Coat removal device and coat removal method

Abstract

To provide a coat removal device capable of efficiently and uniformly removing a coat from a substrate film with the coat.SOLUTION: A removal device of the present invention is a device for removing a coat from a film with a coat having a coat on at least one side of the substrate film, and comprises: a removal member used in contact with a surface of the film with the coat in order to remove the coat; a drive device for relatively moving the film with the coat relative to the removal member in the longitudinal direction of the film with the coat; and a vibration suppression member provided at a position opposite to the removal member with sandwiching the film with coat and suppressing the vibration of the film with the coat when the film with coat relatively moves to the removal member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for removing a coating on the surface of a thermoplastic resin film, which can be efficiently and uniformly removed. [Background technology]

[0002] While plastics are used in a variety of fields, they are also considered to be a cause of marine pollution, particularly in the form of microplastics, and there is an urgent need to reduce the environmental impact of plastics.

[0003] In recent years, the evolution of IoT (Internet of Things) has led to an increase in electronic devices such as CPUs installed in computers and smartphones, and the number of multilayer ceramic capacitors (MLCCs) required to drive these electronic devices has also increased rapidly. A typical manufacturing method for MLCCs involves using a release film, which is a plastic base film with a release layer formed on it, as a carrier sheet, forming a ceramic green sheet layer on the release film, and removing the ceramic green sheet layer to obtain a ceramic green sheet. In this process, the release film from which the ceramic sheet has been removed is discarded as waste.

[0004] That is, the increase in waste of release films due to the recent rapid increase in the number of MLCCs has become an environmental problem, and efforts to reuse plastic base films have become active. From the viewpoint of releasability, 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, so if a release film with a release layer is remelted as it 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 method for removing release components from a release film, in which a release film having a water-soluble resin layer formed between a base film and a release layer is used, and the release film is immersed in a hot water bath for 2 seconds or more, and then the release layer is removed by rubbing the surface of the release film with a brush roll.

[0006] Patent Document 2 discloses a method for removing a coating from a substrate film having a coating formed by coating, which includes an apparatus having a dissolution tank that stores an organic solvent and a scraper that is installed at the bottom of the dissolution tank and can come into contact with the coating surface, thereby dissolving and removing the coating from the substrate film having the coating that is being transported. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2004-363140 A [Patent Document 2] JP 2021-146682 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the coating removal method disclosed in Patent Document 1 has a problem that the water-soluble resin layer dissolves in the hot water tank, so that the resin concentration in the hot water increases over the treatment time, and the initial removal ability cannot be continuously demonstrated. Even if a method of increasing the water supply is adopted to suppress the increase in the resin concentration, the amount of wastewater increases together with the amount of water supply, which not only significantly increases the cleaning cost but also increases the environmental load.

[0009] In addition, the method of removing the coating disclosed in Patent Document 2 uses an organic solvent to dissolve and remove the coating, and as in Patent Document 1, a large amount of organic solvent is required to continue to exhibit the initial removal ability, which causes a problem of significantly increasing the environmental load. In addition, the scraper provided at the bottom of the dissolution tank is in direct contact with the coating surface of the substrate film having the coating being transported, and the device is configured to scrape off the coating. However, since the substrate film is transported through the liquid, when the coating is scraped off with the scraper, the organic solvent is likely to be interposed between the coating surface and the scraper, and sufficient scraping ability may not be obtained. In order to improve the scraping ability, it is conceivable to make the angle between the film surface on the upstream side and the downstream side of the substrate film transport direction an acute angle through the scraper, but since it is necessary to deepen the dissolution tank, the volume of the dissolution tank increases, which further increases the amount of organic solvent used, which further worsens the environmental load.

[0010] In order to make a compact device, it is preferable to omit large equipment such as a dissolution tank, and a removal process in the atmosphere has been desired as an alternative to a removal process in a liquid that requires a large device. However, in a removal process in the atmosphere, the film being transported is prone to membrane vibration, and removal residues are likely to remain due to poor removal caused by the vibration, so the development of a removal method that can remove the coating efficiently and uniformly has been desired.

[0011] In this regard, both Patent Document 1 and Patent Document 2 assume that the area where the removal process is performed is in liquid, so that when the removal process is performed while transported in the air, the film undergoes minute vibrations, which can cause unevenness in the removal state, and the measures taken to prevent uneven removal are insufficient.

[0012] Therefore, the present invention provides a coating removal device and a coating removal method that can efficiently and uniformly remove a coating from the surface of a base film having a coating on one side, even when the treatment is performed in air, in order to obtain a base film that can be stably produced into a recycled film even when remelted from a base film having a coating after use. [Means for solving the problem]

[0013] [1] The coating removal device of the present invention that solves the above problems is a device for removing a coating from a coated film having a coating on at least one surface of a base film, the device comprising: a removal member that is used in contact with a surface of the coating of the coated film to remove the coating; a drive device for moving the coated film relative to the removal member in a longitudinal direction of the coated film; and a vibration suppression member that is provided on the opposite side of the coated film from the removal member and that suppresses vibration of the coated film when the coated film moves relative to the removal member.

[0014] [2] The coating removal device of [1] above is preferably used in such a manner that the direction in which the coated film moves relative to the removal member is the transport direction, and the vibration damping member is in contact with the coated film, and the coated film is preferably arranged so that the longitudinal length of the coated film from the contact point between the coated film and the removal member upstream in the transport direction to the contact point between the coated film and the vibration damping member upstream in the transport direction is in the range of 0.00 to 0.10 m.

[0015] [3] The coating removal device of the above [1] or [2], wherein the vibration suppressing member is 1×10 -5 ~5×10 -2 It is preferable that the electrodes are arranged so as to be in contact with each other over a length in the range of m.

[0016] [4] In any of the coating removal devices [1] to [3] above, the vibration suppressing member is used in contact with the coated film, and it is preferable that the JIS-A hardness of the portion that contacts the surface of the coated film is in the range of 5 to 65°.

[0017] [5] In any one of the coating removal devices [1] to [4] above, the vibration suppressing member is preferably in the form of a roller.

[0018] [6] It is preferable that any of the coating removal devices [1] to [5] above includes a tensioning mechanism adjusted to apply a tension in the range of 10 to 1000 N / m to at least one longitudinal direction of the coated film, and that the removal member is positioned such that, when observed from the width direction of the coated film, the angle between the removal member and the coated film is in the range of 20 to 150°.

[0019] [7] In the coating removal device according to any one of [1] to [6] above, a direction in which the coated film moves relatively to the removal member is defined as a transport direction, and a cleaning solution mainly composed of water is provided on the coating on the upstream side of the removal member in the transport direction. 2 It is preferable to provide a water supplying mechanism adjusted to supply an amount in the range of 3 to 650 ml per unit time.

[0020] [8] A coating removal method of the present invention that solves the above problem is a method for removing the coating using the coating removal device described in [7] above, wherein the coating includes a layer made of a water-soluble resin.

[0021] [9] A method for removing the coating using the coating removal device according to [3] above, or a coating removal method according to [8] above, in which the outermost layer of the coating is a layer made of a water-insoluble resin.

[0022] Before the removal member comes into contact with the film, it is a "substrate film having a coating", i.e., a "coated film", and after the removal member comes into contact with the film, it is a "substrate film from which the coating has been removed". However, in order to avoid complicating the explanation, in this application, the film may be described as a "coated film" both before and after the removal member comes into contact with the film. Effect of the Invention

[0023] According to the coating removal device and coating removal method of the present invention, a coating can be efficiently and uniformly removed from a coated film having a coating on at least one surface of a substrate film. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic diagram of a removal device according to one embodiment of the present invention; [Diagram 2] 1 is a schematic cross-sectional view of the vicinity of a removal member in a removal device according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present inventors have conducted extensive research into methods for efficiently and uniformly removing a coating from the surface of a coated film having a coating on one side of a base film, and as a result have discovered the following coating removal apparatus and coating removal method.

[0026] [Applicable coated films] The coating removal device for removing a coating from a coated film of the present invention is a device for removing and cleaning a coating from a coated film having a coating on at least one side of a base film. The coating may be present on one or both sides of the base film, and is not particularly limited.

[0027] The material of the coating is not particularly limited, but in consideration of the burden on the environment, a coating containing a water-soluble resin that can be removed with water is preferable. Among them, as the water-soluble resin, a resin containing at least one of water-soluble polyester resin, polyester urethane resin, acrylic resin, ethylene ionomer resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, ethylene-vinyl alcohol resin, and starch as a main component is more preferable.

[0028] 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.

[0029] In addition, a release film with a coating containing a release component in addition to a water-soluble resin in a part of the coating is particularly preferred, and the effect of removing the coating can be efficiently exhibited. The release component here is 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 a heat-curable silicone resin compound having dimethylsiloxane as the main skeleton, which is a curable silicone resin, a UV-curable silicone resin compound in which a photopolymerization initiator is blended with an organopolysiloxane containing an acryloyl group or a methacryloyl group and cured by irradiating UV light, a compound having a long-chain alkyl group, and a compound having 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, and it is particularly preferable to use a heat-curable silicone resin compound having dimethylsiloxane as the main skeleton, which has high water permeability, as the release component.

[0030] [Coating removal equipment for coated films] The coating removal device of the present invention is a coating removal device that removes the coating from the coated film by contacting a removal member with the coating surface of the coated film and moving the coated film in its longitudinal direction relative to the removal member.

[0031] When the coating contains a water-soluble resin, it is more preferable to provide a mechanism for applying a cleaning liquid containing water as a main component to the coating surface of the coated film and then contacting the above-mentioned removal member with the surface of the coating to which the cleaning liquid has been applied.

[0032] The method of applying the cleaning liquid to the coating surface may be any method. For example, the cleaning liquid may be applied in the form of droplets using a spray nozzle, or a high-pressure or high-temperature cleaning liquid may be applied using a high-pressure cleaner or steam generator. The amount of the cleaning liquid applied is preferably adjusted appropriately depending on the properties and thickness of the coating to be removed, and is preferably properly controlled by the method of applying the cleaning liquid. For example, the cleaning liquid may be controlled by sending it with a metering pump, a flow meter may be installed in the middle of the flow path through which the cleaning liquid is sent, or the cleaning liquid applied to the coating surface may be collected and the mass may be measured. Alternatively, when the water-soluble resin contains the cleaning liquid and it is difficult to measure the mass, the coated film, the applied cleaning liquid, and the coating after removal may all be collected to calculate the amount of the cleaning liquid applied.

[0033] As a result of extensive research by the present inventors, it was found that the thickness of the coating containing the water-soluble resin was 20×10 -6 When the thickness is between 1.0 mm and 1.0 mm, the amount of cleaning solution applied is 1 m 2 It was confirmed that the coating removal effect can be obtained by using 3 ml or more per 1 m of surface area of ​​the coating. 2 It has been confirmed that if the amount of cleaning liquid applied is less than 3 ml per m, the effect of film removal may be reduced, and particularly when the humidity of the surrounding environment is low, the cleaning liquid may dry out before it can dissolve or swell the film containing the water-soluble resin, making it impossible to obtain the effect of film removal. The more the amount of cleaning liquid applied, the more reliably the film containing the water-soluble resin can be dissolved or swelled, improving the effect of film removal. On the other hand, if the amount of cleaning liquid applied is more than 1 ml per m, 2 If the amount of cleaning solution applied exceeds 650 ml per unit time, the amount of cleaning solution required for cleaning will be equal to or greater than that required for cleaning using a dissolution tank or the like in the prior art, which would undermine the significance of the present invention of efficiently removing the coating with a small amount of wastewater. Therefore, it is preferable that the upper limit of the amount of cleaning solution applied is 650 ml or less.

[0034] When the coating removal device of the present invention is provided with a mechanism for applying a cleaning liquid, any solvent capable of dissolving the water-soluble resin can be used as the cleaning liquid to achieve its effect, but in order to reduce the environmental impact, it is preferable to use water. Also, by adding a surfactant or the like to a water-based solvent, the wettability between the cleaning liquid and the coating surface can be improved, and the cleaning liquid can be more easily distributed over the entire coating.

[0035] The removal member in the coating removal device of the present invention may be, but is not limited to, a scraper, a fabric, a metal plate, a rotating brush roll, etc., and may be in any form as long as it can directly contact the coated film and physically remove the coating. The removal member is preferably in direct contact with the surface of the coated film having the coating so as to be pressed into the film, and the coating can be removed from the coated film by bending or curving the coated film with the removal member and moving the coated film in its longitudinal direction relative to the removal member while maintaining the bent or curved state. The coated film in the bent or curved state is preferably arranged so that the angle between the coated film sandwiching the removal member is in the range of 20 to 150° when observed from the width direction, and preferably includes a tension imparting mechanism adjusted to impart tension in the range of 10 to 1000 N / m in at least one longitudinal direction. This allows the removal member to be pressed strongly against the coating surface of the coated film, making it possible to efficiently and uniformly remove the coating dissolved or swollen by the cleaning liquid. Therefore, the smaller the area of ​​contact of the removal member with the coated film, the more strongly the removal member can be pressed locally against the coating surface of the coated film, which is preferable, and among the removal members exemplified above, a scraper or a corner of a metal plate is preferably used.

[0036] It is preferable that the angle between the coated film and the removal member is 20° or more, since the space for installing the removal member is wider. On the other hand, it is preferable that the angle is 150° or less, since the force pressing the removal member against the coating surface of the coated film can be maintained strong. It was confirmed that the strong pressing force can easily suppress air from being entrained between the base film and the removal member when tension fluctuation occurs when the coated film and the removal member are moved relatively in the longitudinal direction of the coated film, or when the removal speed is increased, and that it can suppress a part of the coating from slipping through and remaining on the base film without being removed.

[0037] It was confirmed that the effect of coating removal is achieved by applying a tension of 10 N / m or more in at least one direction of the length of the coated film. By applying a tension of 10 N / m or more, the coated film can be stably transported without slackening when transported, and it is possible to prevent the tension from fluctuating excessively or meandering during transport, which can cause unstable coating removal. On the other hand, by applying a tension of 1000 N / m or less, the coated film is not pulled excessively strongly in one direction, so that it is possible to prevent multiple galvanized iron wrinkles extending in the length direction of the film from occurring in the width direction. If multiple galvanized iron wrinkles occur in the width direction, some of the galvanized iron wrinkles will become folded at the points where they come into contact with the removal member, and the removability of the coating will be impaired at the folded wrinkles, but this can be prevented.

[0038] The coating removal device of the present invention is a device for removing a coating from a coated film by moving the coated film having the above-mentioned preferred form relative to the removal member in its longitudinal direction. Any means may be used to move the coated film relative to the removal member, and the removal member may be fixed and only the coated film may be transported, or the removal member may be made to travel relative to the stationary coated film. Alternatively, both the removal member and the coated film may be moving, and both may move in the same direction or in different directions. When transporting the coated film, it is preferable to keep the tension applied to the coated film constant, and it is also preferable to keep the tension constant even when the transport speed of the coated film is changed or transport is stopped and started repeatedly.

[0039] When the coated film in question has a coating that is continuous or intermittent across the longitudinal direction of the base film, it is preferable to have a method of transporting the coated film and removing the coating with a removal member that extends and is fixed in the transverse direction of the coated film.

[0040] In particular, when the coated film has a coating intermittently in the longitudinal direction of the substrate film, or when the amount of the coating formed on the substrate film varies across the longitudinal direction of the substrate film, it is preferable to provide a mechanism for appropriately adjusting the conveying speed of the coated film so that the time for the coating to be dissolved or swelled by the cleaning liquid or the time for the portion having the coating to come into contact with the removal member can be changed by varying the conveying speed of the coated film, thereby making it possible to more efficiently remove the coating. The time for the coating to be dissolved or swelled, i.e., the time from the application of the cleaning liquid to the removal of the coating by the removal member, is preferably appropriately determined depending on the properties of the coating, but is preferably set to 0.05 to 10 seconds in consideration of the size of the device, etc.

[0041] In addition, when the coated film has coatings at regular intervals in the longitudinal direction of the base film, a mechanism may be provided for removing the coating by stopping or changing the conveying speed after conveying the coated film for a certain length and moving the removal member relative to the portion of the coated film where the coating is present, and after removing the coating, the conveying may be restarted or the conveying speed may be restored, which may allow for highly efficient and uniform coating removal. It is also preferable to provide a mechanism for stopping the conveying or changing the conveying speed during the coating removal process to check the base film after the coating has been removed and whether any coating remains. The inspection mechanism may be any type as long as it can detect the remaining coating.

[0042] The coating removal device of the present invention is provided with a vibration suppression member, located on the opposite side of the coated film from the removal member, for suppressing vibration of the coated film when the coated film moves relative to the removal member.

[0043] A vibration suppression member is a member for absorbing, blocking, or offsetting vibrations that are generated at a vibration source and propagate to attenuate the vibrations. For attenuation by absorbing vibrations, a material with a large loss tangent, such as an elastomer, is preferably used. In particular, a material that maintains a high loss tangent over a wide frequency band is more preferable because it can absorb vibrations without any change even if the transport speed of the coated film changes and the vibration period changes.

[0044] Considering that the source of vibration in the coating removal device of the present invention is the contact point between the removal part and the film, it is substantially difficult to block the propagation of vibration to the film.

[0045] Vibration cancellation is a method of attenuating vibration by applying vibrations of opposite phase to the vibration of the film to the vibrating film, and examples of such methods include a non-contact method of irradiating sound waves, a method of pressing a contact type vibrator against the film, etc. In order to control the frequency of the applied vibration, it is preferable that the vibration suppression member has a mechanism for measuring the vibration frequency of the film and feeding it back to the output frequency.

[0046] When the vibration damping member absorbs vibrations, the vibration damping member is used in contact with the coated film, and is preferably arranged so that the length of the coated film in the longitudinal direction from the contact point between the coated film and the removal member on the upstream side in the transport direction to the contact point between the coated film and the vibration damping member on the upstream side in the transport direction is in the range of 0.00 to 0.10 m. By having the length in the range of 0.00 to 0.10 m, the frequency of vibration of the coated film falls within a range that can be easily absorbed by the vibration damping member, and vibrations can be suppressed more effectively, allowing the coating to be removed more reliably and uniformly.

[0047] By setting the length to 0.10 m or less, it is possible to prevent the vibration suppression member from being too far away from the removal member, which can result in insufficient vibration suppression effect and therefore insufficient removal of the coating in some areas across the width of the film.

[0048] The vibration suppression material is a film with a coating and a 1×10 -5 ~5×10 -2 It is preferable that the contact length is in the range of 1×10 -5 ~5×10 -2 By setting the contact length in the range of 1×10 -5 By setting the contact length to 5×10 or more, it is possible to prevent the film from instantly separating from the vibration suppressing member even if the film vibrates in a direction perpendicular to the film surface while being transported, thereby improving the uniformity and stability of the coating removal. -2By keeping the contact length at 1×10 m or less, it is possible to prevent the interface friction between the film and the vibration suppression member from becoming too high during transport, and to prevent the loss of uniformity in coating removal due to poor transport caused by friction. -4 m is more preferable, with an upper limit of 1×10 -2 m is more preferred.

[0049] When the vibration suppressing member is used in contact with a coated film, the JIS-A hardness of the portion in contact with the surface of the coated film is preferably in the range of 5 to 65°. When the JIS-A hardness is in the range of 5 to 65°, a high loss tangent is maintained in a wide frequency band as described above, and the film deformation caused by vibration can be followed, enabling more uniform removal of the coating. When the hardness is 5° or more, the vibration suppressing member can be prevented from being deformed during transportation, and the increase in interfacial friction caused by the deformation can be prevented from causing transportation problems and impairing the uniformity of the coating removal. When the hardness is 65° or less, vibrations in a wide frequency band can be absorbed, and high coating removability can be maintained even when the transportation speed is changed.

[0050] The vibration suppression member is preferably in the form of a roller. The roller shape allows the shear force in the transport direction that occurs with the transport of the film to be dissipated by the rotation of the roller, and the vibration suppression function can be fully exerted. In addition, the rotation of the roller also has the effect of stretching and reducing wrinkles that occur in the film during the film transport, and the deterioration of removability due to wrinkles that occur in the film can be suppressed.

[0051] A preferred embodiment of the coating removal device of the present invention will be described with reference to the drawings. Note that the following description is merely an example of one embodiment of the present invention, and the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0052] FIG. 1 is a schematic diagram of a coating removal apparatus 101 according to one embodiment of the present invention. The coating removal apparatus 101 includes an unwinding device 3 that unwinds a coated film 1 and a winding device 4 that winds up a base film 2 after the coating has been removed. Between the unwinding device 3 and the winding device 4, the coating removal apparatus 101 includes a drive device 5 for transporting the coated film 1, a discharge head 7 as a cleaning liquid application mechanism for applying cleaning liquid 8 to the coating of the coated film 1, a removal member 10 for removing the coating of the coated film 1, a vibration suppression member 12 located on the opposite side of the removal member 10 with the coated film 1 sandwiched therebetween, and a drive device 6 for transporting the base film 2 after the coating has been removed. In addition to the discharge head 7, the cleaning liquid application mechanism also includes a liquid delivery pump 9 for delivering cleaning liquid 8 to the discharge head 7, and a tank (not shown) for storing the cleaning liquid.

[0053] The coated film is transported by the driving devices 5 and 6, and the coated film moves in the transport direction a relative to the removal member 10. The driving devices 5 and 6 are preferably configured to be capable of cutting tension so as to stably transport the coated film. When tension cutting is performed using a suction roll, a part of the coating of the coated film 1 may be sucked in, which may cause trouble, so a configuration in which the coated film is nipped by a metal driving roll and a rubber roll is more preferably used. The driving devices 5 and 6 also function as tension applying mechanisms. Furthermore, it is preferable that the driving rolls of the driving devices 5 and 6 are each capable of individually setting their rotation speeds, and that the driving devices 5 and 6 are provided with a mechanism (tension control mechanism) that can control the tension applied to the coated film in the longitudinal direction of the coated film by controlling the rotation speed. There is no limitation thereto as long as the driving devices 5 and 6 are provided with a mechanism that can control the tension applied to the coated film in the longitudinal direction of the coated film. In order to control the tension, it is preferable to install a tensiometer (not shown) between the drive device 5 and the removing member 10, or between the removing member 10 and the drive device 6, or both, and to provide feedback to the rotation speed of the drive rolls of the drive devices 5 and 6 so as to maintain a predetermined tension. Also, an accumulator (not shown) may be provided on the unwinding device 3 side rather than the removing member 10 so that the speed at which the coated film 1 is unwound from the unwinding device 3 can be varied to enable the coating to be removed at a constant speed even when the coated film 1 is transported intermittently for purposes such as replacing the rolled coated film 1 set in the unwinding device 3, dealing with operational problems that occur in the coating removal device 101, or inspection before coating removal.

[0054] In this embodiment, the coated film is transported by the driving devices 5 and 6, so that the coated film moves in its longitudinal direction relative to the removal member 10, but as long as the coated film can move in its longitudinal direction relative to the removal member 10, there is no need to be limited to a mechanism that transports the coated film by the driving devices 5 and 6. A mechanism for running the removal member 10 relative to a stationary coated film may be provided, or a mechanism for moving both the removal member 10 and the coated film may be used, or a mechanism for moving both in the same direction or in different directions may be used.

[0055] Furthermore, the discharge head 7 and removal member 10, which are part of the cleaning liquid application mechanism, are surrounded by a booth 11. The discharge head 7 may be any type capable of discharging the cleaning liquid 8 and applying it to the coating surface of the coated film 1, and may be, for example, a slit nozzle or a spray nozzle, but is not limited to these. The amount of cleaning liquid 8 applied to the coating surface of the coated film 1 is set to 3 to 650 ml / m so as to sufficiently dissolve the coating containing the water-soluble resin. 2 It is preferable that the amount of cleaning liquid 8 applied can be within the range of 100 to 200 mm. The specifications of the discharge head 7 and the liquid feed pump 9 are determined and adjusted so that the amount of cleaning liquid 8 required to remove the coating can be applied to the coating surface of the coated film 1. The amount of cleaning liquid 8 applied can be controlled by using a metering pump as the liquid feed pump 9, or by installing a flow meter (not shown) between the liquid feed pump 9 and the discharge head 7 and feeding back the indicated value of the flow meter. Alternatively, the discharged cleaning liquid 8 can be recovered, the amount applied can be determined from its mass, and the amount applied can be controlled by feeding back the amount to the liquid feed pump.

[0056] The discharge head 7 and the removal member 10 may be disposed opposite the coating surface of the coated film 1. In Fig. 1, the coating is laminated on the lower surface side of the base film, and the discharge head 7 and the removal member 10 are disposed opposite the lower surface side of the coated film 1, but the discharge head 7 and the removal member 10 are not limited to being disposed on the lower surface side of the coated film 1. It is more preferable that the unwinding device has a mechanism capable of handling either upward or downward unwinding so that the unwinding direction of the coated base film 1 can be switched so that the coating surface of the coated film 1 can be conveyed opposite the discharge head 7 and the removal member 10, regardless of whether the coating of the coated film 1 wound in a roll is on the inside or outside of the roll.

[0057] The discharge head 7 is preferably capable of discharging heated cleaning liquid 8 in order to quickly dissolve the water-soluble resin contained in the coating. The cleaning liquid 8 may be heated by providing a heat source such as a cartridge heater in the discharge head 7, or by heating a tank (not shown) that stores the cleaning liquid, but any means capable of heating the cleaning liquid 8 may be used, and is not limited to these. In order to more quickly dissolve the water-soluble resin contained in the coating, the cleaning liquid 8 may be discharged from the discharge head 7 in the form of steam. Since it is generally difficult to accurately measure the amount of steam discharged, it is preferable to determine the amount of cleaning liquid 8 applied by measuring the amount of liquid that has decreased in a certain period of time from a tank that stores the cleaning liquid 8.

[0058] The vibration suppression member 12 is located on the opposite side of the coated film 1 to the removal member 10, and is preferably in contact with the coated film 1 when absorbing and attenuating vibrations, but does not have to be in contact when counteracting and attenuating vibrations.

[0059] FIG. 2 is a schematic cross-sectional view of the vicinity of the removal member 10 of the first embodiment in the coating removal device 101. The removal member 10 is placed so that it directly contacts the coating surface of the coated base film 1 and the angle formed by the coated film through the removal member 10, that is, the angle (θ1+θ2) formed by the base film 2 from which the coating has been removed and the coated film 1 before the coating is removed, is in the range of 20 to 150°. If the angle is less than 20°, the removal member 10 may bend when removing the coating from the coated film 1, or may be deformed or broken if the tension applied to the coated film 1 is high, which may cause problems in removing the coating. If the angle is made larger than 150°, the force pressing the removal member 10 against the coated film 1 becomes weak, and if the coated film 1 is transported in this state to remove the coating, the coating may not be removed and a part of the coating may remain on the base film.

[0060] The tension (T1, T2) applied to the coated film in the longitudinal direction of the coated film is controlled by the above-mentioned tension control mechanism, and the tension is preferably adjustable in the range of 10 to 1000 N / m. The applied tension and the angle formed by the coated film via the removal member 10 can be adjusted according to the properties of the coating of the coated substrate film 1 to be removed. The higher the tension and the smaller the angle between the coated films, the stronger the coated film 1 can be pressed against the removal member 10, so that the coating can be removed more reliably and uniformly. However, if the pressing force is too strong, it may exceed the breaking strength of the coated film and break the coated film. If the coated film breaks, the coating cannot be removed continuously, and the operating efficiency of the coating removal device 101 is significantly reduced. After repeated investigations, the inventors confirmed that by setting the tension to 1000 N / m or less, it is possible to continuously remove the coating without breaking the coated film, even when the angle formed by the coated film is small.

[0061] As shown in FIG. 2, the removal member 10 and the vibration suppressing member 12 in the removal device 101 of the present invention are preferably arranged so that the length L1 of the coated film 1 in the longitudinal direction from the contact point p1 between the coated film 1 and the removal member 10 on the upstream side in the conveying direction to the contact point p2 between the coated film 1 and the vibration suppressing member 12 on the upstream side in the conveying direction is in the range of 0.00 to 0.10 m. By setting L1 in the range of 0.00 to 0.10 m, the vibration frequency of the coated film is in a range that is easily absorbed by the vibration suppressing member, and the vibration can be suppressed more effectively, so that the coating can be removed more reliably and uniformly. When L1 exceeds 0.10 m, the vibration frequency is lowered, so that the efficiency of absorbing vibration by the vibration suppressing member is reduced, and the force pressing the coating against the removal member 10 is weakened in some parts, and some of the coating remains. L1 is more preferably in the range of 0.00 to 0.05 m.

[0062] As shown in FIG. 2, the vibration suppressing member 12 in the removal device 101 of the present invention has a contact length L2 between the vibration suppressing member 12 and the coated film 1 of 1×10 -5 ~5×10 -2 It is preferable that the contact length L2 is in the range of 1×10 -5 ~5×10 -2 By setting the contact length L2 in the range of 1×10 -5 When the contact length L2 was less than 5×10 m, the contact area between the vibration suppression material and the film was too small, resulting in insufficient vibration suppression effect and leaving some of the coating behind. -2 When the film thickness exceeds 1×10, the shear force generated between the film and the vibration suppression member during film transport becomes too large, impairing the film transportability, causing damage to the film or wrinkles in the film, making it difficult to remove stably, and some of the coating remains. The lower limit of L2 is 1×10 -4 m is preferred, with an upper limit of 1×10 -2 m is preferred.

[0063] Contact length L2 can be adjusted as appropriate by changing the external shape of vibration damping member 12 or by changing the amount of pressure by which vibration damping member 12 is pressed against coated film 1. Note that, although Fig. 2 shows a circular cross section for the example in which vibration damping member 12 is roller-shaped, the cross section may be a shape other than a circle, such as a polygon.

[0064] The booth 11 of the removal device 101 is provided to enclose the area from the discharge head 7 to the removal member 10 in order to prevent the cleaning liquid 8 from scattering around and, when the cleaning liquid 8 is heated, to prevent the temperature of the cleaning liquid 8 from dropping. The material of the booth 11 is preferably heat resistant since the inside of the booth 11 becomes hot, and metal, glass, or the like is preferably used.

[0065] It is more preferable to completely remove moisture from the base film 2 taken up by the take-up device 4 so that it can be stably formed into a recycled film after being remelted, and a drying device (not shown) may be provided between the removing member 10 and the take-up device 4. The drying device may be provided before take-up, and may be provided either before or after the drive device 6.

[0066] In addition, in order to check the quality of the base film 2 after removing the coating, an inspection machine (not shown) for detecting the residue of the coating or environmental foreign matter attached during the process may be provided before the winding device 4. The inspection machine may be selected according to the properties of the base film 2, and an inspection machine using transmitted light or reflected light is preferably used. In addition, a marking machine (not shown) for recording the position of the residue of the coating or the environmental foreign matter attached during the process detected by the inspection machine may be provided between the inspection machine and the winding device 4. The marking method by the marking machine may be any method, such as a pen, a sticker, or a laser, as long as the position of the detection target can be marked. By marking the residue of the coating or the environmental foreign matter attached during the process, it is possible to remove the part before remelting, so that the recycled film can be produced more stably and the deterioration of the quality of the recycled film can be prevented.

[0067] In the coating removal device of the present invention, the form of the coated film may be in the form of cut sheets, but it is particularly preferred that the coated film is wound in a roll. The coated film wound in a roll is unwound, the coating is removed by the coating removal device of the present invention, and the substrate film after the coating is removed is wound up, whereby the coating removal process can be performed continuously and efficiently.

[0068] In addition, in order to more efficiently dissolve and swell the coating by the cleaning liquid 8 applied to the coating surface of the coated film, a device for exposing the layer of the coating of the coated film 1 that contains a large amount of water-soluble resin may be provided between the unwinding device 3 and the driving device 5. In particular, when the coating of the coated film is a thermosetting silicone resin compound having dimethylsiloxane as the main skeleton, the coated film is preferably used as a process release film due to its surface free energy characteristics, and specifically, it is used as a release film for removing a release object in a desired shape after providing the release object on the coating of the coated film. Since the release object may remain on the coating surface of the coated film after being used as such a process release film, it is preferable to provide a device for exposing the coating surface of the coated film between the unwinding device 3 and the driving device 5 to expose the coating surface of the coated film. The device for exposing the coating surface may be a contact type or a non-contact type, and is appropriately selected depending on the remaining state of the release object.

[0069] The material to be released is selected appropriately depending on the characteristics of the coating, but examples include inorganic materials such as metals applied by vapor deposition, adhesives made of organic materials such as acrylic applied by coating, and ceramic green sheets whose main component is barium titanate.

[0070] [How to remove the coating from a coated film] The coating removal method of the present invention is a method for removing a coating from a coated film having a coating on at least one side of a substrate film using a coating removal device. The coating is preferably a coating containing a water-soluble resin that can be removed by water. A method for removing a coating made of a water-soluble resin has been known in the past in which the substrate film is immersed in a liquid such as water, but in this case, the liquid is a viscous body that absorbs the vibration of the film, so that removal defects caused by the vibration of the film in the removal process are suppressed. In the coating removal method of the present invention, even when a cleaning liquid is applied, removal is performed in the atmosphere, and in this case, a problem occurs in that removal defects caused by the vibration of the film in the removal process become apparent. The coating removal method of the present invention can solve the above problems caused by using a coating removal device.

[0071] In the coating removal method of the present invention, it is preferable that the outermost layer of the coating is a layer made of a water-insoluble resin. When the outermost layer is a water-insoluble resin, the part in contact with the removal member does not dissolve in water, so that when the coating is removed with the removal member after applying water as a cleaning liquid, the shear force between the removal member and the coated film is likely to increase, and vibration is likely to occur. As a result, the effect of vibration suppression by the vibration suppression member is also evident, making it easier to obtain the effect of the present invention.

[0072] As described above, the coating removal device and coating removal method of the present invention can be used to efficiently and uniformly remove the coating from the surface of a coated film. Furthermore, the coating removal device and coating removal method of the present invention can provide high-purity resin chips free of foreign matter at low cost without significantly increasing the environmental load, and therefore recycled films can be stably produced. EXAMPLES

[0073] The present invention will be described below with reference to examples, but the present invention is not necessarily limited thereto.

[0074] <Coated film> The following coated films were prepared.

[0075] <Coated film> A coating of polyvinyl alcohol resin as a water-soluble resin was formed to a thickness of 0.1 μm on one side of a polyethylene terephthalate substrate film having a thickness of 30 μm and a width of 500 mm.

[0076] Furthermore, a coating of a curable silicone resin, which is a release component, was formed on top of that with a thickness of 0.1 μm as follows, with reference to the coating material described in JP 2015-189226 A. - Thermosetting silicone, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KS-847T": 100 parts by weight, Platinum catalyst, manufactured by Shin-Etsu Chemical Co., Ltd., product name "CAT-PL-50T": 3 parts by weight, The resin was dissolved in a mixture of toluene and MEK (mass ratio of toluene:MEK is 1:1) as a solvent so that the solid content was 1.8 mass%. The resin was then applied onto the polyvinyl alcohol resin coating using a bar coater and dried in an oven at 90°C for 20 seconds to form a coating of the release component, and a coated film was obtained.

[0077] <Removal evaluation method> (1) Removability of the coating The removability was evaluated by the following method using a commercially available dyne pen (surface energy: 30, 70 mN / m). When a drawing was made on the surface of a sample with a dyne pen at room temperature of 23°C and the state was maintained for 4 seconds or more, it was determined that the surface energy of the sample surface was higher than that of the dyne pen. If the release component coating of the coated film remains on the surface, the surface energies of both are less than 30 mN / m, so the reagent is repelled by the sample surface and neither dyne pen can maintain the drawing. On the other hand, when the release component coating is removed and the water-soluble polyvinyl alcohol resin is exposed, the surface energy is 70 mN / m or more, so both dyne pens can maintain the drawing. When both the release component coating and the water-soluble polyvinyl alcohol resin coating are removed and the polyethylene terephthalate is exposed, the surface energy is 43.8 mN / m, so the drawing made with the 30 mN / m dyne pen is maintained, but the drawing made with the 70 mN / m dyne pen is not maintained. By the above evaluation method, it was judged whether or not the coating of the coated film could be removed.

[0078] (2) Uniformity of coating removal In the evaluation of the removability of the coating, a 500 mm wide substrate was divided into 20 sections at 25 mm intervals in the width direction, and the center position of each of the 20 sections was drawn with a dyne pen to evaluate the removability of the coating. The uniformity of the removal of the coating was judged based on the presence of water-soluble resin on the surface of the substrate, using the following criteria. [Judgment criteria] Good uniformity: Both the release component curable silicone resin and the water-soluble polyvinyl alcohol resin coating were successfully removed in all 20 sections. Poor uniformity: In one or more of the 20 sections, a coating of the release component, cured silicone resin or water-soluble polyvinyl alcohol resin, remains. The uniformity of the removal of the coating was evaluated for each speed by changing the substrate conveying speed to 25 m / min, 50 m / min, and 100 m / min in each of the examples and comparative examples. Since the uniformity of the removal is easily affected by the conveying speed, if the uniformity is good at all speeds, it can be judged that the removal device or method has excellent uniformity of removal.

[0079] <Example 1> The coated film was set in the unwinding device 3 of the removing device 101 shown in FIG.

[0080] A spray nozzle (two-fluid type) was used for the discharge head 7 that discharged the cleaning liquid 8. The cleaning liquid was hot water at 60°C, and a diaphragm pump was used to discharge the cleaning liquid 8 at a rate of 1 m2 per coating surface area. 2 The solution was adjusted to 3 to 650 ml per coating and applied directly to the coating.

[0081] The removal member 10 is a stainless steel plate having a tip shape as shown in FIG. 2, and the width of the tip in the substrate conveying direction is 1.0×10 -5 The removal member 10 was disposed so that the angle (θ1+θ2) between the base films via the removal member 10 was 80°.

[0082] The coating was removed by conveying the base film while applying a tension of 50 N / m in the longitudinal direction of the base film.

[0083] The vibration damping member 12 was a silicone rubber roll with a roll surface JIS-A hardness of 45°, arranged as shown in Figure 2. A freely rotating rubber roll was selected. The length L1 of the coated film 1 in the longitudinal direction from the contact point between the coated film 1 and the removal member 10 on the upstream side in the transport direction to the contact point between the coated film 1 and the vibration damping member 12 on the upstream side in the transport direction was 0.07 m, and the contact length L2 between the vibration damping member 12 and the coated film 1 was 1 x 10 -3 It was m.

[0084] The film was taken up by the take-up device 4, and the base film 2 from which the coating had been removed was sampled and checked with a dyne pen for the uniformity of the removal of the coating. As shown in Table 1, when the conveying speed was 100 m / min, the polyvinyl alcohol resin coating remained in some sections in the width direction of the film, and the uniformity of the removal was poor. However, it was confirmed that at conveying speeds of 25 m / min and 50 m / min, both the coating of the curable silicone resin, which is the release component, and the coating of the water-soluble polyvinyl alcohol resin were removed uniformly.

[0085] <Example 2> Except for changing the position of the vibration suppression member so that L1 was 0.05 m, the coating was removed in the same manner as in Example 1. When the uniformity of the coating removal was confirmed, it was confirmed that both the coating of the curable silicone resin, which is the release component, and the coating of the water-soluble polyvinyl alcohol resin were uniformly removed at all conveying speeds, as shown in Table 1.

[0086] <Example 3> The coating was removed in the same manner as in Example 1, except that the position of the vibration suppression member was changed so that L1 was 0.20 m. When the uniformity of the coating removal was confirmed, as shown in Table 1, when the conveying speed was 25 m / min, both the coating of the curable silicone resin, which is a release component, and the coating of the water-soluble polyvinyl alcohol resin were uniformly removed, but when the conveying speed was 50 m / min and 100 m / min, the polyvinyl alcohol resin coating remained in some sections in the film width direction, and the uniformity of removal was poor.

[0087] <Example 4> L2 is 3×10 -2 The coating was removed in the same manner as in Example 1, except that the position of the vibration suppression member was changed so that the distance between the film and the roll was 1.5 m. When the uniformity of the coating removal was confirmed, as shown in Table 1, when the conveying speed was 25 m / min, both the coatings of the curable silicone resin, which is a release component, and the water-soluble polyvinyl alcohol resin were uniformly removed, but when the conveying speed was 50 m / min and 100 m / min, the polyvinyl alcohol resin coating remained in some sections in the film width direction, and the uniformity of removal was poor.

[0088] <Example 5> Except for changing the silicone rubber roll to one with a JIS-A hardness of 70° on the roll surface, the coating was removed in the same manner as in Example 1. When the uniformity of the coating removal was checked, as shown in Table 1, at a conveying speed of 25 m / min, both the curable silicone resin and water-soluble polyvinyl alcohol resin coatings, which are release components, were uniformly removed, but at conveying speeds of 50 m / min and 100 m / min, the polyvinyl alcohol resin coating remained in some sections in the film width direction, and the uniformity of removal was poor.

[0089] <Comparative Example 1> Except for removing and not using the vibration damping member 12, the coating was removed in the same manner as in Example 1. When the uniformity of the coating removal was checked, as shown in Table 1, the polyvinyl alcohol resin coating remained in some sections in the film width direction at all transport speeds, and the uniformity of removal was poor.

[0090] The results of Examples 1 to 5 and Comparative Example 1 are summarized in Table 1.

[0091] [Table 1] [Industrial Applicability]

[0092] According to the present invention, a coating can be efficiently and uniformly removed from a substrate film having a coating, and a resource with few impurities and suitable for recycling can be provided. [Explanation of symbols]

[0093] 1. Film with coating (base film before coating removal) 2. Base film after removing the coating 3 Unwinding device 4 Winding device 5, 6 Drive unit 10 Removal material 12 Vibration suppression member a Film transport direction

Claims

1. An apparatus for removing a coating from a coated film having a coating on at least one surface of a substrate film, comprising: a removal member that is used in contact with a surface of the coating of the coated film to remove the coating; a drive device for moving the coated film relative to the removal member in a longitudinal direction of the coated film; a vibration suppressing member provided on the opposite side of the coated film from the removal member, the vibration suppressing member suppressing vibration of the coated film when the coated film moves relative to the removal member; A coating removal device comprising:

2. a direction in which the coated film moves relative to the removing member is defined as a conveying direction, The vibration suppressing member is The coated film is used in contact with the coated film, The length of the coated film in the longitudinal direction from a contact point between the coated film and the removing member on the upstream side in the transport direction to a contact point between the coated film and the vibration suppressing member on the upstream side in the transport direction is in the range of 0.00 to 0.10 m. The coating removal device of claim 1.

3. The vibration suppressing member is 1×10 in the longitudinal direction of the coated film. －５ ~5×10 －２ 3. The coating removal device of claim 2, wherein the coating removal device is arranged to make contact over a length in the range of m.

4. The vibration suppressing member is The coated film is used in contact with the coated film, 4. The coating removal device according to claim 1, wherein the portion that comes into contact with the surface of the coated film has a JIS-A hardness in the range of 5 to 65 degrees.

5. 5. The coating removal device of claim 4, wherein the vibration dampening member is in the form of a roller.

6. a tension applying mechanism adjusted to apply a tension in the range of 10 to 1000 N / m in at least one direction of the longitudinal direction of the coated film; The removal member is arranged such that, when observed from the width direction of the coated film, an angle between the removal member and the coated film is in the range of 20 to 150°. The coating removal device according to claim 1 or 3.

7. a direction in which the coated film moves relative to the removing member is defined as a conveying direction, A cleaning solution containing water as a main component is applied to the coating on the upstream side of the removing member in the conveying direction so as to cover a surface area of ​​1 m ２ Equipped with a water dispensing mechanism adjusted to dispense in an amount ranging from 3 to 650 ml per The coating removal device according to claim 1 or 3.

8. A method for removing a coating using the coating removal apparatus of claim 7, wherein the coating includes a layer made of a water-soluble resin.

9. 4. A method for removing a coating using the coating removal apparatus of claim 3, wherein the outermost layer of the coating is a layer made of a water-insoluble resin.

10. 9. The coating removal method according to claim 8, wherein the outermost layer of the coating is a layer made of a water-insoluble resin.

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