Peeling device for coat of coated film

Abstract

To provide a coat peeling device capable of efficiently removing a coat with a very small amount of water from a surface of a coated film having the coat containing a water-soluble resin.SOLUTION: A coat peeling device of the present invention includes: a housing surrounding a coated film having an inlet through which the traveling coated film enters and an outlet through which the coated film exits; humidification means for humidifying a space inside the housing; cooling means for cooling the coated film disposed inside the housing so as to be in contact with or close to a non-coated side of the coated film; and peeling means for peeling off a coat from the coated film cooled by the cooling means.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coating removal device capable of efficiently removing a coating from the surface of a thermoplastic resin film. [Background technology]

[0002] While plastics are used in a variety of fields, they are also considered a cause of marine pollution, such as microplastics, making it urgent to reduce the environmental impact of plastics.

[0003] Furthermore, in recent years, with the evolution of IoT (Internet of Things), the number of electronic devices such as CPUs installed in computers and smartphones has increased, and consequently, the number of multilayer ceramic capacitors (MLCCs) necessary to drive these electronic devices has also increased rapidly. The general manufacturing method for MLCCs involves using a release film, which has a release layer formed on a plastic base film, as a carrier sheet, forming a ceramic green sheet layer on the release film, and peeling off the ceramic green sheet layer to obtain a ceramic green sheet. In this process, the release film from which the ceramic sheet has been peeled off is discarded as waste.

[0004] In other words, the rapid increase in MLCC production volume in recent years has led to an increase in release film waste, which has become an environmental problem, and efforts to reuse the base film are becoming more active. The components of the release layer contained in the release film generally have a different composition from the components that make up the base film from the standpoint of release properties. Therefore, if a release film with the release layer still attached is remelted and recycled film is produced, the components of the release layer are present as foreign matter, making it impossible to produce a stable film.

[0005] Patent Document 1 discloses a peeling device for removing release components from a release film having a water-soluble resin layer. This device has an unwinding device and a winding device for transporting the release film, with a water tank containing a cleaning solution in between and a brush roll at the outlet of the water tank. A peeling method is also disclosed using this device, in which the release components are removed from the release film by contacting the release film with the cleaning solution for 2 seconds or more, and then rubbing the surface with the brush roll. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-363140 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the coating removal apparatus and method disclosed in Patent Document 1 have a problem in that, because the water-soluble resin layer dissolves into the hot water bath, the resin concentration in the hot water increases as the treatment time progresses, making it impossible to maintain the initial peeling ability. Even if a method is adopted to increase the amount of water supplied in order to suppress the increase in resin concentration, the amount of wastewater also increases along with the amount of water supplied, which not only significantly increases cleaning costs but also significantly increases the environmental burden.

[0008] Therefore, the present invention aims to provide a coating removal device that can efficiently remove a coating from the surface of a coated film having a coating containing a water-soluble resin on one side of the base film using a very small amount of water, in order to obtain a base film that can stably produce a recycled film even after remelting a used coated film. [Means for solving the problem]

[0009] The present invention, which solves the above problems, is a device for peeling a coating from a coated film having a coating containing a water-soluble resin on one side of a base film, A housing has an inlet for the film with the coating to enter and an outlet for the film with the coating to exit, and surrounds the film with the coating. A humidification means for humidifying the internal space of the above-mentioned enclosure, Inside the above-mentioned housing, a cooling means is provided for cooling the coated film, which is positioned in contact with or in close proximity to the side of the coated film that does not have the coating. The system includes a peeling means for peeling the coating off the coated film that has been cooled by the cooling means.

[0010] Furthermore, the coating removal device for the coated film of the present invention is preferably in the following configuration. • The enclosure is equipped with means for heating the internal space. The device is equipped with means for heating the coated film, which is positioned between the cooling means and the peeling means. [Effects of the Invention]

[0011] Using the coating peeling device of the present invention, the coating can be efficiently peeled off a coated film having a coating containing a water-soluble resin on one side of the base film using only a very small amount of water. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a peeling apparatus 101 according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram of a peeling apparatus 201 according to a second embodiment of the present invention. [Figure 3] This is a schematic diagram of a peeling apparatus 301 according to a third embodiment of the present invention. [Figure 4] This is a schematic diagram of a peeling apparatus 401 according to a fourth embodiment of the present invention. [Figure 5] This is a schematic diagram of a conventional peeling device 501. [Modes for carrying out the invention]

[0013] As a result of intensive studies on a method for efficiently peeling a coating from the surface of a coated film having a coating containing a water-soluble resin on one side of a base film with a very small amount of water, the inventors have found a coating peeling device from the following coated film.

[0014] [Coating Peeling Device] A preferred embodiment of the coating peeling device of the present invention (hereinafter referred to as the coating peeling device) will be described based on the drawings. The following description is an example of one of the embodiments according to the present invention, and is not limited thereto, and various changes can be made without departing from the spirit of the present invention.

[0015] FIG. 1 is a schematic view of a film peeling device 101 according to a first embodiment of the present invention. The film peeling device 101 is provided with a pay-out device 4 for unwinding a film-coated film 2 and a winding device 5 for winding up a base film 3 after the film has been peeled off. Between the pay-out device 4 and the winding device 5, there are a driving device 9 for transporting the film-coated film 2, a cooling roll 6 as a cooling means for cooling the film-coated film 2, and after the cooling roll 6, a peeling device 7 as a peeling means for peeling off together with the film the moisture adhering to the film surface of the film-coated film 2 due to condensation, and a driving device 10 for transporting the base film 3 after the film has been peeled off. A housing 8 is installed so as to surround the cooling roll 6, and the housing 8 has an opening through which the film-coated film 2 enters and exits. Further, the housing 8 is provided with a humidifying nozzle 11 as a humidifying means for supplying humidified air, and the device configuration is such that the inside of the housing 8 can be made into a humid atmosphere. By using the cooling roll 6 installed inside the housing 8 in a humid atmosphere, the film-coated film 2 can be uniformly cooled over the entire surface, and water vapor existing in the surroundings can be made to adhere to the film surface of the film-coated film 2 by condensation. Since the temperature of the portion of the film surface of the film-coated film 2 where moisture has adhered rises due to heat reception from the water vapor, no further condensation occurs, so that a minimum amount of water can be efficiently adhered over the entire area of the film surface without excessive water adhering. Since there is moisture adhering to the surface of the cooling roll 6 due to condensation, which may have an adverse effect on the conveyance state of the film-coated film 2, a blade 12 for removing the moisture on the surface of the cooling roll 6 is also provided. In the film peeling device 101 of FIG. 1, the roll of the film-coated film 2 set in the pay-out device 4 is wound so that the film is on the outside. Therefore, the film of the film-coated film 2 being transported is located on a surface that does not contact the cooling roll 6.

[0016] In the first embodiment of the film peeling apparatus 101, the peeling device 7 is provided with a metal plate with a sharp tip that directly contacts the conveyed coated film 2, but it is not limited to this, and a resin plate with a sharp tip may be provided, or a thin metal plate that flexes when pressed against the coated film 2 like a blade may be provided. Alternatively, a mechanism may be provided to rotate a brush roll made of metal or resin in the same direction as the conveying direction or in the opposite direction, and bring it into direct contact with the coating surface of the coated film 2, or a cloth or fabric may be used to peel off the coating by pressing it against the coated film 2 and wiping it off.

[0017] In the present invention, the drive devices 9 and 10 are preferably configured to cut tension in order to stably transport the coated film 2 and the base film 3 from which the coating has been removed. However, if tension is cut with a suction roll, some of the coating on the coated film 2 or moisture adhering to the coated film 2 may be sucked in, which can cause problems. Therefore, a configuration with a metal drive roll and a rubber roll used for nipping is more preferable. Furthermore, since moisture adhering to the coating surface of the coated film 2 may flow into the drive device 10, stainless steel or a surface-treated material is preferably used as a measure against rust.

[0018] After peeling off the coating wound up by the winding device 5, it is more preferable to completely remove moisture from the base film in order to stably form a recycled film after remelting. A drying device (not shown) may be provided between the peeling device 7 and the winding device 5. The drying device can be provided before winding and may be located either before or after the drive device 10.

[0019] Furthermore, to confirm the quality of the base film after the coating has been removed, an inspection machine (not shown) for detecting coating residue and environmental foreign matter attached during the process may be installed in front of the winding device 5. The inspection machine should be selected according to the properties of the base film, and an inspection machine using transmitted or reflected light is preferably used. In addition, a marking device (not shown) for recording the location of the coating residue and environmental foreign matter attached during the process detected by the above inspection machine may be installed between the inspection machine and the winding device 5. The marking method by the marking device can be any method that can mark the location of the object to be detected, such as a pen, sticker, or laser. By marking the coating residue and environmental foreign matter attached during the process, it becomes possible to remove those areas before remelting, so that recycled film can be manufactured more stably and a deterioration in the quality of the recycled film can be prevented.

[0020] To peel the coating from the coated film 2, it is necessary to add moisture to the water-soluble coating to dissolve it. In this embodiment, this is achieved by cooling the coated film 2 with a cooling roll 6. Specifically, moisture is added to the coating surface by utilizing the condensation of water vapor inside the housing 8 on the coating surface of the coated film 2 cooled by the cooling roll 6. To increase the speed of coating peeling, it is important to add moisture as quickly as possible, so it is preferable to lower the surface temperature of the coated film 2 with the cooling roll 6 as much as possible, and the surface temperature of the cooling roll 6 is preferably 10°C or lower. The lower the temperature of the cooling roll 6, the more efficiently condensation can be formed on the surface of the coated film 2. However, if the temperature is too low, the water that condenses on the surface of the cooling roll 6 in areas not in contact with the coated film 2 may freeze and get stuck between the cooling roll and the coated film 2, negatively affecting transport. Therefore, the surface temperature of the cooling roll 6 is preferably 0°C or higher, but this is not the case if a blade 12 or the like is installed to scrape off the frozen ice that adheres to it. Furthermore, even if the water does not freeze, if condensed water gets caught between the cooling roll 6 and the coated film 2, the coated film 2 may meander, which can negatively affect the conveyance. Therefore, it is preferable to have a blade 12 installed to scrape off the water adhering to the surface of the cooling roll 6.

[0021] To further increase the speed of peeling off the coating, it is preferable to heat the inside of the housing 8. Heating the inside of the housing 8 increases the amount of saturated water vapor inside the housing 8, creating an environment where condensation is more likely to occur on the cooling roll 6. In other words, moisture can be applied to the surface of the coated film 2 more quickly, enabling high-speed peeling of the coating. The means of heating the inside of the housing 8 are not particularly limited, and a heat source such as a heater may be installed inside the housing 8, but since the heat from the heat source is used not only to heat the internal environment of the housing 8 but also to heat the cooling roll 6, it is preferable to supply heated humidified air using the humidifying nozzle 11 in Figure 1, which allows for more efficient heating of the internal environment of the housing 8. Also, when the internal environment of the housing 8 is heated, the amount of saturated water vapor increases, which can raise the dew point temperature. In other words, it is not necessary to lower the surface temperature of the cooling roll 6 to the aforementioned temperature, and this method can be used suitably. Alternatively, if there is insufficient moisture condensing on the surface of the water-soluble coating and the coating does not dissolve completely, the surface temperature of the cooling roll 6 can be lowered to increase the amount of moisture condensing on its surface. These conditions are adjusted each time depending on the solubility of the water-soluble coating and the rate at which the coating is peeled off the coated film 2.

[0022] Figure 2 is a schematic diagram of a coating peeling device 201 according to a second embodiment of the present invention. The coating peeling device 201 has water 13 stored inside the housing 8 of the coating peeling device 101 of the first embodiment, is equipped with a liquid supply pump 14 for supplying water to the housing 8, and is also equipped with a discharge channel 15 for discharging water 13 from inside the housing 8. Water vapor present inside the housing 8 condenses and adheres to the surface of the coating film 2 and is carried out to the outside of the housing 8, i.e., to the peeling mechanism 7. However, water stored inside the housing 8 evaporates and replenishes it, so moisture is always present inside the housing 8, and condensation can be carried out continuously without any problems. In this second embodiment, water can be considered a humidifying means.

[0023] To further increase the rate at which the coating is peeled off, it is preferable to heat the inside of the housing 8 as described above, and it is preferable that the water 13 supplied from the liquid supply pump 14 is hot water. Since the hot water stored inside the housing 8 gradually dissipates heat and cools down, it is even more preferable to have a system configuration that allows the hot water inside the housing 8 to be discharged from the discharge channel 15, reheated by a heating device (not shown), and then supplied again as hot water from the liquid supply pump 14.

[0024] Although not shown in the diagram, the housing 8 may also have a humidifying nozzle 11 inside, similar to the coating removal device 101 of the first embodiment, in which case the outlet of the humidifying nozzle 11 is located in a place separate from the water 13.

[0025] Figure 3 is a schematic diagram of a coating stripping apparatus 301 according to a third embodiment of the present invention. The coating stripping apparatus 301 is equipped with a heater 16 in water 13 inside the housing 8 of the coating stripping apparatus 201 of the second embodiment. As mentioned above, in order to increase the speed of stripping the coating, it is preferable that the water 13 stored inside the housing 8 be hot water, and the water 13 inside the housing 8 can be heated to hot water using the heater 16. In Figure 3, an immersion heater is shown as the heater 16, but it is not limited to this as long as the water 13 inside the housing 8 can be heated to hot water as a heat source.

[0026] Figure 4 is a schematic diagram of a coating peeling apparatus 401 according to a fourth embodiment of the present invention. The coating peeling apparatus 401 is located between the cooling roll 6 and the peeling device 7 of the coating peeling apparatus 201 of the second embodiment, and is equipped with a heating roll 17 as a heating means on the outside of the housing 8. In the coating peeling apparatus 401, the coated film 2 is cooled by the cooling roll 6 and moisture adheres to it due to condensation, then it is transported to the outside of the housing 8, where the coated film 2 and the attached moisture are heated by the heating roll 17. Next, the peeling device 7 can peel off both the moisture attached to the coating surface due to condensation and the coating. According to this embodiment, since the water-soluble coating and moisture can be dissolved more quickly by raising their temperatures, it is suitable for increasing the speed of coating peeling. As other heating means, for example, hot air generated by a hot air generator may be blown onto the film, or a heat source such as an infrared heater may be used, and any means is acceptable as long as the coated film 2 and the attached moisture are heated.

[0027] In Figures 1-4, the first to fourth peeling devices 101, 201, 301, and 401 are equipped with a metal plate with a sharp tip that directly contacts the conveyed coated film 2 as the peeling device 7. However, the device is not limited to this, and a resin plate with a sharp tip may be provided, or a thin metal plate that flexes when pressed against the coated film 2 like a blade may be provided. Alternatively, a mechanism may be provided to rotate a brush roll made of metal or resin in the same direction as or opposite to the conveying direction, and it may be brought into direct contact with the coating surface of the coated film 2, or a cloth or fabric may be used to peel off the coating by pressing it against the coated film 2 and wiping it off. Furthermore, the peeling device 7 may employ a non-contact peeling device 7' (not shown) that does not come into contact with the conveyed coated film 2. Examples of non-contact peeling devices 7' include means of blowing air or water. As a result, compared to peeling equipment 7 that directly contacts the surface of the coating, this method prevents an increase in the transport resistance of the coated film 2 and avoids causing scratches or damage to the recovered base film 3 due to contact, and is therefore sometimes preferred for use.

[0028] In the peeling devices 101, 201, 301, and 401 shown in Figures 1-4, a cooling roll 6 was used to cool the coated film by contacting the side of the coated film that does not have a coating. However, a means of cooling the coated film without contacting it may be used, which is positioned close to the side of the coated film that does not have a coating. Specifically, a cooling nozzle for discharging cooled air is positioned close to the side of the coated film that does not have a coating. By blowing cooled air from the cooling nozzle onto the coated film, the coating is cooled, and moisture can be deposited on the surface of the coating due to condensation. If the cooling nozzle is installed on the side with the coating, the most moisture will adhere to the outlet of the cooling nozzle, so it is preferable to install it on the side without the coating.

[0029] The cooling method is appropriately selected depending on the properties of the coated film and the amount of moisture to be condensed. For example, if the thickness of the coated film is 200 μm or less and the heat capacity is small, the cooled coated film may be immediately heated by the ambient temperature, resulting in insufficient moisture adhering due to condensation. In such cases, if the amount of moisture to be condensed is insufficient, a method of cooling by contacting the coated film is preferably selected.

[0030] [Applicable coated films] The target coated film 2 may include all coated films having a coating containing a water-soluble resin, taking into consideration the environmental impact. Among these, the water-soluble resin is more preferably one in which at least one of the following is the main component: water-soluble polyester resin, polyester urethane resin, acrylic resin, ethylene ionomer resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, ethylene-vinyl alcohol resin, or starch.

[0031] The coating containing the water-soluble resin may be a single layer containing the water-soluble resin, a laminate of two or more layers containing the water-soluble resin, or a laminate of a layer containing the water-soluble resin and a layer not containing the water-soluble resin.

[0032] Furthermore, a release film with a coating that includes a release component in addition to a water-soluble resin in part of the coating is particularly preferred, as it can efficiently exhibit the effect of coating removal. The release component referred to here is a component that increases the contact angle with water on the surface of the coating, that is, reduces the surface energy of the coating, and examples include a curable silicone resin compound with dimethylsiloxane as the main skeleton, a compound having a long-chain alkyl group, and a compound having fluorine. The coating may be a mixture of the water-soluble resin and the release component, or the respective layers may be laminated. In the case of a laminated coating, it is preferable that a layer containing the water-soluble resin is formed directly above the base film, followed by a layer containing the release component on the outermost surface, and it is particularly preferable to use a curable silicone resin compound with dimethylsiloxane as the main skeleton, which has high water permeability, as the release component. [Examples]

[0033] The present invention will be described below with reference to examples, but the present invention is not necessarily limited thereto.

[0034] <Coated film> A coated film was prepared by forming a 0.1 μm thick layer of polyvinyl alcohol resin as a water-soluble resin on a 30 μm thick polyethylene terephthalate base film, and then forming a 0.1 μm thick layer of curable silicone resin as a release agent on top of that.

[0035] <Method for evaluating peeling> The peeling properties were evaluated using commercially available DynePens (surface energy: 30, 70 mN / m) and measured using the following method. Under room temperature conditions of 23°C, if a DynePen was used to draw on the sample surface and the state was maintained for 4 seconds or more, it was determined that the surface energy of the sample surface was higher than the surface energy of the DynePen. If the cured silicone resin release component of the coated film remained on the surface, the surface energy was less than 30 mN / m, and therefore the reagent was repelled from the sample surface by all DynePens, preventing the drawing from being maintained. On the other hand, if the cured silicone resin release component was peeled off and the polyvinyl alcohol resin was exposed, the surface energy was 70 mN / m or higher, and therefore all DynePens could maintain the drawing. When both the release agent coatings of the hardened silicone resin and the water-soluble polyvinyl alcohol resin are peeled off, exposing the polyethylene terephthalate, the surface energy is 43.8 mN / m. Therefore, drawing with a 30 mN / m Dyne pen is maintained, but drawing with a 70 mN / m Dyne pen is not. Based on the above evaluation method, it was determined whether or not the coating on the coated film had been peeled off.

[0036] <Measurement of water usage> The amount of water used for peeling was measured by measuring the amount of water supplied to the humidifying nozzle 11, which creates a humidified atmosphere inside the housing 8 of the film peeling device 101. Specifically, a flow meter (Keyence Corporation: clamp-on flow sensor) was installed in the piping that supplies water to the humidifying nozzle 11, and the actual amount of water supplied was measured. From the measured amount of water and the area of ​​the peeled coated film 2, the unit area [m²] of the coated film 2 was calculated. 2 The amount of water used per unit area [m²] was estimated. In addition, for the film stripping devices 201, 301, and 401, the amount of water required to maintain the liquid level of the water 13 stored inside the housing 8 was measured. Specifically, a flow meter (Keyence Corporation: clamp-on flow sensor) was installed in the piping that supplies water from the liquid supply pump 14 to the housing 8, and the actual amount of water supplied was measured. From the measured amount of water and the area of ​​the actually stripped coated film 2, the amount of water used per unit area [m²] of the coated film 2 was estimated. 2 We estimated the amount of water used per [unit].

[0037] <Removal of the coating from the coated film> [Example 1] The coated film was set in the unwinding device 4 of the peeling device 101 shown in Figure 1. The coated film was transported to the housing 8 by the drive device 9, while the coated film 2 was cooled inside the housing 8 by a cooling roll 6. After moisture was deposited on the surface of the coating by condensation, the peeling device 7 peeled off both the deposited moisture and the coating, and the base film 3 with the coating removed was wound up by the winding device 5. The transport speed was set to 10, 30, and 50 m / min. The cooling roll 6 had an outer diameter of 250 mm and was set to a surface temperature of 10°C. Humidified air was supplied to the inside of the housing 8 from a humidifying nozzle 11, and the environment inside the housing 8 during peeling was checked with a thermometer and hygrometer, and the temperature was 60°C and the humidity was 85%RH. The peeling device 7 was a metal plate, and the surface temperature of the coated film 2 transported to the metal plate was checked with an infrared thermometer, and it was 20°C. When the substrate film, after being wound up by the winding device 5 and the coating was peeled off, was collected, the maximum transport speed at which both the hardened silicone resin and water-soluble polyvinyl alcohol resin coatings could be peeled off was 10 m / min. At transport speeds of 30 and 50 m / min or higher, peeling evaluation confirmed that a portion of the hardened silicone resin or polyvinyl alcohol resin coating remained. The amount of water used to peel off the coating at a transport speed of 10 m / min was 30 ml / m 2 The amount of water used was 20 ml / min at conveying speeds of 30 and 50 m / min. 2 , 15 ml / m 2 That was the case.

[0038] [Example 2] The procedure for Example 1 was performed, except that the surface temperature of the cooling roll 6 in Example 1 was set to 0°C. Humidified air was supplied to the inside of the housing 8 from the humidifying nozzle 11, and the environment inside the housing 8 during peeling was checked with a thermometer and hygrometer, and the temperature was 60°C and the humidity was 85%RH. The surface temperature of the coated film 2 that was conveyed to the metal plate of the peeling machine 7 was checked with an infrared thermometer and it was 20°C. When the substrate film from which the coating had been peeled off after being wound up with the winding device 5 was taken, the maximum conveying speed at which both the hardened silicone resin and the water-soluble polyvinyl alcohol resin coatings could be peeled off was 30 m / min. At a conveying speed of 50 m / min, peeling evaluation confirmed that a portion of the hardened silicone resin or polyvinyl alcohol resin coating remained. The amount of water used to peel off the coating at a conveying speed of 30 m / min was 30 ml / m 2 At a transport speed of 50 m / min, the amount of water used was 20 ml / min. 2 That was the case.

[0039] [Example 3] Using the film peeling device 201 shown in FIG. 2, film peeling from the film 2 with a coating was carried out. Instead of the humidifying nozzle 11 of Example 2, the film peeling device 201 constitutes a circulation flow path such that water 13 is fed, stored, a part of the water 13 is taken out from the discharge flow path 15, and then fed again into the housing 8 from the liquid supply pump 14 by using a liquid supply pump 14 inside the housing 8. Further, by providing a thermostat in the middle of the circulation flow path, the temperature of the circulating water can be adjusted, and the water temperature inside the housing 8 was adjusted to 60°C. When the circulating water was insufficient, water was replenished using a liquid supply pump (not shown) prepared outside the device. Otherwise, the same operations as in Example 2 were carried out. The temperature of the water supplied to the housing 8 was 60°C as set. When the internal environment of the housing 8 at that time was checked with a thermo-hygrometer, the temperature was 40°C and the humidity was 100%RH. Also, when the surface temperature of the film 2 with a coating conveyed to the metal plate of the peeling device 7 was checked with a radiation thermometer, it was 20°C. When the base film from which the coating was peeled after being wound by the winding device 5 was collected, the maximum conveyance speed at which both the cured silicone resin of the release component and the water-soluble polyvinyl alcohol resin coating could be peeled was 30 m / min. At a conveyance speed of 50 m / min, in the peeling evaluation, it was confirmed that a part of the coating of the cured silicone resin or polyvinyl alcohol resin remained. The amount of water used for coating peeling at a conveyance speed of 30 m / min was 30 ml / m 2 was. At a conveyance speed of 50 m / min, the amount of water used was 20 ml / m 2 was.

[0040] [Example 4] The coating was removed from the coated film 2 using the coating removal device 301 shown in Figure 3. The coating removal device 301 has an immersion heater 16 installed in water 13 stored inside the housing 8 of Example 3. The heater output was controlled so that the water temperature inside the housing 8 was 80°C. Otherwise, the same operation as in Example 3 was performed. The temperature of the water supplied to the housing 8 was 60°C as set, and the water temperature inside the housing 8 was 80°C. When the environment inside the housing 8 at that time was checked with a thermometer and hygrometer, the temperature was 55°C and the humidity was 100%RH. The surface temperature of the coated film 2 that had been transported to the metal plate of the removal device 7 was checked with an infrared thermometer and was 20°C. When the base film from which the coating had been removed after being wound up with the winding device 5 was taken, it was found that the maximum transport speed at which both the hardened silicone resin and water-soluble polyvinyl alcohol resin coatings of the release component could be removed was 50 m / min. At a transport speed of 50 m / min, the amount of water used to remove the coating was 30 ml / m 2 That was the case.

[0041] [Example 5] The coating was removed from the coated film 2 using the coating removal device 401 shown in Figure 4. The coating removal device 401 has an additional heating roll 17 installed outside the housing 8, between the cooling roll 6 and the peeling machine 7 of Example 3. An induction heating roll was used for temperature control of the heating roll 17. Specifically, the set temperature of the heating roll 17 was adjusted so that the surface temperature of the coating on the coated film 2 that was transported to the peeling machine 7 was 60°C. Otherwise, the coating was removed using the same procedure as in Example 3. The temperature of the water supplied to the housing 8 was 60°C as set, and when the internal environment of the housing 8 was checked with a thermometer and hygrometer at that time, the temperature was 40°C and the humidity was 100%RH. The surface temperature of the coated film 2 that was transported to the metal plate of the peeling machine 7 was checked with an infrared thermometer and was 60°C. When the substrate film, after being wound up by the winding device 5 and the coating was peeled off, was collected, it was found that the maximum transport speed at which both the hardened silicone resin and water-soluble polyvinyl alcohol resin coatings could be peeled off was 50 m / min. The amount of water used to peel off the coating at a transport speed of 50 m / min was 30 ml / m 2That was the case.

[0042] [Comparative Example 1] The coating on the coated film 2 was removed using a conventional coating removal device 501 shown in Figure 5. The coating removal device 501 includes a water tank 514 containing water 513, an adjacent drainage tank 515 where the liquid level of the water tank 514 overflows and is drained, and a filtration filter 516 for separating the removed coating contained in the drainage.

[0043] The coated film 2 was set in the unwinding device 504 of the peeling device 501, transported to the water tank 514 by the drive device 509 and brought into contact with water 513 (room temperature: 20°C), then brought into contact with a metal plate by the peeling device 507 to peel off both the water and the coating, and the base film 3 from which the coating had been removed was wound up by the winding device 505.

[0044] Fresh water was supplied to the tank by the liquid supply pump 512, and the amount of water supplied was adjusted to the minimum necessary amount while checking the peeling status of the coating, so that the concentration of the water-soluble coating component dissolved in the water 513 inside the tank 514 would not increase and the solubility of the coating would not decrease. When the substrate film 3, from which the coating had been peeled off after being wound up by the winding device 505, was taken, it was found that the maximum transport speed at which both the hardened silicone resin and water-soluble polyvinyl alcohol resin coatings could be peeled off was 50 m / min. The amount of water used to peel off the coating at a transport speed of 50 m / min was 25,000 ml / m 2 In comparison to Examples 1-5, a large amount of water was required to peel off the coating. This is because, as the water-soluble polyvinyl alcohol resin contained in the coating elutes and the concentration of the solution increases, the elution properties of the polyvinyl alcohol resin decrease. Therefore, in order to continuously peel off the coating, the unit area (1 m²) of the coated film was required. 2 This means that 25,000 ml of water was required per unit. Therefore, it was confirmed that the amount of water used for peeling the coating in the coating peeling devices 101, 201, 301, and 401 of the present invention is very small compared to the conventional coating peeling device 501.

[0045] [Table 1]

[0046] [Comparison of Example 1 and Example 2] In Example 2, by setting the surface temperature of the cooling roll 6 to a lower temperature, condensation was made more rapidly on the surface of the coated film 2, allowing moisture to adhere more quickly. In other words, a sufficient amount of moisture to dissolve the water-soluble coating could be quickly applied, and the rate of coating peeling was increased compared to Example 1.

[0047] [Comparison of Example 3 and Example 4] In Example 4, by increasing the temperature of the hot water stored inside the housing 8, the amount of saturated water vapor inside the housing 8 could be increased, allowing a sufficient amount of water to quickly adhere to dissolve the water-soluble coating. As a result, the rate of coating removal was faster than in Example 3, and the coating could be removed even at a transport speed of 50 m / min.

[0048] [Comparison of Example 3 and Example 5] In Example 5, by heating the moisture adhering to the surface of the coated film 2 inside the housing 8 with the heating roll 17, the dissolution of the water-soluble coating was further accelerated. As a result, the rate of coating removal was increased compared to Example 3, and the coating could be removed even at a transport speed of 50 m / min. [Industrial applicability]

[0049] The coated film to which the method and apparatus for peeling coated films of the present invention can be applied is not limited to a film having a coating containing a water-soluble resin on one side of a base film, but may be any recyclable resin film, paper film, or metal film having a coating containing an easily soluble resin layer. [Explanation of Symbols]

[0050] 2. Coated film 3. Base film 4, 504 Unwinding device 5, 505 Winding device 6. Cooling roll (cooling means) 7,507 Peeling equipment (peeling means) 8 cabinets 9, 10, 509, 510 Drive unit 11. Humidifying nozzle (humidification means) 12 blades 13,513 water 14,512 liquid supply pump 15 Discharge channel 16 Heater 17 Heating Roll 101, 201, 301, 401 Film stripping device 501 Conventional coating removal device 514 Aquarium 515 Drain tank 516 Filtration filter 517 Guide Roll

Claims

1. An apparatus for peeling a coating from a coated film having a coating containing a water-soluble resin on one side of a base film, comprising: a housing having an entrance through which the traveling coated film enters and an exit through which the traveling coated film exits, the housing surrounding the coated film; A humidifying means for humidifying the space inside the housing; a cooling means disposed within the housing so as to be in contact with or adjacent to a surface of the coated film that does not have the coating, for cooling the coated film; and a peeling means for peeling off the coating from the coated film cooled by the cooling means. An apparatus for removing coating from coated films.

2. 2. The apparatus for peeling a coating from a coated film according to claim 1, further comprising a means for heating an internal space of said housing.

3. 3. The apparatus for peeling a coating from a coated film according to claim 1, further comprising means for heating the coated film, the means being disposed between the cooling means and the peeling means.

Images