Apparatus for peeling coating from 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 peeling device that can efficiently remove 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 to be a cause of marine pollution, such as microplastics, making it urgent to reduce the environmental impact of plastics.

[0003] Furthermore, in recent years, advances in the Internet of Things (IoT) have led to an increase in electronic devices such as CPUs installed in computers and smartphones, and as a result, the number of multilayer ceramic capacitors (MLCCs) required to drive these electronic devices has also increased dramatically. A typical method for manufacturing MLCCs involves using a release film, which is a plastic substrate film with a release layer formed on it, 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 is discarded as waste.

[0004] That is, the rapid increase in the production volume of MLCCs in recent years has led to an increase in the amount of release film waste, which has become an environmental problem, and efforts to reuse base films are becoming more active.The components of the release layer contained in release films generally have a different composition from the components that make up the base film, from the perspective of release properties, so if a release film with a release layer is remelted as is to produce a recycled film, the components of the release layer will exist as foreign matter, making it impossible to produce a stable film.

[0005] Patent Document 1 discloses a peeling device as an apparatus for removing release components from a release film having a water-soluble resin layer, which has an unwinding device and a winding device for transporting the release film, with a water tank containing a cleaning liquid between them and a brush roll at the outlet of the water tank. It also discloses a peeling method using this device in which the release film is brought into contact with the cleaning liquid for 2 seconds or more, and then the surface is rubbed with the brush roll to remove the release components from the release film. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-363140 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the coating removal device and method disclosed in Patent Document 1 have the problem that the water-soluble resin layer dissolves in the hot water tank, causing the resin concentration in the hot water to increase over the course of treatment, preventing the initial removal ability from continuing. Even if a method of increasing the water supply is adopted to suppress the increase in resin concentration, the amount of wastewater increases along with the water supply, resulting in not only a significant increase in cleaning costs but also a significant increase in the environmental load.

[0008] Therefore, the present invention aims to provide a coating peeling device that can efficiently remove a coating containing a water-soluble resin from the surface of a coated film having a coating on one side thereof using a very small amount of water, in order to obtain a substrate film that can be reliably remelted from used coated film to produce a recycled film. [Means for solving the problem]

[0009] The coating peeling device of the present invention, which solves the above-mentioned 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 substrate film, a housing surrounding the coated film, the housing having an entrance through which the traveling coated film enters and an exit through which the traveling coated film exits; 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 in close proximity to the surface of the coated film that does not have the coating, for cooling the coated film; and peeling means for peeling the coating from the coated film cooled by the cooling means.

[0010] The device for peeling the coating from the coated film of the present invention preferably has the following configuration. The housing is provided with a means for heating the space inside the housing. The apparatus further comprises a means for heating the coated film, the means being disposed between the cooling means and the peeling means. [Effects of the Invention]

[0011] By using the coating peeling device of the present invention, a coating containing a water-soluble resin can be efficiently peeled off from a coated film having a substrate film on one side thereof using only a small amount of water. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a delamination device 101 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a delamination device 201 according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram of a delamination device 301 according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram of a delamination device 401 according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram of a conventional peeling device 501. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present inventors have conducted extensive research into 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 substrate film using a very small amount of water, and as a result have discovered the following device for peeling a coating from a coated film.

[0014] [Coating stripping device] A preferred embodiment of the coating peeling device of the present invention (hereinafter referred to as the coating peeling device) will be described with reference to the drawings. Note that the following description is an example of one embodiment of the present invention, and the present invention is not limited to this, and various modifications are possible within the scope of the spirit of the present invention.

[0015] FIG. 1 is a schematic diagram of a coating peeling apparatus 101 according to a first embodiment of the present invention. The coating peeling apparatus 101 includes an unwinding device 4 that unwinds a coated film 2 and a winding device 5 that winds up the substrate film 3 after the coating has been peeled off. Between the unwinding device 4 and the winding device 5 are a drive device 9 for transporting the coated film 2, a cooling roll 6 as a cooling means for cooling the coated film 2, and a peeling device 7 as a peeling means for peeling off both the coating and moisture that has adhered to the coating surface of the coated film 2 due to condensation, and a drive device 10 for transporting the substrate film 3 after the coating has been peeled off. A housing 8 is disposed around the cooling roll 6 and has an opening through which the coated film 2 can enter and exit. The housing 8 also includes a humidifying nozzle 11 as a humidifying means for supplying humidified air, enabling the interior of the housing 8 to be filled with a humidified atmosphere. By using a cooling roll 6 installed inside a housing 8 with a humid atmosphere, the coated film 2 is uniformly cooled across its entire surface, allowing surrounding water vapor to condense and adhere to the coating surface of the coated film 2. The moisture-adhered portions of the coating surface of the coated film 2 are heated by the heat from the water vapor, preventing further condensation. This prevents excess water from adhering, allowing a minimum amount of water to be efficiently adhered across the entire coating surface. Because moisture adhering to the surface of the cooling roll 6 due to condensation can adversely affect the conveyance of the coated film 2, a blade 12 is also provided to remove moisture from the surface of the cooling roll 6. In the coating peeling device 101 shown in FIG. 1 , the roll of coated film 2 set in the unwinding device 4 is wound with the coating facing outward. Therefore, the coating of the conveyed coated film 2 is positioned on the side that does not come into contact with the cooling roll 6.

[0016] In the coating peeling device 101 of the first embodiment, the peeling device 7 is a metal plate with a sharp tip that comes into direct contact with the coated film 2 being conveyed, but the present invention is not limited to this and may be a resin plate with a sharp tip, or a thin metal plate that bends like a blade when pressed against the coated film 2. Alternatively, a mechanism may be provided that rotates a brush roll made of metal or resin in the same direction as the conveyance direction or in the opposite direction, so that the brush roll comes into direct contact with the coating surface of the coated film 2, or a rag or cloth may be pressed against the coated film 2 to wipe off the coating.

[0017] The drive devices 9 and 10 in the present invention are preferably configured to be able to cut tension so as to stably transport the coated film 2 and the base film 3 from which the coating has been peeled off, but if tension is cut using a suction roll, part of the coating of the coated film 2 or moisture adhering to the coated film 2 may be sucked in, which may cause problems, so a configuration in which a metal drive roll and a rubber roll are used is more preferably used. Furthermore, since moisture adhering to the surface of the coating of the coated film 2 may flow into the drive device 10, it is preferable to use stainless steel or one that has been surface-treated as a rust prevention measure.

[0018] It is more preferable to completely remove moisture from the substrate film after peeling off the coating wound up by the winding device 5 so that it can be re-melted and stably formed into a recycled film, and a drying device (not shown) may be provided between the peeling device 7 and the winding device 5. The drying device may be provided before winding, and may be located either before or after the driving device 10.

[0019] Furthermore, to check the quality of the substrate film after the coating is peeled off, an inspection machine (not shown) that detects coating residues or environmental contaminants that have adhered during the process may be installed before the winding device 5. The inspection machine may be selected according to the properties of the substrate film, and an inspection machine that uses transmitted or reflected light is preferably used. Furthermore, a marking device (not shown) that records the location of coating residues or environmental contaminants that have adhered during the process detected by the inspection machine may be installed between the inspection machine and the winding device 5. The marking method used by the marking device may be any method that can mark the location of the detected object, such as a pen, sticker, or laser. Marking coating residues or environmental contaminants that have adhered during the process allows the corresponding locations to be removed before remelting, thereby enabling more stable production of recycled film and preventing deterioration in the quality of the recycled film.

[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 using the cooling roll 6. Specifically, moisture is added to the coating surface by utilizing the condensation of water vapor from inside the housing 8 on the coating surface of the coated film 2 cooled by the cooling roll 6. Since the speed at which moisture is added is important to increase the speed at which the coating is peeled, it is preferable to lower the surface temperature of the coating of the coated film 2 as much as possible using the cooling roll 6, and the surface temperature of the cooling roll 6 is preferably 10°C or lower. The lower the cooling roll 6 temperature, the more efficiently condensation can occur on the coating surface of the coated film 2. However, if the cooling roll 6 is set too low, the condensed water on the surface of the cooling roll 6 that is not in contact with the coated film 2 may freeze and become trapped between the coated film 2 and the cooling roll 6, adversely affecting transport. Therefore, the surface temperature of the cooling roll 6 is preferably 0°C or higher, but this is not required if a blade 12 or the like is installed to scrape off any frozen ice that has adhered to the cooling roll 6. Furthermore, even if the condensed water does not freeze, if it gets caught between the cooling roll 6 and the coated film 2, it may cause the coated film 2 to meander or otherwise have an adverse effect on transport, so it is preferable to install a blade 12 to scrape off water adhering to the surface of the cooling roll 6.

[0021] Furthermore, to increase the speed at which the coating is peeled off, 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 that is conducive to condensation on the cooling roll 6. In other words, moisture can be applied more quickly to the coating surface of the coated film 2, enabling high-speed coating peeling. The means for heating the inside of the housing 8 is not particularly limited, and a heat source such as a heater can be installed inside the housing 8. However, 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 shown in Figure 1, which allows for more efficient heating of the internal environment of the housing 8. Furthermore, heating the internal environment of the housing 8 increases the amount of saturated water vapor, thereby raising 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 may be used advantageously. Alternatively, if there is insufficient moisture to condense on the surface of the water-soluble coating and the coating does not dissolve sufficiently, the surface temperature of the chill roll 6 can be adjusted to a lower temperature in order to increase the amount of moisture that condenses on the surface of the chill roll 6. These conditions are adjusted each time depending on the solubility of the water-soluble coating and the speed at which the coating is peeled from the coated film 2.

[0022] FIG. 2 is a schematic diagram of a coating film stripping apparatus 201 according to a second embodiment of the present invention. The coating film stripping apparatus 201 differs from the coating film stripping apparatus 101 according to the first embodiment in that water 13 is stored inside the housing 8, and the apparatus includes a liquid supply pump 14 for supplying water to the housing 8 and a discharge flow path 15 for discharging the water 13 from inside the housing 8. Water vapor present inside the housing 8 condenses and adheres to the coating surface of the coating film 2 and is carried out to the outside of the housing 8, i.e., to the stripping mechanism 7. However, since moisture is constantly present inside the housing 8 due to the evaporation of water stored inside the housing 8, continuous condensation can be achieved without any problems. In this second embodiment, the water can be considered as a humidifying means.

[0023] Furthermore, in order to increase the speed 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 delivered from the liquid supply pump 14 is warm water. Because the warm water stored inside the housing 8 gradually releases heat and cools, it is more preferable that the equipment be configured so that the warm water inside the housing 8 can be discharged from the discharge flow path 15, heated again by a heating device (not shown), and then delivered again as warm water from the liquid supply pump 14.

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

[0025] Figure 3 is a schematic diagram of a coating removal apparatus 301 according to a third embodiment of the present invention. The coating removal apparatus 301 includes a heater 16 in the water 13 inside the housing 8 of the coating removal apparatus 201 according to the second embodiment. As described above, in order to increase the speed at which the coating is removed, it is preferable that the water 13 stored inside the housing 8 is warm water, and the heater 16 can be used to heat the water 13 inside the housing 8 to turn it into warm water. While an immersion heater is shown as the heater 16 in Figure 3, the heater 16 is not limited to this as long as it can be used as a heat source to heat the water 13 inside the housing 8.

[0026] FIG. 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 provided with a heating roll 17 as a heating means located outside the housing 8, between the cooling roll 6 and the peeling device 7 of the coating peeling apparatus 201 according to the second embodiment. In the coating peeling apparatus 401, the coated film 2 is cooled by the cooling roll 6 and moisture is attached to the coated film 2 by condensation. The coated film 2 and the attached moisture are then transported to the outside of the housing 8, where the heating roll 17 heats the coated film 2 and the attached moisture. Next, in the peeling device 7, the coating and the moisture attached to the coating surface by condensation can be peeled together. According to this embodiment, the temperature of the water-soluble coating and the moisture is increased, which allows the water-soluble coating to dissolve more quickly, and is therefore preferably used to increase the coating peeling speed. Other heating means include, for example, blowing hot air generated by a hot air generator or using a heat source such as an infrared heater. Any means capable of heating the coated film 2 and the attached moisture may be used.

[0027] The first to fourth peeling devices 101, 201, 301, and 401 in Figures 1 to 4 are provided with a metal plate with a sharp tip that directly contacts the coated film 2 being conveyed as the peeling device 7. However, the present invention is not limited to this. A resin plate with a sharp tip may be provided, or a thin metal plate that bends when pressed against the coated film 2 like a blade. Alternatively, a mechanism for rotating a brush roll made of metal or resin in the same direction as or opposite to the conveyance direction may be provided to directly contact the coating surface of the coated film 2, or a rag or fabric may be pressed against the coated film 2 to wipe off the coating. Furthermore, the peeling device 7 may be a peeling device 7' (not shown) that does not come into contact with the coated film 2 being conveyed. Examples of a non-contact peeling device 7' include a means for spraying air or water. This makes it suitable for use because it prevents the transport resistance of the coated film 2 from increasing and does not cause scratches or damage to the recovered substrate film 3 due to contact, compared to a peeling device 7 that comes into direct contact with the coating surface.

[0028] In the first to fourth peeling devices 101, 201, 301, and 401 in Figures 1 to 4, a cooling roll 6 is used as a means for cooling the coated film by contacting the non-coated surface of the coated film to cool it. However, a cooling means disposed adjacent to the non-coated surface of the coated film and cooling the coated film without contacting the coated film may also be used. Specifically, a cooling nozzle for discharging cooled air is disposed adjacent to the non-coated surface of the coated film. The coating is cooled by blowing cooled air from the cooling nozzle onto the coated film, which allows moisture to adhere to the coating surface by condensation. When a cooling nozzle is disposed on the coated surface, moisture will adhere most to the nozzle outlet, so it is preferable to dispose the cooling nozzle on the non-coated surface.

[0029] The cooling means 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 instantly heated by the ambient temperature, and the amount of moisture that adheres to the film through condensation may be insufficient. Therefore, if the amount of moisture to be condensed is insufficient, a cooling means that brings the coated film into contact with the film is preferably selected.

[0030] [Applicable coated films] The target coated film 2 can be any coated film having a coating containing a water-soluble resin that takes into consideration environmental impact, etc. Among these, more preferred water-soluble resins are those containing at least one of water-soluble polyester resins, polyester urethane resins, acrylic resins, ethylene ionomer resins, polyvinyl alcohol resins, polyvinylpyrrolidone resins, ethylene-vinyl alcohol resins, and starch as the main component.

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

[0032] In addition, a coated release film containing 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 peeling off the coating. The release component here refers to a component that increases the contact angle of the coating surface with water, that is, reduces the surface energy of the coating, and examples thereof include curable silicone resin compounds with a dimethylsiloxane main skeleton, compounds with long-chain alkyl groups, and compounds with fluorine. The coating may be a mixture of a water-soluble resin and a release component, or each layer may be laminated. In the case of a laminated coating, it is preferable that a layer containing a water-soluble resin is formed directly on the substrate film, and then a layer containing a release component is formed on the outermost surface. It is particularly preferable to use a curable silicone resin compound with a dimethylsiloxane main skeleton, which has high water permeability, as the release component. [Example]

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

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

[0035] <Peeling evaluation method> Peeling was evaluated using commercially available dyne pens (surface energy: 30, 70 mN / m) using the following method. At room temperature (23°C), if a drawing was made on the sample surface with a dyne pen and maintained for 4 seconds or longer, the surface energy of the sample surface was determined to be higher than that of the dyne pen. 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 neither dyne pen could retain the drawing, as the reagent was repelled by the sample surface. On the other hand, if the cured silicone resin release component coating was peeled off, exposing the polyvinyl alcohol resin, the surface energy was 70 mN / m or higher, and therefore both dyne pens could retain the drawing. When both the release component coatings of curable silicone resin and water-soluble polyvinyl alcohol resin are peeled off and the polyethylene terephthalate is exposed, the surface energy is 43.8 mN / m, so a 30 mN / m dyne pen drawing will be retained, but a 70 mN / m dyne pen drawing will not be retained. Using the above evaluation method, it was determined whether or not the coating of the coated film could be peeled off.

[0036] <Measurement of the amount of water used> 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 coating peeling device 101. Specifically, a flow meter (Keyence Corporation: clamp-on flow sensor) was installed in the pipe supplying water to the humidifying nozzle 11, and the amount of water actually delivered was measured. From the measured amount of water and the area of ​​the coated film 2 that was actually peeled, the unit area [m 2 The amount of water used per unit area [m ] of the coated film 2 was calculated. In addition, the amount of water required to maintain the liquid level of the water 13 stored inside the housing 8 was measured in the coating peeling devices 201, 301, and 401. Specifically, a flow meter (Keyence Corporation: clamp-on flow sensor) was installed in the pipe that sends water from the liquid supply pump 14 to the housing 8, and the amount of water actually sent was measured. From the measured amount of water and the area of ​​the coated film 2 that was actually peeled, the amount of water used per unit area [m 2 The amount of water used per ] was estimated.

[0037] <Removing the coating from a coated film> [Example 1] The coated film was set in the unwinding device 4 of the peeling device 101 shown in Figure 1. While the coated film was transported to the housing 8 by the drive device 9, the coated film 2 was cooled by the cooling roll 6 inside the housing 8, causing moisture to adhere to the coating surface by condensation. The moisture and coating were then peeled off together in the peeling device 7, and the substrate film 3 from which the coating had been peeled was taken up by the winding device 5. The transport speeds were 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 into the housing 8 from the humidifying nozzle 11. The environment inside the housing 8 during peeling was monitored with a thermo-hygrometer, revealing a temperature of 60°C and a humidity of 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 monitored with a radiation thermometer, revealing a temperature of 20°C. When the substrate film from which the coating had been peeled off after being wound up by the winding device 5 was sampled, it was found that the maximum conveying speed at which both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings, which are release components, could be peeled off was 10 m / min. At conveying speeds of 30 and 50 m / min, peeling evaluation confirmed that part of the curable silicone resin or polyvinyl alcohol resin coating remained. At a conveying speed of 10 m / min, the amount of water used to peel off the coating was 30 ml / m 2 At conveying speeds of 30 and 50 m / min, the amount of water used was 20 ml / m 2 , 15 ml / m 2 It was.

[0038] [Example 2] The operation of Example 1 was carried out, except that the surface temperature of the cooling roll 6 in Example 1 was set to 0°C. Humidified air was supplied into the housing 8 from the humidifying nozzle 11, and the environment inside the housing 8 during peeling was confirmed with a thermo-hygrometer, where the temperature was 60°C and the humidity was 85% RH. Furthermore, the surface temperature of the coated film 2 conveyed to the metal plate of the peeling device 7 was confirmed with a radiation thermometer, where it was 20°C. When the substrate film from which the coating had been peeled after being wound up by the winding device 5 was sampled, the maximum conveying speed at which both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings of the release components could be peeled was 30 m / min. At a conveying speed of 50 m / min, peeling evaluation confirmed that a portion of the curable silicone resin or polyvinyl alcohol resin coating remained. The amount of water used to peel the coating at a conveying speed of 30 m / min was 30 ml / m. 2 At a conveying speed of 50 m / min, the amount of water used was 20 ml / m 2 It was.

[0039] [Example 3] The coating was removed from the coated film 2 using a coating removal device 201 shown in FIG. 2. Instead of the humidifying nozzle 11 used in Example 2, the coating removal device 201 uses a liquid supply pump 14 to supply and store water 13 inside the housing 8. A portion of the water 13 is extracted through a discharge flow path 15 and then returned to the housing 8 via the liquid supply pump 14, forming a circulation flow path. A thermostatic bath was installed midway through the circulation flow path to adjust the temperature of the circulating water, 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) provided outside the device. Other than that, the same operations as in Example 2 were performed. The temperature of the water supplied to the housing 8 was set to 60°C. The environment inside the housing 8 was checked with a thermo-hygrometer, and the temperature was 40°C and the humidity was 100% RH. The surface temperature of the coated film 2 transported to the metal plate of the peeling device 7 was checked with a radiation thermometer, and was found to be 20°C. When the substrate film from which the coating had been peeled off after being wound up by the winding device 5 was sampled, it was found that the maximum conveying speed at which both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings, which are release components, could be peeled off was 30 m / min. At a conveying speed of 50 m / min, peeling evaluation confirmed that part of the curable 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 conveying speed of 50 m / min, the amount of water used was 20 ml / m 2 It was.

[0040] [Example 4] The coating was peeled from the coated film 2 using a coating peeling device 301 shown in FIG. 3 . The coating peeling device 301 had a submersible 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 operations as in Example 3 were performed. The temperature of the water supplied to the housing 8 was set to 60°C, and the temperature of the water inside the housing 8 was 80°C. The environment inside the housing 8 at that time was confirmed with a thermo-hygrometer, and the temperature was 55°C and the humidity was 100% RH. Furthermore, the surface temperature of the coated film 2 transported to the metal plate of the peeling device 7 was confirmed with a radiation thermometer, and was 20°C. The substrate film from which the coating had been peeled after being wound up by the winding device 5 was sampled, and the maximum transport speed at which both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings, which were release components, could be peeled off was 50 m / min. The amount of water used to peel off the coating at a conveying speed of 50 m / min was 30 ml / m 2 It was.

[0041] [Example 5] The coating was peeled from the coated film 2 using a coating peeling device 401 shown in FIG. 4 . The coating peeling device 401 additionally includes a heating roll 17 between the cooling roll 6 and the peeling device 7 of Example 3, outside the housing 8. The heating roll 17 was an induction heating roll for temperature control. Specifically, the set temperature of the heating roll 17 was adjusted so that the surface temperature of the coating of the coated film 2 transported to the peeling device 7 was 60°C. Otherwise, the coating was peeled using the same procedures as in Example 3. The temperature of the water supplied to the housing 8 was set to 60°C, and the environment inside the housing 8 was checked with a thermo-hygrometer at that time, and the temperature was 40°C and the humidity was 100% RH. The surface temperature of the coated film 2 transported to the metal plate of the peeling device 7 was checked with a radiation thermometer, and was 60°C. When the substrate film from which the coating had been peeled off after being wound up by the winding device 5 was sampled, it was found that the maximum conveying speed at which both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings, which are release components, could be peeled off was 50 m / min. The amount of water used to peel off the coatings at a conveying speed of 50 m / min was 30 ml / m. 2It was.

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

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

[0044] Fresh water was supplied to the water tank by a 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 water 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 after being wound up by the winding device 505 was sampled, it was found that the maximum conveying speed at which both the curable silicone resin release component and the water-soluble polyvinyl alcohol resin coating could be peeled off was 50 m / min. The amount of water used to peel the coating at a conveying speed of 50 m / min was 25,000 ml / m 2 Compared with Examples 1 to 5, a large amount of water was required to peel off the coating. This is because the water-soluble polyvinyl alcohol resin contained in the coating was eluted and the concentration of the solution increased, and as a result, the elution of the polyvinyl alcohol resin decreased. Therefore, in order to continuously peel off the coating, it was necessary to increase the unit area (1 m) of the coated film. 2 This means that 25,000 ml of water was required per 1000 ml of coating. From the above, it was confirmed that the coating peeling devices 101, 201, 301, and 401 of the present invention use a much smaller amount of water to peel off the coating than the conventional coating peeling device 501.

[0045] [Table 1]

[0046] [Comparison between Example 1 and Example 2] In Example 2, by setting the surface temperature of the cooling roll 6 at a lower temperature, it was possible to more quickly condense water onto the coating surface of the coated film 2 and attach the water. In other words, it was possible to quickly attach a sufficient amount of water to dissolve the water-soluble coating, and the coating could be peeled off faster than in Example 1.

[0047] [Comparison between Example 3 and Example 4] In Example 4, by increasing the temperature of the hot water stored inside the housing 8, it was possible to increase the amount of saturated water vapor inside the housing 8, and it was possible to quickly attach a sufficient amount of water to dissolve the water-soluble coating. As a result, the coating peeling speed was faster than in Example 3, and the coating could be peeled even at a conveying speed of 50 m / min.

[0048] [Comparison between Example 3 and Example 5] In Example 5, dissolution of the water-soluble coating was further promoted by heating the moisture attached to the coating surface of the coated film 2 inside the housing 8 with the heating roll 17. As a result, the coating could be peeled off at a higher speed than in Example 3, and the coating could be peeled off even at a conveying speed of 50 m / min. [Industrial Applicability]

[0049] The coated film applicable to the coated film peeling method and peeling device of the present invention is not limited to a film having a coating containing a water-soluble resin on one side of a base film, but may be a 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 (peel means) 8. Housing 9, 10, 509, 510 Drive unit 11 Humidification nozzle (humidification means) 12 blades 13,513 water 14,512 Liquid supply pump 15 Discharge flow path 16 Heater 17 Heating Roll 101, 201, 301, 401 Film stripping device 501 Conventional coating peeling 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 substrate film, comprising: a housing surrounding the coated film, the housing having an entrance for the coated film to enter and an exit for the coated film to exit; a humidifying means for humidifying the space inside the housing; a cooling means disposed inside the housing so as to be in contact with or in close proximity to the surface of the coated film that does not have the coating, for cooling the coated film; and a peeling means for peeling the coating from the coated film cooled by the cooling means. A device for removing coatings from coated films.

2. 2. The apparatus for peeling a coating from a coated film according to claim 1, further comprising means for heating the interior 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.

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