JPH09314676A - Optical laminated-disc, its preparation and its apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate curing an adhesive and to prevent a printing design from floating by a method wherein a printed layer is formed on at least one side of the laminated face of a recording disc and the printed layer is covered with a coating layer and an adhesive is placed thereon to perform lamination. SOLUTION: An optical laminated-disc 1 is a product prepd. by laminating a one face disc 1A which is prepd. by a method wherein an information pit is recorded on the lamination face side of the one face disc base sheet 1a and a reflection film 2 is formed on the information pit and a protective film 3 is formed on the reflection film 2 and a printed layer is formed on the protective film 3, and a transparent one face disc 1B on which the information pit is not recorded through an adhesive 9. Here, the printed layer 6 of the recording disc 1A of the laminated disc 1 is covered with a coating layer 10. In this case, the thickness of the coating layer 10 in accordance with the step difference is controlled so as to make a local step difference to be a broad step difference, namely, a gently-sloping step difference.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to audio information,
The present invention relates to an optical bonded disc that optically records or reproduces video information or normal data, a manufacturing method thereof, and a manufacturing apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, an optical information disc for optically reading a recording signal with a laser beam or the like is known in which two disc substrates are bonded to each other.

Recently, a thickness of 0.6, which is called DVD
A video disk is being developed in which substrates (one side) having a diameter of 12 mm and a diameter of 12 cm are bonded to the front and back. Then, the storage capacity of this disk is 4 GB or more on one surface of the bonded one. With a storage capacity of 4 GB or more, compression technology or the like can be used to accommodate as much as 135 minutes in a normal movie or the like. Since 90% or more of movie software is within 135 minutes, if it can be accommodated for 135 minutes, most of the movies can be accommodated on only one side of the DVD bonded disc.

Therefore, the other surface (disk) pasted together may be a disk without recording signals (dummy disk). For this reason, there is a demand for printing such a CD on the surface of the dummy disk. In this case, a method of printing on the front surface side of the dummy disk and a method of printing on the back surface (bonding surface) side of the dummy disk can be considered.

In particular, since this DVD is a bonded disk, printing is performed on the bonded surface side of a transparent dummy disk, and then this dummy disk and a disk (single-sided) on which information such as a movie is recorded are bonded. The demand for matching is increasing.

This is because of the following reasons. That is, when printing is performed on the bonding surface side of the dummy disk, the printing can be seen through the transparent substrate of the dummy disk, so that the irregular reflection of the surface of the printing ink is suppressed. Further, since the printing ink is not exposed on the surface, it can be seen as extremely smooth printing. For this reason, a texture closer to that of a photograph can be obtained as compared with a CD printed on the surface of a disc.

Regarding the bonding of such a DVD, there is a method of using a thermoplastic resin called a hot melt adhesive, which is used in the manufacture of laser disks. In the case of this laminating method, a hot melt adhesive is applied to the disks to be laminated by a roll coater. At this time, since the molten hot melt is attached to the surface of the roll in the coater, the roll has a surface just like an adhesive tape. With this adhesive tape-like surface, for example, when dust adheres to the disk, the roll scoops the dust.

The scooped dust enters the inside of the coater, and is sandwiched between a roll called a doctor for controlling the thickness of the adhesive and the roll to make the thickness of the adhesive uneven. . This cause often causes defects that are not coated on the coating film in a straight line (streaks in the feed direction in which the disc is coated by the roll coater). The coating defect thus generated causes a concave so-called bump-like deformation of the disc when the discs are bonded together, and causes a defect on the disc.

Even when the hot-melt adhesive is applied with such a roll coater after printing on the surface of the transparent dummy disk to be bonded in advance, when the adhesion between the printing ink and the disk is not sufficient, this The printing ink peels off and adheres to the roll in the roll coater to be scooped up, causing the above-mentioned problems. In particular, in the case of multicolor printing, the adhesion between various printing inks and the disc is slightly different, and the risk of peeling by the roll becomes even greater. Furthermore, the size of the ink to be peeled off depends on the design of the printing, and is much larger than that of ordinary dust, so there are many linear coating defects that occur between the roll and the doctor, and they are large. Become.

Further, considering the deterioration (increasing) of the tilt due to the deformation of the disk in a high temperature environment, which is the fate of the hot melt adhesive, that is, the thermoplastic resin, D
It was not optimal to use such an adhesive and a bonding method for highly accurate bonding such as VD.

Further, a method of bonding using an ultraviolet curable resin has already been proposed in Japanese Patent Laid-Open No. 20714/1993. In this method, a UV-curing resin is applied circumferentially on a signal recording substrate placed on a holding table, then a protective substrate is superposed, and the holding table is rotated to bring the UV-curing resin to the inner and outer peripheral end surfaces. After spreading, and finally, ultraviolet rays are irradiated by an ultraviolet ray irradiation lamp to cure the ultraviolet curable resin, and the substrate and the adhesive are integrated.

When a dummy disk printed on the bonding surface side and a recording disk (single-sided) on which information such as a movie is recorded are bonded by using this method, as shown in FIG.
It will take the structure shown in FIG. That is, this structure has one single-sided disk substrate 1a having information pits formed on the bonding surface side, an aluminum reflective film 2 on the information pits, and a recording disk (single-sided disk) 1A having the aluminum reflective film 2, Single-sided disc substrate 1b
The printing ink adhering portion 6 which is a design portion which is formed on the bonding surface and which can be seen 7 through the single-sided disc substrate 1b and the printing ink adhering portion 6 which is formed on the printing ink adhering portion 6 and which serves as the background Single-sided disc (dummy disc) 1B having a portion 8 and this dummy disc 1B
And an ultraviolet curable resin 9 to which the recording disk 1A is attached.

In order to manufacture such an optical bonded disc, first, as shown in FIG. 9A, the dummy disc 1B on which the design portion 6 and the white solid portion 8 are printed.
Is rotated by a motor 53, and then the valve 52 is opened so that the pressure tank 5 is placed on the printing surface of the dummy disk 1B.
The ultraviolet curable resin 9 in 4 is dropped from the discharge nozzle 51 and attached in a ring shape.

Next, as shown in FIG. 9B, the recording disk 1A having the information pits and the aluminum reflection film 2 formed thereon is placed on the ring-shaped UV-curable resin 9 and the UV-curable resin. 9 is shaken off and stretched over the entire bonding surface. Next, as shown in FIG. 9C, ultraviolet rays are radiated from the ultraviolet ray irradiator 45, and the ultraviolet curable resin 9 is radiated.
To cure.

[0015]

However, FIG.
With the structure (a), it becomes extremely difficult to cure the ultraviolet curable resin 9 that is the adhesive. For example, printing inks such as "DICURE SSD F2" manufactured by Dainippon Ink and Chemicals, Inc.
7 ”(white color) on the transparent substrate with a thickness of about 10 μm printed on the dummy disc 1B, as shown in FIG.
The intensity (transmittance) of ultraviolet rays transmitted through the ink No. 3 and the ink (aluminum reflective film) 44 was measured by the ultraviolet illuminance meter 40.

In order to measure the transmittance of ultraviolet rays, as shown in FIG. 6, an ultraviolet illuminance meter 40 having a light receiving portion 42 which is a sensor and a measurement / display portion 41 for displaying based on an electric signal from the light receiving portion. To use. The dummy disk 1B or the recording disk 1A, which is a symmetrical printing disk, is arranged on the light receiving portion 42 of the ultraviolet illuminance meter 40, and ultraviolet rays are irradiated by the ultraviolet irradiation device 45 from above the arranged disk for measurement.

The intensity (transmittance) of ultraviolet rays transmitted through the transparent substrate through the dummy disk 1B at a wavelength of 365 nm is
It was less than 0.1% which is the measurement limit of the measured measuring device. Further, the transmittance of ultraviolet rays of the recording disk 1A having the aluminum reflective film as the other substrate having a film thickness of about 55 nm was measured by the same method, and it was about 0.5 to 1%.

Therefore, in the pasting of the conventional type disk having the structure as shown in FIG. 7A, a large amount of energy is required to cure the resin. The amount of curing light is 10 mJ / c
very low energy curable resin which is one Toshiba Chemical Co. ultraviolet curable resin called m ^2, about "XDV-
011 (viscosity 0.15 Pa.s)] as an adhesive, and the above-mentioned recording disk 1 having an aluminum reflection film.
When A is attached, conveyor speed is 3.5m / min
And the integrated UV light intensity (350 nm) is 780 mJ / cm ^2.
In the 1-light type ultraviolet irradiation device, the conveyor speed is 3.
If the disk is not irradiated three times at 5 m / min, it will not be cured and the apparatus will be large-scale.

Even if a heat ray cut filter is added under the ultraviolet lamp, the substrate temperature is 1 at this conveyor speed.
There is a problem in that the temperature rises to 70 ° C. or more by only irradiating once, and the substrate is thermally damaged.

Further, since such a low energy curable ultraviolet curable resin has a high reactivity, it must be handled with care. For example, in the method of applying and laminating with a spinner as shown in FIG. 9, the amount of resin applied (introduced) to the dummy disk 1B before laminating (before high-speed shaking off) is about 2 to 3 g per sheet, Only 1/10 of the resin amount remains on the bonded disks (after high-speed rotation off). In other words, almost all the amount becomes drain of the spinner, and it is necessary to recover the ultraviolet curable resin 9 from this drain and use it again for bonding from the viewpoint of cost and productivity. For that purpose, in order to prevent the UV-curable resin 9 from reacting and causing gelation, it is necessary to take measures such as shielding the light from the spinner portion that handles the UV-curable resin 9. Such a device not only complicates the structure of the device but also makes the device difficult to handle.

Therefore, as shown in FIG. 7 (b), a single-sided disk substrate 1a having information pits is formed as a bonding structure which does not require the use of a low energy curable ultraviolet curable resin having high reactivity. It is conceivable that the recording disk 1A and the dummy disk 1B having the printed layer 6 formed on the protective film 3 for protecting the reflective film 2 of FIG. In this structure, the dummy disk 1
Since the adhesive 9 can be irradiated with ultraviolet rays from the B side, there is no need to use a low energy curable ultraviolet curable resin having high reactivity. In FIG. 7B, the white solid printing ink adhering portion is omitted.

However, in this structure, the thickness of the adhesive 9 at the step portion of the ink is slightly different before and after curing due to the curing shrinkage of the ultraviolet curable adhesive 9, and as a result, the edge portion (contour) of the print design is produced. However, there is a problem in that the protrusions appear on the reflective film surface of the bonded disc 1.

The protrusion of the conventional print design edge portion is considered to be caused by the following causes. As shown in FIG. 8, the protective film 3 is formed on the reflective film on the pit.
When the printing layer 6 is formed on the bonding surface of the disk on which is formed and the dummy disk 1B is bonded via the adhesive 9, the thickness t of the printing layer 6 after the application of the adhesive (before curing) is
₁ is t ₁ = 10 μm, the adhesive layer 9 in the portion without the printing layer 6
If the thickness d ₁ of the adhesive layer 9 is d ₁ = 30 μm, the thickness d ₂ of the adhesive layer 9 at the portion where the printing layer 6 is present is ₂ from d ₂ = d ₁ −t _1.
0 μm.

Assuming that the volumetric shrinkage of the adhesive is 10%, (10) ^1/3 = 2.15% shrinks in the thickness direction. Therefore, after curing, the thickness a ′ of the adhesive layer in the portion without the printing layer 6 is 29.36 μm, and the thickness b ′ of the adhesive layer in the portion with the printing layer 6 is 19.57 μm. The thickness t ′ = a′−b ′ = 9.79 μm of the adhesive layer corresponding to Therefore, Δ = 10−9.79 = 0.
A difference of 21 μm is produced.

Further, in the direction of the disc bonding surface,
Since the rigidity of the single-sided disks 1A and 1B is higher than the rigidity of the adhesive 9 and the adhesive 9 is less likely to be contracted, the contraction direction is biased in the thickness direction, and the actual difference Δ is considered to be larger than 0.21 μm.

Actually, the adhesive 9 was applied onto the printing layer 6, cured, and the bonded disks were peeled off, and the thickness of each layer (printing ink, adhesive) 6 and 9 was measured. As shown in FIGS. 5 (e) and 5 (f), the thickness of the adhesive layer 9 was reduced by about 0.5 μm due to the difference between the presence and absence of the printing layer 6. Note that FIG. 5E shows a cross section (step) of the printing portion where the screen-printed disk and the transparent disk are separated after being bonded by the UV-curable resin, and (f) is UV-cured between the screen-printed disk and the transparent disk. Cross-section (step) on the resin side peeled off after bonding with mold resin
Is shown.

That is, it is due to the difference in the amount of shrinkage of the adhesive that the print design appears to be visible on the bonded disks, and the cause is the local portion of the thickness of the adhesive layer 9 covering the print layer 6. This is due to the non-uniformity in nature.

The present invention has been made in order to solve the above-mentioned problems, and the adhesive can be easily cured without complicating the structure and handling of the apparatus, and the print design can be prevented from being raised. Optical bonded disc,
It is an object of the present invention to provide a manufacturing method thereof and a manufacturing method thereof.

[0029]

In order to achieve the above object, in the optical bonded disk according to claim 1, a recording disk on which information is recorded on the bonding surface side and the bonding surface of the recording disk are bonded. An optical bonded disc in which two discs are bonded together with an adhesive interposed between the two discs including a translucent disc having a bonded face Forming a printing layer on, forming a coating layer over the printing layer to smooth the steps of the printing layer,
It is characterized in that the above-mentioned adhesive agent is adhered on it and bonded together.

With this structure, the step of the printing layer can be smoothed by the coating layer covering the print layer, so that the design can be prevented from being raised due to the step of the printing layer.

Further, in the optical bonded disk according to claim 2, in the optical bonded disk according to claim 1, when the volume shrinkage ratio of the adhesive is α, a coating corresponding to a step of the printing layer is provided. The coating is characterized in that the gradient β of the layer portion is β ≦ 17 / α.

In this structure, the relationship between the volumetric shrinkage ratio α of the adhesive and the slope β of the coating layer portion corresponding to the step of the printing layer is β ≦ 17 / α, so that the design is embossed due to the step of the printing layer. Can be prevented.

Further, in the optical bonded disk according to claim 3, in the optical bonded disk according to claim 1 or 2, the coating layer is also formed on the bonding surface side of the disk not printed. It has a feature.

In this structure, since the coating layers are formed on both of the bonding surfaces of the pair of bonded disks, even if one coating layer warps on one of the one-sided disks, the coating layer of the other one-sided disk is formed. This can be canceled by the warp of the other one-sided disk due to the above, and the warp of the bonded disk due to the coating layer can be prevented.

In the method of manufacturing an optical bonded disc according to a fourth aspect of the present invention, there is provided a transparent disk having a recording disk on which information is recorded on the bonding surface side and a bonding surface bonded to the bonding surface of the recording disk. In a method for producing an optical laminated disc, which comprises laminating two discs consisting of an optical disc and an adhesive agent between the two discs, a printing layer is formed on at least one side of the laminating surface. The method is characterized by including a step, a step of forming a coating layer for smoothing the step of the printing layer so as to cover the printing layer, and a step of thereafter adhering the coating layer with the adhesive interposed therebetween.

With this structure, since the step of smoothing the step of the printing layer is provided by the coating layer that covers the printing layer, it is possible to manufacture an optical bonded disc which prevents the design from being raised due to the step of the printing layer. It is possible to provide a method for manufacturing an optical bonded disc that can be performed.

Further, in the method of manufacturing an optical bonded disc according to a fifth aspect, when the volume shrinkage ratio of the adhesive is α, the gradient β of the coating layer portion corresponding to the step of the printing layer is β ≦. It is characterized in that it is coated so as to be 17 / α.

In this structure, since the step of setting the relationship between the volumetric shrinkage ratio α of the adhesive and the gradient β of the coating layer portion corresponding to the step of the printing layer to be β ≦ 17 / α, the step of the printing layer is It is possible to provide an optical bonded disc manufacturing method capable of manufacturing an optical bonded disc in which the design of the optical bonded disc is prevented from being raised.

Further, in the method for manufacturing an optical bonded disk according to claim 6, in the method for manufacturing an optical bonded disk according to claim 4 or 5, the bonding surface side of the disk on which the coating layer is not printed The feature is that it is also formed.

In this structure, since the step of forming the coating layer on both of the bonding surfaces of the pair of bonded disks is provided, even if one coating disk is warped by one coating layer, the other one surface is bonded. Provided is a method for producing an optical laminated disc, which can be canceled by the warp of the other one-sided disc due to the coating layer of the disc and which can produce an optical laminated disc in which the warp of the laminated disc due to the coating layer is prevented. can do.

According to the seventh aspect of the present invention, there is provided an optical bonded disk manufacturing apparatus, which has a recording disk having information recorded on the bonding surface side and a bonding surface bonded to the bonding surface of the recording disk. In an optical bonded disc manufacturing apparatus for bonding an adhesive agent between two disks composed of an optical disk and an adhesive, a printing layer is formed on at least one side of the bonded surface. Means, a means for forming a coating layer for smoothing the step of the printing layer over the printing layer of the recording disc, and a means for laminating the printing layer on the printing layer of the recording disk with the adhesive interposed. .

In this structure, the coating layer covering the printing layer is provided with means for smoothing the steps of the printing layer. Therefore, it is possible to manufacture an optical bonded disc which prevents the design from being raised due to the steps of the printing layer. It is possible to provide an optical bonded disc manufacturing apparatus that can be used.

According to the eighth aspect of the present invention, there is provided the optical bonded disc manufacturing apparatus according to the seventh aspect, wherein the volumetric shrinkage of the adhesive is α, the printing is performed. The coating is characterized in that the gradient β of the coating layer portion corresponding to the step of the layer is β ≦ 17 / α.

In this structure, since the means for setting the relationship between the volume contraction rate α of the adhesive and the gradient β of the coating layer portion corresponding to the step of the printing layer to β ≦ 17 / α, the step of the printing layer is changed. It is possible to provide an optical bonded disk manufacturing apparatus capable of manufacturing an optical bonded disk in which the design of the optical disk is prevented from being raised.

According to a ninth aspect of the present invention, there is provided an optical laminated disc manufacturing apparatus according to the seventh aspect, wherein the coating layer is not printed with the coating layer. The feature is that it is also formed.

In this structure, since the means for forming the coating layer on both the bonding surfaces of the pair of bonded disks is provided, even if one coating layer warps on the one-sided disk, the other one-sided disk is warped. We provide an optical bonded disk manufacturing device that can cancel the warp of the other single-sided disk due to the coating layer of the disk and that can manufacture an optical bonded disk that prevents warping of the bonded disk due to the coating layer. can do.

[0047]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals. According to the present invention, when printing is performed on the bonding surface portion of a disk configured by bonding, in order to eliminate a local step (thickness unevenness) due to the ink on the printing ink, the thickness corresponding to the step TECHNICAL FIELD The present invention relates to an optical laminated disc, which is coated with a transparent resin for an appropriate amount and then laminated with an ultraviolet curable adhesive, a manufacturing method thereof, and a manufacturing apparatus thereof.

FIG. 1 is a sectional view showing an optical bonded disk according to a first embodiment of the present invention in the order of manufacturing steps,
FIG. 3 is a view showing an apparatus for manufacturing the optical bonded disc shown in FIG. In FIG. 1, the white solid printing ink adhering portion is omitted.

As shown in FIG. 1D, in the optical bonded disc 1 according to the first embodiment of the present invention, information pits are recorded on the bonded surface side of the single-sided disc substrate 1a, and A single-sided disc (recording disc) 1A in which an aluminum reflective film 2 is formed on the aluminum reflective film 2, a protective film 3 is formed on the aluminum reflective film 2, and a print layer 4 is formed on the protective film 3, and no information pit is recorded. Transparent single-sided disc (dummy disc) that is a translucent disc
1B and the printing layer 6 of the recording disc 1A of the laminated disc 1
The coating layer 10 is formed so as to cover the. It is desirable that this coating layer 10 is transparent to at least visible light and has a refractive index close to that of the single-sided disks 1A, 1B and the adhesive 9.

The print layer 6 on the recording disk 1A is printed so as to look like a normal character through the dummy disk 1B. The single-sided disks 1A and 1B are made of polycarbonate (PC), polymethylmethacrylate (PMM).
It is made of a transparent resin material such as A) and has a through hole formed in the center.

In the present invention, as shown in FIG. 1, the thickness of the coding layer 10 corresponding to the step is controlled so that the local step becomes a broad step, that is, a smooth step.

That is, the thickness of the transparent resin on the printing layer 6 is adjusted according to the height gradient of the edges of the printing layer 6 so that the step of the edge of the printing layer 6 becomes a gentle step. To coat. For example, when the volumetric shrinkage of the adhesive is 8.5%, as shown in FIG. 4, height t ₁ and distance k
Then, the height gradient is t ₁ / k, which is a method in which coating is performed so that the height gradient t ₁ / k after coating is 2 μm / 100 μm or less, and then the pieces are attached.

As shown in FIG. 3, an optical bonded disc manufacturing apparatus 11 according to the first embodiment of the present invention.
Is a recording disk (single-sided disk) 1 on which an information pit and an aluminum reflective film 2 covering the information pit are formed.
Spinner part index table 15 and printing part index table 22 for processing the coating layer 10
The coating layer forming sections 39 and 40 for forming the disk, the conveyor 13 for conveying the dummy disk 1B bonded to the recording disk 1A one pitch at a time like the spinner section index table 15 and the printing section index table 22, and the bonding apparatus 29. ~ 35. Then, the spinner index table 15 is used to protect the protective film 3
To form the protective film 3 on the printing unit index table 22.
The printing layer 6 is formed on the upper surface to perform multicolor printing (two-color printing in this embodiment), the coating layer 10 is formed by the coating layer forming units 39 and 40, and two disks are formed by the laminating devices 29 to 35. to paste together.

Spinner index table 15
Is a disc feeding position 16 at which the recording disc (single-sided disc) 1 is fed from the disc feeding position 12 by the disc loading arm 14, and a spinner portion 17 and a discharge nozzle portion 18 which are one pitch ahead of the disc feeding position 16. A UV (ultraviolet) lamp portion 19 located at a position one pitch ahead of the spinner portion 17 and the discharge nozzle portion 18,
The disc discharge position 20 is located at a position one pitch ahead of the UV lamp unit 19.

The printing section index table 22 is
A disk supply position 23 where a disk is transferred from the disk discharge position 20 of the spinner section index table 15 via a disk transfer arm 21 and a first printing position 24-1 which is a position advanced by one pitch from the disk supply position 23. And a first UV lamp unit 25-1 located at a position one pitch ahead of the first printing position 24-1 and a first U lamp unit 25-1.
No. 1 at a position one pitch ahead of the V ramp section 25-1
Cooling position 26-1 and first cooling position 26-
Second print position 2 which is one pitch ahead of 1
4-2, the second UV lamp section 25-2 located at a position one pitch ahead of the second printing position 24-2, and the second UV
The second cooling position 26-2, which is one pitch ahead of the ramp portion 25-2, and the second cooling position 26-2
And a disc ejecting position 27 which is one pitch ahead of.

The conveyor 13 for conveying the dummy disc 1B conveys 14 pitches from the disc supply position 13-1 to the disc discharge position 13-15 with the bonding surface of the dummy disc 1B facing downward.

The coating layer forming parts 39 and 40 are
Disc ejection position 2 of the printing section index table 22
Coating layer spinner part 3 onto which the recording disk 1A printed from the disk 7 via the disk transfer arm 38 is transferred.
9 and an ultraviolet curable resin 7 for forming a coating layer 10 on the bonding surface of the transferred recording disk 1A.
Discharging arm portion 40 for applying the ultraviolet ray and the ultraviolet ray lamp portion (not shown) for curing the applied ultraviolet ray curable resin 7.
And a recording disc 1A having a coating layer 10 formed thereon
And a transfer arm 28 for reversing and transferring to the bonding spinner portion 29.

In the laminating devices 29 to 35, the recording disk 1A with the coating layer 10 facing upward from the coating layer forming portions 39 and 40 is transferred to the disk transfer arm 28.
The bonding spinner portion 29 that is transferred by reversing via the ejector, the ejection arm portion 31 that applies the ultraviolet curable adhesive 7 onto the bonded surface of the transferred recording disk 1A, and the ultraviolet curable adhesive 7 A disk transfer arm 30 for transferring the dummy disk 1B onto the coated recording disk 1A with the bonding surface facing downward, and a transfer arm 32 for transferring the two superposed disks to the stabilizer set position. A stabilizer pickup arm 33-1 for setting and pressing a stabilizer on the bonded disk; a UV irradiation table 35 for setting the stabilizer and holding the pressed bonded disk;
A UV lamp unit 34 that passes over the bonded disc held on the V irradiation table 35 to cure the ultraviolet curable adhesive 7, and a stabilizer that removes the stabilizer from the bonded disc where the adhesive is cured by the UV lamp unit 34. The pickup arm 33-2 and the disc ejection arm 36 for taking out the pasted bonded disc from the UV irradiation table 35 are provided.

Next, the operation of the above manufacturing apparatus will be described. The recording disk (single-sided disk) 1 having the information pits conveyed from the previous step and the aluminum reflection film 2 covering the information pits is a disk supply position 1 of the spinner part index table 15 via the disk loading arm 14.
6 (the cross section of the recording disk 1A at this time is shown in FIG. 1A).

Next, the spinner index table 1
The recording disk 1 </ b> A is placed in the spinner part 17 by rotating the recording disk 5 by one pitch. In the spinner portion 17, the aluminum reflecting film 2 of the recording disk 1A is ejected by the ejection nozzle 18.
The protective film 3 is applied on top.

Next, the spinner section index table 1
The recording disk 1A is placed on the UV lamp section 19 by rotating the recording disk 5 by one pitch. In the UV lamp unit 19, the protective film 3 is irradiated with ultraviolet rays to cure the protective film 3.

Next, the spinner part index table 1
The recording disk 1A having the protective film 3 formed thereon is rotated at a pitch of 1 pitch and the recording disk 1A is placed at the disk ejection position 20. next,
The recording disk 1A at the disk ejection position 20 is transferred to the disk supply position 23 of the printing section index table 22 by the disk transfer arm 21.

Next, the printing section index table 22 is rotated by one pitch and the recording disk 1A is placed at the first printing position 24-1. This first print position 2
In 4-1 the first color ink is printed on the protective film 3 of the recording disk 1A.

Next, the printing section index table 22 is rotated by one pitch and the recording disk 1A is placed on the first UV lamp section 25-1. This first UV lamp section 25-
In No. 1, ultraviolet rays are irradiated to cure the ink of the first color.

Next, the printing section index table 22 is rotated by one pitch and the recording disk 1A is placed at the first cooling position 26-1. This first cooling position 2
In 6-1 the recording disk 1A on which the first color ink is printed is cooled.

Next, the printing section index table 22 is rotated by one pitch and the recording disk 1A is placed at the second printing position 24-2. This second print position 2
In 4-2, the second color ink is printed on the protective film 3 of the recording disk 1A.

Next, the printing section index table 22 is rotated by one pitch, and the recording disk 1A is placed on the second UV lamp section 25-2. This second UV lamp section 25-
In step 2, ultraviolet rays are irradiated to cure the second color ink.

Next, the printing section index table 22 is rotated by one pitch and the recording disk 1A is placed at the second cooling position 26-2. This second cooling position 2
In 6-2, the recording disk 1A on which the second color ink is printed is cooled.

Next, the printing section index table 22 rotates one pitch and the recording disk 1A is placed at the disk ejecting position 27. The second of the disc ejection position 27
The recording disk 1A on which the color ink is printed is transferred to the coating layer spinner portion 39 by the disk reversing transfer arm 38 (the cross section of the recording disk at this time is shown in FIG. 1B).

Next, an ultraviolet curable resin which becomes the coating layer 10 is applied to the upper surface of the recording disk by the ejection arm 40. The coating layer 10 can cover the print layer 6 and make the step smooth.

Next, the coated ultraviolet curable resin is irradiated with ultraviolet rays by an ultraviolet lamp (not shown) to form the coating layer 10. (A cross section of the recording disk at this time is shown in FIG. 1C).

Next, the recording disk 1A having the coating layer 10 formed on the upper surface thereof by the disk transfer arm 28.
Is transferred to the bonding spinner portion 29 with the bonding surface as the upper surface. Next, the ultraviolet ray-curable adhesive 7 is applied to the bonding surface of the recording disk 1A by the ejection arm 31.
Is applied.

On the other hand, in the present embodiment, the dummy disk 1B conveyed from the previous step is supplied to the disk supply position 13-1 of the conveyor 13 in synchronization with the recording disk 1A. Next, the dummy disks 1B on the conveyor 13 are conveyed one by one pitch to the disk ejection positions 13-15.

Next, the dummy disc 1B at the disc ejecting positions 13-15 is the first recording disc 1A positioned in the laminating spinner portion 29 while the laminating surface is kept downward by the disc transfer arm 30. Transferred onto the adhesive.

Next, the transfer arm 32 is used to move the stacked bonded disks to the U position at the stabilizer set position.
It is transferred onto the V irradiation table 35. Next, the stabilizer pick-up arm 33-1 sets the stabilizer on the bonded disk and pressurizes it.

Next, the UV lamp section 34 is passed over the bonded disk held on the UV irradiation table 35 to cure the ultraviolet curable adhesive 7 (the cross section of the recording disk at this time is shown in FIG. 1D). Shown in). Next, the bonded ejection disks are taken out from the UV irradiation table 35 by the disk ejection arm 37.

(Example) Specifically, regarding the above-described height gradient, "95A32X-" manufactured by Sony Chemical Co., Ltd.
9 "(viscosity 0.24 Pa · s, volume contraction rate 8.5%) was pasted as an adhesive (thickness of unprinted part is approximately 30 μm), and what gradient can be visually observed? did. The results are shown in Table 1 below.

[0078]

[Table 1] However, in Table 1, x indicates “visible to the naked eye”, ◯ indicates “almost unknown”, and ⊚ indicates “not understood”.

From Table 1 it was found that the gradient disappeared with a gradient smaller than 1.9 μm / 100 μm. The coating layer 10 was actually coated with the same adhesive "95A32X-9" manufactured by Sony Chemical Co., Ltd. for 15 to 20 .mu.m, and then the same adhesive was used for adhesion. The printing gradient at this time was as follows.

5A and 5B are diagrams showing the gradient of the edges of the printed layer by screen printing. FIG. 5A is an edge step A of the screen printed portion before coating, and FIG. 5B is an edge step A of the screen printed portion after coating. c) is the edge step B of the linear screen printing portion before coating, (d) is the edge step B of the linear screen printing portion after coating,
(E) shows the cross section (step) of the printing part which peeled after pasting the screen printing disc and the transparent disc with the ultraviolet curing resin, and (f) shows the screen printing disc and the transparent disc pasting with the ultraviolet curing resin. The cross section (step) on the resin side peeled off after the joining is shown. In the figure, D indicates the step of the edge of the printed layer 6 before coating, and D'denotes the step of the edge of the printed layer 6 after coating.

In FIG. 5, (a) and (b), (c) and (d), and (e) and (f) show the same parts. Further, in FIGS. 5A, 5C, and 5E, the vicinity of the step D of the print layer 6 is thick, but this is due to screen printing.

As shown in FIG. 5 (a), in part A, the height gradient of the ink was 15 μm / 100 μm, but as shown in FIG. 5 (b), the height gradient after coating was 0.9 μm / 1.
It was 00 μm.

Further, as shown in FIG. 5 (c), in the portion B, with respect to the ink height gradient of 11 μm / 100 μm,
As shown in (d), the height gradient after coating is 0.6.
It was μm / 100 μm.

Regarding the relational expression between the thickness of the coating layer 10 and the volume shrinkage ratio of the adhesive 9 according to the present invention with respect to the height gradient of the printing ink thickness, the coating thickness and the gradient depend on the shape of the edge portion of the printing layer 6. It is considered difficult to uniquely determine the relational expression from the two points of being influenced by the wettability of the ink and the coating material, and by being affected by the wettability of the ink and the coating material.

Therefore, the inventor of the present invention has found that the volume contraction rate α (%) of the adhesive used and the height gradient β (μm / 100 μm) at which printing is not raised, that is, the volume contraction of the adhesive When the rate was α (%), the relational expression of the gradient β set in the coating was obtained as follows.

First, it can be considered that most of the shrinkage occurs as shrinkage in the thickness direction. This is because when the rigidity of the single-sided disk substrates 1a and 1b is compared with the rigidity of the adhesive 9, the single-sided disk substrate 1 has a large difference in thickness.
This is because the rigidity of a and 1b is much larger and the contraction in the radial direction hardly occurs.

The height difference between the printed layer 6 and the peeled adhesive layer 9 is 0.5 μm, and the shrinkage rate α of the adhesive of the adhesive layer 9 is 8.5% and the measured value. Shrinkage rate based on 5
Although there is a difference with (%), this is considered to be a measurement error. It is considered that this measurement error is due to the fact that the other part of the print layer 6 or the adhesive layer 9 is partially adhered during the peeling.

Next, when the shrinkage rate α is 8.5 (%) in the example using the adhesive “95A32X-9”, the invisible gradient β = 2 (μm / 100 μm). Due to these, the following relationship can be considered between the arbitrary contraction rate α and the gradient β at which it disappears. α × β = const. = 8.5 × 2 ∴β = 17 / α For example, when α = 10%, the gradient is 1.7 μm / 100.
The coating layer 10 according to the present invention needs to be managed in this way. The thickness of the coating layer 10 is appropriately determined so as to satisfy the above relationship.

In the above embodiment, the case where the print layer 6 is formed on the recording disk 1A side has been described.
As shown in FIG. 2, the print layer 6 may be provided on the dummy disc 1B side, and the coating layer 10 may be formed on the print layer 6 on the dummy disc 1B side. Note that FIG.
In, the white solid printing ink adhesion part is omitted.

In the above embodiment, the case where the coating layer 10 is formed on one of the bonding surfaces of the pair of single-sided disks 1A and 1B has been described, but it is also formed on one side by forming the coating layer on the other. The warp of the disk due to the hardening shrinkage of the coating layer 10 can be canceled by the hardening shrinkage of the coating layer formed on the other side.

In the above embodiments, the transparent disc is described as the dummy disc which is the translucent disc. However, the translucent disc is, for example, a disc in which a semitransparent film is formed on the transparent disc. , Including colored discs.

[0092]

As is apparent from the above description, according to the present invention, the step of the printing layer can be smoothed by the coating layer covering the printing layer, so that the design is prevented from being raised due to the step of the printing layer. (EN) Provided are an optical bonded disk, a method for manufacturing the same, and a method for manufacturing the same, in which the adhesive can be easily cured without complicating the structure and handling of the apparatus and preventing the print design from being raised. be able to.

When the relationship between the volumetric shrinkage rate α of the adhesive and the gradient β of the coating layer portion corresponding to the step of the printing layer is β ≦ 17 / α, adhesives having different volumetric shrinkage rates are used. Even if it is used, it is possible to prevent the design from being raised due to the step of the printing layer.

Furthermore, when a coating layer is formed on both the bonding surfaces of a pair of bonded disks,
Even if one coating layer warps on one of the one-sided discs, it can be canceled by the warping of the other one-sided disc by the coating layer on the other one-sided disc, and the warping of the laminated disc by the coating layer can be prevented. You can

[Brief description of drawings]

FIG. 1 is a sectional view showing an optical bonded disk according to a first embodiment of the present invention in the order of manufacturing steps.

FIG. 2 is a sectional view showing an optical bonded disk according to a second embodiment of the present invention in the order of manufacturing steps.

FIG. 3 is a diagram showing an apparatus for manufacturing the optical bonded disc shown in FIG.

FIG. 4 is an enlarged cross-sectional view showing the structure of the main part of the optical bonded disc according to the first embodiment of the invention.

5A and 5B are diagrams showing an edge gradient of a printed layer by screen printing, where FIG. 5A is an edge step A of a screen printed portion before coating, FIG. 5B is an edge step A of a screen printed portion after coating, (C) is the edge step B of the linear screen printing portion before coating, (d) is the edge step B of the linear screen printing portion after coating, (e)
Shows a cross section (step) of the printed part after the screen-printed disc and the transparent disc were bonded together by the UV-curable resin, and (f) was peeled after the screen-printed disk and the transparent disc were bonded by the UV-curable resin. The cross section (step) on the resin side is shown.

FIG. 6 is a diagram showing an ultraviolet transmittance measuring device.

FIG. 7 is a cross-sectional view of a conventional optical bonded disc, (a) is an example in which a printing layer is provided on the dummy disc side,
(B) shows an example in which a printing layer is provided on the recording disk side.

FIG. 8 is an enlarged cross-sectional view showing a structure of a main part of a conventional optical bonded disc having a print layer provided on the recording disc side.

FIG. 9 is a diagram showing a conventional method for manufacturing an optical bonded disc.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laminated disc 1A Recording disc (single-sided disc) 1B Dummy disc (single-sided disc) 1a Single-sided disc substrate 1b Single-sided disc substrate 2 Aluminum reflection film 3 Protective film (UV curing type) 6 Printing ink adhesion part (printing layer) 7 Visual inspection 9 UV curable adhesive 10 Coating layer

Claims (9)

[Claims] 1. An adhesive agent between two disks comprising a recording disk having information recorded on the bonding surface side and a translucent disk having a bonding surface bonded to the bonding surface of the recording disk. In the optical bonded disc in which the two discs are bonded to each other with the interposition of, a printing layer is formed on at least one side of the bonding surface, and a coating layer for smoothing the step of the printing layer is provided in the printing layer. An optical bonded disk, characterized in that the optical bonded disk is formed by covering it with the adhesive agent interposed therebetween. 2. The coating is performed so that a gradient β of a portion of the coating layer corresponding to a step of the printing layer is β ≦ 17 / α, where α is a volume contraction rate of the adhesive. The optical bonded disc according to claim 1, wherein: 3. The optical bonded disk according to claim 1, wherein the coating layer is also formed on the bonding surface side of the disk on which no printing is performed. 4. An adhesive agent between two discs comprising a recording disc on which information is recorded on the bonding surface side and a translucent disc having a bonding surface bonded to the bonding surface of the recording disc. In a method for manufacturing an optical bonded disc that bonds the two discs with each other, a step of forming a printing layer on at least one side of the bonding surface, and a coating layer for smoothing the step of the printing layer A method for manufacturing an optical bonded disc, comprising: a step of forming a printed layer over the printed layer; and a step of bonding the printed layer with the adhesive interposed therebetween. 5. The coating is performed so that a gradient β of a portion of the coating layer corresponding to a step of the printing layer is β ≦ 17 / α, where α is a volume contraction rate of the adhesive. The method for manufacturing the optical bonded disc according to claim 4. 6. The method for producing an optical bonded disc according to claim 4, wherein the coating layer is also formed on the bonding surface side of the disc on which no coating is printed. 7. An adhesive agent between two discs comprising a recording disc on which information is recorded on the bonding surface side and a translucent disc having a bonding surface bonded to the bonding surface of the recording disc. In an optical bonded disc manufacturing apparatus for bonding the two disks with an intervening layer, means for forming a printing layer on at least one side of the bonding surface, and a coating layer for smoothing the step between the printing layers An apparatus for manufacturing an optical bonded disk, comprising: a means for forming the recording layer on the recording layer of the recording disk; and a means for bonding the recording layer on the recording layer via the adhesive. 8. The coating is performed so that a gradient β of a portion of the coating layer corresponding to a step of the printing layer is β ≦ 17 / α, where α is a volume contraction rate of the adhesive. The optical bonded disc manufacturing apparatus according to claim 7. 9. The optical bonded disk manufacturing apparatus according to claim 7, wherein the coating layer is also formed on a bonded surface of a disk on which the coating layer is not printed.