JPH09293280A - Production of optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical recording medium of a sticking type which has a uniform film thickness and is free from deformation and air bubbles by curing the adhesives existing on the light transparent parts of either inner peripheral parts or outer peripheral parts, then curing the adhesives of another uncured parts. SOLUTION: Two sheets of the optical recording medium substrates formed by allowing the inner peripheral parts and outer peripheral parts to remain as transparent parts on the polycarbonate substrates having a prescribed diameter and forming recording layers thereon are used. The film forming surfaces of these substrates are disposed to face each other and the adhesives are applied thereon in such a manner that the film thicknesses of the adhesives are made uniform. The adhesives are UV curing type adhesives to which a thermosetting property is imparted. The superposed substrates formed in such a manner are transported to a UV irradiation device. The device arranges a metallic plate having a hole of a prescribed diameter hole at a place of a prescribed height above the substrate below a heat ray cut filter in such a manner that this plate exists concentric with the center of the substrate existing below the hole. The adhesives in the inner peripheral parts of the substrate are cured by executing irradiation with UV rays. The substrates are transported into an oven set at a prescribed temp,. The substrates are held in metallic disks approximately uniform in temp. over the entire part and are heated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an excellent bonding type optical recording medium having high productivity, a uniform film thickness, and no deformation or bubbles.

[0002]

2. Description of the Related Art Optical recording media include a single plate type and a type in which two or more sheets are bonded together. In recent years, there has been a demand for larger capacity of optical recording media, and two or more bonded types have become the mainstream, including a type in which transparent substrates are bonded in order to maintain the strength accompanying the thinning of optical recording media substrates. It's starting.

Conventionally, a pasting type optical recording medium has a recording layer formed by sputtering on a circular substrate made of a material transparent to a recording / reproducing laser beam such as an acrylic resin or a polycarbonate resin. A two-layer optical recording medium substrate coated with an ultraviolet curable resin or the like for protecting the recording layer is pasted with a hot-melt type adhesive, which has been put into practical use. However, when laminating with a hot-melt adhesive, it is necessary to consider the heat resistance of the optical recording medium substrate because it is applied in a molten state by heating, and it is necessary to perform it at a temperature that does not adversely affect the shape of the substrate. . For example, when a substrate is manufactured using a commonly used polycarbonate resin, the coating temperature needs to be about 100 ° C. or lower. The main component of the hot-melt adhesive is a thermoplastic resin, and the adhesive strength is lowered even after the adhesion at a temperature lower than the application temperature, so that the reliability of mechanical properties during use and storage at high temperature is low. Further, when the roll coating method is used, non-uniform force and heat are applied to the optical recording medium substrate during coating, which adversely affects the mechanical properties, which is not satisfactory.

On the other hand, a method of using an ultraviolet curable resin for an adhesive is disclosed in JP-A-61-110350 and JP-A-61-161350.
No. 126648. By using an ultraviolet curable resin, an adhesive layer having higher heat resistance than a hot melt adhesive can be formed, and in the hot melt adhesive, an ultraviolet curable resin is used in advance for the purpose of protecting the recording layer and the like. Since it is necessary to overcoat, there is also an advantage of reducing this step. However, although these methods are effective for a type in which a transparent substrate is bonded to maintain strength as the optical recording medium substrate is thinned or a substrate in which a semitransparent film is formed are bonded, two or more sheets are used. For the purpose of adhering optical recording medium substrates, the entire surface of the optical recording medium substrate cannot be adhered because the recording film formed on the substrates hardly transmits curing light such as ultraviolet rays.

Therefore, in Japanese Patent Laid-Open No. 1-258247, the transparent inner peripheral portion and the outer peripheral portion of the optical recording medium substrate are masked to cure only the ultraviolet curable resin on the surface of the recording film, and then the two are superposed. A method has been proposed in which the uncured portions, which have been masked together, are cured and then bonded together. But,
In this method, the entire surface such as the back surface of the recording film is not adhered, and there are voids, and there is a problem that the strength is insufficient and the internal air expands at high temperature.

[0006]

Therefore, a method of bonding with an adhesive having both an ultraviolet curing function and a heat curing function is disclosed in JP-A-61-217945 and JP-A-2-214.
It has already been proposed as 041, JP-A-3-116459, JP-A-3-173950, JP-A-3-192547 and JP-A-4-179580.

In both cases, an optical recording medium substrate on which a recording layer is formed with the inner and outer peripheral portions left as a light transmitting portion is used, and the adhesive is applied by irradiating the light transmitting portion with ultraviolet rays. After the two sheets are temporarily fixed by the ultraviolet curing function, the back side of the recording layer which is not transparent to ultraviolet rays is completely hardened by another thermal curing function. As an advantage of adopting this two-step curing method, by temporarily fixing the light transmitting portion to the inner peripheral portion and the outer peripheral portion in advance,
There is no misalignment of the two substrates during the thermosetting process, and there is no need to fix them with a jig, and the adhesive overflows from the inner and outer peripheral parts during the laminating process and thermosetting process. It is mentioned to prevent the outbreak.

However, Japanese Patent Laid-Open No. 2-214041 discloses
JP-A-3-116459 and JP-A-3-17395.
No. 0, JP-A-3-192547 and the like propose methods for spreading the adhesive between two substrates, such as a method of spreading by a pressure plate, a method of spreading by heating and the weight of the substrate, and the like. It takes time to spread by this method, control of the timing of irradiation of curing light to prevent the desired adhesive film thickness and overflow from the inner and outer peripheral parts, and uniform pressure There were problems such as difficulty in controlling the film thickness of the adhesive.

Further, in Japanese Patent Laid-Open No. 4-179580, a curable resin composition for forming a pressure-sensitive adhesive layer is used, the coated surface is masked, and the unmasked portion is irradiated with ultraviolet rays to produce a pressure-sensitive adhesive. A method has been proposed in which after forming a layer, two sheets are bonded and fixed, and then the masked portion is cured. However, in the method of laminating the substrates to which the adhesive is applied in advance, such as this method, it is difficult to carry out without laminating the bonding surface.

Further, Japanese Patent Application Laid-Open No. 61-217945,
JP-A-2-214041, JP-A-3-17395
No. 0, JP-A-3-192547, etc., after temporarily fixing both the inner peripheral portion and the outer peripheral portion of the portion of the substrate where the recording layer is not formed, the recording layer is formed on the back side of the recording layer. The method of curing the uncured adhesive located by heating or the like is good in that it prevents the adhesive from overflowing from the inner peripheral portion and the outer peripheral portion, but as already described in JP-A-1-253845. , Stress due to thermal expansion of the substrate due to reaction heat generated during heating and curing of the adhesive, stress relaxation remaining in the molded substrate, volume change during curing of the adhesive, etc. If both ends of the peripheral portion and the outer peripheral portion are adhered and fixed in advance, there is a problem that the escape area is lost and the portion which is cured later is locally deformed due to stress diffusion.

As described above, the conventional method of laminating two or more optical recording medium substrates having a recording film that hardly transmits curing light such as ultraviolet rays has some drawbacks.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.
It is an object of the present invention to provide a method for producing a bonded type optical recording medium having a uniform film thickness and free from deformation and bubbles with high productivity.

[0013]

To achieve this object, the present invention employs the following means. That is,
The method for producing an optical recording medium of the present invention comprises two or more disc-shaped optical recording media each having a recording layer formed so as to have a central hole and a light transmitting portion at least in an inner peripheral portion and an outer peripheral portion. Of at least one surface of the optical recording medium, the disc-shaped optical recording medium is superposed concentrically so as to sandwich the adhesive, and the adhesive is cured. It is characterized in that after curing the adhesive positioned in the light transmitting portion of either the inner peripheral portion or the outer peripheral portion, the adhesive in the other uncured portion is cured. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention includes at least an inner peripheral portion such as a rewritable type (RAM) such as magneto-optical and phase change, a partial read only type (PROM), a write once type (WO), and a read only type (ROM). Any single plate of an optical recording medium in which a recording layer is formed so as to have a light transmitting portion can be used. The adhesive used in the present invention to bond these optical recording medium substrates has both the ultraviolet curing function and the heat curing function as described above. The composition of the adhesive is composed of a polymerizable oligomer, a polymerizable monomer, a thermal polymerization initiator, a photopolymerization initiator, a photosensitizer, a storage stabilizer and the like.
As the polymerizable oligomer, for example, polyester (meth)
Oligomers such as acrylate-based, urethane (meth) acrylate-based, polyether (meth) acrylate-based, and polybutadiene acrylate-based are used. As the polymerizable monomer, for example, a (meth) acrylate-based monomer or the like is used. A radical polymerization initiator such as an organic peroxide or an azo compound is used as the thermal polymerization initiator. As the photopolymerization initiator, for example, a benzoin ether type compound, an acetophenone type compound, an aromatic ketone type compound or the like is used. Then, in order to superimpose such an adhesive between two or more optical recording medium substrates so as to spread without containing bubbles, in order to overlap the two optical recording medium substrates,
Apply the adhesive on the surface near the center hole of one optical recording medium substrate fixed on the spin table by vacuum adsorption etc. in a concentric circle with the center hole with a dispenser etc., and glue the other optical recording medium substrate Between the two optical recording medium substrates by stacking them so that the center holes are concentric with each other so that the adhesive sandwiched by the self-weight of the optical recording medium substrates stacked from above is spun at high speed Spread the adhesive almost all over and shake off the excess adhesive. afterwards,
While rotating at a rotation speed sufficiently lower than this turning-off rotation speed, the suction nozzle is brought into contact with the outer peripheral edge portion of the superposed optical recording medium substrates, and excess adhesive or the subsequent adhesive adhered to the outer peripheral edge portion is adhered. The adhesive present on the outer peripheral portion that may drip during the agent curing step is removed by suction.
By doing so, it is possible to easily and quickly form the adhesive layer having a uniform film thickness without inclusion of bubbles between the optical recording medium substrates. As a result, a superposed optical recording medium substrate can be obtained which is free from dirt due to the protrusion of the adhesive on the peripheral edge portion of the substrate.

Since the adhesive used above must be spread between the optical recording medium substrates by a spin process,
The viscosity is preferably in the range of 100 to 2000 (cp) (25 ° C).

Next, of the superposed optical recording medium substrate thus produced, only the inner peripheral portion or the outer peripheral portion, which is a light transmitting portion having no recording film, is irradiated with curing light such as ultraviolet rays, and this portion is subjected to the present invention. One of the functions of the adhesive used for UV curing. At this time, for example, a high-pressure mercury lamp, a metal halide lamp, or the like can be used as a curing light source of ultraviolet rays or the like. By doing so, the superposed optical recording medium substrate is temporarily fixed, and thereafter, the misalignment of the superposed optical recording medium substrate does not occur. Further, by curing only the inner peripheral portion or the outer peripheral portion, the above-mentioned problems such as when temporarily fixing the inner peripheral portion and the outer peripheral portion at the same time do not occur.
Furthermore, it is preferable that only the inner peripheral portion is cured and temporarily fixed rather than the outer peripheral portion. This is because it is less likely to be affected by stress such as thermal expansion of the substrate, relaxation of stress remaining in the molded substrate, and volume change during curing of the adhesive.

To this end, when one of the inner peripheral portion and the outer peripheral portion, which is a light transmitting portion, is irradiated with curing light such as ultraviolet rays, it is natural that the adhesive located on the inner peripheral portion is cured. It is necessary to prevent ultraviolet light from hitting the transparent part on the outer peripheral part of the optical recording medium substrate, and when curing the adhesive located on the outer peripheral part, it is natural that the transparent part on the inner peripheral part of this optical recording medium substrate is exposed to ultraviolet light. It is necessary to prevent hits.

Further, it is preferable that the irradiation range of the curing light such as ultraviolet rays, which is applied to the optical recording medium substrate, is limited to the light transmitting portion of the inner peripheral portion or the outer peripheral portion without the recording film. By avoiding unnecessary irradiation to the region that does not contribute to UV curing, loss of UV irradiation energy can be suppressed and the adhesive can be efficiently cured. Further, the temperature of the optical recording medium substrate is increased due to the irradiation of curing light such as ultraviolet rays, and the optical recording medium substrate is deformed such as warped. Instead, by irradiating the light-transmitting portion of the inner peripheral portion or the outer peripheral portion with the minimum necessary amount, deformation such as warpage due to the irradiation can be suppressed. Therefore, it is not necessary to use a pressure plate such as a quartz glass plate for suppressing deformation such as warpage of the optical recording medium substrate that was used in the conventional technique during irradiation. This is advantageous in the process because it is not necessary to handle a glass plate or the like that easily causes chipping during handling. Further, by not irradiating the area of the recording film with curing light such as ultraviolet rays, unnecessary damage to the recording film is prevented.

As one form of the method of irradiating the curing light such as ultraviolet rays only to the light transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate, ultraviolet rays or the like between the light source and the optical recording medium substrate is irradiated. A curing light irradiation device that can block curing light, for example, a curing light irradiation device such as an ultraviolet ray provided with a metal plate having a transmission hole that can irradiate only a desired range is used. At this time, since the illuminance distribution exists in the curing light lamp such as ultraviolet rays, the adhesive is efficiently used by, for example, transmitting the high light intensity range and cutting the low light intensity range with the light shielding plate. It is preferable to adjust the arrangement of the lamp, the light shield plate, the optical recording medium substrate and the diameter of the transmission hole of the light shield plate so as to cure.

As another form, there is a method of directly irradiating a spot from a curing light source such as ultraviolet rays onto the light transmitting portion range of the inner peripheral portion of the optical recording medium substrate. For this implementation, for example, a mercury-xenon lamp or an ultra-high pressure mercury lamp is used as a light source, and a curing light irradiation device capable of narrowing the irradiation spot of the curing light to only a desired range with a converging mirror is provided on the inner peripheral portion of the optical recording medium substrate. Use a device arranged so that it can irradiate only the light-transmitting part of

Alternatively, similarly, a mercury xenon lamp, an ultra-high pressure mercury lamp, or the like is used as a light source, and curing light such as ultraviolet rays condensed by a condenser mirror is irradiated through a light guide such as an optical fiber to an irradiation spot within a desired range. A curing light irradiating device that can be squeezed is arranged so that it can irradiate only the light transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate. The shape of the cured light emitting end of the light guide such as an optical fiber used at this time may be a round shape in which the optical fibers are bundled when irradiating the inner peripheral portion of the optical recording medium substrate, but it has a central hole. In terms of irradiation efficiency, it is preferable to use one that has a ring-shaped emitting end that has been processed to match the shape of the transparent portion of the inner peripheral portion of the optical recording medium substrate. Also, when irradiating the outer peripheral portion, this structure is used. Need to be

In the apparatus for irradiating curing light such as ultraviolet rays used in these implementations, a cold mirror is used as the condensing mirror in order to avoid the temperature rise of the portion of the optical recording medium substrate irradiated with the curing light such as ultraviolet rays as much as possible. It is preferable to use one having a built-in heat ray cut filter. Further, if necessary, it is also preferable to dispose a heat ray cut filter between the curing light emitting end of the curing light irradiation device for ultraviolet rays and the like and the optical recording medium substrate. Furthermore, it is also preferable to suppress the temperature rise by blowing cooling air to the curing light irradiation portion of the optical recording medium substrate.

The irradiation of the curing light such as ultraviolet rays and the blowing of the cooling air onto the optical recording medium substrate may be performed not only above the optical recording medium substrate but also below the optical recording medium substrate at the same time or only from below. When the cooling air is blown from below, when directly blowing on the optical recording medium substrate without using a transmission plate such as glass in the place where the optical recording medium substrate is placed,
It is possible to prevent the optical recording medium substrate from being blown off by the cooling air by using a plate having a hole in the portion for transmitting the curing light such as ultraviolet rays and fixing the optical recording medium substrate thereto by vacuum suction or the like.

By using the above method and apparatus,
It is possible to cure only the adhesive located in the light-transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate efficiently and avoid deformation of the optical recording medium substrate and unnecessary damage to the recording film. It has become possible, and the use of a pressure plate such as a glass plate for suppressing the deformation of the optical recording medium substrate is not necessary, and the handling is improved.

By heating the superposed optical recording medium substrate temporarily fixed on the inner peripheral portion or the outer peripheral portion by such a method, the adhesive used in the present invention is thermally cured, which is another function. As a heating means, for example, there is a method of leaving it in a heating oven. During this heating,
It is preferable to avoid occurrence of temperature unevenness on the superimposed optical recording medium substrate as much as possible. This is the arrangement and structure that hot air in the heating oven does not hit unevenly, the method of rotating the object to be heated, the temperature has already been heated in the heating oven for a long time and the temperature has become almost constant without any temperature distribution. It can be carried out by sandwiching it between existing metal plates. It is preferable that the metal plate used for this has a flat contact surface and is subjected to smoothing processing such as polishing so that the optical recording medium substrate is not scratched. Furthermore, the metal plate overlying the optical recording medium substrate should not be too heavy. This is to prevent the uncured adhesive from being pushed out to the outer peripheral portion of the optical recording medium substrate, and to cause thermal expansion of the substrate due to reaction heat generated at the time of heating and curing of the adhesive and remaining on the molded substrate. This is because it is necessary to appropriately release stress due to stress relaxation and volume change when the adhesive is cured. For this reason,
It is preferably 500 (g) or less. The sandwiching with the metal plate may be performed until the curing of the adhesive is sufficiently completed, or may be removed until the curing is completed depending on the cured state of the adhesive layer and the condition of the optical recording medium substrate. By using a metal plate in this way, it is easy to increase the smoothness of the contact plane with the optical recording medium substrate, uniform heatability is improved due to good thermal conductivity, and handling is easier than with a glass plate that is easily damaged. There are advantages such as na. The diameter of the metal plate is preferably 1 to 2 mm smaller than that of the optical recording medium substrate in order to avoid burrs existing on the outer peripheral portion of the optical recording medium substrate.

As other heating means, infrared or far infrared irradiation heating system can be used. You may use this and the above-mentioned oven heating together.

In order to prevent the thermal deformation of the optical recording medium substrate and the collapse of the transfer surface such as tracks and pits, the heating temperature for curing the adhesive is, when the substrate used is made of polycarbonate, for example, It is preferably 120 (° C) or less. Further, in order to shorten the curing time, it is preferably 50 (° C) or higher.

The optical recording medium substrate thus cured by heating is
Either the inner or outer circumference that had been previously fixed to him, or the edge of the other light-transmitting part, is insufficiently hardened due to the oxygen present in the air in the heating atmosphere. Sometimes. In this case, it is preferable to use a method similar to the method of temporarily fixing and to irradiate the insufficiently cured light-transmitting portion with curing light such as ultraviolet rays again to completely cure.

Further, in order to avoid insufficient curing of the edge portion of the optical medium substrate due to the influence of oxygen, it is preferable to use nitrogen gas as the atmosphere during heating.

By using the above method and apparatus, it is possible to bond two or more optical recording medium substrates having a recording film, which has hardly transmitted curing light such as ultraviolet rays, which has been difficult in the past, with high productivity. Became.

[0031]

The present invention will be further described with reference to the following examples. However, the present invention is not limited by the following examples.

Example 1 On a polycarbonate substrate having a diameter of 120 (mm) molded by an injection compression molding machine, the diameter of 40 (mm) or less and the diameter of 116 (mm) or more of the inner peripheral portion were left as transparent portions, and the recording layer was formed. Two optical recording medium substrates formed by sputtering were used.
One of them was placed on a spin table with the surface on which the film was formed facing upward and fixed by vacuum adsorption. Then, while rotating the spin table at 50 (rpm), the adhesive was applied to the surface of the optical recording medium substrate using a dispenser so as to make one revolution concentric with the central hole. The adhesive is a UV-curable adhesive with thermosetting properties and has a viscosity of 300.
(Cp) (25 ° C.) was used. Then, the coated surface of another optical recording medium substrate was placed so as to sandwich the applied adhesive, and the substrate was stacked so as to be concentric only by its own weight. Due to the weight of the optical recording medium substrate on the side of overlapping, the sandwiched adhesive slowly spreads, and when the distance to the center hole of the optical recording medium substrate spreads to a distance of about 1 (mm), the spin table is set to 1500 (rpm). It was rotated and the excess adhesive was shaken off to make the adhesive film thickness uniform. After that, while rotating at 50 (rpm) again, the excess adhesive adhering to the outer peripheral edge portion of the optical recording medium substrate was sucked while the suction nozzle was in contact. The superposed optical recording medium substrate thus manufactured was conveyed to the ultraviolet irradiation device. The ultraviolet irradiation device uses a metal halide lamp as the light source,
A cold mirror was used as the condenser mirror and a heat ray cut filter was arranged at the exit window. A metal plate (one side 20c) having a hole with a diameter of 42 (mm) at a position 1 cm above the optical recording medium substrate below the heat ray cut filter.
m, 1 mm thick) was arranged such that the hole was concentric with the central hole of the optical recording medium substrate located below. The metal plate is also provided with an inlet for cooling air to the optical recording medium substrate, and the cooling air was blown onto the optical recording medium substrate during irradiation of ultraviolet rays. By irradiating with ultraviolet rays for 6 seconds, the adhesive located in the light transmitting portion of the inner peripheral portion of the optical recording medium substrate was cured. Then, it is transferred into an oven set at 90 (° C), sandwiched in a metal disk (diameter 15 cm, 2 mm thickness) that has been preheated in the oven and has a substantially uniform temperature, and heated as it is for 1 hour. did. The bonded optical recording medium substrate taken out of the oven after removing the metal plate was cooled by cold air from an ionizer. The produced laminated optical recording medium substrate is
The two substrates were in good condition with no misalignment and no local waviness or warpage.

Example 2 As an ultraviolet irradiating device, an ultrahigh pressure mercury lamp was used as a light source, a cold mirror focusing mirror was of a type capable of narrowing the ultraviolet irradiating range into a circular spot shape, and a heat ray cut filter was arranged at an emission window. Was used and the cooling air was blown onto the optical recording medium substrate from a cooling air blowing nozzle provided separately, and the same procedure as in Example 1 was performed. The ultraviolet irradiation range on the surface of the optical recording medium substrate was 42 (mm) in the inner peripheral diameter. Similar to Example 1, a good laminated optical recording medium substrate was obtained.

Example 3 As a UV irradiation device, a mercury xenon lamp was used as a light source.
After passing the light focused by the condenser mirror of the cold mirror through the heat ray cut filter, the incident end is a circular bundle and the exit end has a center hole. Using a ring-shaped optical fiber light guide that was processed together and arranged so that light could pass through, cooling air was blown onto the optical recording medium substrate from a separate cooling air blowing nozzle. The procedure was the same as in Example 1 except for the above. The ultraviolet irradiation range on the surface of the optical recording medium substrate was 15 to 42 (mm) in diameter. Similar to Example 1, a good laminated optical recording medium substrate was obtained.

Comparative Example 1 The laminated optical recording medium substrate obtained in the same manner as in Example 1 was directly transferred into an oven in a nitrogen atmosphere and heated at 80 ° C. for 1 hour. The obtained laminated optical recording medium substrate had two core misalignments and waviness and warpage.

Comparative Example 2 A laminated optical recording medium substrate obtained in the same manner as in Example 1 was covered with a glass plate (diameter 15 cm, thickness 1 cm), and the entire surface of the optical recording medium substrate was irradiated with ultraviolet rays with a metal halide lamp.
The light transmitting portions of the inner peripheral portion and the outer peripheral portion of the optical recording medium substrate were simultaneously cured. After that, convey to the oven, 80 ℃, 1
Heated for hours. The obtained laminated optical recording medium substrate did not have two core misalignments, but had local waviness and warpage.

Comparative Example 3 As in Example 1, the superposed optical recording medium substrate was irradiated with ultraviolet rays for 6 seconds to cure the adhesive located in the light transmitting portion of the inner peripheral portion of the optical recording medium substrate. Then, it was transferred to an oven in an air atmosphere and heated at 80 ° C. for 1 hour. In the obtained laminated optical recording medium substrate, two cores were not misaligned, but the adhesive located near the edge of the outer peripheral light-transmitting portion in contact with the outside air was insufficiently cured.

[0038]

EFFECT OF THE INVENTION By using the manufacturing method and apparatus of the present invention, it is possible to bond two or more optical recording medium substrates having a recording film, which hardly transmits curing light such as ultraviolet rays, with high productivity. is there.

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view of a temporary fixing device used in Example 1.

FIG. 2 shows a schematic cross-sectional view of a temporary fixing device used in Example 2.

FIG. 3 shows a schematic cross-sectional view of a temporary fixing device used in Example 3.

4 shows a schematic cross-sectional view of a temporary fixing device used in Comparative Example 2. FIG.

[Explanation of symbols]

 1: Condensing mirror (cold mirror) 2: Metal halide lamp 3: Ultra-high pressure mercury lamp 4: Mercury xenon lamp 5: Heat ray cut filter 6: Cooling air blowing nozzle 7: Light shield plate 8: Light guide 9: Glass plate 10: Adhesive layer 11: Polycarbonate substrate 12: Film-forming layer

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[Procedure amendment]

[Submission date] May 15, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Title: Method for manufacturing optical recording medium

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an excellent bonding type optical recording medium having high productivity, a uniform film thickness, and no deformation or bubbles.

[0002]

2. Description of the Related Art Optical recording media include a single plate type and a type in which two or more sheets are bonded together. In recent years, there has been a demand for larger capacity of optical recording media, and two or more bonded types have become the mainstream, including a type in which transparent substrates are bonded in order to maintain the strength accompanying the thinning of optical recording media substrates. It's starting.

Conventionally, a pasting type optical recording medium has a recording layer formed by sputtering on a circular substrate made of a material transparent to a recording / reproducing laser beam such as an acrylic resin or a polycarbonate resin. A two-layer optical recording medium substrate coated with an ultraviolet curable resin or the like for protecting the recording layer is pasted with a hot-melt type adhesive, which has been put into practical use. However, when laminating with a hot-melt adhesive, it is necessary to consider the heat resistance of the optical recording medium substrate because it is applied in a molten state by heating, and it is necessary to perform it at a temperature that does not adversely affect the shape of the substrate. . For example, when a substrate is manufactured using a commonly used polycarbonate resin, the coating temperature needs to be about 100 ° C. or lower. The main component of the hot-melt adhesive is a thermoplastic resin, and the adhesive strength is lowered even after the adhesion at a temperature lower than the application temperature, so that the reliability of mechanical properties during use and storage at high temperature is low. Further, when the roll coating method is used, non-uniform force and heat are applied to the optical recording medium substrate during coating, which adversely affects the mechanical properties, which is not satisfactory.

On the other hand, a method of using an ultraviolet curable resin for an adhesive is disclosed in JP-A-61-110350 and JP-A-61-161350.
No. 126648. By using an ultraviolet curable resin, an adhesive layer having higher heat resistance than a hot melt adhesive can be formed, and in the hot melt adhesive, an ultraviolet curable resin is used in advance for the purpose of protecting the recording layer and the like. Since it is necessary to overcoat, there is also an advantage of reducing this step. However, although these methods are effective for a type in which a transparent substrate is bonded to maintain strength as the optical recording medium substrate is thinned or a substrate in which a semitransparent film is formed are bonded, two or more sheets are used. For the purpose of adhering optical recording medium substrates, the entire surface of the optical recording medium substrate cannot be adhered because the recording film formed on the substrates hardly transmits curing light such as ultraviolet rays.

Therefore, in Japanese Patent Laid-Open No. 1-258247, the transparent inner peripheral portion and the outer peripheral portion of the optical recording medium substrate are masked to cure only the ultraviolet curable resin on the surface of the recording film, and then the two are superposed. A method has been proposed in which the uncured portions, which have been masked together, are cured and then bonded together. But,
In this method, the entire surface such as the back surface of the recording film is not adhered, and there are voids, and there is a problem that the strength is insufficient and the internal air expands at high temperature.

[0006]

Therefore, a method of bonding with an adhesive having both an ultraviolet curing function and a heat curing function is disclosed in JP-A-61-217945 and JP-A-2-214.
It has already been proposed as 041, JP-A-3-116459, JP-A-3-173950, JP-A-3-192547 and JP-A-4-179580.

In both cases, an optical recording medium substrate on which a recording layer is formed with the inner and outer peripheral portions left as a light transmitting portion is used, and the adhesive is applied by irradiating the light transmitting portion with ultraviolet rays. After the two sheets are temporarily fixed by the ultraviolet curing function, the back side of the recording layer which is not transparent to ultraviolet rays is completely hardened by another thermal curing function. As an advantage of adopting this two-step curing method, by temporarily fixing the light transmitting portion to the inner peripheral portion and the outer peripheral portion in advance,
There is no misalignment of the two substrates during the thermosetting process, and there is no need to fix them with a jig, and the adhesive overflows from the inner and outer peripheral parts during the laminating process and thermosetting process. It is mentioned to prevent the outbreak.

However, Japanese Patent Laid-Open No. 2-214041 discloses
JP-A-3-116459 and JP-A-3-17395.
No. 0, JP-A-3-192547 and the like propose methods for spreading the adhesive between two substrates, such as a method of spreading by a pressure plate, a method of spreading by heating and the weight of the substrate, and the like. It takes time to spread by this method, control of the timing of irradiation of curing light to prevent the desired adhesive film thickness and overflow from the inner and outer peripheral parts, and uniform pressure There were problems such as difficulty in controlling the film thickness of the adhesive.

Further, in Japanese Patent Laid-Open No. 4-179580, a curable resin composition for forming a pressure-sensitive adhesive layer is used, the coated surface is masked, and the unmasked portion is irradiated with ultraviolet rays to produce a pressure-sensitive adhesive. A method has been proposed in which after forming a layer, two sheets are bonded and fixed, and then the masked portion is cured. However, in the method of laminating the substrates to which the adhesive is applied in advance, such as this method, it is difficult to carry out without laminating the bonding surface.

Further, Japanese Patent Application Laid-Open No. 61-217945,
JP-A-2-214041, JP-A-3-17395
No. 0, JP-A-3-192547, etc., after temporarily fixing both the inner peripheral portion and the outer peripheral portion of the portion of the substrate where the recording layer is not formed, the recording layer is formed on the back side of the recording layer. The method of curing the uncured adhesive located by heating or the like is good in that it prevents the adhesive from overflowing from the inner peripheral portion and the outer peripheral portion, but as already described in JP-A-1-253845. , Stress due to thermal expansion of the substrate due to reaction heat generated during heating and curing of the adhesive, stress relaxation remaining in the molded substrate, volume change during curing of the adhesive, etc. If both ends of the peripheral portion and the outer peripheral portion are adhered and fixed in advance, there is a problem that the escape area is lost and local deformation occurs due to stress concentration in a portion which is cured later.

As described above, the conventional method of laminating two or more optical recording medium substrates having a recording film that hardly transmits curing light such as ultraviolet rays has some drawbacks.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.
It is an object of the present invention to provide a method for producing a bonded type optical recording medium having a uniform film thickness and free from deformation and bubbles with high productivity.

[0013]

To achieve this object, the present invention employs the following means. That is,
The method for producing an optical recording medium according to the present invention comprises two or more disc-shaped optical films each having a recording layer formed so as to have a central hole and a light transmitting portion at least in an inner peripheral portion and / or an outer peripheral portion. Manufacture of an optical recording medium in which an adhesive is applied to at least one surface of a recording medium, the disc-shaped optical recording media are concentrically overlapped with each other so as to sandwich the adhesive, and then the adhesive is cured. The method is characterized in that after curing the adhesive located in the light transmitting portion of either the inner peripheral portion or the outer peripheral portion, the adhesive in the other uncured portion is cured. Is.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention includes at least an inner peripheral portion such as a rewritable type (RAM) such as magneto-optical and phase change, a partial read only type (PROM), a write once type (WO), and a read only type (ROM). Any single plate of an optical recording medium in which a recording layer is formed so as to have a light transmitting portion can be used. The adhesive used in the present invention to is laminated to these optical recording media substrate are those having both a heat curable functionality as ultraviolet curing function. As the curing light of the adhesive
For the active energy ray such as ultraviolet rays is used. The composition of the adhesive comprises a polymerizable oligomer, a polymerizable monomer, a thermal polymerization initiator, a photopolymerization initiator, a photosensitizer, a storage stabilizer and the like. As the polymerizable oligomer, for example, a polyester (meth) acrylate-based, urethane (meth) acrylate-based, polyether (meth) acrylate-based, polybutadiene acrylate-based oligomer or the like is used. As the polymerizable monomer, for example, a (meth) acrylate-based monomer or the like is used. A radical polymerization initiator such as an organic peroxide or an azo compound is used as the thermal polymerization initiator. As the photopolymerization initiator, for example, a benzoin ether type compound, an acetophenone type compound, an aromatic ketone type compound or the like is used.

In order to superimpose such an adhesive between two or more optical recording medium substrates so as to be spread without containing air bubbles, the two optical recording medium substrates are the surface near the center hole of one of the optical recording medium substrate was fixed by a vacuum suction or the like on the spin table, then applying an adhesive to the center hole of the same mind circular in a dispenser or the like, the other optical recording medium substrate adhesive the superimposed as the heart center hole so as to sandwich, by the adhesive sandwiched by the weight of the optical recording medium substrate superimposed from above is to spin at high speed with little spread state, between two optical recording medium substrate Spread the adhesive almost all over and shake off the excess adhesive. After that, while rotating at a rotation speed sufficiently lower than the shake-off rotation speed, a suction nozzle is brought into contact with the outer peripheral edge portion of the superposed optical recording medium substrates to remove excess adhesive or other adhesive adhered to the outer peripheral edge portion. The adhesive existing on the outer peripheral portion that may drip in the adhesive curing step is removed by suction. By doing so, it is possible to easily and quickly form the adhesive layer having a uniform film thickness without inclusion of bubbles between the optical recording medium substrates. As a result, a superposed optical recording medium substrate can be obtained which is free from dirt due to the protrusion of the adhesive on the peripheral edge portion of the substrate.

Since the adhesive used above must be spread between the optical recording medium substrates by a spin process,
The viscosity is preferably in the range of 100 to 2000 (cp) (25 ° C).

Next, in the superposed optical recording medium substrate thus produced, either the inner peripheral portion or the outer peripheral portion, which is a transparent portion without a recording film, is irradiated with curing light such as ultraviolet rays, and this portion is irradiated. Is UV cured, which is one of the functions of the adhesive used in the present invention. At this time, for example, a high-pressure mercury lamp, a metal halide lamp, or the like can be used as a curing light source of ultraviolet rays or the like. By doing so, the superposed optical recording medium substrate is temporarily fixed, and thereafter, the misalignment of the superposed optical recording medium substrate does not occur. In addition, by curing either the inner peripheral portion or the outer peripheral portion, the above-mentioned problems such as when temporarily fixing the inner peripheral portion and the outer peripheral portion at the same time do not occur. Furthermore, it is preferable that only the inner peripheral portion is cured and temporarily fixed rather than the outer peripheral portion. this is,
This is because it is less likely to be affected by stress such as thermal expansion of the substrate, relaxation of stress remaining in the molded substrate, and volume change when the adhesive is cured.

[0018] For this purpose, also the inner peripheral portion is translucent portion
As the time of irradiating the curing light such as ultraviolet rays to one either the outer peripheral portion, to cure the adhesive positioned on the inner peripheral portion not exposed to ultraviolet naturally transparent portion of the optical recording medium substrate peripheral part When curing the adhesive located on the outer peripheral portion, it is of course necessary to prevent the transparent portion on the inner peripheral portion of the optical recording medium substrate from being exposed to ultraviolet rays.

Further, it is preferable that the irradiation range of the curing light such as ultraviolet rays, which is applied to the optical recording medium substrate, is limited to the light transmitting portion of the inner peripheral portion or the outer peripheral portion where there is no recording film. By avoiding unnecessary irradiation to the region that does not contribute to UV curing, loss of UV irradiation energy can be suppressed and the adhesive can be efficiently cured. Further, the temperature of the optical recording medium substrate is increased due to the irradiation of curing light such as ultraviolet rays, and the optical recording medium substrate is deformed such as warped. Instead, by irradiating the light-transmitting portion of the inner peripheral portion or the outer peripheral portion with the minimum necessary amount, deformation such as warpage due to the irradiation can be suppressed. Therefore, it is not necessary to use a pressure plate such as a quartz glass plate for suppressing deformation such as warpage of the optical recording medium substrate that was used in the conventional technique during irradiation. This is advantageous in the process because it is not necessary to handle a glass plate or the like that easily causes chipping during handling. Further, by not irradiating the area of the recording film with curing light such as ultraviolet rays, unnecessary damage to the recording film is prevented.

As one form of the method of irradiating the curing light such as ultraviolet rays only to the light transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate, the ultraviolet light or the like is provided between the light source and the optical recording medium substrate. A curing light irradiation device that can block curing light, for example, a curing light irradiation device such as an ultraviolet ray provided with a metal plate having a transmission hole that can irradiate only a desired range is used. At this time, since the illuminance distribution exists in the curing light lamp such as ultraviolet rays, the adhesive is efficiently used by, for example, transmitting the high light intensity range and cutting the low light intensity range with the light shielding plate. It is preferable to adjust the arrangement of the lamp, the light shielding plate, the optical recording medium substrate and the diameter of the transmission hole of the light shielding plate so as to cure.

As another form, there is a method of directly irradiating a spot from a curing light source such as ultraviolet rays onto a light transmitting portion range of an inner peripheral portion of an optical recording medium substrate. For this implementation, for example, a mercury-xenon lamp or an ultra-high pressure mercury lamp is used as a light source, and a curing light irradiation device capable of narrowing the irradiation spot of the curing light to only a desired range with a converging mirror is provided on the inner peripheral portion of the optical recording medium substrate. Use a device that is arranged so that it can illuminate only the light-transmitting part of.

Alternatively, similarly, a mercury xenon lamp, an ultra-high pressure mercury lamp, or the like is used as a light source, and curing light such as ultraviolet rays condensed by a condenser mirror is irradiated through a light guide such as an optical fiber to an irradiation spot within a desired range. A curing light irradiating device that can be squeezed is arranged so that it can irradiate only the light transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate. The shape of the cured light emitting end of the light guide such as an optical fiber used at this time may be a round shape in which the optical fibers are bundled when irradiating the inner peripheral portion of the optical recording medium substrate, but it has a central hole. In terms of irradiation efficiency, it is preferable to use one that has a ring-shaped emitting end that has been processed to match the shape of the transparent portion of the inner peripheral portion of the optical recording medium substrate. Also, when irradiating the outer peripheral portion, this structure is used. Need to be

The curing light irradiating device for ultraviolet rays used in these implementations uses a cold mirror for the condensing mirror in order to avoid the temperature rise of the portion of the optical recording medium substrate irradiated with the curing light for ultraviolet rays or the like as much as possible. It is preferable to use one having a built-in heat ray cut filter. Further, if necessary, it is also preferable to dispose a heat ray cut filter between the curing light emitting end of the curing light irradiation device for ultraviolet rays and the like and the optical recording medium substrate. Furthermore, it is also preferable to suppress the temperature rise by blowing cooling air to the curing light irradiation portion of the optical recording medium substrate.

The spraying these optical recording medium air irradiation and cooling of the curing light such as ultraviolet rays to the substrate, may be performed simultaneously from, or lower only from the lower not only above the optical recording medium substrate. When the cooling air is blown from below, when directly blowing on the optical recording medium substrate without using a transmission plate such as glass in the place where the optical recording medium substrate is placed,
It is possible to prevent the optical recording medium substrate from being blown off by the cooling air by using a plate having a hole in the portion for transmitting the curing light such as ultraviolet rays and fixing the optical recording medium substrate thereto by vacuum suction or the like.

By using the above method and apparatus,
It is possible to cure only the adhesive located in the light-transmitting portion of the inner peripheral portion or the outer peripheral portion of the optical recording medium substrate efficiently and avoid deformation of the optical recording medium substrate and unnecessary damage to the recording film. It has become possible, and the use of a pressure plate such as a glass plate for suppressing the deformation of the optical recording medium substrate is not necessary, and the handling is improved.

By heating the laminated optical recording medium substrate temporarily fixed on the inner peripheral portion or the outer peripheral portion by such a method, the adhesive used in the present invention is thermally cured, which is another function. As a heating means, for example, there is a method of leaving it in a heating oven. During this heating,
It is preferable to avoid occurrence of temperature unevenness on the superimposed optical recording medium substrate as much as possible. This is the arrangement and structure that hot air in the heating oven does not hit unevenly, the method of rotating the object to be heated, the temperature has already been heated in the heating oven for a long time and the temperature has become almost constant without any temperature distribution. It can be carried out by sandwiching it between existing metal plates. It is preferable that the metal plate used for this has a flat contact surface and is subjected to smoothing processing such as polishing so that the optical recording medium substrate is not scratched. Furthermore, the metal plate overlying the optical recording medium substrate should not be too heavy. This is to prevent the uncured adhesive from being pushed out to the outer peripheral portion of the optical recording medium substrate, and to cause thermal expansion of the substrate due to reaction heat generated at the time of heating and curing of the adhesive and remaining on the molded substrate. This is because it is necessary to appropriately release stress due to stress relaxation and volume change when the adhesive is cured. For this reason,
It is preferably 500 (g) or less. The sandwiching with the metal plate may be performed until the curing of the adhesive is sufficiently completed, or may be removed until the curing is completed depending on the cured state of the adhesive layer and the condition of the optical recording medium substrate. By using a metal plate in this way, it is easy to increase the smoothness of the contact plane with the optical recording medium substrate, uniform heatability is improved due to good thermal conductivity, and handling is easier than with a glass plate that is easily damaged. There are advantages such as na. The diameter of the metal plate is preferably 1 to 2 mm smaller than that of the optical recording medium substrate in order to avoid burrs existing on the outer peripheral portion of the optical recording medium substrate.

As another heating means, infrared or far infrared irradiation heating method can be used. You may use this and the above-mentioned oven heating together.

In order to prevent the thermal deformation of the optical recording medium substrate and the collapse of the transfer surface such as tracks and pits, the heating temperature for curing the adhesive is, when the substrate used is made of polycarbonate, for example, It is preferably 120 (° C) or less. Further, in order to shorten the curing time, it is preferably 50 (° C) or higher.

The optical recording medium substrate thus cured by heating is
Edge portion of the other of the transparent portion and the transparent portion of any hand of peripheral portion and / or the outer peripheral portion that had previously provisionally fixed, cured under the influence of oxygen present in the air in the heating atmosphere not It may be sufficient. In this case, it is preferable to use a method similar to the method of temporarily fixing and to irradiate the insufficiently cured light-transmitting portion with curing light such as ultraviolet rays again to completely cure.

Further, in order to avoid insufficient curing of the edge portion of the optical medium substrate due to the influence of oxygen, it is preferable to use nitrogen gas as the atmosphere during heating.

By using the above method and apparatus, it is possible to bond two or more optical recording medium substrates having a recording film, which has hardly transmitted curing light such as ultraviolet rays, which has been difficult in the past, with high productivity. Became.

[0032]

The present invention will be further described with reference to the following examples. However, the present invention is not limited by the following examples.

Example 1 On a polycarbonate substrate having a diameter of 120 (mm) molded by an injection compression molding machine, the diameter of 40 (mm) or less and the diameter of 116 (mm) or more of the inner peripheral portion were left as transparent portions, and the recording layer was formed. Two optical recording medium substrates formed by sputtering were used.
One of them was placed on a spin table with the surface on which the film was formed facing upward and fixed by vacuum adsorption. Then while rotating the spin table 50 (rpm), and applying the adhesive using a dispenser to rotate by one rotation center hole and the heart circular on the surface of the optical recording medium substrate. The adhesive is a UV-curable adhesive with thermosetting properties and has a viscosity of 300.
(Cp) (25 ° C.) was used. The overlapped faces that are deposited the other one of the optical recording medium substrate so as to sandwich the applied adhesive such that the heart only by its own weight in the bottom. Due to the weight of the optical recording medium substrate on the side of overlapping, the sandwiched adhesive slowly spreads, and when the distance to the center hole of the optical recording medium substrate spreads to a distance of about 1 (mm), the spin table is set to 1500 (rpm). It was rotated and the excess adhesive was shaken off to make the adhesive film thickness uniform. After that, while rotating at 50 (rpm) again, the excess adhesive adhering to the outer peripheral edge portion of the optical recording medium substrate was sucked while the suction nozzle was in contact. The superposed optical recording medium substrate thus manufactured was conveyed to the ultraviolet irradiation device. The ultraviolet irradiation device uses a metal halide lamp as the light source,
A cold mirror was used as the condenser mirror and a heat ray cut filter was arranged at the exit window. A metal plate (one side 20c) having a hole with a diameter of 42 (mm) at a position 1 cm above the optical recording medium substrate below the heat ray cut filter.
m, a 1mm thick), holes are arranged so that the central hole and the core optical recording medium substrate located below. The metal plate is also provided with an inlet for cooling air to the optical recording medium substrate, and the cooling air was blown onto the optical recording medium substrate during irradiation of ultraviolet rays. By irradiating with ultraviolet rays for 6 seconds, the adhesive located in the light transmitting portion of the inner peripheral portion of the optical recording medium substrate was cured. Then, it is conveyed into an oven set at 90 (° C), sandwiched between metal discs (diameter 118 mm , thickness 2 mm) that have been preheated in the oven and have a temperature that is almost uniform, and heated for 1 hour. did. The bonded optical recording medium substrate taken out of the oven after removing the metal plate was cooled by cold air from an ionizer. The produced laminated optical recording medium substrate was a good one in which neither center misalignment of the two substrates occurred nor local waving or warpage.

Example 2 As an ultraviolet irradiation device, an ultra-high pressure mercury lamp was used as a light source, a cold mirror focusing mirror was of a type capable of narrowing the ultraviolet irradiation range into a circular spot shape, and a heat ray cut filter was arranged at the exit window. Was used and the cooling air was blown onto the optical recording medium substrate from a cooling air blowing nozzle provided separately, and the same procedure as in Example 1 was performed. The ultraviolet irradiation range on the surface of the optical recording medium substrate was 42 (mm) in the inner peripheral diameter. Similar to Example 1, a good laminated optical recording medium substrate was obtained.

Example 3 A mercury-xenon lamp was used as a light source as an ultraviolet irradiation device.
After passing the light focused by the condenser mirror of the cold mirror through the heat ray cut filter, the incident end is a circular bundle and the exit end has a center hole. Using a ring-shaped optical fiber light guide that was processed together and arranged so that light could pass through, cooling air was blown onto the optical recording medium substrate from a separate cooling air blowing nozzle. The procedure was the same as in Example 1 except for the above. The ultraviolet irradiation range on the surface of the optical recording medium substrate was 15 to 42 (mm) in diameter. Similar to Example 1, a good laminated optical recording medium substrate was obtained.

Comparative Example 1 The laminated optical recording medium substrate obtained in the same manner as in Example 1 was directly transferred into an oven in a nitrogen atmosphere and heated at 80 ° C. for 1 hour. The obtained laminated optical recording medium substrate had two core misalignments and waviness and warpage.

Comparative Example 2 A laminated optical recording medium substrate obtained in the same manner as in Example 1 was covered with a glass plate (diameter: 15 cm, 1 cm thickness), and the entire surface of the optical recording medium substrate was irradiated with ultraviolet rays with a metal halide lamp.
The light transmitting portions of the inner peripheral portion and the outer peripheral portion of the optical recording medium substrate were simultaneously cured. After that, it is transferred into the oven at 80 ° C for 1
Heated for hours. The obtained laminated optical recording medium substrate did not have two core misalignments, but had local waviness and warpage.

Comparative Example 3 In the same manner as in Example 1, the superposed optical recording medium substrate was irradiated with ultraviolet rays for 6 seconds to cure the adhesive located in the light transmitting portion of the inner peripheral portion of the optical recording medium substrate. Then, it was transferred to an oven in an air atmosphere and heated at 80 ° C. for 1 hour. In the obtained laminated optical recording medium substrate, two cores were not misaligned, but the adhesive located near the edge of the outer peripheral light-transmitting portion in contact with the outside air was insufficiently cured.

[0039]

EFFECT OF THE INVENTION By using the manufacturing method and apparatus of the present invention, it is possible to bond two or more optical recording medium substrates having a recording film, which hardly transmits curing light such as ultraviolet rays, with high productivity. is there.

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view of a temporary fixing device used in Example 1.

FIG. 2 shows a schematic cross-sectional view of a temporary fixing device used in Example 2.

FIG. 3 shows a schematic cross-sectional view of a temporary fixing device used in Example 3.

4 shows a schematic cross-sectional view of a temporary fixing device used in Comparative Example 2. FIG.

[Explanation of symbols] 1: Condensing mirror (cold mirror) 2: Metal halide lamp 3: Ultra high pressure mercury lamp 4: Mercury xenon lamp 5: Heat ray cut filter 6: Cooling air blowing nozzle 7: Light shield plate 8: Light guide 9 : Glass plate 10: Adhesive layer 11: Polycarbonate substrate 12: Film-forming layer

Claims (9)

[Claims] 1. A recording layer is formed so as to have a center hole and a light-transmitting portion at least in an inner peripheral portion and an outer peripheral portion.
An adhesive is applied to at least one surface of at least one disk-shaped optical recording medium, the disk-shaped optical recording media are concentrically overlapped with each other so as to sandwich the adhesive, and then the adhesive is applied. A method for producing an optical recording medium to be cured, wherein after curing the adhesive positioned at the light transmitting portion of either the inner peripheral portion or the outer peripheral portion, curing the adhesive at another uncured portion. A method for manufacturing an optical recording medium, which comprises: 2. The adhesive is spread between the disc-shaped optical recording mediums after the disc-shaped optical recording mediums are superposed on each other and rotated around a center hole of the disc-shaped optical recording mediums. The method of manufacturing an optical recording medium according to claim 1, which is operated. 3. The optical recording according to claim 1, wherein the light-transmissive portion is cured by masking the light-transmitting portion of either the inner peripheral portion or the outer peripheral portion and irradiating curing light. Medium manufacturing method. 4. The method of manufacturing an optical recording medium according to claim 1, wherein the transparent portion is cured by spot-irradiating the transparent portion with curing light. 5. When irradiating with the curing light, cooling air is blown onto the portion of the surface of the optical recording medium irradiated with the curing light.
Alternatively, the method of manufacturing the optical recording medium according to the item 4. 6. The method for producing an optical recording medium according to claim 1, wherein the uncured portion is cured by heating. 7. The method for producing an optical recording medium according to claim 6, wherein the heat curing is performed in a nitrogen atmosphere. 8. The method of manufacturing an optical recording medium according to claim 6, wherein the heat curing is a method of sandwiching the metal plates. 9. The method for producing an optical recording medium according to claim 1, wherein the adhesive has a property of being cured by light and heat.