JP2504928B2 - Disc coating method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a resin coating on the surface of a high density information recording disk such as a compact disk.

[0002]

2. Description of the Related Art A high-density information recording disk is molded by an injection molding machine or the like, aluminum is vapor-deposited on the information recording surface of the disk for sputtering, and a resin coating is further applied thereon. Coating is a step of dropping a resin in a donut shape near the inner end of sputtering on the disk surface, and a step of rotating the disk at a high speed and extending the dropped resin to the disk surface by centrifugal force.
And a step of curing the resin. FIG. 4 is an end view of the disk d showing resin dropping in the conventional method. The resin is dropped in a ring shape by discharging the resin from the nozzle 25 stationary on the disk d rotating at a low speed. The dropping of the resin is performed aiming slightly outside the boundary of the inner end 23 of the sputtering 22. This is to prevent the resin from flowing into the groove 24 formed inside the sputtering. This is because if the resin flows into the groove 24, a striped pattern will be formed on the surface of the resin when the disk is rotated at a high speed later and the resin is spread over the surface of the disk. When the dropping is started on the disc, the resin 20 forms a high mountain as shown by the dotted line in FIG. 4, but when the disc makes one round and the dropping is finished, the resin 21 at the dropping start end is already formed. As shown by the solid line in FIG. 4, it spreads low. At this time, the dropping end end has a high peak as shown by the dotted line in the figure and does not cover the sputtering inner end 23. Therefore, as shown by the dotted line in FIG. 5, after waiting for the resin 20 at the end of dropping to spread low and cover the inner end 23 of the sputtering, the disk is rotated at a high speed so that the resin is deposited on the disk as shown in FIG. The resin is stretched and excess resin is thrown out. Finally, the resin is cured by irradiating ultraviolet rays to complete the coating, and the coating layer 27 is formed on the sputtering 22.

[0003]

In the above-mentioned disk coating method, after the dropping of the resin is completed, it is necessary to wait until the end of the dropping covers the inner end of the sputtering. The control of the waiting time and the viscosity of the resin was extremely delicate and difficult, and the yield was poor. That is, if the waiting time is too long, the resin will enter the groove, and if the waiting time is too short, the vicinity of the inner end of the sputtering will remain uncoated. If the viscosity of the resin is low, the resin will enter the groove, and if the viscosity is high, the waiting time will be too long. The present invention has been made for the purpose of improving the difficulty of manufacturing control, improving the yield of products, and eliminating the waiting time to shorten the coating process time.

[0004]

According to the present invention, a step of dropping a resin in a ring shape near the inner end of sputtering on the surface of a disk and a step of rotating the disk at a high speed and extending the dropped resin to the surface of the disk by centrifugal force. The present invention relates to an improvement of a disk coating method, which comprises a step of curing a resin, in particular, a step of dropping a resin in a ring shape. The first is an invention characterized in that the nozzle for dropping the resin is moved slightly inward from the start of dropping to the end of dropping, and the second is that the dropping of the resin on the disk is performed by sputtering. It is characterized in that it is applied near the edge and at an appropriate position outside the edge and is dripped in at least a double ring shape.

[0005]

If the nozzle 6 for dropping the resin is moved slightly inward from the start of the dropping to the end of the dropping, as shown in FIG. 1, the dropping start end of the resin 1 dropped on the disk d is shown. 2 and the end 3 of dropping are almost the same on the inside,
The inner circumference of the resin 1 is almost a perfect circle. As shown in FIG. 2, the dropping start end 2 and the dropping end end 3 at the end of the dropping both cover the inner end 5 of the sputtering, and the waiting time is unnecessary. The dripping start end 2 of the resin 1 dripping on the disc gradually spreads low and the inner end portion gradually moves inward, but if this moving speed and the moving speed of the nozzle 6 are made to substantially match each other. Although it is ideal, the difference in level between the dropping start end 2 and the dropping end end 3 of the resin 1 is extremely small as compared with the conventional method, and even if the resin 1 is slightly different, the resin enters the groove. The risk is reduced and the waiting time can be very small, if necessary.

If the resin is dropped on the disk near the inner end of the sputtering and at an appropriate position outside the inner end of the spatter and drops in at least a double ring shape, as shown in FIG. Resin 10 to be dropped
Therefore, the risk of resin flowing into the groove 12 is significantly reduced. Therefore, the resin 10 can be dropped aiming right above the inner end 14 of the sputtering and can be covered, so that no waiting time is required and the viscosity of the resin does not need to be precisely managed as in the conventional case. is there.

[0007]

Embodiment 1 FIGS. 1 and 2 relate to Embodiment 1 and illustrate a process of coating a compact disc d. Viscosity 30 CPS (25 ° C B type viscometer) from the nozzle 6 while rotating the disk d at a speed of 1 rotation per second.
UV resin is dripped in an amount of 1.2 CC per second. The resin is dropped aiming at a slightly outer side of the inner end 5 of the sputtering 4. As shown in FIG. 2, the start of dropping is performed at the position of the nozzle 6, and by the end of the dropping, the nozzle 6a is moved toward the position of the nozzle 6a by 1 mm. As a result, the resin is
As shown in FIG. 5, the inside of the dropping start end 2 and the inside of the dropping end 3 substantially coincide with each other, and the inside is a substantially perfect circle with a constant distance from the groove 7. After that, the disk is rotated at a high speed of 50 rpm for 1 second to spread the resin dropped by centrifugal force on the disk surface, and the resin is cured by irradiating with ultraviolet rays,
The coating is complete.

[0008]

[Embodiment 2] FIG. 3 is for explaining the process of coating the compact disc of Embodiment 2. While rotating the disk d at a speed of 1 rotation per second, from the nozzle 15 arranged directly above the inner end 14 of the sputtering 13,
UV resin having a viscosity of 30 CPS (B-type viscometer at 25 ° C.) is dropped in an amount of 0.1 CC per second. Almost at the same time, a UV resin having a viscosity viscosity of 30 CPS (25 ° C. B type viscometer) is dropped from a nozzle 16 arranged 10 mm outside the nozzle 15 in an amount of 1.1 CC per second. The amount of the resin 10 dropped from the nozzle 15 may be an amount that covers the area of FIG. 3A, and the resin 11 dropped from the nozzle 16 covers the area b. Resin 1 dropped from nozzle 15
Since 0 is an extremely small amount, there is no danger of flowing into the groove 12. After that, the disk is rotated at a high speed, the resin dropped by centrifugal force is spread on the surface of the disk, and the resin is cured by irradiating with ultraviolet rays to complete the coating.

[0009]

According to the present invention, after dropping the resin,
Since the disk can be immediately rotated at a high speed to stretch the resin without requiring a waiting time, the time loss of the coating process in the entire disk manufacturing can be eliminated.
The dropped resin is extremely unlikely to flow into the groove, the complexity of managing the viscosity and waiting time of the resin is eliminated, and the product yield is improved.

[Brief description of drawings]

FIG. 1 is a top view of a disk on which resin is dropped in the method of the present invention.

FIG. 2 is a schematic end view of a disk on which resin is dropped in the method of the present invention.

FIG. 3 is a schematic end view of a disk on which resin is dropped in the method of the present invention.

FIG. 4 is a schematic end view of a disk on which resin is dropped according to a conventional method.

FIG. 5 is a schematic end view of a disk on which resin is dropped according to a conventional method.

FIG. 6 is a schematic end view of a resin-stretched disk.

[Explanation of symbols]

 1 Resin 2 Dropping Start End 3 Dropping End End 4 Sputtering 5 Sputtering Inner End 6 Nozzle 7 Groove 10 Resin 11 Resin 12 Groove 13 Sputtering 14 Sputtering Inner End 15 Nozzle 16 Nozzle 20 Resin 21 Resin 22 Sputtering 23 Sputtering Inner End 24 Groove 25 Nozzle 27 coating layer

Claims (2)

(57) [Claims] 1. A step of dropping a resin in a ring shape near an inner end of sputtering on a disk surface, a step of rotating the disk at a high speed to extend the dropped resin to the disk surface by centrifugal force, and a step of curing the resin. In the method for coating a disk, the method for coating a disk is characterized in that the nozzle for dropping the resin is slightly moved inward between the start of the dropping and the end of the dropping. 2. A step of dropping the resin in a ring shape near the inner end of the sputtering on the surface of the disk, a step of rotating the disk at a high speed to extend the dropped resin to the surface of the disk by centrifugal force, and a step of curing the resin. In the method for coating a disk, the method for coating a disk is characterized in that the resin is dripped onto the disk near the inner end of the sputtering and at an appropriate position outside the inner end of the spatter, and is dripped in at least a double ring shape.