JPH11273164A - Production of disk and disk production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a disk free from unequal curing by radiating a cation type UV curing compsn. with UV rays prior to coating application on disk substrates and then spreading the compsn. with the disk substrates. SOLUTION: After the disk substrate 4 is placed on a table 3, the cation type UV curing compsn. is applied to an annular form on the surface of the disk substrate 4 while the table 3 is kept rotated. The cation type UV curing compsn. 5 is irradiated with the UV rays by a UV irradiation means 2 after the compsn. is dropped from the front end of a nozzle 1 and before the compsn. is applied on the disk substrate 4. Two sheets of the disk substrates coated with the cation type UV curing compsn. 5 in such a manner are prepd. and are bonded together after the surfaces dropped with the cation type UV curing compsn. to the annular form are disposed to face each other. Namely, the cation type UV curing compsns. are brought into contact with each other in the state of inclining the other disk substrate with the one disk substrate and are lowered until the disk substrates are paralleled with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a disk and an apparatus for manufacturing a disk, and more particularly to a digital video / versatile disk (hereinafter referred to as a D) which employs a lamination method.
VD) and a disk manufacturing apparatus suitable for manufacturing the disk.

[0002]

2. Description of the Related Art Conventionally, when two plate-like objects are bonded to each other using an ultraviolet-curable composition as an adhesive, a radical polymerization type ultraviolet-curable composition is spin-coated by an existing technique,
After uniformly applying to the bonding surface by a screen printing method or the like, the bonding surfaces are overlapped so that the bonding surfaces face each other, and thereafter, ultraviolet light for continuously emitting light is irradiated to cure.

As a light source for ultraviolet irradiation, a high-pressure mercury lamp, a metal halide lamp, a mercury-xenon lamp and the like have been conventionally used. In such a method, since the light emission of the lamp is continuous, heat is likely to be generated, and this heat has a problem that the heat adversely affects the warpage and mechanical properties of the plate-like object.

On the other hand, in the case of a lamp of a type that emits light continuously, it usually takes several minutes or more from when the lamp is turned on until the light emission becomes stable, so that it cannot be easily turned on or off. Therefore,
In the case of continuously producing a plate-like object, the lamp must be kept on. Assuming that the time required for one bonding (one cycle) (production cycle time) is 5 seconds, the time required for ultraviolet irradiation is 2 seconds.
In seconds, energy is wasted for the remaining three seconds.

[0005] In the case where two plate-like objects are bonded together using an ultraviolet-curable composition as an adhesive, if at least one of the two plate-like objects is transparent to ultraviolet light, a serious problem arises. Does not occur. However, for example, DVDs manufactured by lamination, such as DVDs, have a large attenuation in ultraviolet intensity due to a thin film or layer of Al or the like until ultraviolet rays reach an adhesive layer using the radical polymerization type ultraviolet curable composition as an adhesive. There is a problem that efficient curing adhesion is not performed.

[0006] Therefore, if it is intended to accelerate the curing,
There is a problem that large-capacity lamp equipment is required, which inevitably leads to an increase in product cost. In addition, when a large-capacity lamp is used, there is a possibility that problems such as deformation of a plate-like object may occur due to radiant heat from the lamp.
In order to prevent this, a cooling facility around the lamp was additionally required, and the entire apparatus had to be large and more complicated. Conversely, if UV curing is to be performed while the lamp equipment capacity is small, the irradiation time is required to be several tens of seconds or more, and the practicality must be poor.

A method of laminating disks that solves the above problems is proposed in Japanese Patent Application Laid-Open No. 9-193249. That is, the method of laminating disks disclosed in Japanese Patent Application Laid-Open No. 9-193249 is characterized in that the object to be irradiated is irradiated with ultraviolet rays instead of continuously irradiating the object with ultraviolet rays. This method of irradiating ultraviolet light in a flash is capable of increasing the number of sheets to be bonded per unit time while suppressing the power consumption for irradiating ultraviolet light, as compared with the case of continuously irradiating the light. This is an epoch-making method that can prevent occurrence of disk warpage after alignment.

However, the method using flash ultraviolet irradiation also has the following problems. That is, when a DVD is to be bonded, due to its structure, ultraviolet light passes through an Al film having poor ultraviolet transmittance and reaches an ultraviolet curable resin and is cured. If the thickness is large, the curing efficiency will be poor. Also, no ultraviolet rays substantially transparent among DVD film (e.g., ZnS-SiO ₂ film) DVD-RAM which is present
In this method, it is not possible to employ a method of irradiating ultraviolet light to the ultraviolet curable resin existing on the bonding surface of the two disks to cure and adhere the resin.

An effective bonding method for solving the above problems is disclosed in Japanese Patent Application Laid-Open No. 9-69239. The method described in Japanese Patent Application Laid-Open No. 9-69239 is characterized by using a slow-curing cationic UV-curable composition, whereas a conventional radical-curable UV-curable resin is used as an adhesive. ing. More specifically, a cationic UV-curable composition is applied to the entire surface of one of the disks to be bonded, and after application, the cationic UV-curable composition is irradiated with ultraviolet light, and then the other of the objects to be bonded is applied. The disks are overlapped, and the pressure is further increased to cure the cationic ultraviolet curable composition.

[0010]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 9-69239
Method using the cationic ultraviolet curable composition according to JP, when the Al film is thick, or ultraviolet rays substantially transparent non ZnS-SiO ₂ film or the like is present DVD-
This is an effective method that enables bonding even in a RAM.
However, it was confirmed that the method described in JP-A-9-69239 should be further improved. That is, as described above, the method described in Japanese Patent Application Laid-Open No. 9-69239 discloses a method in which a cationic UV-curable composition is applied to the entire surface of one disk and then the other disk is overlaid. And the adhesive performance may be degraded.

In other words, the resin around the bubbles is not completely cured due to polymerization inhibition by the moisture (moisture) contained in the bubbles, which may impair the product quality after bonding. Further, if the bonded body in which bubbles are entrained is exposed to high temperature and high humidity for a long time, the air inside expands, and in the worst case, the surface may rise.

In order to prevent the generation of such bubbles, it is conceivable to employ a spin coating method known to those skilled in the art for applying the cationic ultraviolet curable composition. But,
Since the cationic ultraviolet ray curable composition dropped in a ring shape has a considerable thickness, it is difficult to irradiate and reach ultraviolet rays inside the composition. Therefore, curing unevenness easily occurs in the adhesive layer formed by this method.

In the method described in Japanese Patent Application Laid-Open No. 9-69239, pressure is applied after two disks are superimposed.
The mechanism for pressurization may cause scratches on the disk surface. The occurrence of this flaw becomes remarkable in the case of continuous production, which may cause a decrease in product yield. Further, due to the characteristics of the cationic ultraviolet curable composition, a predetermined time is required until curing after bonding, so that the bonded body is allowed to stand still for a certain time, or measures are taken to prevent deformation, displacement, etc. from occurring. Must be taken, which is an obstacle to constructing mass production equipment.

The cationic UV-curable composition near the end face of the disc obtained by lamination suffers from polymerization failure due to the moisture of the outside air, so that the part slightly protruding from the joint surface of the two disc substrates by lamination is obtained. There were problems such as difficulty in curing, stickiness and sticking to hands. Further, in the method in which the cationic UV-curable composition is applied to the disk substrate and then irradiated with UV-rays, the UV-irradiation is basically required only for the cationic UV-curable composition. Ultraviolet rays are inevitably irradiated to a disk substrate made of a certain polycarbonate or the like. This unnecessary irradiation of the ultraviolet light to the disk substrate may cause thermal deformation due to heat from a lamp as an ultraviolet light source on a thin disk substrate (0.6 mm thick) such as a DVD.

Therefore, the present invention provides a method which does not easily cause uneven curing on the adhesive layer and does not directly irradiate the disk surface with ultraviolet light, even when a cationic ultraviolet curable composition is used. An object of the present invention is to provide a method for efficiently manufacturing a disk, which does not cause deformation of the disk due to conduction heat or radiant heat from a lamp, which tends to occur. Another object of the present invention is to provide a method for manufacturing a disk that can prevent deformation after bonding a disk substrate and can prevent stickiness or the like caused by a cationic ultraviolet curable composition that protrudes from an end surface of the disk. Another object of the present invention is to provide a disk manufacturing apparatus suitable for the above manufacturing method.

[0016]

According to the present invention, there is provided a method of manufacturing a disk, comprising irradiating a cationic ultraviolet curable composition dropped from a nozzle with an ultraviolet ray while irradiating the first or second disk substrate with a ring. Applying to the
A step of laminating the first and second disk substrates via the surface coated with the cationic ultraviolet curable composition to form one disk, a step of stacking a plurality of disks, and a step of stacking the stacked disks. Irradiating the end face of each disk with ultraviolet rays.

The present inventors have studied to prevent the occurrence of uneven curing of the adhesive layer even when a cationic ultraviolet curable composition is used. If the ultraviolet light is applied after applying the cationic ultraviolet-curable composition to a disk substrate in a ring shape as in the prior art, the inside of the composition will not be sufficiently irradiated. Therefore, the present inventor can sufficiently suppress the occurrence of curing unevenness of the adhesive layer by sufficiently irradiating the cationic ultraviolet curable composition with ultraviolet rays in advance and then applying the cationic ultraviolet curable composition to a disk substrate. I found that I can do it.

In the present invention, in order to irradiate the cationic ultraviolet ray-curable composition with ultraviolet rays before dropping onto the disk substrate, the space until the cationic ultraviolet ray-curable composition dropped from the nozzle reaches the disk substrate is reached. The method of irradiating with ultraviolet rays was adopted. For example, it is conceivable to irradiate ultraviolet rays in the process of passing the cationic ultraviolet-curable composition through the light-transmitting tube, but in such a case, the cationic ultraviolet-curable composition cures and adheres to the inner wall of the tube. In other words, it is difficult to ensure the passage of the cationic ultraviolet curable composition unless the tube is appropriately replaced, whereas in a space, such a problem does not occur.

In the present invention, a cationic UV curable composition comprising a cationic UV curable resin (epoxy resin) and a cationic polymerization type photoinitiator is used. The composition comprises:
Unlike ordinary UV-curable compositions, in which the degree of curing is substantially immediately saturated almost immediately with the irradiation of ultraviolet light (in the sense of fast-curing, it is called fast-acting), the degree of curing does not saturate immediately after irradiation with ultraviolet light, and a predetermined time has elapsed. After that, the degree of cure is substantially saturated (called "slow effect"). That is, since there is a certain period of time (pot life) from the time of ultraviolet irradiation to the time when the degree of curing is saturated, the bonding work and fine adjustment can be performed during that time. The cationic UV-curable composition containing the cationic UV-curable resin and the cationic polymerization-type photoinitiator as essential components is preferably a substantially solvent-free liquid in that it can be easily dropped onto a disk substrate. . More preferably, the composition is selected so that both the composition itself and the cured adhesive layer are transparent.

The viscosity of the composition is usually 50 at 25 ° C.
~ 1000 mPas, preferably 100-1000 mP
as. The time from the end of ultraviolet irradiation until the curing degree is saturated and the absolute value of the saturated curing degree are as follows:
It is adjusted by the type of the cationic ultraviolet curable resin and the cationic polymerization type photoinitiator used in combination with the resin and their weight ratio, for example, 3 to 30 minutes, preferably 5 to 2 minutes.
5 minutes, more preferably 5 to 15 minutes, particularly preferably 5 to
Adjusted to 10 minutes.

[0021] All known compositions can be used as the cationic type ultraviolet curable composition, and an epoxy resin containing a cationic polymerization type photoinitiator corresponds to this. Examples of the cationic polymerization type photoinitiator include a diazonium salt and an onium compound. An example of the diazonium salt is as follows. 2,5-dibutoxy-4 morpholinobenzenediazonium tetrachloroborate 2,5-diethoxy-4-
(4-Ethoxyphenyl) benzenediazoniumtetrafluoroborate 1-chloro-5-methoxy-4-N, N-dibenzylaminobenzenediazoniumtetrafluoroborate On the other hand, as onium compounds, sulfonium salts and derivatives thereof, and iodonium salts And its derivatives.

Epoxy resins include bisphenol A-epichlorhydrin type, alicyclic epoxy, long-chain aliphatic type,
Any of various types such as a brominated epoxy resin, a glycidyl ester type, and a heterocyclic type may be used. As a preferable specific example, Dikonal EX-313, 314, 321, 421, 512, 52 manufactured by Nagase Kasei Kogyo Co., Ltd.
There is one.

Examples of the epoxy resin include DVD
-To obtain a RAM, it is preferable to minimize the deterioration of the information recording layer made of a metal film that reflects ultraviolet rays with time as much as possible. The polymerization ratio between the cationic ultraviolet-curable resin and the cationic polymerization-type photoinitiator can be selected based on the above.
0.1 to 20 parts by weight per 100 parts by weight, preferably 0.1 to 20 parts by weight.
It is 2 to 5 parts by weight. In order to more effectively use the wavelength in the near ultraviolet region or the visible region of the wavelength range of the ultraviolet light source, for example, a known and commonly used photosensitizer can be used in combination. In this case, examples of the photosensitizer include anthracene, phenothiazine, benzanthracene, benzylmethyl ketal, benzophenone, acetophenone and the like.

In order to irradiate the cationic UV-curable composition to be dropped with ultraviolet rays, an ultraviolet irradiation means may be provided on the side of the cationic UV-curable composition to be dropped. Known lamps such as a xenon lamp, a xenon-mercury lamp, and a metal halide lamp may be used.

In order to uniformly irradiate the ultraviolet rays with the cationic ultraviolet curable composition to be dropped, it is effective to reduce the diameter of the cationic ultraviolet curable composition to be dropped by reducing the nozzle diameter. It is also effective to irradiate ultraviolet rays from all around the cationic ultraviolet curable composition to be dropped. As a specific means for irradiating ultraviolet rays from all around the cationic UV-curable composition to be dropped, a plurality of UV irradiating means may be arranged around the cationic UV-curable composition to be dropped and irradiating the ultraviolet rays. However, if the surroundings of the cationic-type UV-curable composition to be dropped are surrounded by a reflector and the inside of the surroundings is irradiated with ultraviolet rays, it is not necessary to prepare a plurality of ultraviolet irradiation means, so that cost is reduced. Is advantageous.

During the dropping of the cationic ultraviolet curable composition from the nozzle to the disk substrate, the amount of ultraviolet irradiation on the composition is usually 50 to 500 mJ / c.
m ² , preferably 100 to 400 mJ / cm ² . In the present invention, since continuous ultraviolet irradiation is not directly performed on the disk substrate, when the disk substrate does not have heat resistance, deformation due to heat does not occur,
This is more advantageous than the conventional method of directly irradiating the disk substrate with continuous ultraviolet rays.

In the present invention, it is preferable to spread the cationic ultraviolet curable composition by the following method.
That is, the cation type ultraviolet curable composition previously irradiated with ultraviolet light is dropped on two disk substrates in a ring shape so as to have the same radius, and the surfaces on which the cation type ultraviolet curable composition is dropped face each other. The cationic ultraviolet curable composition can be spread by making the distance (thickness of the adhesive) between the two disk substrates close together to a desired distance.

At this time, in order to prevent the entrapment of air bubbles, the two disk substrates are not superposed in parallel but superposed initially in an inclined state, and then the two disks are brought into a parallel state. (Hereinafter, this method is referred to as a 2P method). Further, when reducing the gap between the two disks, it is desirable to control so as to approach in micron units per second, and it is desirable that the approach be performed intermittently. According to this method, the adhesive does not scatter around the disk unlike the spin coating method, which is advantageous in terms of resources. The total thickness of the adhesive layer (after curing) of the cationic UV-curable composition comprising the cationic UV-curable resin and the cationic polymerization-type photoinitiator is not particularly limited, but is usually 15 to 60 μm, preferably 20 to 55 μm.
m.

Since the cationic ultraviolet ray curable composition near the end face of the disk undergoes polymerization failure due to the moisture of the outside air, the portion slightly protruding from the joint surface of the two disk substrates by bonding is hard to cure. Therefore, the end surface of the disk is further irradiated with ultraviolet rays to cure the cationic ultraviolet curable composition near the end surface of the disk. In the case of irradiating light intensively on the end face, the adverse effect caused by the heat from the lamp light source to the disk substrate hardly causes a problem. At this time, it is not efficient to irradiate ultraviolet rays for each disk, so that a plurality of disks are stacked,
By irradiating an end face of each disk with ultraviolet rays to the aggregate of the stacked disks, it is possible to perform hardening processing of the end faces of many disks at once.

The following effects are also produced by stacking the disks. That is, 2P
In the method, when no load is applied to the disk, it is 1 to 1 until the spreading of the cationic ultraviolet curable composition is completed.
It takes 5 minutes. If the completion of the spread is waited for at the position where the bonding is performed, the next bonding cannot be performed during that time, which hinders the production efficiency. Therefore, before the spreading is completed, the discs are transferred to a position different from the bonding position and stacked. If the completion of the spreading is waited in the stacked state, the next bonding can be performed quickly. By this UV irradiation, the cationic UV curable composition on the end face of the disk is cured at an early stage, so that problems such as stickiness can be solved, and a shift at the time of conveyance can be prevented. Thereby, the processing time can be reduced.

When the aggregate of the stacked disks is subjected to the ultraviolet treatment, the ultraviolet light may be distributed to all the end faces, and an ultraviolet light source may be installed in several places to perform the treatment. It may be placed around the aggregate, but by irradiating the ultraviolet light while rotating the aggregate of the stacked disks, the ultraviolet light source can be concentrated in one place, and the ultraviolet light can be uniformly applied to all the end faces. Irradiation is preferred. Irradiation of the ultraviolet rays to the end face may be performed continuously or may be performed by flash light irradiation, but flash light irradiation is preferable because it is more advantageous in energy.

The flash of ultraviolet light may be performed once, but may be performed twice or more. In performing flash irradiation with ultraviolet light, for example, a light emitting device including an ultraviolet light source lamp and a flash discharge mechanism can be used. Ultraviolet light sources used in the present invention include those capable of emitting light in a flashing manner and repeatedly. As the lamp, for example, various lamps such as a xenon lamp, a xenon-mercury lamp, and a metal halide lamp can be used, but it is preferable to use a lamp having excellent durability that can withstand repeated light emission. As a flash discharge mechanism for flashing the lamp, for example, a capacitor for storing electric charge, a coil for controlling a current waveform at the time of discharge, and a circuit in which the lamp electrode is connected in series are used. be able to.

As means for charging the capacitor with electric charge, for example, an element in which a DC voltage power supply and a charging current control resistor are connected in series can be implemented by a circuit in which the element is connected in parallel to the capacitor. As means for giving a trigger to discharge the electric charge accumulated in the capacitor to the lamp, for example, a wire-like auxiliary electrode wound several times around the lamp is provided, and between the auxiliary electrode and one electrode of the lamp, for example, By the trigger generation circuit,
There is a method of applying a high-voltage pulse.

In this manner, the application of the high-voltage pulse causes the gas sealed in the lamp to instantaneously cause dielectric breakdown, which triggers the electric energy stored in the capacitor to be extremely high. During a short time t, the light is emitted into the lamp at once, and then emits an intense flash. Since the electric energy is released in a very short time on the order of μsec to msec, the voltage between the two electrodes of the lamp rapidly decreases with the start of discharge, and the discharge itself ends instantaneously.

Further, as the above-mentioned mechanism in the case where the lamp repeatedly emits light in a flashing manner, for example, the following mechanism can be mentioned. In the discharge accompanied by the flash, charging of the capacitor is started from the DC voltage power supply side almost simultaneously with the start of the discharge. The time required for charging is related to a time constant τ determined by the product of the capacitance (Farad) of the capacitor and the charging current control resistor (Ohm). In general, when the relationship between the time constant τ and the discharge time t is τ >> t, the light emission due to the discharge does not become continuous but ends only once. However, the charging is performed continuously thereafter.

When the high-voltage pulse is applied again when the charge accumulation in the capacitor has reached a certain level of saturation and has reached a level at which discharge is possible again, a second flash is emitted. Flash-type repetitive light emission can be performed by repeating the above operations. In performing flash irradiation with ultraviolet light, when light from a light source contains infrared light, it is preferable to block the infrared light and irradiate only ultraviolet light. By doing so, it is possible to prevent infrared rays from being irradiated on the disk substrate,
The heat hardly causes warping or deformation of the disk itself, and hardly causes deterioration of recorded information.

In selectively blocking infrared rays from light emitted from a light source lamp that emits ultraviolet rays including infrared rays, an infrared cutoff filter can be generally used. According to the findings of the present inventors, even if the discharge energy per discharge is the same, if the peak value or the time width of the discharge current is changed, the intensity and spectral distribution of light emitted from the lamp change, and the same. It was found that the curability of the ultraviolet curable composition having the composition also changed.

The disk substrate mainly targeted by the present invention is:
It is made of a material that hardly transmits or substantially does not transmit ultraviolet light. However, the material is not limited to a single material, but may be a composite material of a material that sufficiently transmits ultraviolet light and a material that hardly transmits or substantially does not transmit ultraviolet light. One example of such a device is the aforementioned Al in a DVD-ROM.
DVD-10, DVD-18, or DVD-RAM with a thick metal film.

In the case of a DVD-RAM, at least one of the two disk substrates is a disk substrate (first disk substrate) having an information recording layer on an ultraviolet transmitting substrate, and the other disk substrate (second disk substrate) Disc substrate) may or may not have an information recording layer. In other words, the discs targeted by the present invention include a case where both disc substrates have an information recording layer and a case where one disc substrate has an information recording layer but the other disc substrate does not have an information recording layer. There is. In any case, the disk substrate usually has a thickness of 0.3 to 1 mm.

As the first and second disk substrates,
Any known and commonly used materials can be used, and examples thereof include heat-resistant thermoplastic synthetic resins such as acryl, polycarbonate, and amorphous polyolefin. The information recording layer is provided with irregularities corresponding to recorded information on one surface of the substrate,
It is configured by laminating a metal film thereon.

In the present invention, the cationic ultraviolet curable composition can be directly dropped and spread on a metal film typified by a semi-reflective film or a reflective film. After spreading and curing a conventional ultraviolet curable resin adjusted so that deterioration of the metal film with time can be prevented as much as possible on the metal film as described above, a cationic ultraviolet ray is formed on a protective layer made of the cured product. The curable composition may be dropped, spread, and cured. This protective layer is 5
It is preferable that the thickness be up to 20 μm. In this case, both protective layers of the first and second disk substrates are adhered to each other with the cationic ultraviolet curable composition.

As the metal film, it is preferable to use a film which reflects the visible light employed for reading recorded information at a high rate so that the irregularities can be accurately confirmed. A film that reflects visible light at a high rate generally reflects ultraviolet light at a high rate. Examples of the metal film include Al, Ni, and alloys thereof, and have a visible light reflectance of 80 to 100% and a transmittance of more than 0 to 10% over the entire ultraviolet wavelength range.
And preferably, more than 0 and less than 0.5%. In addition, in a disc of a standard called DVD-9 or DVD-18, a film made of a material having a light transmittance of 70 to 82%, for example, gold, which is called a semi-reflective film, is formed.

The DVD-RAM has a characteristic layer configuration different from the above DVD. As an example, a ZnS—SiO ₂ layer, GeSbT
An e-layer, a ZnS—SiO ₂ layer, an Al alloy layer, and a protective layer are sequentially laminated to prepare two disk substrates, and the protective layer is opposed to each other, and cured and bonded with an adhesive. Have been.

The apparatus for manufacturing a disk according to the present invention comprises a dropping means for dropping a cationic ultraviolet-curable composition onto a disk substrate, and a first ultraviolet irradiation for applying ultraviolet rays to the cationic ultraviolet-curable composition during the dropping. Means, a stacking means for stacking two disc substrates via a coating surface on which the cationic ultraviolet curable composition is applied to form a disc, and a holding means for stacking and holding a plurality of discs, and It is characterized by comprising second ultraviolet irradiation means for irradiating each end face of a plurality of disks with ultraviolet light, and transport means for transporting the disk substrate and the disk between each means.

This nozzle is not limited to a single slit for ejecting the cationic ultraviolet curable composition, and a plurality of nozzles can be provided. This makes it possible to easily adjust the amount of the cationic ultraviolet curable composition dropped. Although the installation position of the first ultraviolet irradiation means is not particularly limited, it may be provided on the side of the cationic UV curable composition to be dropped, and the UV light is uniformly applied to the cationic UV curable composition to be dropped. In order to irradiate, a plurality of ultraviolet irradiating means are dropped around the entire circumference to arrange ultraviolet light irradiating means, and the ultraviolet light is arranged around the cationic ultraviolet curable composition, or the periphery of the cationic ultraviolet curable composition is reflected by a reflector. The surroundings may be irradiated with ultraviolet rays.

When the cation type ultraviolet curable composition in the vicinity of the end surface of the disk is cured by further irradiating the end surface of the disk with ultraviolet light, it is inefficient to irradiate the ultraviolet light for each disk. It is preferable to irradiate the end face of each disk with an ultraviolet ray to an aggregate of a plurality of stacked disks. As a result, it is possible to perform the hardening process of the end faces of many disks at a time. At this time, it is preferable that the plurality of discs held by the holding means rotate around a line connecting the centers of the discs when the second ultraviolet irradiation means irradiates ultraviolet rays. As a result, it is easy to uniformly irradiate the ultraviolet rays to the end faces of all the disks. It is desirable that the second ultraviolet irradiation means be of a flash type because it is advantageous in terms of energy.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to only these embodiments. FIG. 1 shows a schematic configuration of an apparatus used for applying a cationic ultraviolet curable composition to a disk substrate. In FIG. 1, reference numeral 1 denotes a nozzle for dropping a cationic ultraviolet curable composition, 2 denotes an ultraviolet irradiation means, and 3 denotes a table. The table 3 is rotatable by a drive mechanism (not shown).

After placing the disk substrate 4 on the table 3 of the apparatus shown in FIG. 1, the above-mentioned cationic ultraviolet curable composition is applied in a ring shape to the surface of the disk substrate 4 while rotating the table 3. The cationic ultraviolet curable composition 5 is irradiated with ultraviolet rays by causing the ultraviolet irradiating means 2 to emit light before the cationic ultraviolet curable composition 5 is dropped from the tip of the nozzle 1 and applied to the disk substrate 4. I do.

Thus, two disk substrates on which the cationic ultraviolet curable composition 5 is applied are prepared. This is bonded after facing the surfaces on which the cationic ultraviolet curable composition has been dropped in a ring shape. As shown in FIG. 2, by contacting the cationic ultraviolet curable compositions with one disk substrate in a state where the other disk substrate is inclined with respect to the other disk substrate, and then lowering the disk substrates so that the disk substrates are parallel to each other. Then, the dripped resins gradually come into contact all over the circumference and spread. By adjusting the lowering speed of the upper disk substrate, entrainment of air bubbles is prevented.

The disk obtained in this way is spindle 8
The disk assembly 6 is formed by stacking a plurality of sheets around the center axis. It has been confirmed that even when a plurality of disks are stacked, the resin does not unnecessarily protrude from the end surfaces of the disks. Ultraviolet light is emitted by causing the ultraviolet irradiation means 7 to flash light while rotating the disk assembly 6 about the spindle 8. At this time, since the spindle 8 restrains the movement of the disk in the horizontal direction, it is possible to prevent the occurrence of the displacement. By the above operation, a disk in which the two disk substrates 4 are bonded together using the cationic ultraviolet curable composition is obtained.

FIG. 4 is a schematic configuration diagram showing a disk manufacturing apparatus according to this embodiment. This disk manufacturing apparatus 11
Are a composition application section 12 (dropping means and first ultraviolet irradiation means), a disk overlapping section 13 (overlapping means), a disk holding section 14 (holding means), and an ultraviolet irradiation section 15 (second ultraviolet irradiation means). , The first arm 16 (transporting means),
It is schematically composed of a second arm 17 (transporting means) and a third arm 18 (transporting means).

In the composition application section 12, a cationic ultraviolet curable composition irradiated with ultraviolet rays is applied to a disk substrate. The method of application is as shown in FIG. In the disk overlapping portion 13, two disk substrates coated with the cationic ultraviolet curable composition by the method shown in FIG. 2 are bonded to each other with the coated surfaces facing each other. In the disk holding unit 14, disks obtained by bonding disk substrates are stacked and held. In the ultraviolet irradiation section 15,
The aggregate of disks stacked by the disk holding unit 14 is irradiated with ultraviolet rays. 1st arm 16, 2nd arm 1
7. The third arm 18 carries a disk substrate and a disk, respectively.

Next, the flow of the process of manufacturing a disk using the disk manufacturing apparatus 11 will be described. First, the first arm 16 takes one first disk substrate from the first disk substrate storage place 21 and transports it onto the table 23. The substrate composition application section 12 is the first
Is applied with a cationic ultraviolet curable composition irradiated with ultraviolet rays. After the application, the second arm 17
Transports the first disk substrate to the disk stacking unit 13.

Next, the same operation is performed on the second disk substrate placed in the second disk substrate storage area 22, and the second disk substrate coated with the cationic ultraviolet curable composition is placed in the disk overlapping portion. To 13. In the disk overlapping portion 13, the first disk substrate and the second disk substrate are bonded together with the surface coated with the cationic ultraviolet curable composition facing each other.

The bonded disc is moved to the third arm 18.
Is transported to the disk holding unit 14. At the time of this transfer, the cationic ultraviolet curable composition between the disk substrates does not need to be completely spread. That is, the spreading of the cationic ultraviolet curable composition is completed while the disks are stacked in the disk holding unit 14. As described above, the disk stacking unit 13 does not need to wait for the completion of spreading of the individual disks, and can start the next bonding operation, so that the cycle time can be reduced.

By repeating the above operation, the disk holding unit 1
Stack disks on 4. For the stacking, a rotatable spindle 8 is used as shown in FIG. At the time when the cationic UV-curable composition between each disk substrate was completely spread, an aggregate of stacked disks was obtained.
It is transported on the table 24. The table 24 rotates the aggregate of the disks, and the ultraviolet irradiator 15 irradiates the ultraviolet rays to cure the cationic ultraviolet curable composition near the end surface of the disk.

In the disk holding unit 14, the waiting time until the irradiation of the ultraviolet rays differs between the disk stacked on the lower side and the disk stacked on the upper side, and the standby time is inevitably longer for the lower disk. Become. In addition, the lower the disk, the larger the number of disks to be mounted thereon, and inevitably tends to receive those weight loads. In this case, there is a concern that the lower the disk, the more the cationic ultraviolet-curable composition of the adhesive layer in the uncured state protrudes from the end face of the disc and stains the vicinity of the end face. However, such protrusion rarely occurs in reality. The reason is that the cationic ultraviolet curable composition as an adhesive has already been irradiated with a predetermined amount of ultraviolet light, and then the curing reaction is started slowly but gradually, and the viscosity gradually increases, so that the adhesive is protruded. It is thought that it became difficult to occur. Alternatively, it is considered that the viscosity and surface tension inherently possessed by the cationic ultraviolet curable composition acted to suppress the protrusion from the end face. Thus, a disk can be manufactured using the disk manufacturing apparatus 11. Note that the technical scope of the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention.

[0058]

As described above in detail, according to the present invention, the cationic ultraviolet ray-curable composition is irradiated with ultraviolet rays before application to the disk substrate and then spread on the disk substrate, so that there is no uneven curing. You can get a disc. In other words, if the ultraviolet rays are irradiated during the dropping from the nozzle to the disk substrate, the ultraviolet rays can be uniformly irradiated to the inside of the cationic ultraviolet curable composition, so that the cationic ultraviolet curable composition is dropped in a ring shape. The curing method does not cause uneven curing. Further, according to the present invention, since the bonding can be performed without directly irradiating the main surface of the disk substrate with ultraviolet rays, deformation of the disk due to heat can be avoided.

According to the present invention, by irradiating the end face of the bonded disc with ultraviolet rays, the cationic ultraviolet curable composition near the end face of the disc can be effectively cured. At this time, in the case of performing the bonding by the 2P method, a plurality of disks are stacked at another position different from the position where the disks in a state where the spread of the cationic ultraviolet curable composition is not completely finished are bonded, and the stacked disks are stacked. By irradiating ultraviolet rays while rotating the aggregate of disks, the number of processed sheets can be increased and efficiency can be increased. By performing the ultraviolet irradiation in a flashing manner, the power consumption can be reduced. The disk can be efficiently manufactured by using the disk manufacturing apparatus of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an apparatus used for applying a cationic ultraviolet curable composition to a disk substrate.

FIG. 2 is a schematic view showing a state in which two disk substrates are being overlapped.

FIG. 3 is a schematic view showing a state where a disk assembly is irradiated with ultraviolet rays.

FIG. 4 is a schematic configuration diagram showing a disk manufacturing apparatus according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nozzle 2 ... Ultraviolet irradiation means 3 ... Table 4 ... Disk substrate 5 ... Cationic ultraviolet curable composition 6 ... Disk aggregate 7 ... Ultraviolet irradiation means 8. ··· Spindle 11 ··· Disk manufacturing device 12 ··· Compound application unit (dropping unit and first ultraviolet irradiation unit) 13 ··· Disk overlapping unit (overlapping unit) 14 ··· Disk holding unit (holding) 15) Ultraviolet irradiation section (second ultraviolet irradiation section) 16 ... First arm (transport section) 17 ... Second arm (transport section) 18 ... Third arm (transport section)

Claims (6)

[Claims] 1. A method for manufacturing a disk in which two disk substrates are bonded together with a cationic ultraviolet curable composition to form one disk, wherein the cationic ultraviolet curable composition dropped from a nozzle is irradiated with ultraviolet light. Applying a ring to at least one of the first and second disk substrates while bonding, bonding the first and second disk substrates via a surface coated with a cationic ultraviolet curable composition to form one disk And a step of stacking a plurality of the disks; and a step of irradiating an end face of each of the disks with an ultraviolet ray to an aggregate of the stacked disks. 2. The method for manufacturing a disk according to claim 1, wherein the ultraviolet irradiation is performed while rotating the aggregate of the disks. 3. The method of manufacturing a disk according to claim 1, wherein the ultraviolet irradiation of the aggregate of the disks is performed in a flash manner. 4. A dripping means for dropping a cationic ultraviolet curable composition onto a disk substrate; a first ultraviolet light irradiating means for irradiating the cationic ultraviolet curable composition with ultraviolet rays in the course of dripping; Superimposing means for superimposing the two disk substrates to form a disk through an application surface on which the curable composition has been applied; holding means for stacking and holding a plurality of the disks; and A disk manufacturing apparatus comprising: a second ultraviolet light irradiating means for irradiating each end face of a disk with ultraviolet light; and a transport means for transporting the disk substrate and the disk between the respective means. 5. The plurality of discs held by the holding means rotate around a line connecting the centers of the discs when the second ultraviolet irradiation means irradiates ultraviolet rays. The disk manufacturing apparatus according to the above. 6. The disk manufacturing apparatus according to claim 4, wherein said second ultraviolet irradiation means is of a flash type.