JPH10124932A - Optical recording medium with optical recording proof and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the surface properties, such as scratch resistance, wear resistance and contamination resistance by subjecting only the optical recording proof part to a surface treatment with a UV laser. SOLUTION: A reflection layer 8 is formed by material vapor deposition, etc., of Al, etc., on the surface of an information recording region 2 having many pits 7 formed by compression molding, injection molding, etc., on the surface of a transparent resin substrate 6 consisting of an acrylic resin, polycarbonate resin, etc., then, a protective layer 7 of the pits 7 is formed by coating. A protective film 9 is formed by spin coating of a UV curing resin coating liquid, such as acrylate resin. The information recording region 2 is formed to completely cover the same. The optical recording proof 1 is attached to the surface reforming part 5 of the protective film 9. While the UV rays by the laser are used for the surface reforming, only the required part of the surface is rapidly subjected to surface reforming by using an excimer laser obtd. by exciting a gaseous mixture composed of a rare gas and halogen. The light source may be arranged apart from the optical recording medium 10 with the optical recording proof. This device is suitable for a continuous production apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CD (compact disk), a CD-ROM (read-only compact disk), a DVD (digital versatile disk),
The present invention relates to an optical recording medium, such as an optical card, for distributing large-capacity digital data, and more particularly to an optical recording medium having an optical recording certificate based on an optical diffraction pattern represented by a hologram.

[0002]

2. Description of the Related Art Today, as the capacity of digital information recording by computer processing has increased dramatically, digital information has been stored in optical recording media called optical disks, such as CD-ROMs, which are large-capacity information recording media. In service. In an optical recording medium such as a CD-ROM, by providing a large number of physical fine irregularities called pits,
Records digital information. In addition, with such high-capacity digital information, a large amount of highly valuable work information as a copyrighted work is recorded along with the increase in the recording content. However, in such an environment, the digital information can be easily and accurately copied, and the recorded high-value-added work information is illegally copied, so that the same optical information that cannot be distinguished at first glance It has become easy to create counterfeit products of recording media, and this has created a situation in which the purpose and significance of the information distribution and copyright activities of the copyrighted work are greatly violated. Therefore, there is a demand for measures such as attaching an authentication record certificate, which is a certificate certifying that the work is legitimate, to the optical recording medium capable of performing such duplication and high-density digital recording.

[0003]

In such a situation, C
Attempts have been made to apply holograms to D-ROMs as authentication records so that those without a predetermined hologram cannot reproduce digital information. There has also been proposed a form in which a hologram is provided on a pit-forming surface inside an optical recording medium, and whether or not the hologram is present is used to visually determine whether the hologram is true or false. However, in this method, the position of the hologram needs to be avoided from the information recording area where the pit is located, so the position and size are limited. In order to duplicate pits and holograms by compression molding, injection molding, or the like, exposure and formation of both pits and holograms (different from pits called light interference patterns) on one photoresist are performed, or separate holograms are formed. When a photoresist on a substrate is formed by exposure and finally formed into one stamper, or each stamper is placed in a mold of a molding machine and molded, a complicated manufacturing process is required. Another form in which an optical recording medium is provided with an optical recording certificate such as a hologram as an authentication recording certificate is a form in which the optical recording medium is formed on the surface of the optical recording medium by transfer using a transfer foil or by sticking a label. But CD
-The surface of the optical recording medium such as ROM (on the side opposite to the information reading surface) is coated with an ultraviolet curable resin for the purpose of abrasion resistance, scratch resistance, stain resistance, etc. Sufficient adhesion cannot be obtained because the protective film, which is a three-dimensionally crosslinked cured resin layer, is provided. This is because the protective film contains a small amount of wax in order to further enhance the abrasion resistance, so that the affinity with the adhesive is extremely low at the molecular level, and the adhesion decreases over time. Further, items are often printed on the protective film by screen printing or the like. However, since UV curable ink is used in terms of continuous productivity, sufficient adhesion cannot be obtained on the surface on the ink. For this reason, the optical record certificate may be peeled off and abused. This is because, when the optical record certificate is peeled off, the optical record certificate itself may be falsified by a method of copying the unevenness of the light diffraction pattern by any method. Therefore, it is required that the optical recording certificate attached to the optical recording medium be securely adhered and not peeled off so that the light diffraction pattern cannot be imitated.

Therefore, in order to improve the adhesion, the surface of the protective film resin has been conventionally modified by corona discharge. However, the effect of this surface treatment is only temporary because of deterioration with time due to the atmosphere. Adhesion is not durable due to low molecular weight substances such as wax bleeding from the inside to the surface, mainly to generate polar groups as modifying groups of the polymer chain of the resin in the extremely shallow part of the resin surface. Was. Alternatively, it has been proposed to use a UV surface treatment apparatus to break the chemical bonds of the polymer chains on the resin surface with the energy of UV rays to generate a polar group, thereby improving the easy adhesion and increasing the adhesion. . In the case of treatment with ultraviolet light, the above-mentioned problem of the decrease in adhesion due to bleeding of the low-molecular substance has the effect of saturating the unsaturated bonds of the low-molecular substance and promoting the bonding of the low-molecular substance to the polymer chain. It is resolved because it has been modified and fixed at the molecular level. However, since the surface is uniformly irradiated with ultraviolet light, the inherent properties of the protective film are lost, such as a decrease in the abrasion resistance of the surface where no optical record certificate is given. there were. In addition, the effect of such surface treatment by the UV surface treatment apparatus is determined by the correlation between the irradiation light amount, irradiation light energy intensity, irradiation time, and irradiation distance, but the irradiation time is particularly long and rapid treatment is not possible. Met.

[0005] As described above, the method of transferring an optical record certificate onto the surface of an optical recording medium by transfer or sticking has a problem in its adhesive strength, and a sufficiently reliable one has not been obtained.
On the other hand, there has been proposed a method of forming unevenness of an optical diffraction pattern by heat embossing on the surface of an optical recording medium instead of transferring or sticking, but in order to emboss heat, the surface is plastically deformed by heat. It is necessary to apply the protective film before forming the protective film because the protective film to be highly three-dimensionally crosslinked cannot be heat-embossed. To emboss,
In terms of the heating temperature and the heating amount, it is difficult to process the light diffraction pattern of the hologram. That is, when it is necessary to separately form the digital information formed by the pits and the light diffraction pattern, this method is inconvenient. Separately forming refers to forming a mother plate using a dedicated device for digital information pit formation processing, duplicating and then adding an optical diffraction pattern as necessary for shipping, or pits already copied Or a case where a light diffraction pattern is added to a medium that does not rely on hot emboss duplication, such as a magneto-optical recording medium or an optical bubble recording medium.
The solution to the problem of hot embossing of the light diffraction pattern after the formation of the pit is to form the pit and the light diffraction pattern at the same time, as described above. Also,
When a pit and a light diffraction pattern are formed simultaneously, the pit formation surface and the light diffraction pattern formation surface are the same, so that it is inevitable that the entire surface cannot be used for pit formation, and digital information recording On the other hand, in the light diffraction pattern formation by sticking or transfer, which is limited by the area, there is an advantage that the entire surface may be used for pit formation and the back surface may be used for the light diffraction pattern.

As described above, in the case of the optical recording medium with the optical recording certificate according to the prior art, when the surface treatment is first performed, there is a problem in the stability of the quality, and the high-speed processing is not possible. The cost was high due to the low performance and it was not practical. In addition, the method of directly forming the optical record certificate on the resin surface of the substrate of the optical record medium by hot embossing or compression molding is not only a problem of processing stability but also a quality stability of the optical record medium itself which requires shape stability and accuracy. The effect on gender was a problem, and again was not a practical solution.

[0007]

In order to solve the above-mentioned problems, the present invention provides an optical recording medium with an optical recording certificate and a method of manufacturing the optical recording medium, wherein only a part of the surface of the optical recording medium is irradiated with an ultraviolet laser. After the surface has been modified by performing typical UV irradiation, the optical record with the optical diffraction pattern is attached to the surface-modified part by attaching a label or transferring from a transfer foil, so that the optical record with the optical record is attached. Medium. An excimer laser is used as the ultraviolet laser, and far ultraviolet is applied as the ultraviolet light. As a result, a high-speed surface modification treatment can be performed in a short time, and sufficient adhesion of the optical record certificate can be obtained by partial surface modification by partial irradiation of only the portion where the optical record certificate is provided. The surface physical properties such as the abrasion resistance of the surface of the optical recording medium in the portion are maintained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an optical recording medium with an optical recording certificate and a method for manufacturing the same according to the present invention will be described with reference to the drawings. First, FIG. 1 shows an embodiment of the optical recording medium with an optical recording certificate of the present invention. 1A is a plan view as viewed from the front side (information is read from the back side), and FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A.
The optical recording medium 10 with an optical recording certificate shown in FIG.
-An optical disk such as a ROM or a CD. An information recording area 2 is provided outside the disc, an information non-recording area 3 is provided inside the disc, and a spindle hole 4 is provided at the center. The optical recording card 1 has an area which can be accommodated in the surface modified portion 5 formed in a part of the information recording area 2 and has the optical recording card 1 attached thereto. Further, the surface reforming section 5 is not provided except for the portion where the optical record certificate 1 is attached. Optical recording medium 10
As shown in the sectional view of FIG. 1B, a large number of pits 7 formed by compression molding, injection molding or the like on the front surface of a substrate 6 made of a transparent resin such as an acrylic resin or a polycarbonate resin.
On the surface side of the information recording area 2 having a reflective layer 8, a protective film 9 for protecting pits is formed by coating after forming a reflective layer 8 by vapor deposition of metal such as aluminum. The protective film 9 is formed by a coating method such as spinner coating of an ultraviolet curable resin coating liquid such as an acrylate resin, and is formed so as to completely cover the information recording area 2 at least. Then, an optical record certificate 1 is attached to the surface modified portion 5 of the protective film 9.

Although not shown in FIG. 1, most or a part of the protective film on the front side of the optical recording medium is formed by printing such as screen printing using ultraviolet curable ink or the like. Some embodiments have a printed layer. By providing the printing layer on almost the entire surface of the protective film, it also functions as a second protective layer. When a part or the whole of the optical record certificate 1 is on the print layer in the configuration having the print layer, the surface of the print layer to which the optical record certificate 1 is attached is also surface-modified (with the protective film) at the same time. . The surface-modified part of the present invention modifies the surface of the protective film (including the surface of the printed layer when an optical record is attached on the printed layer) by irradiation with an ultraviolet laser to improve the adhesion. This is an improved portion, and an optical record certificate is attached to the surface modified portion.

The surface modification includes, as already described in the prior art, surface modification by corona discharge treatment and surface modification by irradiation with ultraviolet rays from an ultraviolet lamp. But,
The surface modification in the present invention uses ultraviolet rays, but has a fundamental feature in using ultraviolet rays by a laser. By using a laser, only a necessary portion of the surface can be optically reduced in a short time and also in terms of equipment. The light source (laser oscillator) can be arranged at a distance from the recording medium, and advantages such as being suitable for a continuous manufacturing apparatus can be obtained.

By the way, the relation of the energy with respect to the wavelength of light is, for example, 327.7 kJ at 365 nm.
/ Mol, 471.5 kJ / mo at a wavelength of 253.7 nm
1, energy is 647 kJ / mol at a wavelength of 184.9 nm, and the energy increases as the wavelength decreases. On the other hand, the binding energy of the molecule is as follows: C = C bond is 607 kJ / mol,
O = O bond is 491 kJ / mol, OH bond is 463
kJ / mol, CH bond 413 kJ / mol, C-
O bond is 352 kK / mol, CC bond is 348 kJ
/ Mol, CN bond is 292 kJ / mol, etc.
Light having a wavelength of 200 nm or less is larger than most coupling energy. Ultraviolet light in the ultraviolet region having a wavelength of 200 nm or less is also called far ultraviolet light. Therefore, if the ultraviolet light irradiated as a laser is far ultraviolet light, the molecular bond of the protective film made of a carbon-based resin will be dissociated with a high probability.

For irradiating ultraviolet rays with a laser, an excimer laser is preferable. An excimer laser is obtained by exciting a mixed gas of a rare gas and a halogen. An excimer laser is a pulse laser, and a laser of a far ultraviolet ray can be obtained by selecting a combination of a rare gas and a halogen as an oscillation wavelength. For example, when the rare gas is Xe, and when the halogen is F, 350 nm (X
eF gas), 308 nm when halogen is Cl (Xe
Cl gas), 208 nm when halogen is Br (Xe
(Br gas). Ultraviolet rays of 249 nm (KrF gas) when the rare gas is Kr and halogen is F, and 222 nm (KrCl gas) when the halogen is Cl. 193 nm (ArF gas) when the rare gas is Ar and halogen is F, 175 nm (ArCl gas) when the halogen is Cl, and 157 nm when the rare gas is F and the halogen is F
(F ₂ gas) ultraviolet rays. Of these, specifically,
Ozone emits far ultraviolet range of 100~200nm at the point tends to dissociate molecular binding to easily protective film generates, 193 nm by ArF gas, 175 nm by ArCl gas, excimer laser 157nm by F ₂ gas is preferable.

The surface modification by laser irradiation with far ultraviolet rays acts on the molecular bond of the resin forming the protective layer (or the printed layer) to dissociate the resin, and acts on the oxygen molecules present in the atmosphere to produce ozone. And produce active oxygen. Ozone has a strong oxidizing power, while its surface is unstable because the hydrogen atoms are pulled out by the dissociation of molecular bonds by direct action, so that it is oxidized very effectively. Then, as a result of the surface modification by these actions, polar groups such as carbonyl groups, hydroxyl groups, and carboxylic acid groups are generated on the surface, and this contributes to the improvement of the adhesion.

By the way, since an excimer laser used as an ultraviolet light source has a strong photon energy among lasers, a fine processing method called laser ablation utilizing the energy is known. YAG
Laser processing, such as laser or carbon dioxide laser, is a processing method in which a hollow is formed by melting and evaporating an object by heat.However, an excimer laser can break molecular bonds, so that the object is heated. It is so powerful that it can decompose and dissipate the material without forming a depression. Although the surface modification of the present invention utilizes this ability to break molecular bonds, it is not necessary to give enough energy to form a depression. Therefore, it is not necessary to focus the laser output from the laser oscillator to a minute spot. Depending on the size of the surface modified portion to be formed, an optical system such as a lens or a reflecting mirror,
For example, the light is focused (or defocused) into a circular beam shape having a diameter of about 20 mm, and if the shape of the surface modified portion is not circular, it is further passed through an aperture grill having a window shape such as a rectangle corresponding to the shape of the surface modified portion. By irradiating the surface of the optical recording medium with a desired beam shape, a surface modified portion having a predetermined shape can be formed without scanning the surface with a laser. The aperture grill can be used like a mask by contacting the optical recording medium,
Non-contact is preferred in terms of high-speed processing. When the aperture grill is non-contact, the laser irradiating the optical recording medium has the same shape and the same size as the window of the aperture grill if it is made parallel by the optical system, and if it is non-parallel light, it has a shape similar to the window. (Even non-parallel light has the same shape if used in contact.) With parallel light, a sufficient distance between the optical recording medium and the aperture grille can be obtained. Therefore, as compared with the case where a low-pressure mercury lamp or the like is used as a far-ultraviolet light source, a manufacturing apparatus for an optical recording medium that can design the distance between the light source and the optical recording medium without difficulty is preferable. This also means that a low-pressure mercury lamp or the like emits ultraviolet light having a wavelength of 254 nm or 185 nm, but also emits a considerable amount of infrared light. Therefore, a cooling device for the lamp is required, and the optical recording medium and its transport mechanism are heated. However, the excimer laser has the advantage that it is not necessary to pay attention to such heating. In the case of an ArF excimer laser that outputs a wavelength of 193, the energy required for surface modification is, for example, a laser from an oscillator with a laser output of 50 W at a power density of about 2.0 × 10 ¹ W / cm ² , 1 pulse 10
By irradiating a laser for ^-8 seconds, the energy surface density is 4.
Irradiation at about 0 × 10 ⁻¹ J / cm ^{2 for} about 0.2 seconds (this is based on the number of pulses and the pulse period) provides a sufficient surface modification effect. Also, in order to prevent attenuation of the far-infrared laser light due to active oxygen / ozone, the optical path between the mask or the aperture grill and the laser light source opening surface reforming section is vacuum or nitrogen purged, and the mask or the aperture grill and the surface thereof are purged. Setting the gap (optical path) to the modified portion to be about 10 mm is effective for shortening the irradiation time. The surface of the protective film before the treatment is a smooth surface close to a mirror surface, but if laser irradiation is performed to the extent that the surface is roughened after the treatment (it is also light laser ablation), the chemical effect due to the generation of polar groups and the generation of minute irregularities A stronger adhesion can be obtained by both the anchor effect and the anchor effect.

The shape of the surface-modified portion formed by the irradiation of ultraviolet light with an excimer laser is the same as or slightly larger than the optical record certificate because the optical record certificate is adhered to the optical recording medium with a sufficient adhesive force. . When the size is smaller than the optical record certificate, the periphery of the optical record certificate is easily peeled off. In addition, with the same shape, the allowable range of positional error when attaching the optical record certificate becomes zero. Therefore, it is preferable to use a slightly larger shape having a margin enough to allow positioning accuracy when the optical record certificate is mechanically attached to the label or the transfer foil. For example, in the case of a rectangle, it is larger by about 1.0 mm in each of the vertical and horizontal directions. In this way, even if a part of the surface-modified part is exposed around the optical record after the optical record certificate is attached, and the surface physical properties such as abrasion resistance of the part are deteriorated, the overall practicality is reduced. No adverse effects occur.

The surface of the optical recording medium on which the surface-modified portion is formed is a surface treatment means that is so powerful that the excimer laser decomposes and evaporates the substance. Although it does not matter, it is usually the surface of a resin such as a polyester resin, an acrylic resin or a polycarbonate resin, or the surface of a protective film made of an ultraviolet curable resin formed on the resin surface. The ultraviolet curable resin forming the protective film is an acrylate resin or the like, but is not particularly limited, and any resin can provide a good surface modified portion with strong energy by laser.

Although the optical record certificate is provided for the surface-modified portion formed as described above, any conventionally known optical record certificate may be used. The optical record certificate has a light diffraction pattern, and the light diffraction pattern is a hologram, a diffraction grating, or the like. In order to attach an optical record certificate, an optical record certificate is transferred from a transfer foil, or an optical record certificate as a label is attached. The use of a label is preferable to the use of a transfer foil in that the support of the label can be easily used as a strong protective layer having a light diffraction pattern. Incidentally, even in the case of using a transfer foil, a strong curable protective resin layer can be formed on the side of the release layer which is transferred and becomes the upper layer of the light diffraction pattern, and can be used as a protective layer of the light diffraction pattern.
In addition, although the physical properties of the protective film after the surface modification as the protective film are reduced, the optical record certificate functions as the protective film by attaching the optical record certificate. For example, a transparent and solvent-resistant polyethylene terephthalate resin film is used as a support, a curable resin that is cured by ultraviolet light or heat is applied thereto, the light diffraction pattern is hot-embossed, and then cured to form a relief layer. Then, aluminum is vacuum-deposited to form a light-reflective layer, and a heat- or pressure-sensitive adhesive is further applied to form an adhesive layer to obtain a heat- or pressure-sensitive label.
In the transfer foil, after the polyethylene terephthalate resin film is released with wax or the like, the above-mentioned curable protective resin layer, relief layer, reflection layer, and heat-sensitive adhesive layer may be formed. In addition, in order to make better use of the characteristics of the surface modified portion in which the adhesion of the present invention has been improved, adhere to the surface modified portion,
As an adhesive as a pressure-sensitive adhesive layer of a label or an adhesive layer of a transfer foil, after bonding or transfer, a surface that has been surface-modified with far ultraviolet light, hydrogen bonding, ligand bonding, polar bonding, non-polar bonding It is preferable that a portion contributing to adhesion at a molecular level by chemical bonds such as ionic bonds be densely distributed over a wide range,
For this purpose, a water-soluble emulsion-based adhesive in which the molecular weight distribution of the polymer is wide, large and small spherical molecules are used, and the adhesive modifying group is not self-associated in the polymer chain, is preferred. As such, for example, a water-based urethane emulsion adhesive or a water-based acrylic emulsion adhesive,
There is a water-based acrylic acid emulsion adhesive.

What is obtained by the light diffraction pattern of the optical record certificate is a hologram image, a geometric pattern by a diffraction grating, and the like, and may be a mechanically readable pattern such as a bar code. . If it is a mechanically readable optical record certificate, depending on the reading device side that reads the information recorded on the optical recording medium, the optical record certificate can also be read, and if the predetermined information is not obtained from the optical record certificate, By making it impossible to read the digital data recorded on the recording medium itself, it is possible to make it difficult to produce a counterfeit product. In this case, the optical record certificate having a bar code as shown in FIG. In addition, by forming the light diffraction pattern as a Fresnel hologram, a point-like optical record certificate can be obtained. In the present invention, the surface position to which the optical record certificate is attached may be any place that does not hinder reading of information recorded on the optical recording medium. There are few restrictions such as an inner part, an information recording area on the front side, and an information non-recording area.

[0019]

The present invention will be further described below with reference to examples and comparative examples.

EXAMPLE A reflective layer was formed by vacuum-depositing aluminum on an information recording area of a disk substrate having a diameter of about 12 cm in which pits were formed by compression injection molding of an optical recording medium acrylic resin. A protective film was formed thereon by applying a UV curable paint to the surface of the protective layer by spinner, and an optical disk was obtained as an optical recording medium.

After forming a release layer and a protective layer on the optical recording certificate label polyethylene terephthalate film, and further applying an ultraviolet curable resin liquid,
The resin liquid is cured by irradiating ultraviolet rays while pressing the hologram stamper to form a hologram layer having hologram irregularities, and then aluminum is vacuum-deposited to form a reflection layer. A heat seal layer was formed to obtain an optical recording certificate transfer foil.

Surface Modification Next, in the information recording area on the front side (opposite side of the information reading surface) of the optical disc, a rectangular portion having a length of 19 mm and a width of 12 mm was radiated by a 50 W output ArF excimer laser at a wavelength of 193 nm. Ultraviolet laser light, a laser with a diameter of about 20 mm by a condenser lens, further 18 mm in length,
Irradiation (3.0 × 10 ⁷ pulses) for 0.3 seconds through an aperture grill having a rectangular window with a width of 11 mm, surface modification was performed, and a surface modification portion was formed on a part of the protective film surface. .

Optical recording medium with optical recording certificate Next, the optical recording certificate transfer foil, which is slightly smaller than the surface modified portion and has a rectangular shape of 18 mm in length and 11 mm in width, is thermally transferred so as to fit in the surface modified portion. Thus, an optical recording medium with optical recording of the present invention was obtained.

( Comparative Example ) As a comparative example, only the surface modification performed in the above embodiment was performed by irradiating the entire surface of the protective film with an ultraviolet ray by using an ultraviolet ray surface treatment apparatus using a low-pressure mercury lamp emitting ultraviolet rays having wavelengths of 185 nm and 254 nm. I went. The surface modification conditions were as follows: lamp power 140 W x 1 lamp, irradiation distance 9
mm (ultraviolet illuminance: 5 mW / cm ² ), and the irradiation time is from 1 second to 160 seconds.

Performance Comparison As an effect of improving the adhesion, a comparison was made between the surface tension of the optical disk surface before and after the surface modification treatment by an ultraviolet excimer laser. As a result, the surface tension was 32 dyne before treatment and became 68 dyne before treatment. . Further, after the above-mentioned optical recording paper transfer foil was thermally transferred, it was left at a temperature of 40 ° C. for 24 hours, and then the adhesion was evaluated by a cross-cut tape method (1) according to JIS-K5400.
Cut with a knife to reach 11 adhesive planes vertically and horizontally at intervals of 100 mm to form 100 squares. After adhering Nichiban Cellophane adhesive tape, peel off the tape and leave it. When the residual ratio of the number of eyes was evaluated by percentage, the residual ratio against peeling was less than 1% (no residual) before the surface treatment with the ultraviolet excimer laser and 100% after the treatment. Further, it was 100% by irradiation with a low-pressure mercury lamp treatment. However, in the case of UV irradiation with a low-pressure mercury lamp, irradiation of 120 seconds to 160 seconds is required to achieve an image retention of 100%, and an irradiation time of 1 second close to 0.3 seconds of excimer laser irradiation (still about 3 seconds). In this case, the residual ratio was 4.5%, the residual ratio was 10% even with 5 seconds of irradiation, and the residual ratio of 50% was barely obtained with 100 seconds of irradiation.

[0026]

According to the optical recording medium with the optical recording certificate and the manufacturing method of the present invention, an optical recording certificate having an optical diffraction pattern such as a hologram or a diffraction grating can be attached to the optical recording medium with a reliable adhesion. it can. In addition, since the surface treatment with the ultraviolet laser is performed only on the portion where the optical record certificate is provided, the surface properties such as scratch resistance, abrasion resistance, and stain resistance of the other portions of the protective film can be maintained as they are. In addition, since the modifying effect is strong and permanent, the bleeding of the wax component or the like in the protective film does not cause a temporal decrease in the unadhered force of the optical record certificate.
Further, as long as the position of the optical record certificate is other than the information recording area on the back surface, the optical record certificate can be freely provided and may be the information record area on the front surface side. In addition, in the manufacturing method, since the surface modification is completed in about 1/400 second as compared with the ultraviolet irradiation by the ultraviolet lamp, even if it is incorporated in a continuous manufacturing line or a continuous manufacturing apparatus, the productivity is not affected and does not decrease. Moreover, in the case of an ultraviolet lamp, there is a light component that is dissipated wastefully even when a lens system is used, but in the case of a laser, there is no light dissipation because of coherence light, and output light can be used without waste.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of an optical recording medium with an optical recording certificate of the present invention. FIG. 1A is a plan view seen from above. FIG.
FIG. 2B is a sectional view taken along line AA in FIG.

FIG. 2 is a plan view showing another embodiment of the optical recording medium with an optical recording certificate of the present invention.

FIG. 3 is a plan view showing another embodiment of the optical recording medium with an optical recording certificate of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Optical record certificate 2 Information recording area 3 Information non-recording area 4 Spindle hole 5 Surface modification part 6 Substrate 7 Pit 8 Reflective layer 9 Protective film 10 Optical recording medium with optical record certificate

Claims (3)

[Claims] 1. An optical recording medium provided with an optical record certificate by an optical diffraction pattern, wherein a surface modified portion by ultraviolet laser irradiation is provided only on a part of the medium surface, and the optical record certificate is transferred to the surface modified portion. Or, an optical recording medium with an optical recording certificate attached by sticking. 2. A method of manufacturing an optical recording medium provided with an optical recording certificate based on an optical diffraction pattern, wherein only a part of the surface of the optical recording medium is partially irradiated with an ultraviolet laser to modify the surface, A method for producing an optical recording medium with an optical record certificate, wherein the optical record certificate is attached or transferred to the surface modified portion. 3. The method for producing an optical recording medium with an optical recording certificate according to claim 2, wherein an excimer laser is used as the ultraviolet laser, and far ultraviolet is irradiated as the ultraviolet.