Coating peeling device and coating peeling method

Abstract

Provided are a coating peeling device capable of diminishing a coating remaining on a base material film, and a coating peeling method. A coating peeling device according to the present invention peels, from a coating-equipped film that has a coating containing a water-soluble resin on at least one surface of a base material film, the coating, and comprises: a conveyance mechanism that conveys the coating-equipped film; a cleaning liquid application mechanism that applies cleaning liquid to the surface of the coating; a coating peeling mechanism that is disposed to the downstream side from the cleaning liquid application mechanism in the conveyance direction and peels, from the coating-equipped film in which the cleaning liquid has been applied to the surface of the coating, the coating containing the cleaning liquid; a cleaning liquid re-application mechanism that is disposed to the downstream side from the coating peeling mechanism in the conveyance direction and applies cleaning liquid to the surface of the coating remaining on the base material film; and a suction mechanism that is disposed to the downstream side from the cleaning liquid re-application mechanism in the conveyance direction and sucks up the cleaning liquid and residue of the coating remaining on the base material film.

Description

Coating peeling device and coating peeling method

[0001] The present invention relates to a coating peeling device and a coating peeling method that can efficiently remove a coating from the surface of a substrate film.

[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. Furthermore, with the recent advancement of the Internet of Things (IoT), the number of electronic devices, such as CPUs, installed in computers and smartphones has increased, and 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 has a release layer formed on a plastic substrate film, as a carrier sheet, forming a ceramic green sheet layer on the release film, and peeling 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.

[0003] That is, the recent rapid increase in the production volume of MLCCs has led to an increase in the amount of release film waste, which has become an environmental problem, and efforts to reuse base films have been intensified. From the viewpoint of releasability, the components of the release layer contained in a release film generally have a different composition from the components constituting the base film. Therefore, if a release film with a release layer is directly remelted to produce a recycled film, the components of the release layer are present as foreign matter, making it impossible to produce a stable film. Patent Document 1 discloses a method for removing a release layer containing a water-soluble resin from a release film, in which a cleaning solution in the form of droplets is applied to the release layer, the cleaning solution is retained in the form of droplets on the surface of the release layer, and then the release layer containing the cleaning solution is peeled off.

[0004] International Publication No. 2022 / 190713

[0005] The peeling method of Patent Document 1 has a problem in that when the substrate film has a large surface roughness or is scratched, the coating, particularly the water-soluble resin layer provided in contact with the substrate film, remains, resulting in a decrease in quality when the substrate film is recycled into chips. Therefore, an object of the present invention is to provide a coating peeling device and a coating peeling method that can reduce the amount of coating remaining on the substrate film.

[0006] [1] A coating peeling device of the present invention that solves the above-mentioned problem is a coating peeling device that peels a coating from a coated film having a coating containing a water-soluble resin on at least one surface of a base film, and includes: a conveying mechanism that conveys the coated film; a cleaning liquid application mechanism that applies a cleaning liquid to the surface of the coating; a coating peeling mechanism that is arranged downstream in the conveying direction from the cleaning liquid application mechanism and peels the coating containing the cleaning liquid from the coated film having the cleaning liquid applied to the surface of the coating; a cleaning liquid re-application mechanism that is arranged downstream in the conveying direction from the coating peeling mechanism and applies a cleaning liquid to the surface of the coating remaining on the base film; and a suction mechanism that is arranged downstream in the conveying direction from the cleaning liquid re-application mechanism and sucks up residue of the coating remaining on the base film together with the cleaning liquid.

[0007] The coating peeling device of the present invention is preferably any one of the following [2] to [4]. [2] The coating peeling device according to [1] above, wherein the suction mechanism is a suction roll having a tubular roll shaft with a large number of holes formed therein and a nonwoven fabric layer provided on the outer periphery of the roll shaft. [3] The coating peeling device according to [1] or [2] above, wherein the suction mechanism comprises a speed adjustment mechanism for adjusting the rotation speed of the suction roll. [4] The coating peeling device according to [2] or [3] above, wherein the suction mechanism comprises a back roll positioned opposite the suction roll across the coated film, and a nip mechanism for pressing the suction roll and / or the back roll against the coated film.

[0008] [5] Furthermore, a coating peeling method of the present invention that solves the above problem is a method of peeling a coating containing a water-soluble resin from a coated film having a substrate film on at least one side thereof using the coating peeling device described in any of [1] to [4] above, in which the cleaning liquid is applied to the surface of the coating while the coated film is being transported, the coating peeling mechanism is brought into contact with the surface of the coating to peel off the coating containing the cleaning liquid, and then the cleaning liquid is applied to the surface remaining on the substrate film, and the residue of the coating remaining on the substrate film is removed by suction together with the cleaning liquid. The coating peeling method of the present invention is preferably the following [6]. [6] The coating peeling method described in [5] above, in which the coating contains cured silicone.

[0009] According to the coating peeling device and coating peeling method of the present invention, it is possible to reduce the amount of coating remaining on the substrate film and obtain high-quality recycled chips.

[0010] Fig. 1 is a schematic diagram of a coating peeling device according to an embodiment of the present invention. Fig. 2 is a cross-sectional view parallel to the film width direction of a suction mechanism used in Fig. 1. Fig. 3 is a schematic diagram of a coating peeling device according to a first modified embodiment of the present invention. Fig. 4 is a schematic diagram of a coating peeling device according to a second modified embodiment of the present invention.

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description is merely an example of an embodiment of the present invention, and the present invention is not limited thereto, and various modifications and combinations are possible without departing from the spirit of the present invention.

[0012] 1 is a schematic diagram of a coating peeling apparatus 100 of the present invention. The coating peeling apparatus 100 includes an unwinding device 10 that unwinds a film 1 having a coating 3 on one side of a substrate film 2 (hereinafter, sometimes referred to as a coated film), a winding device 20 that winds up the substrate film 2 after the coating 3 on the surface of the coated film 1 has been peeled off, and drive devices 30-1 and 30-2 that transport the film in the direction of arrow X while applying tension to the film. The coating peeling apparatus 100 further includes, between the drive devices 30-1 and 30-2, a cleaning liquid application mechanism 40 that applies cleaning liquid 41 to the surface of the coating 3 of the coated film 1, a coating peeling mechanism 50 that is arranged downstream in the transport direction from the cleaning liquid application mechanism 40 and that peels the coating 3 containing the cleaning liquid 41 from the coated film 1 to which the cleaning liquid 41 has been applied, a cleaning liquid re-application mechanism 60 that is arranged downstream in the transport direction from the coating peeling mechanism 50 and that applies cleaning liquid 61 to the surface of the coating 3 remaining on the substrate film 2, a suction mechanism 70 that is arranged downstream in the transport direction from the cleaning liquid re-application mechanism 60 and that sucks up the residue of the coating 3 remaining on the substrate film 2 together with the cleaning liquid 61, rollers 81, 82, 83, 84, and 85 that adjust the transport direction of the coated film 1 or the substrate film 2, and a suction member 90 that sucks up the coating 3 that is the peeled material peeled off by the coating peeling mechanism 50. The coating peeling apparatus 100 according to this embodiment will now be described.

[0013] [Coated Film] In the coating peeling apparatus 100 of the present invention, the coated film 1 to be peeled has a coating 3 on at least one surface of a substrate film 2. The coated film 1 to be peeled is a coated film having a coating containing a water-soluble resin that takes into consideration environmental impact, etc. Among these, water-soluble resins are more preferably 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 a main component. 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.

[0014] Furthermore, 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 the cleaning liquid, i.e., reduces the surface energy of the coating. Examples include curable silicone resin compounds with a dimethylsiloxane main skeleton, compounds with a long-chain alkyl group, and compounds with fluorine. The coating may be a layer containing a water-soluble resin and a release component, or a layer containing a water-soluble resin and a layer containing a release component 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 as the release component, which has high water permeability and can be suitably used as a cleaning liquid.

[0015] [Coating Peeling Device] The driving devices 30-1 and 30-2 are preferably configured to be able to cut tension so as to stably transport the coated film 1 and the base film 2 from which the coating 3 has been peeled. If tension is cut using a suction roll, part of the coating of the coated film 1 may be sucked in, which may cause problems, so a configuration in which the driving device is nipped between a metal driving roll and a rubber roll is more preferably used. The driving devices 30-1 and 30-2 are preferably made of stainless steel or have been surface-treated to prevent rust.

[0016] The cleaning liquid application mechanism 40 has a discharge nozzle that discharges the cleaning liquid 41, a liquid feed pump that sends the cleaning liquid 41 to the discharge nozzle, and a tank that stores the cleaning liquid 41. The amount of cleaning liquid applied to the coating surface of the coated film 1 is set to 1 cm so as to be able to sufficiently dissolve at least a portion of the components of the coating. ３ / m ２It is preferable that the above be possible, and the specifications of the discharge head and liquid feed pump should be determined so that the liquid feed pump can be adjusted according to the transport speed of the coated film 1 and the required amount of cleaning liquid 41 can be applied to the coating surface of the coated film 1. The discharge nozzle may be any nozzle capable of applying cleaning liquid 41 to the coating surface of the coated film 1, and examples thereof include a spray nozzle, a shower head nozzle, and a high-pressure water jet nozzle. The cleaning liquid application mechanism 40 may be any nozzle capable of applying cleaning liquid 41 to the coating surface of the coated film 1, and may have a liquid tank that stores cleaning liquid 41, and the cleaning liquid 41 may be applied to the coating surface by immersing the coated film 1 in the liquid tank.

[0017] The cleaning liquid 41 used in the coating peeling apparatus 100 can be any solvent capable of dissolving at least a portion of the components of the coating, but water is preferred to reduce environmental impact. A surfactant or the like may be added to the cleaning liquid 41 to improve wettability with the coated film and facilitate spreading of the cleaning liquid 41 over the coating surface. To quickly dissolve at least a portion of the components of the coating, it is preferable to apply a heated cleaning liquid 41 to the coating surface of the coated film 1. When a discharge head is used, the discharge head may be equipped with a heat source such as a cartridge heater, or the tank storing the cleaning liquid 41 may be heated. When a liquid tank is used, the liquid tank may be heated, or an immersion heater may be installed inside the liquid tank. Any means capable of heating the cleaning liquid 41 may be used, and is not limited to these.

[0018] The coating peeling mechanism 50 has a tip 51 that extends in a ridge-like shape in the film width direction and contacts the surface of the coating 3 of the coated film 1 to peel off the coating 3. The tip 51 is composed of an upstream surface 52 in the film transport direction, a downstream surface 53 in the film transport direction, and a side surface between the upstream surface 52 and the downstream surface 53. The downstream surface 53 in the film transport direction has a slope 53a to make the tip 51 acute-angled. The coating peeling mechanism 50 is preferably made of metal, but is not limited to this and may be made of resin. The coating peeling mechanism 50 is installed facing the coating surface of the coated film 1.

[0019] The suction member 90 sucks the coating 3, which is the peeled material peeled off by the coating peeling mechanism 50. To improve the removability of the coating 3 from the coated film 1, it is necessary to press the leading end 15 firmly against the coated film 1. In this embodiment, the conveying direction of the coated film 1 is adjusted by the rollers 81 and 82 to reduce the angle θ between the coated film 1 and the base film 2, thereby firmly pressing the leading end 51 against the coated film 1. If the angle θ between the coated film 1 and the base film 2 is reduced, the removability by the coating peeling mechanism 50 is improved, but the removed coating 3 may re-adhere to the base film 2. Therefore, it is preferable to suction and remove the peeled coating 3 using the suction member 90. The rollers 81, 82, the coating peeling mechanism 50, and the suction member 90 are surrounded by a booth 91. When a heated cleaning liquid 41 is used to quickly dissolve at least a portion of the components of the coating 3, it is preferable to also surround the cleaning liquid application mechanism 40 with a booth 91 to keep it warm and moist.

[0020] The cleaning liquid re-application mechanism 60 has a discharge nozzle that discharges the cleaning liquid 61 and a liquid feed pump that feeds the cleaning liquid 61 to the discharge nozzle. Furthermore, similar to the cleaning liquid application mechanism 40, it may have a tank that stores the cleaning liquid 61. The cleaning liquid 61 may be any solvent that can dissolve at least a portion of the components of the coating 3, and may be the same as or different from the cleaning liquid 41. However, in order to reduce the environmental impact, it is preferable to use water. The amount of cleaning liquid 61 applied to the coating surface of the substrate film 2 may be an amount that can dissolve the coating 3 remaining on the substrate film 2. Furthermore, in order to improve the performance of removing the remaining coating 3, it is preferable to apply a heated cleaning liquid 61 to the surface of the substrate film 2.

[0021] The suction mechanism 70 sucks the residue of the coating 3 remaining on the substrate film 2 together with the cleaning liquid 61 applied to the substrate film 2 by the cleaning liquid re-application mechanism 60. A suction roll or the like can be used as the suction mechanism 70. Figure 2 is a cross-sectional view parallel to the film width direction of the suction mechanism 70 used in Figure 1. The suction mechanism 70 is composed of a tubular main body 71 having a hollow portion 72 therein and a roll layer 75 made of nonwoven fabric provided on the outer periphery of the main body 71.

[0022] The main body 71 has joints 73a, 73b at both ends, with the joint 73b at one end being closed and the joint 73a at the other end being connected to a suction device such as a vacuum pump. The main body 71 is made of a metal material such as iron, SUS, or aluminum, and has a plurality of circular holes 74 perforated in a staggered pattern around its outer periphery. The cleaning solution 61 containing the components of the coating 3 absorbed by the roll layer 75 is discharged from the joint 73a to the outside of the suction mechanism 70 via the holes 74 and the hollow portion 72. Alternatively, the joint 73b may be left unclosed and connected to a blower or the like, allowing air to be intermittently introduced through the joint 73b to promote drainage of the liquid from the hollow portion 72. Furthermore, in the above embodiment, the cross section of the hollow portion 72 perpendicular to the central axis of the main body portion 71 is cylindrical and remains the same from the joint portion 73a side to the joint portion 73b side, but it may also be conical in shape with the cross section becoming larger toward the joint portion 73b side.

[0023] FIG. 3 is a schematic diagram of a coating peeling apparatus 100A according to a first modification of the present invention. The roller 84 is disposed opposite the suction mechanism 70, sandwiching the substrate film 2 therebetween. As shown in FIG. 3, the roller 84 is preferably provided with a nip mechanism 86. By applying a pressing force to the substrate film 2 using the nip mechanism 86, the amount of cleaning liquid 61 containing the remaining coating 3 that can be sucked by the suction mechanism 70 can be increased. Furthermore, the effect of blocking the cleaning liquid 61 containing the coating 3 from flowing downstream in the conveying direction from the suction mechanism 70 is enhanced. A cylinder or the like can be used as the nip mechanism 86. The nip mechanism 86 may be disposed on the suction mechanism 70 side instead of the roller 84 side, or may be disposed on both the roller 84 and the suction mechanism 70.

[0024] The rollers 83 and 85 adjust the conveyance direction of the base film 2 and change their relative positions with the suction mechanism 70 to adjust the contact area between the base film 2 and the suction mechanism 70. The suction mechanism 70 is preferably rotated around the central axis of the main body 71. When rotating, the suction mechanism 70 rotates in the same direction as the conveyance direction of the base film 2 at a peripheral speed substantially equal to the conveyance speed. This allows the base film 2 to be stably conveyed without slack or excessively high tension occurring in the base film 2 before or after the suction mechanism 70. The peripheral speed of the suction mechanism 70 may be either free rotation or driven rotation, as long as it is substantially equal to the conveyance speed of the base film 2. In the case of driven rotation, a speed adjustment mechanism for adjusting the rotation speed of the main body 71 of the suction mechanism 70 is preferably provided. The rollers 83 to 85, the cleaning liquid re-application mechanism 60, and the suction mechanism 70 are surrounded by a booth 92.

[0025] Fig. 4 is a schematic diagram of a coating peeling apparatus 100B according to Modification 2 of the present invention. This coating peeling apparatus 100B differs from the coating peeling apparatus 100 shown in Fig. 1 in that it does not have roller 84, which was disposed opposite suction mechanism 70 across base film 2, and instead changes the relative positions of rollers 83 and 85 and suction mechanism 70 to increase the contact area between base film 2 and suction mechanism 70.

[0026] Because the coating peeling device 100B does not have a roller 84, it is possible to intentionally slide the substrate film 2 on the suction mechanism 70 while transporting it, thereby creating a relative speed difference between the transport speed of the substrate film 2 and the peripheral speed of the suction mechanism 70. This creates a state in which the suction mechanism 70 is wiping the surface of the substrate film 2. Furthermore, by increasing the relative speed difference, the wiping distance per unit time increases. Furthermore, by increasing the contact area, the suction section increases, which tends to improve the ability to remove the cleaning solution 61 containing the components of the coating 3. However, if the suction mechanism 70 has a strong holding force on the substrate film 2 and the substrate film 2 does not slide easily, slack or extremely high tension may occur in the substrate film 2 before and after the suction mechanism 70, which may interfere with transport. Therefore, it is preferable to determine the relative speed difference and contact area while checking the transport state of the substrate film 2. Furthermore, it is preferable to determine the rotation direction of the suction mechanism 70 while checking the transport state of the base film 2, and the rotation direction may be either the same direction as the transport direction or the opposite direction as long as a relative speed difference occurs.

[0027] In addition, in the coating peeling devices 100, 100A, and 100B, an inspection machine (not shown) for detecting residues of the coating 3 or environmental contaminants attached during the process may be provided before the winding device 20 in order to confirm the quality of the substrate film 2 from which the coating 3 has been peeled by the coating peeling mechanism 40. The inspection machine may be selected according to the properties of the substrate film 2, and an inspection machine using transmitted light or reflected light is preferably used. Furthermore, a marking device (not shown) for recording the location of the coating residue or environmental contaminants attached during the process detected by the inspection machine may be provided between the inspection machine and the winding device 20. The marking method used by the marking device may be any method capable of marking the position of the detected object, such as a pen, sticker, or laser. Marking the residues of the coating or environmental contaminants attached during the process allows the locations to be removed before remelting, thereby enabling more stable production of recycled film and preventing deterioration in the quality of the recycled film.

[0028] In the coating peeling devices 100, 100A, and 100B, it is more preferable to completely remove the cleaning liquid from the substrate film 2 after peeling the coating 3 taken up by the winding device 20 so that the substrate film 2 can be re-melted and stably formed into a recycled film, and a drying device (not shown) may be provided between the suction mechanism 70 and the winding device 20. The drying device may be provided before winding, and may be located either before or after the drive device 30-2.

[0029] The coating peeling device and coating peeling method of this embodiment can remove the coating remaining on the substrate film by applying cleaning liquid again and then removing the cleaning liquid containing the coating using a suction mechanism, making it possible to obtain recycled chips with no remaining coating and excellent quality.

[0030] REFERENCE SIGNS LIST 1 Coated film 2 Base film 3 Coating 10 Unwinding device 20 Winding device 30-1, 30-2 Drive device 40 Cleaning liquid application mechanism 41 Cleaning liquid 50 Coating peeling mechanism 51 Tip portion 52 Upstream surface 53 Downstream surface 53a Slope 60 Cleaning liquid re-application mechanism 61 Cleaning liquid 70 Suction mechanism 71 Main body portion 72 Hollow portion 73a, 73b Joint portion 74 Hole portion 75 Roll layer 81, 82, 83, 84, 85 Roller 91, 92 Booth 86 Nip mechanism 90 Suction member 91, 92 Booth 100, 100A, 100B Coating peeling device

Claims

1. A coating peeling device for peeling a coating from a coated film having a coating containing a water-soluble resin on at least one surface of a base film, comprising: a transport mechanism for transporting the coated film; a cleaning liquid application mechanism for applying a cleaning liquid to a surface of the coating; a coating peeling mechanism arranged downstream in the transport direction from the cleaning liquid application mechanism for peeling a coating containing the cleaning liquid from the coated film having the cleaning liquid applied to its surface; a cleaning liquid re-application mechanism arranged downstream in the transport direction from the coating peeling mechanism for applying a cleaning liquid to the surface of the coating remaining on the base film; and a suction mechanism arranged downstream in the transport direction from the cleaning liquid re-application mechanism for sucking in residue of the coating remaining on the base film together with the cleaning liquid.

2. The coating peeling device according to claim 1, wherein the suction mechanism is a suction roll having a tubular main body having a hollow interior and a large number of holes formed therein, and a roll layer made of nonwoven fabric provided on the outer periphery of the main body.

3. The coating peeling device according to claim 2, wherein the suction mechanism is provided with a speed adjusting mechanism for adjusting the rotation speed of the suction roll.

4. The coating peeling device according to claim 2, wherein the suction mechanism comprises: a back roll arranged in a position opposite the suction roll across the coated film; and a nip mechanism that presses the suction roll and / or the back roll against the coated film.

5. A method for peeling a coating from a coated film having a coating containing a water-soluble resin on at least one side of a base film, using a coating peeling device according to any one of claims 1 to 4, comprising the steps of: applying the cleaning liquid to a surface of the coating while transporting the coated film, bringing the coating peeling mechanism into contact with the surface of the coating to peel off the coating containing the cleaning liquid, and then applying the cleaning liquid to the surface remaining on the base film, and removing the residue of the coating remaining on the base film together with the cleaning liquid by suction.

6. The method of claim 5, wherein the coating comprises a cured silicone.

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