JP2024110668A - Coating layer removing method and coating layer removing device - Google Patents

Abstract

To provide a method for removing a coating layer, which can easily remove a coating layer from a laminated film in a simple manner regardless of a material of the coating layer.SOLUTION: A method for removing a coating layer 14 includes the steps of: preparing a laminated film 10 having a substrate film 12 and a coating layer 14; pressing the laminated film 10 at multiple pressing points; and removing the coating layer 14 from the laminated film 10 after pressing the laminated film 10. The pressing step is a step of pressing the laminated film 10 so that a tensile stress is applied to one side of the laminated film 10 and a compressive stress is applied to the other side of the laminated film 10 at each of the multiple pressing points.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for removing a coating layer and an apparatus for removing a coating layer.

In recent years, from the perspective of protecting global resources and the environment, there has been an increasing movement in various fields to build a recycling-oriented society through efforts such as reducing waste generation, reusing, and recycling.
For example, Patent Document 1 discloses a method for separating a laminated film, which comprises contacting a surface film layer of a laminated film made of different materials with a transfer material that is thermally bonded to the surface film layer under heat and pressure, and transferring the surface film layer to the transfer material side and peeling it off to separate it from the base film layer.

Japanese Patent Application Publication No. 10-034650

The separation method described in Patent Document 1 is a technique for removing the surface film layer from the laminated film by heating the surface film layer to thermally bond it to the transfer material, and utilizing the difference in adhesive strength between the transfer material and the base film to the surface film layer. Therefore, the surface film layer is limited to a material that can be thermally transferred to the transfer material.

The object of the present invention is to provide a coating layer removal method and coating layer removal device that can easily remove a coating layer from a laminated film in a simple manner regardless of the material of the coating layer.

[1] A method for removing a coating layer, comprising the steps of: preparing a laminate film having a base film and a coating layer; pressing the laminate film at a plurality of pressing locations; and removing the coating layer from the laminate film after pressing the laminate film, wherein the pressing step is a step of pressing such that, at each of the plurality of pressing locations, a tensile stress is applied to one side of the laminate film and a compressive stress is applied to the other side of the laminate film.
[2] The method for removing a coating layer described in [1] above, wherein the preparing step is a step of preparing a roll around which the laminated film is wound, and further includes a step of unwinding the laminated film from the roll after the preparing step, and a step of winding up the base film from which the coating layer has been removed into a roll after the coating layer removing step.
[3] The method for removing a coating layer described in [1] or [2], wherein the pressing step is a step of pressing the laminated film with a first shaping member having a plurality of protrusions protruding in the thickness direction of the laminated film at each of the plurality of pressing locations.
[4] The method for removing a coating layer described in [3], wherein the pressing step is a step of pressing the laminated film so that at least the coating layer of the laminated film comes into contact with the protrusions.
[5] The method for removing a coating layer described in [3] or [4], wherein the pressing step is a step of pressing the laminated film by sandwiching the laminated film between the first shaping member and the second shaping member, the first shaping member and the second shaping member each including a base and an uneven portion having a plurality of convex portions and a plurality of concave portions as the protrusions provided on the surface of the base, the convex portions of the first shaping member and the concave portions of the second shaping member are arranged so that they fit together, and the concave portions of the first shaping member and the convex portions of the second shaping member are arranged so that they fit together, and the first shaping member and the second shaping member are the same or different from each other.
[6] The method for removing a coating layer according to any one of [1] to [5], wherein the step of removing the coating layer is a step of transferring the coating layer from the base film to an adhesive roll.
[7] The method for removing a coating layer described in any one of [1] to [5], wherein the step of removing the coating layer is a step of scraping the coating layer off the base film using a blade or a wire brush.
[8] The method for removing a coating layer described in any one of [1] to [5], wherein the step of removing the coating layer is a step of scraping off the coating layer from the base film with a blasting material.
[9] An apparatus for removing a coating layer from a laminate film having a base film and a coating layer, comprising: a pressing means for pressing the laminate film at a plurality of pressing points; and a removing means for removing the coating layer from the pressed laminate film, wherein the pressing means presses the laminate film so that a tensile stress is applied to one side of the laminate film and a compressive stress is applied to the other side of the laminate film at each of the plurality of pressing points.

According to one aspect of the present invention, a coating layer removal method and a coating layer removal device can be provided that can easily remove a coating layer from a laminated film in a simple manner regardless of the material of the coating layer.

5A to 5C are diagrams for explaining a pressing step according to the first embodiment. 13 is an SEM photograph of region R1 after the laminated film has passed over the first shaping member in the pressing step according to the first embodiment. 1 is a SEM photograph of a laminated film after it has passed through a plate having no concaves or convexes. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. 5A to 5C are diagrams illustrating an example of a shaping member used in a pressing step according to the first embodiment. FIG. 11 is a schematic diagram of an example of a coating layer removal device according to a second embodiment.

First Embodiment
(Method of Removing Coating Layer)
The method for removing a coating layer according to this embodiment (hereinafter also referred to as the removal method according to this embodiment) includes a step of preparing a laminate film having a base film and a coating layer (hereinafter also referred to as the preparation step), a step of pressing the laminate film at a plurality of pressing points (hereinafter also referred to as the pressing step), and a step of removing the coating layer from the laminate film after pressing the laminate film (hereinafter also referred to as the removal step).
The pressing step is a step of pressing the laminated film so that, at each of the multiple pressing locations, a tensile stress is applied to one side of the laminated film and a compressive stress is applied to the other side of the laminated film.

In the pressing step according to this embodiment, a shaping member can be used as a means (pressing means) for pressing the laminated film at a plurality of pressing points.
Examples of the shaping member include a first shaping member having a plurality of protrusions (convex portions) protruding in the thickness direction of the laminated film, and a pair of shaping members consisting of a first shaping member and a second shaping member.
It is preferable that the first shaping member and the second shaping member each include a base, a concave-convex portion having a plurality of protrusions (convex portions) provided on the surface of the base, and a plurality of concave portions surrounded by the convex portions.
The first shaping member and the second shaping member may be the same or different from each other. The first shaping member and the second shaping member are different from each other in that at least one of the base, the recessed portion, and the protruding portion constituting the first shaping member and the second shaping member is different. The specific structure of the shaping member will be described later.

In the pressing step according to the present embodiment, a shaping member is used as a pressing means, so that the laminated film is lifted. In other words, the pressing step causes the coating layer to be lifted from the base film. This makes it possible to easily remove the coating layer from the laminated film in the subsequent removal step.
The mechanism by which the coating layer floats off the substrate film will be described with reference to FIG.
In the following description, a case will be described in which the pressing step is performed using a first shaping member 300 shown in FIG. 3A, which will be described later, as the pressing means.
Fig. 1 is a diagram for explaining the pressing process according to the present embodiment. The X-axis, Y-axis, and Z-axis in Fig. 1 are in a mutually orthogonal relationship, the X-axis and Y-axis are axes in a predetermined plane, and the Z-axis is an axis perpendicular to the predetermined plane. When directions are indicated based on a view from the front direction of Fig. 1 parallel to the X-axis, "up" is the direction of the Z-axis arrow, "down" is the opposite direction, "right" is the direction of the Y-axis arrow, "left" is the opposite direction, "front" is the front direction in Fig. 1 parallel to the X-axis, and "rear" is the opposite direction.
The X-axis is the direction in which the laminate film is transported, the Y-axis is the direction perpendicular to the direction in which the laminate film is transported, and the Z-axis is the thickness direction of the laminate film.
1 shows a state in which the laminated film 10 is transported in the X-axis direction on the first shaping member 300. The first shaping member 300 has an uneven portion formed on the surface of a base 32, the uneven portion having a plurality of convex portions 321 (projections) and concave portions 322. The uneven portion has a striped structure (see FIG. 3A).
The laminate film 10 has a base film 12 and a coating layer 14. In Fig. 1, the laminate film 10 has the base film 12 and the coating layer 14 directly laminated to each other.
In the region R1, when the laminate film 10 passes over the convex portion 321 of the first shaping member 300, a compressive stress _C1 is applied to the coating layer 14 side, and a tensile stress _T1 is applied to the base film 12 side. The same is true in the region R2.
Thus, in the pressing step according to the first embodiment, compressive stress or tensile stress is applied to the coating layer 14 side and the base film 12 side of the laminated film 10 at each of the multiple pressing points of the laminated film 10, so that the base film 12 follows the unevenness of the first shaping member 300, while localized compressive deformation occurs at each pressing point. In the regions R1 to R2 of the laminated film 10, the coating layer 14 is pressed in direct contact with the convex portions 321 of the first shaping member 300, so that localized compressive deformation is more likely to occur. As a result, shear stress is generated at the interface between the base film 12 and the coating layer 14, and the coating layer 14 is thought to float from the base film 12.

2A is an SEM photograph of region R1 after the laminated film has passed over the first shaping member under tension (3000 N/m). FIG. 2B is an SEM photograph of the laminated film after passing over a plate without a textured portion under tension (3000 N/m). Both photographs are top views of the laminated film 10 from the coating layer 14 side.
From Figures 2A and 2B, it can be seen that multiple floating portions occur in the laminated film 10 after passing over the first shaping member 300, but no floating portions occur in the laminated film after passing over a plate that does not have an uneven portion.

As described above, according to the removal method of the present embodiment, the coating layer 14 that has been lifted from the base film 12 in the pressing step is removed from the laminate film 10 in the removal step, so that the coating layer 14 can be easily removed. This makes it easy to recover the remaining base film 12. The recovered base film 12 can be reused for various purposes.
In addition, according to the removal method of the present embodiment, the coating layer can be removed by a simple method of pressing the laminated film with a shaping member. Therefore, compared with the technique of removing the coating layer by thermally transferring the coating layer to a transfer material as in Patent Document 1, the method is not dependent on the material of the coating layer, and the setting of conditions for the separation process (heating conditions, pressure conditions, etc.) is not complicated. The cost of the separation process can also be reduced.
Therefore, according to the removal method of this embodiment, the coating layer can be easily removed from the laminated film in a simple manner regardless of the material of the coating layer.

Each step of the removal method according to this embodiment will be explained below.

<Preparation process>
The preparation step according to this embodiment is a step of preparing a laminate film 10 having a base film 12 and a coating layer 14 .
Examples of the preparation process include a process of cutting a specified laminate film into sheets if the subsequent process is to be carried out in sheets, and a process of winding up a specified laminate film onto a core that can be set into a device (unwinding means) that unwinds the roll, so as to form a roll of a specified size, if the process is carried out using a roll-to-roll method.
The form of the laminate film 10 in the preparation step is not particularly limited, and may be, for example, a sheet piece with one side measuring several tens of centimeters, or a laminate film wound into a roll.
The preparation step may be a step of simply preparing a laminated film 10 that has been manufactured in advance, or may be a step of manufacturing the laminated film 10 .

The laminate film 10 is preferably used for producing a ceramic green sheet, and is a laminate film after the ceramic green sheet is peeled off. The ceramic green sheet is preferably used for producing a multilayer ceramic capacitor (MLCC).
The laminated film 10 is a laminated film with a ceramic green sheet, and the ceramic green sheet may be attached to the side of the coating layer opposite to the base film.
Even when such a laminate film with a ceramic green sheet is used, shear stress occurs at the interface between the base film 12 and the coating layer 14 during the pressing process, causing the coating layer 14 (the coating layer with the ceramic green sheet) to float away from the base film 12.

The preparation step in this embodiment is a step of preparing a roll around which the laminated film is wound, and it is preferable that the preparation step further includes a step of unwinding the laminated film from the roll after the preparation step, and a step of winding up the base film from which the coating layer has been removed into a roll after the coating layer removal step.
In other words, the removal method according to the present embodiment is preferably carried out by a roll-to-roll system, which allows the coating layer to be removed continuously.

<Pressing process>
The pressing step according to this embodiment can be carried out using the above-mentioned shaping member as the pressing means.
The shaping member is preferably the above-mentioned first shaping member, or a pair of shaping members consisting of a first shaping member and a second shaping member.

The pressing process in this embodiment is preferably a process of pressing the laminated film with a first shaping member having a plurality of protrusions (convex portions) protruding in the thickness direction of the laminated film at each of a plurality of pressing locations.
The pressing step according to the present embodiment is more preferably a step of pressing the laminated film so that at least the coating layer of the laminated film comes into contact with the protrusions.

When the first shaping member is used alone as the shaping member, it is preferable to carry out the pressing step while applying tension to the laminated film when placing or passing the laminated film on the first shaping member. As a method for applying tension to the laminated film, for example, a method of providing pinch rolls before and after the first shaping member and providing a speed difference before and after the transport of the laminated film can be mentioned. When applying tension to the laminated film by this method, it is more preferable to provide a guide roll that provides a wrap angle between the pinch rolls. This makes it easier for compression deformation to occur in the laminated film, and makes it easier for the coating layer to float from the base film.

The pressing step according to this embodiment is preferably a step of pressing the laminated film by sandwiching the laminated film between a first shaping member and a second shaping member.
In this embodiment, the first shaping member and the second shaping member each include a base and an uneven portion having a plurality of convex portions and a plurality of concave portions as the protrusions provided on the surface of the base, and are preferably arranged so that the convex portions of the first shaping member and the concave portions of the second shaping member fit together, and the concave portions of the first shaping member and the convex portions of the second shaping member fit together. The first shaping member and the second shaping member are the same or different from each other.
The projections and recesses fit together, so that the laminate film is easily deformed by pressure from both sides, and large tensile and compressive stresses are applied to the laminate film, which makes the coating layer more likely to separate from the substrate film.

Examples of the first shaping member and the second shaping member include a plate having an uneven portion and a roll having an uneven portion. The first shaping member may be a rotary type or a non-rotary type, but a rotary type is preferable because it is less likely to generate frictional heat and cutting powder.
As the roll having the uneven portion, a known embossing roll can be used.
The shape of the concaves and convexities constituting the uneven portion is not particularly limited, and examples thereof include a cylindrical shape, a polygonal prism shape, a frustum shape, a truncated cone shape, a hemispherical shape, a semicylinder shape, and a cone shape.
The height of each of the recesses and protrusions is preferably 10 μm or more and 3000 μm or less.
Examples of the uneven portion include a structure in which concave and convex portions are arranged in a stripe pattern, a structure in which concave and convex portions are arranged in a spiral pattern, a structure in which pillars as convex portions are dispersedly arranged, and a structure in which dimples as concave portions are dispersedly arranged.
The unevenness may be formed regularly or irregularly. Also, the unevenness may have a composite shape that combines the above-mentioned shapes of the concave and convex portions.
When the concave and convex portions are formed regularly, the pitch interval of the concave portions and the pitch interval of the convex portions are preferably each independently 30 μm or more and 5000 μm or less.

Examples of usage modes of the shaping member include the following (M1) to (M3).
(M1) An embodiment in which the first shaping member is used alone;
(M2) A mode in which a first shaping member and a second shaping member are arranged opposite to each other and used as a pair of shaping members (a first shaping member and a second shaping member);
(M3) An example of an embodiment is one in which a first shaping member and a support member (e.g., a backup roll and a backup plate, etc.) are arranged opposite each other and used as a member consisting of the first shaping member and the support member (hereinafter also referred to as a shaping member with a support member).
The material of the first shaping member or the second shaping member is not particularly limited, but may be, for example, a metal, a resin, etc. The material of the support member is not particularly limited, but may be, for example, a metal, a rubber, etc.

Specific examples of the use of the shaping member include the following (1) to (8).
The rolls and backup rolls used in (1) and (3) to (6) may each be of the rotating or non-rotating type.
(1) A pair of shaping members, in which the first shaping member and the second shaping member are rolls having uneven portions.
(2) A pair of shaping members, in which the first shaping member and the second shaping member are two plates having concave and convex portions.
(3) A shaping member with support, in which the first shaping member is a roll having an uneven portion, and the supporting member is a backup roll.
(4) A shaping member with support, in which the first shaping member is a roll having an uneven portion, and the support member is a backup plate.
(5) A first shaping member that does not have a support member and is composed of a roll having an uneven portion.
(6) A shaping member with support, in which the first shaping member is a plate having an uneven portion, and the supporting member is a backup roll.
(7) A shaping member with support, in which the first shaping member is a plate having an uneven portion, and the support member is a backup plate.
(8) A first shaping member consisting of a plate having a concave-convex portion and no support member.

A specific structure of the shaping member will be described with reference to FIGS. 3A to 3F.
3A to 3F show a state in which the laminated film 10 is pressed by a first shaping member or a pair of shaping members.
3A, a first shaping member 300 has an uneven portion having a plurality of protrusions 321 and recesses 322 formed on the surface of a base 32. The uneven portion has a striped structure.
3B, a concave-convex portion having a plurality of convex portions 341 and concave portions 342 is formed on the surface of a base 34. The concave-convex portion has a spiral structure.
In the first shaping member 302 shown in FIG. 3C, an uneven portion having pillars 361 as a plurality of protrusions and recesses 362 surrounded by pillars 361 is formed on the surface of a base 36 .
The pair of shaping members 303 shown in Fig. 3D includes two first shaping members 300 (Fig. 3A). A convex portion 321 of one shaping member 300 and a concave portion 322 of the other shaping member 300 are arranged to fit together.
The pair of shaping members 304 shown in Fig. 3E includes two first shaping members 301 (Fig. 3B). A convex portion 341 of one shaping member 301 and a concave portion 342 of the other shaping member 300 are arranged to fit together.
The pair of shaping members 305 shown in Fig. 3F includes a first shaping member 302 (Fig. 3C) and a second shaping member 302A. The second shaping member 302A has an uneven portion formed on the surface of the base 38, the uneven portion having dimples 381 as a plurality of recesses and a protrusion 382 surrounded by the dimples 381. The pair of shaping members 305 are arranged such that the pillar 361 of the first shaping member 302 and the dimple 381 of the second shaping member 302A are fitted together, and the recess 362 of the first shaping member 302 and the protrusion 382 of the second shaping member 302A are fitted together.

When the removal method according to this embodiment is carried out using a roll-to-roll method, it is preferable to place multiple shaping members on the same line and carry out the pressing process multiple times.

<Removal process>
The removing step according to this embodiment is a step of removing the coating layer 14 from the laminated film 10 after the laminated film 10 is pressed.
In the removing step, for example, an adhesive roll, a blade, a wire brush, a blast material, etc. can be used as a means (removing means) for removing the coating layer 14 from the laminate film 10. The adhesive roll, the blade, the wire brush, and the blast material can each be a known member.

The removing step according to one embodiment is a step of transferring the coating layer 14 from the substrate film 12 to an adhesive roll.
In one embodiment, the removing step is a step of scraping the coating layer 14 off the substrate film using a blade or a wire brush.

The removal process in one embodiment is a process of scraping off the coating layer 14 from the substrate film 12 with a blasting material, specifically, a process of scraping off the coating layer 14 from the substrate film 12 by spraying a blasting material from a known blasting treatment device.
Examples of the blasting material include silica particles, calcium carbonate particles, silicon carbide particles, alumina particles, dry ice particles, and melamine resin particles. When dry ice particles are used as the blasting material, the dry ice particles disappear after the blasting process, which is preferable because it eliminates the need for a particle removal operation. The particle size of the blasting material is preferably 5 μm or more and 40 μm or less.
The conditions for spraying the blasting material are determined by the material of the coating layer.

Second Embodiment
[Coating Layer Removal Device]
FIG. 4 is a schematic diagram of an example of a coating layer removing device according to the second embodiment.
The X-axis, Y-axis, and Z-axis in Fig. 4 are mutually orthogonal, similarly to Fig. 1. In the case of Fig. 4, the view from the front direction of Fig. 4 parallel to the Y-axis is used as a reference, and when showing directions, "up" is the direction of the Z-axis arrow, "down" is the opposite direction, "right" is the direction of the X-axis arrow, "left" is the opposite direction, "front" is the front direction in Fig. 4 parallel to the Y-axis, and "rear" is the opposite direction.
The removing device 100 is a device that transports the laminated film by a roll-to-roll method.
The removal method according to the first embodiment is carried out using, for example, a removal apparatus 100 .

In the second embodiment, a case will be described in which a pair of shaping members 303 shown in FIG. 3D is used as the pressing means.
The coating layer removal device 100 of the second embodiment is a coating layer removal device 100 that removes the coating layer 14 from a laminated film 10 having a base film 12 and a coating layer 14, and is equipped with a pressing means (in the case of Figure 4, a pair of shaping members 303) that presses the laminated film 10 at multiple pressing points, and a removal means (not shown) that removes the coating layer from the pressed laminated film.
The pressing means is a means for pressing such that a tensile stress is applied to one surface of the laminated film 10 and a compressive stress is applied to the other surface of the laminated film 10 at each of the multiple pressing locations.
In the case of Fig. 4, a pair of shaping members 303 as pressing means is composed of two first shaping members 300 (see Fig. 3A). The two first shaping members 300 are rolls, but plates may also be used.
The removal device 100 also includes a payout means 11 that pays out the laminated film 10 from the roll 1 on which the laminated film 10 is wound, and a winding means (not shown) that winds up the base film 12 into a roll.

The unwinding means 11 includes a support member (not shown) that rotatably supports the roll 1 around which the laminate film 10 is wound, and a drive roller (not shown).
As the removing means (not shown), the removing means described in the first embodiment can be used. The removing means is provided at an arbitrary position downstream of the pressing means.
The winding means (not shown) includes a winding roll for winding the base film 12 into a roll.

When the removal device 100 shown in FIG. 4 is used, the removal method according to the first embodiment is carried out, for example, as follows.
The laminated film 10 wound around the roll 1 is unwound from the roll 1 by the unwound means 11 (unwound process) and transported toward a pair of shaping members 303 (an example of a pressing means). In the pair of shaping members 303, the embrace angle of the first shaping member 300 disposed on the lower side is adjusted to about 80° so that tension is applied to the laminated film.
When the laminated film 10 passes between the pair of shaping members 303, multiple locations are pressed, causing compressive deformation in the laminated film and lifting the coating layer from the base film (pressing process). The laminated film that has passed through the pressing means passes through two guide rolls 22, 23, and is then transported toward a removing means that removes the coating layer 14. In the removing means, the coating layer 14 that has lifted from the base film is removed from the laminated film 10 (removing process). After the coating layer 14 has been removed, the remaining base film 12 is wound into a roll by a winding means (winding process).
According to the second embodiment, a coating layer removing device is realized that can easily remove a coating layer from a laminated film in a simple manner regardless of the material of the coating layer.

[Modifications of the embodiment]
When the removal method according to the first embodiment is carried out by a roll-to-roll method, the removal method according to the first embodiment may further include a stretching step of stretching the laminated film before or after the pressing step.
The stretching step is a step of generating cracks in the coating layer. Generating cracks in the coating layer means that fissures (cracks) are generated in the thickness direction of the coating layer.
When the removal method according to the first embodiment includes a stretching step, the order of steps is preferably such that the stretching step is followed by the pressing step, which allows the coating layer to be pressed in a direction crossing the direction of the cracks in the pressing step after the coating layer is cracked in the stretching step, making it easier for the coating layer to be lifted off the substrate film.
As a method for stretching the laminated film, for example, two stretching rolls (an upstream stretching roll and a downstream stretching roll) are provided on the conveying path,
Examples of such a method include a method of controlling the peripheral speed of a downstream stretching roll provided downstream of the transport path so that it is faster than the peripheral speed of an upstream stretching roll provided upstream of the transport path, and a method of providing one or more other stretching rolls between the upstream stretching roll and the downstream stretching roll, and transporting the laminated film while winding it around the upstream stretching roll, the other stretching roll, and the downstream stretching roll.
The stretching step is preferably carried out while heating the laminated film, from the viewpoint of facilitating the generation of cracks in the coating layer.
Moreover, the laminated film is preferably heated at a temperature equal to or higher than the glass transition temperature _Tg1 of the base film for the following reasons.
The glass transition temperature Tg ₁ of the base film and the glass transition temperature Tg ₂ of the coating layer are determined in accordance with the method specified in JIS K7121 (2012) and measured using a differential scanning calorimeter (DSC). The temperature during stretching is preferably equal to or higher than the glass transition temperature Tg 1 of the base film, and more preferably equal to or higher than the glass transition temperature Tg ₁ of the base film and equal to or lower than the glass transition temperature Tg ₂ of the coating layer, in order to facilitate stretching of the base film without _breaking and to facilitate breaking of the coating layer.
By combining the stretching step and the pressing step, cracks are generated in the coating layer and the coating layer is brought into a floating state, so that the coating layer can be more easily removed.

The removal method according to the first embodiment may further include a step of blowing superheated steam toward the coating layer after the pressing step and before the removing step.
When the removal method according to the first embodiment includes a step of spraying superheated steam, the order of the steps is preferably such that the step of spraying superheated steam is carried out after the step of pressing, or that the step of spraying superheated steam is carried out after the step of stretching and the step of pressing in this order.
The means for spraying the superheated steam may include a heater for heating the steam and a steam spray nozzle for spraying the superheated steam.
The temperature of the superheated steam is preferably 100°C or higher and 450°C or lower, more preferably 150°C or higher and 400°C or lower, and even more preferably 200°C or higher and 350°C or lower.
The time for spraying the superheated steam is determined depending on the material of the coating layer, the transport speed of the laminated film, and the like.
The laminated film is rapidly cooled when it is discharged from the treatment chamber after being sprayed with superheated steam in the treatment chamber. This rapid cooling makes the coating layer more likely to be distorted due to the difference in thermal expansion coefficient between the coating layer and the base film, and promotes interfacial peeling of the coating layer.
Therefore, by combining the pressing step with the step of spraying superheated steam, the coating layer can be removed more easily.

The present invention is not limited to the above-described embodiment. The present invention may include modifications and improvements within the scope of the invention.

The configuration of the laminated film used in the above embodiment will be explained.

[Laminated film]
The laminated film used in the above embodiment has a base film and a coating layer. The coating layer may be a single layer or a multilayer consisting of two or more coating layers of the same or different types. In addition, a coating layer may be formed on both sides of the base film.
From the viewpoint of facilitating removal of the coating layer from the laminate film and recovery of the remaining base film, the laminate film preferably has a configuration in which the base film and the coating layer are directly laminated together. Here, "direct lamination" refers to, for example, a configuration in which the base film and the coating layer are in direct contact with each other without any other layer between them.

<Base film>
The base film used is a resin film formed from a resin component to be recycled.
Examples of the resin film that can be used include polyester films such as polyethylene terephthalate film, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene film and polypropylene film; polyimide films; polyamide films; polycarbonate films; polyacetate films; ethylene-vinyl acetate copolymer (EVA) films; ethylene-(meth)acrylic acid copolymer films; ethylene-(meth)acrylic acid ester copolymer films; cycloolefin polymer films; polyurethane films; polyphenylene sulfide films; cellophane; and the like.
Among these, polyester films are preferred from the viewpoints of heat resistance and strength. As the polyester film, polyester films mainly composed of any one of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are preferred from the viewpoint of easy recovery and regeneration of the resin. In this specification, the term "main component" or "principal component" means that the proportion of the main component in the mass of the entire material is 50% by mass or more.
The resin film may contain a known filler, colorant, antistatic agent, antioxidant, organic lubricant, catalyst, etc. The resin film may be transparent or may be colored, etc., as desired. At least one surface of the base film may be previously subjected to a surface treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, and etching such as oxidation, as necessary.

There are no particular limitations on the thickness of the substrate film, but from the standpoint of strength, rigidity, etc., it is preferably 10 μm or more and 500 μm or less, more preferably 15 μm or more and 300 μm or less, and even more preferably 20 μm or more and 200 μm or less.

<Coating Layer>
The coating layer is preferably a functional layer. Examples of the functional layer include a release agent layer, a printing layer, a hard coat layer, an easy-adhesion layer, and a pressure-sensitive adhesive layer. Among these, the coating layer is preferably a release agent layer.
When the coating layer is a release agent layer, the release agent layer is preferably a layer formed from a release agent composition.
The release agent composition used to form the release agent layer is not particularly limited as long as it has releasability, and for example, a release agent composition mainly composed of a silicone compound; a fluorine compound; a long-chain alkyl group-containing compound; a thermoplastic resin material such as an olefin resin or a diene resin; or the like can be used. In addition, it is preferable to use a release agent composition mainly composed of an energy ray curable or thermosetting resin. These release agent compositions may be used alone or in combination of two or more.

In the release agent composition mainly composed of a silicone-based compound, the silicone-based compound may be a silicone-based compound having an organopolysiloxane as a basic skeleton. In addition, the silicone-based compound may be a heat-curable silicone-based compound such as an addition reaction type or a condensation reaction type; an energy beam-curable silicone-based compound such as an ultraviolet-curable type or an electron beam-curable type; etc.

In the release agent composition containing a fluorine compound as a main component, the fluorine compound may include a fluorine silicone compound, a fluorine boron compound, and a compound containing a poly(perfluoroalkylene ether) chain.

In the release agent composition mainly composed of a long-chain alkyl group-containing compound, examples of the long-chain alkyl group-containing compound include polyvinyl carbamate obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate, alkyl urea derivatives obtained by reacting a polyethyleneimine with a long-chain alkyl isocyanate, and copolymers of long-chain alkyl (meth)acrylates. Furthermore, a long-chain alkyl modified alkyd resin may be used in which a long-chain fatty acid is used as a modifier in an alkyd resin obtained by a condensation reaction between a polyhydric alcohol and a polybasic acid.

As a release agent composition mainly composed of an energy ray curable resin, for example, one containing an energy ray curable compound having a reactive functional group selected from a (meth)acryloyl group, an alkenyl group, and a maleimide group, and a polyorganosiloxane is preferable. In the release agent layer formed by this release agent composition, an energy ray curable compound and a polyorganosiloxane having different molecular structures, polarities, and molecular weights are used, so that before curing, the components derived from the polyorganosiloxane are in a state of segregation near the outer surface of the release agent layer, and then the segregation is fixed by curing with energy rays. This improves the releasability of the release agent layer. The release agent composition mainly composed of an energy ray curable resin may further contain a photopolymerization initiator.

Examples of the release agent composition mainly composed of a thermosetting resin include a release agent composition mainly composed of a melamine resin and a release agent composition mainly composed of an epoxy resin. Examples of the release agent composition mainly composed of a melamine resin include a composition containing a melamine resin as a main component, an acid catalyst for thermally curing the melamine resin, and a polyorganosiloxane that imparts release properties to the release agent layer. Examples of the release agent composition mainly composed of an epoxy resin include a composition containing an epoxy resin as a main component, an acid or basic thermosetting catalyst for thermally curing the epoxy resin, and a polyorganosiloxane that imparts release properties to the release agent layer. Before curing, the components derived from the polyorganosiloxane are in a state of segregation near the outer surface of the release agent layer, and then the segregation is fixed by curing. This can improve the release properties of the release agent layer.

In addition to the resin components described above, the coating layer may contain other additives. Examples of other additives include antioxidants, light stabilizers, flame retardants, conductive agents, antistatic agents, and plasticizers.

The thickness of the coating layer can be selected appropriately and is not particularly limited, but is preferably 0.02 μm or more and 5 μm or less, more preferably 0.03 μm or more and 2 μm or less, and even more preferably 0.05 μm or more and 1.5 μm or less.

The laminated film used in each embodiment is generally used for the purpose of protecting the surfaces of other functional sheets or various parts used for specific purposes during the manufacture, transportation, storage, etc. of these functional sheets or parts. After fulfilling its role of protecting these parts, the film is often peeled off from the surface and discarded. Therefore, by using the laminated film, the coating layer and the base film can be easily separated from the laminated film, making it a highly beneficial use from the standpoint of resource conservation and environmental protection.

1...roll, 10...laminated film, 11...unwinding means, 12...substrate film, 14...coating layer, 22, 23...guide rolls, 32...substrate, 100...removal device, 300, 301, 302, 303, 304, 305, 302A...shaping member, 321, 341, 382...protruding portion, 322, 342, 362...recessed portion, 361...pillar, 381...dimple.

Claims (9)

A step of preparing a laminate film having a substrate film and a coating layer;
pressing the laminated film at a plurality of pressing points;
and removing the coating layer from the laminated film after pressing the laminated film.
The pressing step is a step of pressing the laminate film so that a tensile stress is applied to one surface of the laminate film and a compressive stress is applied to the other surface of the laminate film at each of the plurality of pressing locations.
How to remove a coating layer. The preparing step is a step of preparing a roll around which the laminated film is wound,
After the preparing step, unwinding the laminated film from the roll;
The method further includes a step of winding up the base film from which the coating layer has been removed into a roll after the step of removing the coating layer.
The method for removing a coating layer according to claim 1 . The pressing step is a step of pressing the laminated film with a first shaping member having a plurality of protrusions protruding in a thickness direction of the laminated film at each of the plurality of pressing locations.
The method for removing a coating layer according to claim 1 or 2. The pressing step is a step of pressing the laminated film so that at least the coating layer of the laminated film and the protrusions are in contact with each other.
The method for removing a coating layer according to claim 3 . The pressing step is a step of pressing the laminated film by sandwiching the laminated film between the first shaping member and the second shaping member,
The first shaping member and the second shaping member each include a base body and an uneven portion having a plurality of convex portions and a plurality of concave portions as the protrusion portion provided on a surface of the base body,
The convex portion of the first shaping member and the concave portion of the second shaping member are fitted together, and the concave portion of the first shaping member and the convex portion of the second shaping member are arranged to fit together,
The first shaping member and the second shaping member are the same or different from each other;
The method for removing a coating layer according to claim 3 or 4. The step of removing the coating layer is a step of transferring the coating layer from the base film to an adhesive roll.
The method for removing a coating layer according to claim 1 or 2. The step of removing the coating layer is a step of scraping the coating layer off the base film using a blade or a wire brush.
The method for removing a coating layer according to claim 1 or 2. The step of removing the coating layer is a step of scraping off the coating layer from the base film with a blast material.
The method for removing a coating layer according to claim 1 or 2. 1. An apparatus for removing a coating layer from a laminate film having a base film and a coating layer, comprising:
A pressing means for pressing the laminated film at a plurality of pressing points;
a removing means for removing the coating layer from the pressed laminated film,
the pressing means is a means for pressing such that a tensile stress is applied to one surface of the laminated film and a compressive stress is applied to the other surface of the laminated film at each of the plurality of pressing points;
Coating layer removal device.

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