JP3598535B2 - Coating device for forming protective film - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a coating apparatus for forming a protective film, which applies a UV-curable coating material serving as a protective film to a surface of an object to be coated, for example, an optical disk.
[0002]
[Prior art]
2. Description of the Related Art In general, two types of pump discharge type and pressure discharge type are used as a coating apparatus for applying an ultraviolet-curable coating material, for example, a UV resin, which serves as a protective film on a surface of an object to be coated, for example, an optical disk. .
[0003]
First, a pump discharge type coating device (hereinafter simply referred to as a pump type device) is a device which sucks up this UV resin from a resin supply tank which is a supply source of the UV resin and supplies it to the surface of the optical disk. The pump-type device includes the above resin supply tank storing a UV resin and usually having a volume of 5 to 10 liters, a suction pump for sucking a predetermined amount of the UV resin from the resin supply tank, and discharging the UV resin from the suction pump. A paint supply pipe, which is a passage for the paint for supplying the paint to the application nozzle, which is a unit, and a storage unit in which these members are disposed. The coating nozzle protrudes from the storage unit. It is shaped.
[0004]
Further, the pump-type device is provided with an optical disk support on which an optical disk as an object to be coated is mounted and the optical disk is rotated at a constant rotation speed. Here, a suck-back valve for preventing unnecessary discharge of the UV resin from the application nozzle may be provided in the paint supply pipe or the like.
[0005]
In the above pump type apparatus, a predetermined amount of UV resin sucked up from the resin supply tank by the suction pump is discharged from the application nozzle, so that the UV resin is applied to the surface of the optical disk located below the application nozzle. Here, the UV resin is applied while rotating the optical disk at a constant rotation speed on the optical disk support, and unnecessary UV resin is shaken off, whereby the UV resin is uniformly applied to the optical disk.
[0006]
On the other hand, a pressure-discharge type coating apparatus (hereinafter simply referred to as a pressure-type apparatus) supplies a pressurized gas to a resin supply tank which is a UV resin supply source, and supplies the coating material to an object to be coated by this pressure. Device. The pressurized type apparatus includes a resin supply tank storing a UV resin, a pressurized gas supply mechanism for supplying a pressurized gas into the resin supply tank to apply a predetermined pressure, and a UV resin from the supply tank. A paint supply pipe, which is a passage for the paint for supplying the paint to the application nozzle, which is a discharge section, and a housing section in which these members are arranged. It has a prominent shape.
[0007]
Further, similarly to the pump-type device, the pressure-type device is provided with an optical disk support on which an optical disk as an object to be coated is placed and the optical disk is rotated at a constant rotation speed. Here, a suck-back valve for preventing unnecessary discharge of the UV resin from the application nozzle may be provided in the paint supply pipe or the like.
[0008]
In the above-mentioned pressurization type device, by supplying a pressurized gas to the resin supply tank to discharge a predetermined amount of UV resin supplied from the resin supply tank from the application nozzle, the optical disk located below the application nozzle This UV resin is applied to the surface of the substrate. Also in this case, similarly to the pump type device, the UV resin is applied while rotating the optical disk at a constant rotation speed on the optical disk support, and unnecessary UV resin is shaken off so that the UV resin is uniformly applied to the optical disk. Will be applied.
[0009]
[Problems to be solved by the invention]
By the way, the UV resin used for forming the protective film of the optical disc has a property that its viscosity greatly depends on the temperature. That is, as shown in FIG. 3, when the temperature rises (falls), the viscosity sharply falls (increases).
[0010]
Therefore, in the above pump type apparatus, it is necessary to control the amount of UV resin suctioned from the resin supply tank by the suction pump in accordance with the temperature of the UV resin. Control is very difficult. For this reason, a variation occurs in the ejection amount of the UV resin due to a change in temperature, which causes a problem that the protective film of the UV resin formed on the surface of the optical disc becomes uneven.
[0011]
On the other hand, in the pressurized type device, the viscosity of the UV resin is controlled by controlling the pressure of the pressurized gas supplied to the resin supply tank. Accurate control is very difficult because the viscosity of the UV resin changes sensitively. In fact, as shown in FIG. 4, for example, as the temperature rises (from 20 ° C. to 28 ° C.), the discharge amount of the UV resin greatly increases. As described above, the discharge amount of the UV resin varies due to the temperature change, and the protective film of the UV resin formed on the surface of the optical disc becomes uneven.
[0012]
Further, assuming that conditions such as temperature are constant in both the pump type apparatus and the pressurizing type apparatus, as shown in FIG. 5, the optical disk is rotated at a constant rotational speed on the optical disk support to shake off unnecessary UV resin. The time required for this is approximately linear with the viscosity of the UV resin. Therefore, the change in the viscosity causes variation in the unnecessary UV resin shake-off time, which is one of the major problems in manufacturing.
[0013]
As described above, at present, it is very difficult to apply a UV resin, which serves as a protective film of the optical disk, to the optical disk stably and uniformly.
[0014]
The present invention has been made in view of the above-described various problems, and has as its object the purpose of making the application of the ultraviolet curable coating material constant and uniformly applying it to the object to be coated, Significant improvement in yield and reliability can be achieved.
[0015]
[Means for Solving the Problems]
The coating device for forming a protective film according to the present invention that has achieved the above object is a coating device that supplies the coating material to the surface of an optical disc by discharging a UV-curable coating material, wherein the coating device stores the coating material. A supply tank, a suction pump for sucking paint from the supply tank, a paint supply pipe through which the paint sucked by the suction pump flows, and a coating for discharging paint guided by passing through the inside of the paint supply pipe to the optical disc. A nozzle, a temperature control mechanism for maintaining the resin at a predetermined temperature, a supply tank, a suction pump, a paint supply pipe, a housing for disposing a temperature control mechanism, and a heating unit for maintaining the optical disc at a predetermined temperature. The paint supply pipe is provided with a liquid circulator from the front end to the rear end thereof, and the temperature control mechanism is provided around the suction pump. And a second warming means for circulating a warming liquid around a paint supply pipe provided between the suction pump and the application nozzle, and protruding from the housing portion. A paint is supplied to the optical disk by the application nozzle.
[0016]
Further, the coating device for forming a protective film according to the present invention is a coating device for supplying the coating material to the surface of an optical disc by discharging a UV-curable coating material, wherein the coating device includes a supply tank in which the coating material is stored. A pressurized gas supply mechanism having a pressure sensor for supplying a pressurized gas to the supply tank and applying a predetermined pressure, a paint supply pipe through which a resin supplied by the pressure flows, and a passage through the paint supply pipe. A coating nozzle for discharging the paint guided by the above-mentioned method onto the optical disc, a temperature control mechanism for maintaining the resin at a predetermined temperature, a supply tank, a pressurized gas supply mechanism, a paint supply pipe, and a temperature control mechanism. The paint supply pipe is provided with a liquid circulator from the front end to the rear end of the housing, and a heating means for holding the optical disk at a predetermined temperature. The adjusting mechanism includes a first heat insulating means including a temperature adjusting unit having a temperature sensor provided in the supply tank, and a second heat insulating means having a temperature sensor provided in the liquid circulator. A coating material is supplied to the optical disk by the application nozzle protruding from the optical disk.
[0017]
[Action]
The coating apparatus according to the present invention is provided with a temperature control mechanism that always keeps the coating material at a constant predetermined temperature when discharging the ultraviolet curing coating material onto the surface of the coating object. This UV-curable paint has the property that its viscosity changes greatly depending on the change in temperature. In the present invention, the temperature control mechanism is specifically, for example, around the suction pump or A first heat retaining means is provided in the paint supply source, and a second heat retaining liquid is circulated around a paint supply pipe provided between the suction pump or the supply source and an application nozzle which is a paint discharge section. The temperature of the paint is maintained at a predetermined temperature, and the paint at the predetermined temperature is always supplied to the object to be coated. Therefore, a predetermined amount of the paint is stably and uniformly applied to the surface of the object to be applied, without being affected by the above-described characteristics of the paint.
[0018]
At this time, by using the heating means for maintaining the object to be coated at the predetermined temperature as an auxiliary means of the temperature adjusting mechanism, a predetermined amount of the coating material can be more stably and uniformly applied to the surface of the object to be coated. .
[0019]
【Example】
Hereinafter, several specific examples in which the coating apparatus according to the present invention is applied to an optical disc as a coated object will be described with reference to the drawings.
[0020]
2. Description of the Related Art In general, two types of pump discharge type and pressure discharge type are used as a coating apparatus for applying an ultraviolet-curable coating material, for example, a UV resin, which serves as a protective film on a surface of an object to be coated, for example, an optical disk. .
[0021]
This pump discharge type coating device (hereinafter simply referred to as a pump type device) is a device which sucks up this UV resin from a resin supply tank which is a UV resin supply source and supplies it to the surface of the optical disk. First, a first embodiment in which the present invention is applied to the above pump type device will be described.
[0022]
As shown in FIG. 1, the pump-type apparatus according to the first embodiment includes a resin supply tank 1 storing a UV resin and having a normal volume of 5 to 10 liters, and the UV supply from the resin supply tank 1 at a predetermined speed. A suction pump 2 for sucking up the resin, and a paint supply pipe 3 as a paint passage for supplying the paint from the suction pump 2 to a coating nozzle 4 which is a discharge portion of the UV resin, are provided. The application nozzle 4 protrudes from the storage section 5.
[0023]
Further, the pump type device is provided with an optical disk support 12 for mounting the optical disk 11 as an object to be coated and rotating the optical disk 11 at a constant rotation speed. The optical disk support 12 is composed of a support table 12a on which the optical disk 11 is mounted, and a drive motor 12b for driving the support table 12a to rotate at a predetermined constant rotation speed. An appropriate UV resin is shaken off by this rotation drive. The surplus UV resin that has been shaken off is collected by the collecting means 13 and returned to the supply tank 1 for reuse.
[0024]
Further, a suck-back valve (not shown) for preventing unnecessary discharge of the UV resin from the coating nozzle 4 is provided in the coating material supply pipe 3.
[0025]
In particular, the pump-type device is provided with a temperature control mechanism for keeping the UV resin at a constant predetermined temperature. In the first embodiment, first and second heat retaining means are provided as the temperature adjusting mechanism.
[0026]
First, a paper heater 21 is used as first heat retaining means, and the paper heater 21 surrounds the suction pump 2 and keeps the temperature at a constant predetermined temperature of 30 to 80 ° C. At this time, a tape heater, a silicon heater, or the like may be used instead of the paper heater 21. Further, as a first heat retaining means for keeping the temperature of the suction pump 2, a means for passing a heat retaining liquid around the suction pump 2 may be used.
[0027]
Next, as a second heat retaining means, a liquid circulator 22 for passing a liquid for keeping heat around the paint supply pipe 3 is used. Here, a protective tube 23 surrounding the paint supply tube 3 is provided around the paint supply tube 3, and the leading end and the rear end of the protective tube 23 are connected to the liquid circulator 22. Then, a liquid or gas for keeping the UV resin warm is circulated from the liquid circulator 22 into the protection tube 23, and the UV resin passing from the suction pump 2 and passing through the paint supply tube 3 is maintained at the predetermined temperature. Further, a method of surrounding the supply pipe 3 with the paper heater 21 and setting the temperature to the predetermined temperature may be used. Further, a tape heater, a silicon heater, or the like may be used instead of the paper heater 21.
[0028]
Here, a description will be given of a use criterion of the second heat retaining means depending on the temperature difference between the inside and the outside of the storage section 5. First, when the above-mentioned temperature difference is less than 10 ° C., it is possible to use even a state in which a heat insulating material is wound around the paint supply pipe 3 without using the liquid circulator 22. When the temperature difference is about 10 to 20 ° C., it is necessary to circulate a liquid or gas for keeping the UV resin warm in the protective tube 23. Further, if the temperature difference exceeds 20 ° C., it is necessary to circulate the liquid for keeping the UV resin warm in the protective tube 23 using the liquid circulator 22. That is, if the liquid circulator 22 is used, it is possible to cope with all the above-mentioned temperature differences.
[0029]
Further, in the first embodiment, the radiant heat generating means 24 for irradiating the optical disk 11 with heat rays such as infrared rays is provided above the optical disk support 12. By the radiant heat from the radiant heat generating means 24, the surface of the optical disk 11 is kept at the predetermined temperature. Here, a heater may be provided on the optical disk support 12 instead of the radiant heat generating means 24, and the optical disk 11 may be kept at the predetermined temperature by the heater.
[0030]
In addition, it is necessary to introduce outside air into the storage section 5 to maintain the temperature in the storage section 5 at a slightly lower constant temperature of 20 to 25 ° C. This is because if the temperature of the inside of the housing portion 5 is high, the curing of the UV resin gradually progresses, so that inconvenience occurs when the UV resin is circulated.
[0031]
In order to supply the UV resin to the surface of the optical disk 11 using the above pump type device, first, the suction pump 2 is operated to suck up the UV resin from the resin supply tank 1 at a predetermined speed. The UV resin heated to a predetermined temperature by a paper heater 21 provided around the suction pump 2, and the liquid for keeping the UV resin at the predetermined temperature is circulated in the protective tube 23 by the operation of the liquid circulator 22. By doing so, it passes through the paint supply pipe 3 kept warm and is discharged from the coating nozzle 4. The discharged UV resin is supplied to the surface of the optical disk 11 provided below the coating nozzle 4, and the optical disk 11 is rotated at a predetermined speed by the drive motor 12b of the optical disk support 12 on which the optical disk 11 is installed. Unnecessary UV resin supplied to the surface of the optical disk 11 is shaken off by this rotation drive.
[0032]
Thereafter, the UV resin is cured by irradiating the optical disk 11 coated with the UV resin with ultraviolet light in an inert gas atmosphere, and a protective film is formed on the surface of the optical disk 11.
[0033]
As described above, in the pump-type apparatus according to the first embodiment, the UV resin, which is a UV-curable paint, is always kept at a predetermined temperature when the UV resin is discharged onto the surface of the optical disk 11. A temperature control mechanism is provided. This UV resin has a characteristic that its viscosity changes greatly depending on a change in temperature. In the first embodiment, however, a first heat insulating mechanism is provided around the suction pump 2 as the temperature adjusting mechanism. A second heater for circulating a liquid for keeping the UV resin in a paint supply pipe 3 provided between the suction pump 2 and the application nozzle 4 as a UV resin discharge unit. Is provided, the temperature of the UV resin is maintained at a constant predetermined temperature, and the UV resin at the predetermined temperature is always supplied to the optical disc 11. Therefore, a predetermined amount of the UV resin is stably and uniformly applied to the surface of the optical disk 11 without being affected by the above-described characteristics of the UV resin.
[0034]
Further, by using the radiant heat generating means 24, which is a heating means for maintaining the optical disk 11 at the predetermined temperature, as an auxiliary means of the temperature control mechanism, a predetermined amount of UV resin is more stably and uniformly applied to the surface of the optical disk 11. Will be done.
[0035]
Therefore, according to the pump-type device, the supply of the UV resin to the optical disk 11 can be made uniform, and the yield and reliability of the product can be greatly improved. It is also possible to use a high-viscosity UV-curable coating material which has been described above.
[0036]
Next, a description will be given of a second embodiment in which the present invention is applied to the above-described pressurizing / discharging type coating apparatus (hereinafter simply referred to as a pressurizing type apparatus). This pressure-type device is a device that supplies a pressurized gas to a resin supply tank, which is a supply source of a UV resin, and supplies the coating material to an object to be coated by the pressure. The same reference numerals are given to members and the like corresponding to the first embodiment, and the description thereof will be omitted.
[0037]
As shown in FIG. 2, the pressurized type apparatus includes a sealed resin supply tank 1 in which a UV resin is stored, and a pressurized gas that supplies a pressurized gas into the resin supply tank 1 to apply a predetermined pressure. It has a gas supply mechanism 31 and a paint supply pipe 3 which is a paint passage for supplying the paint from the supply tank 1 to the application nozzle 4 which is a discharge portion of the UV resin, and these members are arranged. The application nozzle 4 protrudes from the housing 5.
[0038]
Further, similarly to the pump type device, the pressure type device includes a support table 12a on which the optical disk 11 is placed, and a drive motor 12b for rotating the support table 12a at a predetermined constant rotation speed. An optical disk support 12 is provided. The optical disk support 12 is composed of a support table 12a on which the optical disk 11 is mounted, and a drive motor 12b for driving the support table 12a to rotate at a predetermined constant rotation speed. An appropriate UV resin is shaken off by this rotation drive. The surplus UV resin that has been shaken off is collected in the collection tank 33 by the rotating means 13. The sack valve is also provided in the paint supply pipe 3.
[0039]
In particular, the pressurized type device is provided with a temperature adjusting mechanism for keeping the UV resin at a constant predetermined temperature, similarly to the pump type device. In the second embodiment, the first and second heat retaining means are provided as the temperature adjusting mechanism. Here, the second heat retaining means of the heat retaining means is the same as that of the pump type device according to the first embodiment.
[0040]
As the first heat retaining means, a temperature control unit 32 is provided in the resin supply tank 1, and the temperature control unit 32 keeps the UV resin in the resin supply tank 1 at a constant predetermined temperature of 30 to 80 ° C. The temperature controller 32 has a temperature sensor 32a, and the temperature sensor 32a is installed at a lower portion of the resin supply tank 1. The temperature of the UV resin in the resin supply tank 1 is detected by a temperature sensor 32a, and the detected value is transmitted and received by a temperature controller in a temperature controller 32 to be adjusted to the predetermined temperature. Here, a temperature sensor different from the temperature sensor 32a may be provided in the temperature adjusting unit 32, and abnormal heating may be prevented by this temperature sensor.
[0041]
Similarly, a temperature sensor is also provided in the liquid circulator 22 as the second heat retaining means, and a detection value detected by this temperature sensor is sent to a temperature controller in the temperature control unit 32 and is sent to the resin supply tank 1. May be adjusted to the predetermined temperature.
[0042]
Further, it is possible to provide a pressure sensor in the pressurized gas supply mechanism 31 to control the discharge amount of the UV resin by arbitrarily changing the pressure, or to temporarily stop the apparatus when an abnormality occurs by providing an alarm means.
[0043]
In the pressure-type apparatus according to the second embodiment, similarly to the pump-type apparatus, when the UV resin, which is a UV-curable paint, is discharged onto the surface of the optical disk 11, the UV resin is always kept at a predetermined temperature. Is provided with a temperature control mechanism. This UV resin has a characteristic that its viscosity changes greatly depending on a change in temperature. However, in the second embodiment, the first heat retaining means is provided in the resin supply tank 1 as the temperature adjusting mechanism. And a second temperature keeping means for circulating a UV resin keeping liquid in a paint supply pipe 3 provided between the resin supply tank 1 and the application nozzle 4 which is a UV resin discharge section. Is provided, the temperature of the UV resin is maintained at a constant predetermined temperature, and the UV resin at the predetermined temperature is always supplied to the optical disc 11. Therefore, a predetermined amount of the UV resin is stably and uniformly applied to the surface of the optical disk 11 without being affected by the above-described characteristics of the UV resin.
[0044]
Further, by using the radiant heat generating means 24, which is a heating means for maintaining the optical disk 11 at the predetermined temperature, as an auxiliary means of the temperature control mechanism, a predetermined amount of UV resin is more stably and uniformly applied to the surface of the optical disk 11. Is done.
[0045]
Therefore, according to the above-mentioned pressurized apparatus, it is possible to make the supply of the UV resin to the optical disk 11 uniform, to greatly improve the yield and reliability of the product, and to obtain a high-viscosity ultraviolet-curable paint. Can also be used.
[0046]
【The invention's effect】
According to the coating apparatus according to the present invention, in the coating apparatus that supplies the coating material to the surface of the optical disc by discharging the ultraviolet-curing coating material, the temperature at which the coating material is always maintained at a predetermined temperature when performing the discharging. Since the adjustment mechanism is provided, the protective film can be uniformly applied to the optical disc while the discharge amount of the ultraviolet curable paint is kept constant, and the yield and reliability of the product can be greatly improved. . In addition, a high-viscosity ultraviolet-curable paint can be used.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a pump type coating apparatus according to a first embodiment.
FIG. 2 is a schematic view showing a pressurizing type coating apparatus according to a second embodiment.
FIG. 3 is a characteristic diagram showing a relationship between temperature and viscosity of a UV resin.
FIG. 4 is a characteristic diagram illustrating a relationship between a discharge amount of a UV resin and a pressure.
FIG. 5 is a characteristic diagram showing a relationship between a viscosity of a UV resin and a shake-off time.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 resin supply tank 2 suction pump 3 paint supply pipe 4 coating nozzle 11 optical disk 12 optical disk support 13 recovery means 21 paper heater 22 liquid circulator 23 protection pipe 24 radiant heat generation means 31 pressurized gas supply mechanism 32 temperature control unit 33 recovery tank

Claims (4)

In a coating apparatus for supplying the coating material to the surface of the optical disk by discharging a UV-curable coating material,
The coating device includes a supply tank in which the paint is stored,
A suction pump that sucks paint from the supply tank,
A paint supply pipe through which the paint sucked up by the suction pump flows,
A coating nozzle for discharging a paint guided by passing through the inside of the paint supply pipe to the optical disc;
A temperature adjusting mechanism for holding the resin at a predetermined temperature,
A housing section in which the supply tank, the suction pump, the paint supply pipe, and the temperature control mechanism are arranged;
The optical disk is constituted by heating means for maintaining the optical disk at a predetermined temperature,
The paint supply pipe is provided with a liquid circulator from its front end to its rear end,
The temperature control mechanism includes a first heat retaining means disposed around the suction pump;
A second heat insulation means for circulating a heat insulation liquid around a paint supply pipe provided between the suction pump and the application nozzle,
A coating device for forming a protective film, wherein a coating material is supplied to the optical disk by the coating nozzle protruding from the storage section . In a coating apparatus for supplying the coating material to the surface of the optical disk by discharging a UV-curable coating material,
The coating device includes a supply tank in which the paint is stored,
A pressurized gas supply mechanism having a pressure sensor for supplying a pressurized gas to the supply tank and applying a predetermined pressure;
A paint supply pipe through which the resin supplied by the pressure flows,
A coating nozzle for discharging a paint guided by passing through the inside of the paint supply pipe to the optical disc;
A temperature adjusting mechanism for holding the resin at a predetermined temperature,
A storage unit for disposing the supply tank, a pressurized gas supply mechanism, a paint supply pipe, and a temperature control mechanism;
The optical disk is constituted by heating means for maintaining the optical disk at a predetermined temperature,
The paint supply pipe is provided with a liquid circulator from its front end to its rear end,
The temperature control mechanism includes a first temperature control unit including a temperature control unit having a temperature sensor provided in the supply tank;
It comprises a second heat retaining means having a temperature sensor provided in the liquid circulator,
A coating device for forming a protective film, wherein a coating material is supplied to the optical disk by the coating nozzle protruding from the storage section . 3. The coating apparatus for forming a protective film according to claim 1, wherein the means for heating the optical disc to a predetermined temperature is a radiant heat generating means for supplying radiant heat from above the optical disc. The coating device for forming a protective film according to claim 1 or 2, wherein the means for heating the optical disk to a predetermined temperature is a heater disposed on a support on which the optical disk is mounted.

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