Manufacturing methods for recycled materials

Abstract

This recycle material manufacturing method comprises: a step for unspooling a laminate film in one direction from a roll on which the laminate film is spooled, the laminate film comprising an elongate base material film extending in the one direction and at least one layer of a function layer formed on one surface of the base material film; a step for pressing a removal member for peeling the function layer onto the one surface side of the laminate film to remove the function layer; and a step for spooling the laminate film from which the function layer has been removed into a roll. Between the unspooling step and the spooling step, the laminate film is not contacted with an organic solvent.

Description

Technical Field

[0001] The present invention relates to a method for producing a recycled material, a recycled material, a method for producing a reclaimed material, and an apparatus for producing a recycled material. The present application claims priority based on Japanese Patent Application No. 2022-054763 filed on March 30, 2022 and Japanese Patent Application No. 2022-189933 filed on November 29, 2022, the contents of which are incorporated herein by reference. Background Art

[0002] With the increasing environmental awareness in recent years, reduction and reuse of waste plastics have been actively studied as a response to a recycling-oriented society. For example, regarding a laminated film in which functional layers such as a hard coat layer and an adhesive layer are provided on the surface of a polyester film (resin film), a technology is known in which the functional layers are removed to obtain a polyester film, and the obtained polyester film is reused (see, for example, Patent Document 1). Specifically, Patent Document 1 discloses a method of removing functional layers such as a hard coat layer and an adhesive layer by treating with a chemical containing an alkalizing agent and a compound having a hydroxyl group such as benzyl alcohol. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2021-160350 Summary of the Invention Problems to be Solved by the Invention

[0004] However, in the method described in Patent Document 1, the polyester constituting the polyester film may swell and deteriorate due to the benzyl alcohol used when removing the functional layer. In addition, the polyester constituting the polyester film may be hydrolyzed by the alkalizing agent used to remove the functional layer. Therefore, in the method described in Patent Document 1, the physical properties of the polyester film obtained as recycled material may deteriorate from those of the polyester film constituting the original laminated film, potentially limiting the uses of the recycled material.

[0005] Furthermore, when reusing a resin film by removing the functional layer from a laminated film that uses a material other than polyester film as the resin film, a similar method is required to suppress the degradation of the resin film.

[0006] The present invention has been made in view of these circumstances, and aims to provide a method for manufacturing recycled material and an apparatus for manufacturing recycled material, which remove the functional layer from a laminated film of a base film and a functional layer without degrading the physical properties of the base film. The invention also aims to provide a method for manufacturing recycled material, which is obtained, and a method for manufacturing recycled material, which is produced by using the recycled material as a raw material for a molded article. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present invention includes the following aspects.

[0008] [A1] A method for manufacturing recycled material, comprising the steps of: unwinding a laminated film in the one direction from a roll from which a laminated film comprising a long base film extending in one direction and at least one functional layer formed on one surface of the base film has been wound; pressing a removal member for peeling off the functional layer against the side of the one surface of the laminated film to remove the functional layer; and winding the laminated film from which the functional layer has been removed into a roll, wherein the base film is made of polyester, and the laminated film is not brought into contact with an alkaline solution between the unwinding step and the winding step.

[0009] [A2] The method for producing recycled material according to [A1], wherein the laminated film is not brought into contact with the organic solvent between the unwinding step and the winding step.

[0010] [A3] A method for manufacturing recycled material according to [A1] or [A2], wherein in the step of removing the functional layer, the functional layer is polished while water is sprayed on the surface.

[0011] [A4] The method for manufacturing recycled material according to [A3], wherein in the step of removing the functional layer, hot water is sprayed on one surface.

[0012] [A5] A method for manufacturing recycled material according to any one of [A1] to [A4], comprising the step of heating the laminated film prior to the step of removing the functional layer.

[0013] [A6] The method for manufacturing recycled material according to [A5], wherein in the heating step, the laminated film is immersed in hot water.

[0014] [A7] A recycled material comprising a long base film extending in one direction, wherein a plurality of grooves extending along the one direction are formed on one surface of the base film, the base film is made of polyester, and the intrinsic viscosity of the polyester is 0.5 dL / g or more.

[0015] A method for manufacturing recycled material, comprising a step of melting and molding the recycled material described in [A8] and [A7].

[0016] Furthermore, in order to solve the above-mentioned problems, the present invention includes the following embodiments.

[0017] [1] A method for manufacturing recycled material, comprising the steps of: unwinding a laminated film in the one direction from a roll from which a laminated film comprising a long base film extending in one direction and at least one functional layer formed on one surface of the base film has been wound; pressing a removal member for peeling off the functional layer against the side of the one surface of the laminated film to remove the functional layer; and winding the laminated film from which the functional layer has been removed into a roll, wherein the laminated film and organic solvent are not brought into contact between the unwinding step and the winding step.

[0018] [2] The method for producing recycled material according to [1], wherein the base film is made of polyester, and the laminated film is not brought into contact with the alkaline solution between the unwinding step and the winding step.

[0019] [3] A method for manufacturing recycled material according to [1] or [2], wherein in the step of removing the functional layer, the functional layer is removed while water is sprayed on the surface.

[0020] [4] The method for manufacturing recycled material according to [3], wherein in the step of removing the functional layer, hot water is sprayed on the surface.

[0021] [5] A method for manufacturing recycled material according to any one of [1] to [4], comprising the step of heating the laminated film prior to the step of removing the functional layer.

[0022] [6] The method for producing recycled material according to [5], wherein in the heating step, the laminated film is immersed in hot water.

[0023] [7] A recycled material comprising a long base film extending in one direction, wherein one surface of said base film has a plurality of recessed grooves extending along said one direction.

[0024] [8] The recycled material according to [7], wherein said base film is made of polyester, and the intrinsic viscosity of said polyester is 0.5 dL / g or more.

[0025] [9] A method for producing a regenerated material, comprising a step of melting and molding the recycled material according to [7] or [8].

[0026]

[10] A roll obtained by winding a laminated film comprising a long base film extending in one direction and at least one functional layer formed on one surface of said base film , an apparatus for producing a recycled material, comprising: a feeding section that feeds out said laminated film in said one direction from the roll; a pretreatment section that performs a pretreatment promoting removal of said functional layer without using an organic solvent; a removing section that removes said functional layer by pressing a removing member for peeling off said functional layer against the one surface side of said laminated film; and a winding section that winds said laminated film from which said functional layer has been removed into a roll. Advantageous Effects of the Invention

[0027] According to the present invention, it is possible to provide a method and an apparatus for producing a recycled material, which remove the functional layer from a laminated film composed of a base film and the functional layer without deteriorating the physical properties of the base film. Furthermore, the present invention can provide the obtained recycled material, and a method for producing a regenerated material that uses the recycled material as a raw material to produce a molded article. Brief Description of the Drawings

[0028] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a laminated film 5 to be processed in the method for producing a recycled material. [Figure 2] FIG. 2 is a schematic explanatory view of the method for producing a recycled material and the apparatus for producing a recycled material according to the present embodiment. [Figure 3]Figure 3 is a magnified photograph of recycled material 1. [Figure 4] Figure 4 is a schematic diagram illustrating a modified example of a recycled material manufacturing apparatus. [Figure 5] Figure 5 is a schematic diagram illustrating a modified example of a recycled material manufacturing apparatus. [Figure 6] Figure 6 is a graph showing the results of the example. [Modes for carrying out the invention]

[0029] The following description will explain the method for manufacturing recycled materials, the method for manufacturing recycled materials and recycled materials, and the apparatus for manufacturing recycled materials according to this embodiment, with reference to Figures 1 to 5. Note that in all the following drawings, the dimensions and proportions of each component have been appropriately altered for clarity.

[0030] Figure 1 is a schematic cross-sectional view showing a laminated film 5 processed in the manufacturing method of recycled material according to this embodiment. The laminated film 5 has a base film 2 and a functional layer 3 provided on one surface 2a of the base film 2. The laminated film 5 shown in Figure 1 has the functional layer 3 on only one surface 2a of the base film 2, but is not limited to this. The laminated film 5 may have the functional layer 3 on both sides of the base film 2. Furthermore, the layers to be removed from the laminated film 5 may be provided discretely, such as dirt or partially printed paint.

[0031] The base film 2 is a long resin film that extends in one direction. Polyester can be used as the material for the resin film. Examples of polyesters that can be used include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). In addition to these, any polyester that can be used as a film material can be used as appropriate. These polyesters may be used individually or in combination of two or more types (polymer blend).

[0032] Polyethylene, polyolefins such as polypropylene, and polyamides can also be used as materials for the resin film. In addition, any other resin known as a material for resin films may be used as appropriate.

[0033] The functional layer 3 is provided on one surface 2a of the base film 2 and imparts various functions to the base film 2. The functional layer 3 is not particularly limited and can be, for example, a release layer, a mold release layer, an antistatic layer, a printing layer, an adhesive layer, etc. The functional layer 3 may be provided as a single layer on one surface 2a, or two or more layers may be laminated together.

[0034] For example, if the functional layer 3 is a release layer, a silicone-based release agent may be used as the material for the release layer, and the functional layer 3 may be formed on one surface 2a of the base film 2. A laminated film 5 having such a functional layer 3 is used as a release film that is bonded to the adhesive surface of surface protection films for various industrial products. The laminated film 5 is also used as a carrier film when manufacturing ceramic chip capacitors.

[0035] Traditionally, laminated films used in these applications were collected and discarded by the manufacturer after their use in each application was complete. Furthermore, even when attempts were made to recycle these laminated films materially or chemically, the inclusion of materials from functional layer 3 (for example, silicone-based release agents if functional layer 3 is a release layer) reduced the value of the laminated film as a recyclable material.

[0036] Furthermore, a method using alkaline treatment is known for removing the functional layer 3 from the laminated film 5 (see Patent Document 1 mentioned above). However, when the base film 2 is made of polyester, the polyester undergoes hydrolysis due to the alkaline treatment. As a result, the polyester in the base film 2 obtained by removing the functional layer 3 becomes low molecular weight, which may reduce the value of the base film 2 as a material.

[0037] While the conventional problems were explained using the example of a case where the functional layer 3 is a release layer, similar problems can arise when recycling a laminated film in which the functional layer 3 has other functions, namely, the inclusion of materials from the functional layer or a decrease in the value of the base film due to the removal of the functional layer.

[0038] In the method for manufacturing recycled material according to this embodiment, the above-mentioned problems are solved, and the functional layer 3 can be easily removed from the laminated film 5 to obtain recycled material consisting of a base film 2.

[0039] Figure 2 is a schematic diagram illustrating the method for manufacturing recycled materials and the apparatus for manufacturing recycled materials according to this embodiment. The apparatus for manufacturing recycled materials 100 shown in Figure 2 (hereinafter referred to as the apparatus for manufacturing materials 100) is used to carry out the method for manufacturing recycled materials according to this embodiment.

[0040] The manufacturing apparatus 100 includes a dispensing unit 10, a heating unit 20, a removal unit 30, a washing unit 40, a drying unit 50, a winding unit 60, and a control unit 90. The manufacturing apparatus 100 is a device that produces recycled material consisting of a base film 2 by transporting a long laminated film 5 in the longitudinal direction and removing the functional layer during the transport process.

[0041] In Figure 2, the relative positions are sometimes explained by defining the horizontal direction, which is the transport direction of the laminated film 5, as the x-direction and the vertical direction as the y-direction. The following explains the process step by step.

[0042] (Retraction mechanism) The dispensing unit 10 dispenses the laminated film 5 in the longitudinal direction from the roll 5R on which the laminated film 5 is wound. The operation performed by the dispensing unit 10 corresponds to the "dispensing process" in the present invention. An example of the roll 5R is a roll of used release film or carrier film wound into a roll shape.

[0043] These laminated films are typically wound into a roll after use and recovered from the point of use. The recovered roll of laminated film may be used as roll 5R as is. Alternatively, if the width (length in the shorter direction) of the laminated film 5 constituting roll 5R is wider than the width that can be processed by the manufacturing device 100, the laminated film 5 may be slit beforehand to adjust the width of roll 5R.

[0044] The laminated film 5 is transported with the functional layer 3 facing upwards (+y side). The transport speed of the laminated film 5 is, for example, 1 m / min to 10 m / min.

[0045] (heating part) The heating unit 20 is located downstream (+x side) of the conveying direction of the laminated film 5 relative to the dispensing unit 10, and heats the conveyed laminated film 5. The processing performed in the heating unit 20 corresponds to the "heating process" in the present invention. By heating the laminated film 5 in the heating unit 20, it is expected that the removal of the functional layer 3 in the removal unit 30, which will be described later, will be accelerated. The heating unit 20 performs a pretreatment that accelerates the removal of the functional layer 3 without using organic solvents. For this reason, the heating unit 20 corresponds to the "pretreatment unit" in the present invention.

[0046] The heating unit 20 has a treatment tank 21 in which hot water HW is stored. The treatment tank 21 may have a heater (not shown) for adjusting the temperature of the hot water HW, as well as water supply piping and drainage piping connected to the treatment tank 21.

[0047] In the heating section 20, the laminated film 5 is conveyed using conveyor rolls 101, 102, and 103. Of these, conveyor roll 102 is placed in the hot water HW of the processing tank 21. As a result, the conveyed laminated film 5 passes through the hot water HW and is heated.

[0048] The temperature of the hot water HW should be set according to the type of laminated film being processed, based on the relationship between the heating temperature of the laminated film 5 after passing through the heating section 20 and the effect of removing the functional layer 3 in the removal section 30, which will be described later. The relationship between the temperature of the hot water HW and the effect of removing the functional layer 3 should be determined in advance through preliminary experiments.

[0049] The heating temperature of the laminated film 5 refers to "the temperature of the laminated film 5 at the outlet of the heating section 20." The heating temperature of the laminated film 5 can be measured using a known non-contact thermometer.

[0050] Furthermore, when the transport speed of the laminated film 5 is relatively fast within the settable speed range, the time it takes to pass through the hot water HW becomes relatively shorter. Therefore, when increasing the transport speed, it is advisable to raise the temperature of the hot water HW so that the desired heating can be achieved in a short time.

[0051] For example, the temperature of the hot water HW is 40°C to 90°C. It is preferable to use a treatment tank 21 containing hot water HW as the heating unit 20 and immerse the laminated film 5 in the hot water HW, as this allows for effective heating of the laminated film 5 in a short time.

[0052] In addition to immersing the laminated film 5 in the hot water HW described above, other heating methods in the heating section 20 include blowing hot air onto the laminated film 5 and passing the laminated film 5 through a heated environment. Examples of "passing through a heated environment" include passing through a chamber with a heated interior or passing near a heat source such as a heater. By adopting these methods for the heating section 20, the laminated film 5 can be heated to a temperature higher than the boiling point of water.

[0053] The heating temperature in the heating section 20 is, for example, 20°C to 250°C. The lower limit of the heating temperature is set to a temperature higher than the ambient temperature in which the recycled material manufacturing method of this embodiment is carried out. For example, when carrying out the recycled material manufacturing method in winter or in a cold region, heating to 20°C may be considered heating. The upper limit of the heating temperature is set to a temperature below the melting point of the base film that constitutes the laminated film to be processed.

[0054] (Removal part) The removal unit 30 is located downstream of the heating unit 20 in the direction of transport of the laminated film 5, and removes the functional layer 3 from the transported laminated film 5. The processing performed in the heating unit 20 corresponds to the "removal step" in the present invention. (Removal step). The removal unit 30 has a first removal means 30A and a second removal means 30B.

[0055] The first removal means 30A includes nip rolls 31 and 32, a buff roll (removal member) 33, and a watering means 34.

[0056] The nip roll 31 has rolls 311 and 312. The nip roll 31 holds the laminated film 5 between the rolls 311 and 312 and conveys it.

[0057] Furthermore, the nip roll 32 has rolls 321 and 322. The nip roll 32 is located downstream of the nip roll 31 and conveys the laminated film 5 by clamping it between the rolls 321 and 322.

[0058] The buff roll 33 is a cylindrical member positioned between the nip roll 31 and the nip roll 32, and rotates around its cylindrical axis. The axial length of the buff roll 33 is longer than the widthwise length of the laminated film 5 being conveyed. The buff roll 33 is positioned to intersect and straddle the laminated film 5, and in its rotated state, is pressed against the side of the laminated film 5 from above (+y side) towards one surface 2a. As a result, the buff roll 33 polishes and physically peels off the functional layer 3 provided on the side of one surface 2a.

[0059] The buff roll 33 may be fixed in position during operation, or it may swing in the axial direction of the cylinder, i.e., in the width direction of the laminated film 5. If the buff roll 33 is swingable, it is preferable that it has a swinging part that swings the buff roll 33 in the width direction of the laminated film 5 while it is rotated. The swinging part should be able to appropriately set the swing width and swing period of the buff roll 33.

[0060] The rotation direction of the buff roll 33 may be in the same direction as the transport direction of the laminated film 5 (forward rotation) at the point of contact with the laminated film 5, or it may be in the opposite direction to the transport direction of the laminated film 5 (reverse rotation). If the buff roll 33 is set to rotate in the reverse direction, it is expected that the effect of removing the functional layer 3 will be enhanced.

[0061] Furthermore, when the buff roll 33 is rotating forward, the laminated film 5 will be fed in the transport direction, and it is expected that the speed will exceed the set film transport speed. Therefore, when the buff roll 33 is rotating forward, it is advisable to adjust the film transport speed so as not to exceed the winding speed of the winding unit 60.

[0062] A backup roll or support plate may be provided below the point where the buff roll 33 and the laminated film 5 come into contact (on the opposite side of the laminated film 5 from the buff roll 33). By providing these backup rolls or support plates, the laminated film 5 will not bend due to the pressure from the buff roll 33, and the functional layer 3 can be removed efficiently.

[0063] Buffroll 33 is a component formed from a nonwoven fabric containing an abrasive into a cylindrical shape. Natural fibers such as cotton and linen, or synthetic fibers such as polyester and nylon can be used as materials for Buffroll 33. The material and particle size of the abrasive contained in Buffroll 33 can be appropriately selected according to the composition (material, thickness) of the functional layer 3 to be removed.

[0064] The rotation speed of the buffing wheel 33 should be set according to the type of laminated film being processed, based on the relationship between the rotation speed and the effect of removing the functional layer 3. The relationship between the rotation speed and the effect of removing the functional layer 3 should be determined in advance through preliminary experiments.

[0065] The pressure applied to the laminated film 5 from the buffing roll 33 can be adjusted by the height of the central axis of the buffing roll 33. That is, the height of the central axis of the buffing roll 33 that contacts the laminated film 5 without pressing when it is supported without slack by the nip rolls 31 and 32 is used as the reference position, and the pressure can be adjusted by the distance the central axis moves when the buffing roll 33 is lowered. The above pressure should be set according to the type of laminated film being processed, based on the correspondence between the position of the buffing roll 33 and the effect of removing the functional layer 3. The correspondence between the position of the buffing roll 33 and the effect of removing the functional layer 3 should be determined in advance through preliminary experiments.

[0066] Alternatively, the pressure applied to the laminated film 5 from the buff roll 33 may be used to adjust the entry angle of the laminated film 5 relative to the buff roll. The "entry angle of the film relative to the buff roll" can be understood as a downward angle relative to a virtual straight line connecting the laminated films supported by the nip rolls before and after the buff roll. For example, if the virtual straight line connecting the laminated films 5 supported by the nip rolls 31 and 32 (the transport position of the laminated film 5 when the buff roll 33 is absent) extends horizontally, the downward angle can be expressed as a downward angle relative to the horizontal direction. The downward angle can be increased by lowering the buff roll 33. The relationship between the entry angle of the film relative to the buff roll and the effect of removing the functional layer 3 should be determined in advance through preliminary experiments.

[0067] When the buffing wheel 33 pushes down the laminated film 5, strong pressure is applied to the laminated film 5 from the buffing wheel 33, making it easier for a force corresponding to the rotation direction of the buffing wheel 33 to be applied. When the buffing wheel 33 is rotating in the forward direction, a force is applied that pushes the laminated film 5 located downstream of the buffing wheel 33 further downstream. As a result, the laminated film 5 may slacken downstream, which can lead to uneven processing and difficulty in winding in the winding section 60 described later.

[0068] Furthermore, when the buff roll 33 rotates in reverse, a force is applied that pulls the laminated film 5, which is located downstream of the buff roll 33, back upstream. If the pressure applied to the laminated film 5 from the buff roll 33 is increased, the resulting "pull-back force" becomes stronger than the winding force applied downstream by the winding unit 60, which will be described later, and the laminated film 5 may move in reverse, preventing the processing from progressing.

[0069] In these cases, by adjusting the holding force of the laminated film 5 by the nip rolls 31 and 32, the laminated film 5 can be held securely between the nip rolls 31 and 32, and even if high pressure is applied from the buff roll 33, the reverse movement of the laminated film 5 can be suppressed.

[0070] Furthermore, the nip rolls 31 and 32 are designed to feed the laminated film 5 downstream at the same speed as the winding speed of the winding unit 60. Since the laminated film 5 is fed downstream using both the winding unit 60 and the nip rolls 31 and 32, a difference in transport speed between the winding unit 60 and the nip rolls 31 and 32 will occur, which may cause slack in the laminated film 5 downstream of the nip roll 32. For this reason, a dancer roll may be provided downstream of the nip roll 32 to allow adjustment of the tension of the laminated film 5.

[0071] The watering means 34 sprays water onto the upper surface (+x side) of the laminated film 5 from the upstream side (-x side) of the contact point between the buffing roll 33 and the laminated film 5. The buffing roll 33 polishes the surface of the laminated film 5 while the surface of the laminated film 5 is wet. The watering means 34 suppresses the frictional heat at the contact point between the buffing roll 34 and the laminated film 5 and washes away the fine shavings generated by polishing.

[0072] The configuration of the watering means 34 is not particularly limited; for example, a known shower head capable of spraying water in the width direction of the laminated film 5 can be used.

[0073] The water W used for watering may be at room temperature or it may be hot water. The temperature of the hot water is, for example, 30°C to 40°C.

[0074] The second removal means 30B includes nip rolls 35 and 36, a buff roll (removal member) 37, and a watering means 38. The nip roll 35 has rolls 351 and 352. The nip roll 36 has rolls 361 and 362. The nip rolls 35 and 36 and the watering means 38 can be configured in the same way as the first removal means 30A.

[0075] The buffing rod 37 of the second removal means 30B may be the same as or different from the buffing rod 33 of the first removal means 30A. Furthermore, the operating conditions of the buffing rod 37 may be the same as or different from those of the buffing rod 33.

[0076] In Figure 2, the removal unit 30 is shown to have a first removal means 30A and a second removal means 30B, but it is not limited to this. The removal unit 30 may have one or more removal means, with a configuration similar to the first removal means 30A (nip roll, buff roll, watering means) as a set of removal means. The removal unit 30 is preferably configured to have two to four removal means.

[0077] Furthermore, although a buffing roller is used as the removal member in this embodiment, other configurations can be adopted as long as they can strip off the functional layer. For example, cylindrical rotating brushes, rubber rollers, and grinding wheels can also be used as removal members.

[0078] The removal member is preferably configured to remove the functional layer by applying friction to the contact point while rotating and bringing it into contact with the functional layer. The rotation axis of the removal member is preferably set in a direction intersecting the transport direction of the laminated film 5. In the manufacturing apparatus 100 in Figure 2, the buff rolls 33 and 37, which are removal members, are both set in a direction perpendicular to the transport direction of the laminated film 5. However, the angle of the rotation axis with respect to the transport direction of the laminated film may be the same or different for multiple buff rolls (removal members).

[0079] (Washing section, drying section) The laminated film 5 (i.e., the base film 2) from which the functional layer 3 has been removed in the removal section 30 is conveyed downstream using conveyor rolls 104, 105, 106, and 107. The manufacturing apparatus 100 has a washing section 40 and a drying section 50 downstream of the removal section 30, in that order.

[0080] The washing unit 40 has a water spraying means 41 provided above the conveyed base film 2, and washes the upper surface (one side 2a) of the laminated film 5 after the functional layer 3 has been removed. The water spraying means 41 sprays water onto the upper surface of the laminated film 5. The configuration of the water spraying means 41 is not particularly limited, and for example, a known shower head capable of spraying water in the width direction of the laminated film 5 can be used.

[0081] The drying section 50 has an air knife 51 and a hot air blower 52, in that order from the upstream side. The air knife 51 blows compressed air toward one surface 2a of the base film 2 to remove water from that surface 2a. The direction in which the compressed air is blown should be inclined toward the upstream side relative to the surface 2a.

[0082] The hot air blower 52 blows hot air H toward one surface 2a of the base film 2 to dry that surface 2a. The temperature of the hot air H is, for example, 50°C to 70°C.

[0083] (winding section) The winding unit 60 winds the transported base film 2 (i.e., recycled material 1) into a roll. The roll 1R wound by the winding unit 60 is used as raw material for material recycling or chemical recycling.

[0084] Furthermore, if the functional layer is formed on both sides of the base film in the laminated film to be processed, the recycled material can be obtained by passing the laminated film through the manufacturing apparatus 100 twice to remove the functional layer from both sides of the base film.

[0085] (Control Unit) The control unit 90 controls the operating conditions of each component of the manufacturing apparatus 100. Furthermore, the control unit 90 should store the correspondence between the type of laminated film 5 to be processed and the operating conditions of each part, allowing it to retrieve and change the appropriate operating conditions each time the type of laminated film 5 being processed is changed.

[0086] For example, if the functional layer of the laminated film 5 is a release layer, a silicone-based release agent is provided across the entire surface of the laminated film 5. In this case, the buffing tool pressed against the functional layer may slip on the surface of the functional layer (release layer), preventing proper removal. In this case, it is necessary to press the buffing tool firmly against the laminated film.

[0087] Furthermore, if the functional layer is a printed layer, the ease of removing the functional layer will vary depending on the printing conditions, such as whether it is a single-color or multi-color print, the presence or absence of an undercoat (overcoat), and the type of ink used.

[0088] Therefore, it is necessary to set appropriate operating conditions according to the type of laminated film 5 being processed, that is, according to the type of functional layer. On the other hand, when recycling laminated films, it is expected that laminated films with the same configuration will be processed repeatedly. Therefore, by storing the correspondence between the type of laminated film 5 and the operating conditions of each part in the control unit 90, switching between processing targets becomes easier.

[0089] As described above, in the manufacturing apparatus 100, the functional layer 3 is physically peeled off using buffing rods 33 and 37. In other words, in the method for manufacturing recycled material using the manufacturing apparatus 100 described above, the laminated film 5 is not brought into contact with the organic solvent from the dispensing section 10 to the winding section 60, that is, from the dispensing process to the winding process. This suppresses deterioration and swelling of the recycled material 1, and allows the functional layer 3 to be removed from the laminated film 5 without degrading the physical properties of the base film 2, thereby manufacturing the recycled material 1. Furthermore, it reduces the environmental impact of manufacturing the recycled material 1.

[0090] Furthermore, in the manufacturing apparatus 100, the laminated film 5 is not brought into contact with the alkaline solution. As a result, when the material of the base film 2 is polyester, hydrolysis of the base film 2 can be suppressed, and the functional layer 3 can be removed from the laminated film 5 without degrading the physical properties of the base film 2, thereby producing the recycled material 1.

[0091] In this embodiment, "alkaline solution" refers to a solution with a pH of 8 or higher. Weakly basic solutions with a pH of 7 to 8 are not included in the definition of alkaline solution in this embodiment. In this regard, for example, the water W sprayed from the watering means in the removal unit 30 described above may contain a small amount of surfactant, in an amount that does not hinder the effects of the invention.

[0092] (Recycled material) Figure 3 is a magnified photograph of the recycled material 1 obtained by the above method. The recycled material 1 consists of a polyester base film 2 from which the functional layer 3 has been removed.

[0093] In the figure, the direction indicated by symbol A is the width direction of the laminated film, and the direction indicated by symbol B is the longitudinal direction of the laminated film. As shown in Figure 3, multiple grooves extending in the longitudinal direction are formed on one surface 2a of the base film 2. In Figure 3, the grooves can be seen as white lines. The grooves are scratches formed by the buffing process described above.

[0094] Furthermore, if the recycled material 1 is made of polyester, the intrinsic viscosity (IV value) of the polyester constituting the recycled material 1 (base film 2) is 0.5 dL / g or higher. The intrinsic viscosity of the polyester constituting the base film 2 is preferably 0.55 dL / g or higher, and more preferably 0.6 dL / g or higher.

[0095] The intrinsic viscosity of films (base films, recycled materials) can be measured using a method compliant with JIS K 7390.

[0096] Generally, in laminated films 5 used as release films or carrier films, the intrinsic viscosity of the base film 2 is approximately 0.6 dL / g. When removing the functional layer 3 from such a laminated film 5, using an alkaline solution (basic substance) may cause hydrolysis of the base film 2, potentially reducing its intrinsic viscosity.

[0097] For example, when forming a film, the intrinsic viscosity of the polyester material is approximately 0.6 dL / g, and similarly, when spinning fibers, the intrinsic viscosity is approximately 0.5 dL / g. Therefore, when using recycled materials obtained from laminated films as materials for chemical recycling or material recycling, the recycled materials must have the intrinsic viscosity of each of the molded products mentioned above.

[0098] In contrast, in the manufacturing method of the recycled material of this embodiment, the alkaline solution does not come into contact with the laminated film 5, as described above. Therefore, the resulting recycled material 1 does not have a decrease in the intrinsic viscosity of polyester and can be suitably used as a material for chemical recycling or material recycling.

[0099] Furthermore, "without decrease" means that a decrease in intrinsic viscosity within the measurement error range is acceptable.

[0100] Furthermore, recycled material 1 may be made from a resin other than polyester, which is exemplified as a material for the resin film.

[0101] The obtained recycled material can be melted and molded to produce recycled material. In other words, the method for producing recycled material according to this embodiment includes a step of melting and molding the recycled material described above. Examples of recycled material include the films and fibers described above.

[0102] According to the manufacturing method and apparatus for recycled materials with the above configuration, the functional layer can be removed from a laminated film of a base film and a functional layer without degrading the physical properties of the base film, and recycled materials that can be suitably used as materials for chemical recycling and material recycling can be manufactured.

[0103] Furthermore, recycled materials with the above composition can be suitably used as materials for chemical recycling and material recycling.

[0104] Furthermore, since the manufacturing method of recycled materials with the above-described configuration uses the aforementioned recycled materials as raw materials, it has a low environmental impact and can contribute to a circular economy.

[0105] Figures 4 and 5 are schematic diagrams illustrating modified examples of recycled material manufacturing equipment.

[0106] As shown in Figure 4, the recycled material manufacturing apparatus 150 (hereinafter referred to as the manufacturing apparatus 150) has a feeding unit 10 that feeds the laminated film 5 from two rolls 5R in the longitudinal direction of the laminated film 5. The feeding unit 10 feeds the laminated film 5 from, for example, roll 5RA, and as soon as it finishes feeding from roll 5RA it begins feeding from roll 5RB.

[0107] In the manufacturing device 150, roll 5RA is replaced with a new roll while unloading from roll 5RB. The roll replacement may be performed manually by an operator or the manager of the manufacturing device 150, or it may be performed automatically by the manufacturing device 150.

[0108] The manufacturing apparatus 150 has a connecting section 80 between the dispensing section 10 and the heating section 20 that connects the laminated film 5A dispensed from the roll 5RA and the laminated film 5RB dispensed from the roll 5RB within the transport path. The connecting section 80 has the function of connecting the rear end of one laminated film (e.g., laminated film 5A) and the front end of the other laminated film (e.g., laminated film 5B), and combining the two laminated films 5 dispensed from the two rolls 5R into one.

[0109] Furthermore, the manufacturing apparatus 150 has a dividing section 90 between the hot air blower 52 (drying section 50) and the winding section 60 that divides the conveyed recycled material 1 into two recycled materials 1A and 1B in the longitudinal direction. The dividing section 90 may divide the recycled material 1 into two recycled materials 1A and 1B at a location corresponding to the location where the laminated film 5A and laminated film 5B are connected, or it may be divided at any location.

[0110] For example, a known turret unwinding machine can be used for the unwinding section 10 and the connecting section 80.

[0111] For example, a known turret winding machine can be used for the winding section 60 and the splitting section 90.

[0112] The winding unit 60 alternately winds the recycled material 1 onto two rolls 1RA and 1RB. In the winding unit 60, for example, recycled material 1A is wound onto roll 1RA, and as soon as the set amount of material wound onto roll 1RA is reached, the winding unit switches to winding onto roll 1RB.

[0113] The roll replacement may be performed manually by an operator or the manager of the manufacturing equipment 150, or it may be performed automatically by the manufacturing equipment 150.

[0114] The control unit 90 controls the connection unit 80 and the splitting unit 90 to continuously perform the unwinding of the laminated film 5 and the winding of the recycled material 1. This enables continuous operation of the manufacturing apparatus 150.

[0115] Furthermore, as shown in Figure 5, the watering means 34 in the removal section 30 of the manufacturing apparatus 150 may include a wastewater tank 341, a filter 342, piping 343, a pump 344, and a shower head 345.

[0116] The wastewater tank 341 is located below the buffing rod 33 and receives and stores wastewater WW generated from the contact point between the buffing rod 33 and the laminated film 5.

[0117] Filter 342 removes solid matter (shavings) contained in the wastewater WW.

[0118] Piping 343 connects the wastewater tank 341, the filter 342, and the showerhead 345. The wastewater WW from which solid matter has been removed is supplied to the showerhead 345 via piping 343 by a pump 344 located within the path of piping 343.

[0119] The showerhead 345 sprays water W, from which solid matter has been removed from wastewater WW, onto the buffing rod 33.

[0120] Similarly, in the removal section 30, the watering means 38 may include a wastewater tank 381, a filter 382, ​​piping 383, a pump 384, and a shower head 385. Each component of the watering means 38 can be the same as each component of the watering means 34.

[0121] Furthermore, the watering means 34 and 38 may also be equipped with heating equipment to heat the water flowing through the pipes.

[0122] Because the manufacturing apparatus 150 has the above-described watering means, it is possible to recycle the water used to spray the buffing rod. This makes it possible to reduce the amount of wastewater and lower the environmental burden.

[0123] By combining the manufacturing method for recycled materials and the manufacturing method for regenerated materials of this embodiment, for example, used release films can be collected, and the functional layer can be removed from the collected release films to produce recycled materials. Furthermore, the obtained recycled material can be melted to produce a base film as a regenerated material, and a release layer (functional layer) can be formed on one surface to regenerate and use the release film. In this way, the present invention makes it possible to contribute to a circular economy.

[0124] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention. [Examples]

[0125] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0126] <Examples 1-3> In Examples 1-3, a release film was used as the laminated film, which had a release layer (functional layer) made of a silicone-based release agent on one side of a PET film. A 7cm x 12cm small piece was cut from the release film, and the base film side of the small piece was attached to a stainless steel plate to be used as a test specimen.

[0127] For the obtained test specimens, the functional layer exposed on the side opposite to the stainless steel plate was removed using a test machine similar to the removal section 30 of this embodiment.

[0128] (Method for measuring survival rate) The removal of the functional layer from the laminated film of the test specimen was determined by measuring the amount of silicone using a wavelength-dispersive X-ray fluorescence analyzer (ZSX Primus, Rigaku Corporation). A calibration curve was created by setting the amount of silicone A obtained from X-ray fluorescence measurement of the laminated film before the removal of the functional layer to 100%, and the amount of silicone B obtained from X-ray fluorescence measurement of only the PET film to 0%. The remaining percentage of the functional layer was then estimated from the amount of silicone C obtained from X-ray fluorescence measurement of the laminated film of the test specimen from which the functional layer had been removed.

[0129] Furthermore, if the measured value of silicone amount C was smaller than the measured value of silicone amount B, the remaining percentage of the functional layer was evaluated as 0% in all cases.

[0130] [Examples 1-1 to 1-5] In Examples 1-1 to 1-5, a test machine with the following configuration was used. (Common configuration of test machines) • First removal method: Buffroll: No. 320 • Second removal method: Buffroll: No. 600 • Buffing speed: 2000 rpm • Buff roll rotation direction: reverse direction • Watering method available • Distance traveled by the central axis of the buff roll relative to the reference position: 0.2 mm • Test specimen transport speed: 4 m / min

[0131] As shown in Table 1, the temperature conditions were changed and the survival rate of the functional layer was determined.

[0132] In the table, "preheating" refers to the immersion treatment in the heating section 20 of this embodiment. When "preheating" is performed, the test piece is immersed in warm water for 1 minute.

[0133] Furthermore, in the table, "shower temperature" refers to the temperature of the water sprayed from the water spraying means in the removal unit 30 of this embodiment.

[0134] [Table 1]

[0135] The evaluation results showed that the functional layer could be removed in all cases. Furthermore, it was found that heating the laminated film before removing the functional layer in the removal area made it easier to remove.

[0136] [Examples 2-1 to 2-4] In Examples 2-1 to 2-4, the test machine with the above configuration was used, and the rotation speed of the buffing roller was varied to 500 rpm (Example 2-1), 1000 rpm (Example 2-2), 1500 rpm (Example 2-3), and 2000 rpm (Example 2-4). In all cases, preheating was performed at 80°C.

[0137] Figure 4 is a graph showing the results for Examples 2-1 to 2-4. As shown in Figure 4, it can be seen that as the rotation speed of the buffing wheel increases, the retention rate of the functional layer decreases (the removal rate of the functional layer improves).

[0138] [Examples 3-1 to 3-24] In Examples 3-1 to 3-24, a test machine with the following configuration was used. In all cases, preheating was performed at 80°C, and the shower temperature was set to 50°C.

[0139] (Common configuration of test machines) • Removal method: Buff roll: No. 320 • Buffing speed: 2000 rpm • Buff roll rotation direction: reverse direction • Watering method available

[0140] As shown in Table 2, the remaining rate of the functional layer was determined by changing (1) the distance the central axis of the buffing roll moved relative to the reference position, (2) the number of times the test machine was passed, and (3) the transport speed. (1) corresponds to the pressure applied from the buffing roll to the laminated film. (2) corresponds to the number of removal means provided in the removal section of the manufacturing apparatus 100 of this embodiment.

[0141] [Table 2]

[0142] The evaluation results showed that, under conditions of high transport speed, the stronger the pressure applied from the buffroller to the laminated film, the easier it was to remove the functional layer. Furthermore, it was confirmed that increasing the number of buff rolls makes it easier to remove the functional layer.

[0143] Furthermore, while the functional layer tends to become more difficult to remove as the transport speed increases, it was found that the functional layer can be made easier to remove by adjusting the pressure applied from the buffing roller to the laminated film, as well as the number of buffing rollers.

[0144] The above results were obtained for release films having a release layer as a functional layer. However, since the functional layer is physically removed by buffing in this invention, it is expected that similar results will be obtained for laminated films having other functional layers.

[0145] <Examples 4, 5> In Example 4, a carrier film was used as the laminated film, in which a residue of MLCC (Multi-Layer Ceramic Capacitor) was attached to one side of a PET film. In Example 5, a printed film was used as the laminated film, in which a printed layer was formed on one side of a polyethylene film.

[0146] In Examples 4 and 5, the following test machines were used. Also, in both Examples 4 and 5, no preheating was performed. • First removal method: Buff roll: No. 240 • Second removal method: Buffroll: None • Buffing speed: 2000 rpm • Buff roll rotation direction: reverse direction • Watering method available; shower temperature 50℃ • Distance traveled by the central axis of the buff roll relative to the reference position: 0.3 mm

[0147] In Example 4, it was visually confirmed that the black MLCC residue had been removed. In laminated films, a release layer may be provided on the surface where the MLCC is laminated. If the laminated film has a release layer, it is assumed that the release layer is also removed by polishing to the extent that the MLCC residue is removed. In Example 5, it was visually confirmed that the printed layer had been removed.

[0148] The evaluation results showed that in Example 4, the MLCC residue was completely removed by passing the test specimen through the test machine only once at a transport speed of 4 m / min. These conditions are the same as those in Example 3-21, where some of the peeled layer remained.

[0149] Furthermore, in Example 5, the printed layer was removed by simply passing the test piece through the test machine once at a transport speed of 1 m / min. These conditions were the same as those in Examples 3-13, in which some of the release layer remained.

[0150] These results confirm that the appropriate operating conditions differ depending on the configuration of the laminated film.

[0151] <Examples 6-10> In Examples 6 to 10, the manufacturing apparatus with the configuration shown in Figure 2 was used. (Configuration of the manufacturing equipment) • Roll diameter of raw material: Maximum diameter 300mm • Conveying speed: 10m / min • Hot water temperature in the heating section: 90℃ • Immersion time in the heated section: 12 seconds per pass • First removal method: Buff roll: No. 240 • Second removal method: Buffroll: No. 240 • Buffing motion: Yes (except in Example 9) • Buff roll oscillation range: 10mm • Buffroll oscillation period: 140 cycles / minute Shower temperature: 50℃ • Buffing speed: Maximum 2000 rpm • Film entry angle relative to the buff roll: 30°, 50°, 70° • Buff roll rotation direction: reverse direction

[0152] In Examples 6 to 10, similar to Example 1, a release film (laminated film) was used as the laminated film, having a release layer (functional layer) made of a silicone-based release agent on one side of a PET film. The release film was sequentially unwound from a roll of raw material wound with a long length of release film, and the functional layer was continuously removed.

[0153] A 30mm x 30mm test piece was cut from the film from which the functional layer had been removed, and the remaining percentage of the obtained test piece was determined according to the method described above (method for measuring remaining percentage).

[0154] <Example 6> The functional layer was removed under the following conditions. The remaining percentage of the functional layer is shown in Table 3. (conditions) Temperature of hot water in the heating section: 50°C or 90°C Buff roll rotation speed: 2000 rpm Number of passes (processing times): 1

[0155] [Table 3]

[0156] The evaluation results showed that the functional layer could be removed in all cases. Furthermore, it was found that a larger angle of film penetration into the buffing roll, i.e., lowering the position of the buffing roll and applying greater pressure from it, made it easier to remove the functional layer. Additionally, it was found that heating the laminated film before removing the functional layer in the removal section made it easier to remove.

[0157] <Example 7> The functional layer was removed under the following conditions. The remaining percentage of the functional layer is shown in Table 4. (conditions) Temperature of hot water in the heating section: 90℃ Buff roll rotation speeds: 1000 rpm, 1500 rpm, 2000 rpm Number of passes (processing times): 1

[0158] [Table 4]

[0159] The evaluation results showed that the functional layer could be removed in all cases. Furthermore, it was found that the higher the rotation speed of the buffing wheel, the easier it was to remove the functional layer.

[0160] <Example 8> The functional layer was removed under the following conditions. The remaining percentage of the functional layer is shown in Tables 5 and 6. Table 5 shows the results at a heating temperature of 90°C, and Table 6 shows the results at a heating temperature of 50°C. (conditions) Hot water temperature in the heating section: 50°C, 90°C Buff roll rotation speed: 1500 rpm, 2000 rpm Number of passes (processing times): 1 time, 2 times, 3 times

[0161] [Table 5]

[0162] [Table 6]

[0163] The evaluation results showed that the functional layer could be removed in all cases. Furthermore, as shown in Table 6, under the condition of a relatively low heating temperature of 50°C, it was found that a small angle of film penetration into the buffing rod tended to result in variability.

[0164] <Example 9> The functional layer was removed under the following conditions, and the effect of buff flow (with or without) was confirmed. The remaining percentage of the functional layer is shown in Table 7. (conditions) Temperature of hot water in the heating section: 90℃ Buff roll rotation speed: 1000 rpm, 2000 rpm Number of passes (processing times): 1

[0165] [Table 7]

[0166] The evaluation results showed that the functional layer could be removed in all cases. Furthermore, it was found that the higher the rotation speed of the buffing wheel, the easier it was to remove the functional layer by oscillating the buffing wheel.

[0167] Based on the above results, it has been confirmed that the present invention is useful. [Explanation of Symbols]

[0168] 1...Recycled material, 2...Base film, 2a...Single surface, 3...Functional layer, 5...Laminated film, 33,37...Buffing

Claims

1. A process of unwinding a laminated film from a roll from which a laminated film comprising a long base film extending in one direction and at least one functional layer formed on one surface of the base film has been wound, in the same direction. A step of pressing a removal member for peeling off the functional layer against one side of the laminated film and removing the functional layer, The process includes winding the laminated film, from which the functional layer has been removed, into a roll shape. The functional layer includes a silicone-based release layer provided in contact with the one surface, The removal member is pivotable in the width direction of the laminated film, A method for producing recycled material in which the laminated film and the organic solvent are not brought into contact between the unwinding step and the winding step.

2. The aforementioned base film is made of polyester, The method for producing recycled material according to claim 1, wherein the laminated film and the alkaline solution are not brought into contact between the unwinding step and the winding step.

3. A method for manufacturing recycled material according to claim 1 or 2, in the step of removing the functional layer, while spraying water on the surface of the functional layer.

4. The method for manufacturing recycled material according to claim 3, wherein in the step of removing the functional layer, hot water is sprayed onto the surface.

5. A method for manufacturing recycled material according to claim 1, further comprising the step of heating the laminated film prior to the step of removing the functional layer.

6. The method for producing recycled material according to claim 5, wherein in the heating step, the laminated film is immersed in hot water.

Images