhesive." (6) The manufacturing of the optical recording medium according to the above (5), wherein, when laminating the light transmitting layer sheet, a sheet that can transmit ultraviolet light is laminated between the sheets. (7) "The method for manufacturing an optical recording medium according to the above (6), wherein a polyethylene terephthalate film is used for the mount", (8) "Silicone or fluorine-based mount for the mount. (9) The method for manufacturing an optical recording medium according to the above (6) or (7), wherein the release material is coated. Hard In a state where the mold adhesive is applied, ultraviolet light is irradiated from the light transmitting layer side to the substrate side to bond the substrates together, and then the light transmitting layer sheet is peeled off to manufacture an optical recording medium. Manufacturing method of recording medium ",
(10) "The laminated light transmitting layer is one head,
A method for manufacturing an optical recording medium, comprising using a device for bonding a light transmitting layer having two or more heads ”, (1.
1) A method for manufacturing an optical recording medium, wherein the head of the light transmitting layer uses an apparatus for bonding a light transmitting layer having an automatically supplied system.

Hereinafter, the configuration of the present invention will be described in detail. A method for manufacturing an optical recording medium in which a light transmitting layer is formed on one or both surfaces of a substrate, and light is irradiated from the light transmitting layer side to reproduce / record information, wherein the light transmitting layer and the substrate are Laminated with an ultraviolet-curable adhesive. At the time of bonding, the light transmission layer is made of a member that transmits ultraviolet light, and has a flat jig, for example, a flat jig made of glass or quartz that has been corrected to the flat surface. It is a feature. Since the ultraviolet curable adhesive is cured while being corrected, the light transmitting layer and the substrate are bonded together while the flat surface of the jig is maintained, and the optical recording medium is completed.

The light transmitting layer is made of a sheet of polycarbonate or amorphous polyolefin. These are materials used as substrates for optical recording media because of their good light transmittance and small deformation due to water absorption and the like. The thickness of these light transmitting layers is 10 μm to 300 μm.
It is. When the light transmitting layer has a thickness of 300 μm or more, a method of bonding substrates by injection molding has been established as already manufactured as a DVD. However, in a recording medium having a higher density than that of a DVD, the NA of the pickup lens is increased, and durability against tilt of the substrate is required. In this case, it is possible to cope with this by making the substrate thinner. However, when the substrate thickness is 300 μm or less, injection molding cannot be used. The light transmission layer has a degree of freedom in design by adjusting the thickness, but if it is 10 μm or less, it is difficult to prepare a sheet, and it is too thin to be easily handled during manufacture.

The light transmitting layer is bonded in a state where it is corrected by a flat jig, but it is difficult to stabilize a sheet feeding method and flattening due to its thinness. In the present invention, the problem of correction and supply to a flat surface is solved by laminating the light transmitting layer in a layered manner. Lamination is performed by using an adhesive between sheets or using an adhesive material, and is adhered so as not to damage the flat surface. After lamination, the laminated film is peeled off to complete the optical recording medium. When peeling off the laminate, it is necessary to peel off the sheets one by one, so that the adhesive force between the laminated sheets is weaker than the adhesive strength between the sheet and the substrate bonded with the ultraviolet curing adhesive. Need to be designed. In order to peel off the sheets one by one more reliably, hold the backing sheet between the sheets and adjust the adhesion, and also provide tabs on the backing sheet to ensure the work of peeling off the backing sheet it can. Since the mount needs to transmit ultraviolet rays, polyethylene or polyethylene terephthalate having optical transparency is used. In particular, polyethylene terephthalate is an optimal material for the backing paper because it is stiff and hard to wrinkle.
Further, in order to ensure the peeling of the sheet, the backing sheet may be coated with a release material. For these, a silicon-based or fluorine-based release material is used.

By preparing a plurality of sheets laminated on a flat jig, it becomes possible to supply the sheets smoothly without cutting the sheets in manufacturing. In addition, the automatic supply enables the production as a sheet bonding system.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation will be described below in detail. FIG. 1 is the simplest of the present invention. In the drawing, a flat jig (1) is made of quartz having good ultraviolet transmittance, and a polycarbonate sheet (2) of 100 μm is adsorbed in a vacuum. Quartz plate has a surface roughness of 10n by plane processing
m or less. The sheet has the same diameter as the substrate.
It is cut in advance into a circle of nm. on the other hand,
The substrate (3) has a guide groove formed by injection molding.
The ultraviolet-curable adhesive (4) is applied to a 1 mm-thick polycarbonate substrate on which a reflective layer, a dielectric layer, a recording layer, and a protective layer are provided by sputtering. Place the sheet that has been flattened by the jig on this,
After the adhesive (4) is evenly penetrated between the substrate (3) and the sheet (2) by spinning, the sheet is irradiated with ultraviolet rays (5) from the sheet side by an ultraviolet irradiation device to be cured.
Thereafter, the flat jig is peeled off from the sheet to obtain 1.2 mm.
A rewritable optical recording medium having a thickness of mm was completed. The completed one is shown in FIG.

FIGS. 3 and 4 show the state of the laminated sheet. FIG. 3 shows a laminated sheet, and FIG.
Indicates a laminate obtained by sandwiching a polyethylene terephthalate mount between sheets. These are made to oppose the substrate and the sheet similarly to FIG. 1, and an adhesive is filled between them.
As the method, there is a method in which an adhesive is injected into a gap previously set or spin-coated as described above, and the gap is filled with a penetrating force. As in FIG. 1, ultraviolet rays are irradiated from the sheet side to cure the adhesive, and then the bonded sheet is peeled off to obtain a recording medium as shown in FIG. As shown in FIG. 4, the presence of the backing sheet makes it possible to easily and surely peel off the sheet in the process.

FIG. 5 is a view for explaining a case where a plurality of sheets laminated on a quartz plate as shown in FIG. 3 or FIG. 4 are prepared and used for manufacturing. By preparing a plurality of heads for laminated sheets, it is possible to produce sheets without interruption of sheet supply. The quartz plate from which the sheet has disappeared is again used by laminating the sheet. When the head is automatically supplied as shown in FIG. 6, it is possible to construct a stable production line as a production system.

[0013]

As is apparent from the detailed and concrete description, according to the first aspect of the present invention, a sheet can be stably stuck on a flat surface on a substrate, and according to the second aspect of the present invention. UV light can be irradiated through a flat jig and a sheet, and bonding can be performed while holding a flat surface. According to the present invention, a thin light transmitting layer that cannot be achieved by injection molding can be provided. According to the fourth aspect of the present invention, the sheet can be stably supplied without wrinkling. According to the fifth aspect of the present invention,
The sheet bonded to the substrate can be easily peeled off. According to the present invention of claim 6, the sheet bonded to the substrate can be stably and easily peeled off.
According to the present invention, the sheets can be laminated without impairing the ultraviolet transmittance, and can be stably and easily peeled off. According to the present invention of claim 8, peeling of the sheets one by one becomes more stable, According to the invention of claim 9,
2. A sheet can be stuck while maintaining the flatness of the supplied sheet, and the sheet can be stably supplied.
According to the present inventions of 0 and 11, the sheet can be supplied more stably, and an extremely excellent effect that it can be applied as a continuous production system can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing the simplest rewritable optical recording medium according to the present invention.

FIG. 2 is a diagram showing a completed drawing of FIG. 1;

FIG. 3 is a diagram showing a state in which sheets are laminated in the present invention.

FIG. 4 is a view showing a laminate in which a mount of polyethylene terephthalate is sandwiched between sheets in the present invention.

FIG. 5 is a diagram illustrating a case where a plurality of sheets laminated on a quartz plate are prepared and used for manufacturing in the present invention.

FIG. 6 is a diagram showing a production system for automatically supplying a head of a laminated sheet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat jig (plate) 2 Light transmission layer (sheet) 3 Molded substrate 4 Ultraviolet curing adhesive 5 Ultraviolet irradiation light 6 Backing paper

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/24 534 G11B 7/24 535E 535 535K 535L C08L 69:00 // C08L 69:00 B41M 5/26 Y F term (reference) 2H111 EA03 FA11 FA30 4F006 AA36 BA01 CA01 EA03 4J040 MA10 MA11 MB03 MB05 NA21 PA32 PA42 5D029 LA02 LB02 LB13 LB17 LC04 RA08 RA30 RA38 5D121 AA04 FF03 FF11 FF13 FF18 GG02 GG10 GG10

Claims (11)

[Claims] 1. A method for manufacturing an optical recording medium in which a light transmitting layer is formed on one or both surfaces of a substrate, and light is irradiated from the light transmitting layer to reproduce and record information.
The light transmitting layer has an ultraviolet transmitting member having a flat surface,
A method for manufacturing an optical recording medium, wherein the optical recording medium is bonded to a substrate with an ultraviolet curable adhesive in a state where the optical recording medium is flattened. 2. The method for manufacturing an optical recording medium according to claim 1, wherein the light transmitting layer is made of a sheet of polycarbonate or amorphous polyolefin, and a quartz plate is used as a flat ultraviolet transmitting member. . 3. The light transmitting layer has a thickness of 10 μm to 300 μm.
2. The method for manufacturing an optical recording medium according to claim 1, wherein the thickness is μm. 4. The method for manufacturing an optical recording medium according to claim 1, wherein a plurality of the light transmitting layer sheets are set in a state of being laminated on a flat ultraviolet transmitting member. 5. The method for manufacturing an optical recording medium according to claim 1, wherein the correction and lamination of the light transmitting layer sheet using the ultraviolet light transmitting member having the flat surface are performed by an adhesive material. . 6. When laminating a light transmitting layer sheet,
6. The method for manufacturing an optical recording medium according to claim 5, wherein the sheet is laminated by sandwiching a mount capable of transmitting ultraviolet light between the sheets. 7. The method for manufacturing an optical recording medium according to claim 6, wherein a polyethylene terephthalate film is used for the mount. 8. The method according to claim 6, wherein the mount is coated with a silicon-based or fluorine-based release material.
Or a method for manufacturing an optical recording medium according to item 7. 9. In a state where an ultraviolet curable adhesive is applied between the laminated light transmitting layer and the substrate, ultraviolet rays are irradiated from the light transmitting layer side to the substrate side and bonded, and then light A method for manufacturing an optical recording medium, comprising peeling a transmission layer sheet to manufacture an optical recording medium. 10. A method for manufacturing an optical recording medium, comprising using a laminated light transmitting layer as one head and using an apparatus for bonding light transmitting layers having two or more heads. 11. A method for manufacturing an optical recording medium, wherein the head of the light transmitting layer uses an apparatus for bonding a light transmitting layer having an automatically supplied system.