Recycling methods for used PET film, pellets, and resin molded products

Abstract

This makes it possible to expand the uses of recycled PET film with ceramics attached to its surface to resin molded products formed by injection blow molding. [Solution] The method for recycling used PET film includes the steps of mechanically removing ceramics adhering to the surface of the used PET film (step S2), cleaning the surface of the used PET film from which the ceramics have been removed (step S3), processing the used PET film with the cleaned surface into flakes (step S4), processing the flakes into first pellets (step S5), adding a crystallization inhibitor to the first pellets (step S6), processing the first pellets with the added crystallization inhibitor into second pellets (step S7), and using the second pellets to form a resin molded product by injection blow molding (step S8).

Description

[Technical Field]

[0001] The present invention relates to a method for recycling used PET film, pellets, and resin molded articles, and more particularly to a method for recycling used PET film having ceramics attached to its surface, pellets, and resin molded articles. [Background technology]

[0002] In recent years, there has been a demand for the reuse of materials as a measure to conserve environmental resources. For example, PET film is used as a carrier film in the intermediate process of manufacturing multilayer electronic components such as multilayer ceramic capacitors, and there is a demand for the reuse of used PET film as well. For example, Patent Document 1 discloses a method for recycling used PET film, in which foreign matter adhering to the surface of the PET film is washed with a cleaning solution containing an organic solvent, and the cleaning solution adhering to the surface of the PET film is removed, thereby converting the used PET film into new PET film for recycling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-291690 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method for recycling used PET film disclosed in Patent Document 1 is limited to recycling used PET film into new PET film, and the applications in which used PET film can be reused are limited.

[0005] The present invention has been made in consideration of the above circumstances, and aims to expand the uses of recycled PET film with ceramics attached to its surface to resin molded products formed by injection blow molding. [Means for solving the problem]

[0006] A method for recycling used PET film according to one aspect of the present invention is a method for recycling used PET film having ceramics attached to its surface, and includes: a removal step of mechanically removing the ceramics attached to the surface of the used PET film from the used PET film; a flake processing step of processing the used PET film after the ceramics attached to the surface have been removed in the removal step into flakes; a first pellet processing step of processing the flakes produced in the flake processing step into first pellets; an addition step of adding a crystallization inhibitor to the first pellets produced in the first pellet processing step; a second pellet processing step of processing the first pellets to which the crystallization inhibitor has been added in the addition step into second pellets; and a molding step of molding a resin molded product by injection blow molding using the second pellets processed in the second pellet processing step.

[0007] Pellets according to one aspect of the present invention are pellets manufactured using used PET film having ceramics attached to its surface, in which the ceramics attached to the surface of the used PET film are mechanically removed from the used PET film, the used PET film after the ceramics attached to the surface are removed is processed into flakes, the flakes are processed into first pellets, a crystallization inhibitor is added to the first pellets, and the first pellets to which the crystallization inhibitor has been added are processed to produce pellets.

[0008] A resin molded article according to one aspect of the present invention is a resin molded article molded by injection blow molding using the above-described pellets.

[0009] Another aspect of the present invention relates to a method for recycling used PET film, which is a method for recycling used PET film having ceramics attached to its surface, and includes: a removal step of mechanically removing the ceramics attached to the surface of the used PET film from the used PET film; a flake processing step of processing the used PET film after the ceramics attached to the surface have been removed in the removal step into flakes; an addition step of adding a crystallization inhibitor to the flakes produced in the flake processing step; a pellet processing step of processing the flakes to which the crystallization inhibitor has been added in the addition step into pellets; and a molding step of molding a resin molded product by injection blow molding using the pellets processed in the pellet processing step.

[0010] Pellets according to another aspect of the present invention are pellets manufactured using used PET film having ceramics attached to its surface, in which the ceramics attached to the surface of the used PET film are mechanically removed from the used PET film, the used PET film from which the ceramics attached to the surface have been removed is processed into flakes, a crystallization inhibitor is added to the flakes, and the flakes to which the crystallization inhibitor has been added are processed to manufacture pellets.

[0011] A resin molded article according to another aspect of the present invention is a resin molded article molded by injection blow molding using the above-mentioned pellets. [Effects of the Invention]

[0012] In injection blow molding, for example, heated and molten resin is injected and filled into a mold at high temperature and pressure, then cooled and solidified to create a preform (injection molding). The heated and molten preform is then sandwiched between molds, and compressed air or other means is blown into the molten preform to inflate it, almost as if it were attached to the inside of the mold. The preform is then cooled and solidified (blow molding), resulting in a molded resin product. According to the present invention, the addition of a crystallization inhibitor can suppress crystallization of PET during cooling during injection molding (crystallization of the PET contained in the preform as the preform cools). This extends the time it takes for the PET to harden during blow molding after injection molding compared to when the crystallization inhibitor is not added, making it possible to expand the preform into a predetermined shape. This allows for the reuse of used PET film to be expanded to include resin molded products produced by injection blow molding. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an outline of a manufacturing process for a multilayer ceramic capacitor, illustrating that ceramics are attached to the surface of a used PET film used in a method for recycling a used PET film according to a first embodiment of the present invention. [Figure 2] 1A to 1C are diagrams illustrating steps in a method for recycling used PET films according to a first embodiment. [Figure 3] 3 is a diagram showing an outline of products etc. in the process of the method for recycling used PET film shown in FIG. 2. [Figure 4] 3 is an explanatory diagram for explaining the mechanism for removing ceramics adhered to the surface from a used PET film in the ceramic removal step of FIG. 2. FIG. [Figure 5] Graph (A) shows the results of measurements taken with a differential scanning calorimeter when no crystallization inhibitor was added, and graph (B) shows the results of measurements taken with a differential scanning calorimeter when a crystallization inhibitor was added. [Figure 6]10A to 10C are diagrams showing steps of a method for recycling used PET films according to a second embodiment. [Figure 7] 7A to 7C are diagrams showing an outline of products etc. in the process of the method of recycling used PET film shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0014] First Embodiment Hereinafter, a method for recycling used PET films according to a first embodiment of the present invention will be described with reference to the drawings.

[0015] First, we will explain about used PET film with ceramics attached to its surface.

[0016] PET film is used in the intermediate process of manufacturing multilayer electronic components such as multilayer ceramic capacitors. When PET film is used in the intermediate process of manufacturing multilayer electronic components, ceramics adhere to the surface of the PET film. When the multilayer electronic components are removed from the PET film in the intermediate process, the used PET film with the ceramics remaining on its surface becomes eligible for recycling.

[0017] The PET film is, for example, long and contains at least PET (polyethylene terephthalate) and silicone resin, with a PET content of, for example, 98% and a silicone resin content of 2% or less. The used PET film is a PET film that has been used in the manufacture of laminated electronic components, and the ceramics described above remain and adhere to the surface of the used PET film.

[0018] Next, the adhesion of ceramics to the surface of a PET film will be described with reference to Fig. 1. Fig. 1 is a diagram showing an outline of the manufacturing process of a multilayer ceramic capacitor, for explaining the adhesion of ceramics to the surface of a PET film used in a method for recycling used PET film.

[0019] The PET film 1 is, for example, long and includes at least PET and a silicone resin, and has a base film and a release layer formed on one side of the base film. The base film contains PET, and the release layer contains a silicone resin. By including the silicone resin in the release layer, the release layer can be made to have excellent release properties, and the amount of ceramic residue remaining on the surface of the release layer after removing the ceramic green sheet described below can be reduced.

[0020] As shown in Fig. 1(A), a slurry containing a dielectric ceramic powder, a binder, an organic solvent, etc. is applied in sheet form to the surface of a release layer constituting a PET film 1 by a doctor blade method or the like, and the organic solvent component is dried and removed to form a ceramic green sheet 2. The binder material is, for example, polyvinyl butyral (PVB) resin, etc. The organic solvent material is, for example, ethanol, toluene, etc.

[0021] 1(B), electrode patterns 3A to 3F are formed by screen-printing an electrode paste containing, for example, nickel on the surface of the ceramic green sheet 2. In FIG. 1, for the sake of simplicity, each of the electrode patterns 3A to 3F is represented by a square (□).

[0022] The ceramic green sheet 2 on which the electrode patterns 3A to 3F are formed is cut into rectangles, and the cut rectangular portions are peeled off from the PET film 1 to produce parts 4A to 4F of the multilayer ceramic capacitor (for one layer) as shown in Figure 1(C).

[0023] Furthermore, when the cut rectangular portion is peeled off from the PET film 1, a remnant 5 of the ceramic green sheet 2 remains on the used PET film 100, as shown in Figure 1(C). In this way, a used PET film 100 with ceramics attached to its surface is produced.

[0024] A predetermined number of parts for one layer of the multilayer ceramic capacitor are laminated. For example, as shown in Fig. 1(D), three parts 4A to 4C for one layer of the multilayer ceramic capacitor are laminated as the predetermined number, and an electrode pattern is formed on the outer surface of the laminated body to manufacture the multilayer ceramic capacitor 6.

[0025] The above-mentioned used PET film with ceramics attached to its surface is one example, and in the first embodiment, any used PET film with ceramics attached to its surface is eligible for recycling, regardless of how the ceramics became attached to the surface of the used PET film.

[0026] Next, the steps of the method for recycling used PET film having ceramics attached to its surface will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a diagram showing the steps of the method for recycling used PET film according to the first embodiment. Fig. 3 is a diagram showing an outline of the products and the like in the steps of the method for recycling used PET film shown in Fig. 2.

[0027] First, a used PET film having ceramics attached to its surface is prepared (preparation of used PET film: step S1). The used PET film contains at least PET and silicone resin. As shown in FIG. 3(A) , the used PET film 100 prepared in the preparation of used PET film in step S1 has ceramics 102 attached to a surface 101 of the used PET film 100. Note that FIG. 3(A) shows the used PET film 100 in a rolled state.

[0028] The ceramics adhering to the surface of the used PET film are mechanically removed from the used PET film (ceramics removal step: step S2). For example, in the ceramics removal step of step S2, as shown in Fig. 4, the used PET film 100 is unwound by rollers 150, 155, and the used PET film is rewound by rollers 150, 155 while a blade 200 is in contact with the surface 101 of the used PET film 100 to which the ceramics 102 are adhered. During the rewinding of the used PET film 100, the blade 200 contacts the ceramics 102 adhering to the surface 101 of the used PET film 100, thereby peeling and removing the ceramics 102 from the surface 101 of the used PET film 100. Note that a known method can be used for mechanically removing the ceramics in the ceramics removal step (step S2). By the ceramic removal process of step S2, the used PET film 100 having the ceramics 102 attached to the surface 101, the appearance of which is shown in Figure 3(A), becomes the used PET film 100 having the ceramics 102 attached to the surface 101 removed, the appearance of which is shown in Figure 3(B).

[0029] In the ceramic removal process (step S2), the silicone resin contained in the used PET film is left behind, and the ceramics attached to the surface are mechanically removed.In the ceramic removal process (step S2), the silicone resin is left behind when the ceramics attached to the surface are mechanically removed.

[0030] The surface 101 of the used PET film 100 from which the ceramics have been mechanically removed in the ceramics removal step (step S2) is washed (washing step: step S3). This washing is performed using, for example, an organic solvent.

[0031] In the first embodiment, the used PET film 100 after the ceramics 102 adhering to the surface 101 have been removed in the ceramic removal step (step S2) is processed into flakes (flake processing step: step S4). In the flake processing step (step S4), a known method can be used, for example, to crush the used PET film 100 using a known crusher (having a known structure and performing a known operation) to a size that can be fed into a known extruder (having a known structure and performing a known operation). In the flake processing step of step S4, flakes 110 shown in FIG. 3(C) are produced.

[0032] The flakes produced in the flake processing step (step S4) are processed into first pellets (first pellet processing step: step S5). In the first pellet processing step (step S5), a known method can be used, for example, by feeding the flakes produced in the flake processing step (step S4) into a known extruder, thermally melting them in the extruder, and producing first pellets of an easily processable size. In the first pellet processing step of step S5, first pellets 115 shown in FIG. 3(D) are produced.

[0033] A crystallization inhibitor is added to the first pellets produced in the first pellet processing step (step S5) (addition step: step S6). In the addition step of step S6, for example, an operator adds the crystallization inhibitor 120 to the first pellets 115, as shown in FIG. 3(E), and mixes the first pellets 115 and the crystallization inhibitor 120 so that they are evenly dispersed.

[0034] The first pellets to which the crystallization inhibitor has been added in the adding step (step S6) are processed into second pellets (second pellet processing step: step S7). In the second pellet processing step (step S7), a known method can be used, such as the method exemplified in the first pellet processing step (step S5) above. In the second pellet processing step of step S7, second pellets 125 shown in FIG. 3(F) are produced.

[0035] The second pellets produced in the second pellet processing step (step S7) are used to form a resin molded product by injection blow molding (molding step: step S8). In injection blow molding, for example, heated and molten resin is injected and filled into a mold at high temperature and pressure, then cooled and solidified to create a preform (injection molding (sometimes called injection molding)). The heated and molten preform is sandwiched between molds, and compressed air or the like is blown into the molten preform to inflate it and make it adhere to the inside of the mold. The preform is then cooled and solidified (blow molding (sometimes called hollow molding)). In other words, in injection blow molding, resin molded products are formed through two processes: injection molding and blow molding after injection molding. An example of a resin molded product formed by injection blow molding is a toner container bottle 130 for an image forming device, the external appearance of which is shown in FIG. 3(G).

[0036] As described above, in the ceramic removal step (step S2), the silicone resin contained in the used PET film is left behind, and the ceramics attached to the surface are mechanically removed. By leaving the silicone resin in this way, the resin molded product contains silicone resin. Therefore, the resin molded product molded in the molding step (step S8) is, for example, a sliding part, and the sliding part may be a sliding part of an image forming device or a sliding part other than an image forming device. An example of a sliding part of an image forming device is a toner container bottle 130 of an image forming device that requires sliding properties, which includes gears that require sliding properties.

[0037] The resin molded product molded in the molding process (step S8) may be, for example, a sliding part of the image forming device described above, a sliding part of a product other than the image forming device described above, a part other than a sliding part of an image forming device, a part other than a sliding part of a product other than an image forming device, or a product (a product requiring sliding properties, a product not requiring sliding properties).

[0038] Below, the results of measurements by a differential scanning calorimetry (DSC) without adding a crystallization inhibitor are compared with the results of measurements by a differential scanning calorimetry with adding a crystallization inhibitor (the first embodiment described above) using FIG. 5. FIG. 5(A) is a graph showing the results of measurements by a differential scanning calorimetry without adding a crystallization inhibitor, and FIG. 5(B) is a graph showing the results of measurements by a differential scanning calorimetry with adding a crystallization inhibitor. The horizontal axis of FIGS. 5(A) and 5(B) is temperature T (°C), and the vertical axis is heat flow (mW / g). The measurement conditions for FIGS. 5(A) and 5(B) were room temperature → 300°C → room temperature three times, with both the temperature increase and decrease rates being 20°C / min.

[0039] A differential scanning calorimeter is an instrument that measures the temperature of a reference material and a sample while applying a constant amount of heat, capturing the thermal properties of the sample as a temperature difference and measuring endothermic and exothermic reactions due to changes in the state of the sample.Measurements of thermal properties using a differential scanning calorimeter make it possible to understand not only simple heat-induced state changes such as melting, but also structural phase transitions and crystallization, and are widely used to evaluate the physical properties of polymeric materials, organic materials, metals, ceramics, etc.

[0040] As shown in Figure 5(A), the results of measurements using a differential scanning calorimeter when no crystallization inhibitor is added show that the heat flow peak (crystallization peak) is large when the temperature is decreasing (A1 in Figure 5(A)), but no heat flow peak (crystallization peak) can be confirmed when the temperature is increasing (A2 in Figure 5(A)). This type of PET material is not suitable for injection blow molding because it crystallizes when the temperature is decreasing (when the preform is cooling) during injection molding and hardens quickly during blow molding (it hardens before the preform is inflated into the predetermined shape during blow molding).

[0041] On the other hand, when a crystallization inhibitor was added to the first pellets, the results of differential scanning calorimetry (DSC) measurements showed a small heat flow peak (crystallization peak) during cooling (B1 in Figure 5(B)). In other words, crystallization during cooling was suppressed, and a heat flow peak (crystallization peak) was observed during heating (B2 in Figure 5(B)). This PET material (the second pellets used in the molding process in step S8) exhibited suppressed crystallization during cooling (preform cooling) during injection molding. This resulted in a longer crystallization and hardening time during blow molding compared to when a crystallization inhibitor was not added. (The preform can be expanded to a predetermined shape during blow molding by the time the PET material hardens.) Therefore, adding a crystallization inhibitor to the first pellets makes injection blow molding possible.

[0042] Furthermore, when comparing the case in Figure 5(A) where no crystallization inhibitor is added with the case in Figure 5(B) where a crystallization inhibitor is added, it can be seen that by adding the crystallization inhibitor, the peak of the heat flow during cooling shifts to lower temperatures.

[0043] According to the first embodiment described above, by adding a crystallization inhibitor to the first pellets and processing the first pellets with the added crystallization inhibitor into second pellets used to mold a resin molded product in the molding process of step S8, crystallization of the PET when the temperature is lowered during injection blow molding in the molding process of step S8 (crystallization of the PET contained in the preform when the preform is cooled) can be suppressed, and the time until the PET hardens in the blow molding performed after injection molding is longer than when the crystallization inhibitor is not added, making it possible to expand the preform into a predetermined shape. This makes it possible to expand the use of recycled PET film to include resin molded products molded by injection blow molding.

[0044] Second Embodiment A second embodiment of the method for recycling used PET film according to the present invention will be described below with reference to the drawings. The first embodiment of the method for recycling used PET film involves adding a crystallization inhibitor to first pellets produced by processing flakes, whereas the second embodiment of the method for recycling used PET film involves adding a crystallization inhibitor to flakes.

[0045] In the second embodiment, similar to the first embodiment, a used PET film having ceramics attached to its surface is the target for recycling. The PET film is, for example, long and contains at least PET and silicone resin, with a PET content of, for example, 98% and a silicone resin content of 2% or less. The used PET film has been used in the manufacture of laminated electronic components, and the ceramics remain and adhere to the surface of the used PET film.

[0046] Next, steps of a method for recycling used PET film having ceramics attached to its surface will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a diagram showing steps of a method for recycling used PET film according to a second embodiment. Fig. 7 is a diagram showing an outline of products etc. in the steps of the method for recycling used PET film shown in Fig. 6.

[0047] First, a used PET film having ceramics attached to its surface is prepared (preparation of used PET film: step S11). The used PET film contains at least PET and silicone resin. The used PET film 100 prepared in the preparation of used PET film in step S11 has ceramics 102 attached to a surface 101 of the used PET film 100, as shown in FIG. 7(A).

[0048] The ceramics adhering to the surface of the used PET film are mechanically removed from the used PET film (ceramics removal step: step S12). In the ceramics removal step (step S12), a known method can be used, such as the method exemplified in the ceramics removal step (step S2) of the first embodiment. By the ceramics removal step of step S12, the used PET film 100 having the ceramics 102 adhering to the surface 101, the appearance of which is shown in FIG. 7(A), becomes the used PET film 100 having the ceramics 102 adhering to the surface 101 removed, the appearance of which is shown in FIG. 7(B).

[0049] In the ceramic removal process (step S12), the silicone resin contained in the used PET film is left behind, and the ceramics attached to the surface are mechanically removed.In the ceramic removal process (step S12), the silicone resin is left behind when the ceramics attached to the surface are mechanically removed.

[0050] The surface 101 of the used PET film 100 from which the ceramics have been mechanically removed in the ceramics removal step (step S12) is washed (washing step: step S13) by, for example, the same method as in the washing step (step S3) of the first embodiment.

[0051] The used PET film 100 after the ceramics 102 adhering to the surface 101 have been removed in the ceramic removal step (step S12), or in the second embodiment, the used PET film 100 whose surface has been cleaned in the cleaning step (step S13), is processed into flakes (flake processing step: step S14). In the flake processing step (step S14), a known method can be used, such as the method exemplified in the frame processing step (step S4) of the first embodiment. In the flake processing step of step S14, flakes 110 shown in FIG. 7(C) are produced.

[0052] A crystallization inhibitor is added to the flakes produced in the flake processing step (step S14) (addition step: step S15). As the crystallization inhibitor, for example, the same crystallization inhibitor as the crystallization inhibitor added to the first pellets in the addition step (step S6) of the first embodiment can be used. In the addition step of step S15, for example, an operator adds the crystallization inhibitor 120 to the flakes 110 and mixes them so that the flakes 110 and the crystallization inhibitor 120 are evenly dispersed, as shown in FIG. 7(D).

[0053] The flakes to which the crystallization inhibitor has been added in the adding step (step S15) are processed into pellets (pellet processing step: step S16). In the pellet processing step (step S16), a known method can be used, such as the method exemplified in the first pellet processing step (step S5) of the first embodiment. In the pellet processing step of step S16, pellets 127 shown in FIG. 7(E) are produced.

[0054] The pellets produced in the pellet processing step (step S16) are used to form a resin molded product by injection blow molding (molding step: step S17). The resin molded product formed by injection blow molding is, for example, a toner container bottle 130 for an image forming device, the external appearance of which is shown in Figure 7(F).

[0055] As described above, in the ceramic removal step (step S12), the silicone resin contained in the used PET film is left behind, and the ceramics adhering to the surface are mechanically removed. By leaving the silicone resin in this way, the resin molded product contains silicone resin. Therefore, the resin molded product molded in the molding step (step S17) is, for example, a sliding part, and the sliding part may be a sliding part of an image forming device or a sliding part other than an image forming device. An example of a sliding part of an image forming device is a toner container bottle 130 of an image forming device that is equipped with gears and other components that require sliding properties.

[0056] The resin molded product molded in the molding process (step S17) may be, for example, a sliding part of the image forming device described above, a sliding part of a product other than the image forming device described above, a part other than a sliding part of an image forming device, a part other than a sliding part of a product other than an image forming device, or a product (a product requiring sliding properties, a product not requiring sliding properties).

[0057] In the second embodiment, the measurement results using a differential scanning calorimeter when a crystallization inhibitor is added to the flakes are similar to the graph shown in Figure 5(B), and adding a crystallization inhibitor to the flakes makes injection blow molding possible.

[0058] According to the second embodiment described above, by adding a crystallization inhibitor to the flakes and processing the flakes with the added crystallization inhibitor into pellets to be used in molding a resin molded product in the molding process of step S17, crystallization of the PET when the temperature is lowered during injection blow molding in the molding process of step S17 (crystallization of the PET contained in the preform when the preform is cooled) can be suppressed, and the time until the PET hardens in the blow molding performed after injection molding is longer than when the crystallization inhibitor is not added, making it possible to expand the preform into a predetermined shape. This makes it possible to expand the use of recycled PET film to include resin molded products formed by injection blow molding.

[0059] In addition, in the second embodiment, the pellet processing step is one of the pellet processing steps in step S16, so the number of steps from the ceramic removal step (step S12) to the molding step (step S17) can be reduced, making it possible to reduce the manufacturing costs of resin molded products.

[0060] The present invention is not limited to the configurations of the above-described embodiments or modified examples, and various modifications are possible. Furthermore, the configuration and steps shown in the first embodiment using Figures 1 to 5 and the configuration and steps shown in the second embodiment using Figures 6 to 7 are merely one embodiment of the present invention, and are not intended to limit the present invention to these configurations and steps. [Explanation of symbols]

[0061] S1 Preparing used PET film S2 Ceramics removal process S3 Cleaning process S4 Flake processing process S5 First pellet processing process S6 addition process S7 Second pellet processing process S8 Molding process S11 Preparation of used PET film S12 Ceramics removal process S13 Cleaning process S14 Flake processing process S15 Addition process S16 Pellet processing process S17 Molding process

Claims

1. A method for recycling used PET film having ceramics attached to its surface, comprising the steps of: a removing step of mechanically removing the ceramics adhering to the surface of the used PET film from the used PET film; a flake processing step of processing the used PET film into flakes after the ceramics attached to the surface have been removed in the removing step; a first pellet processing step of processing the flakes produced in the flake processing step into first pellets; an adding step of adding a crystallization inhibitor to the first pellets produced in the first pellet processing step; a second pellet processing step of processing the first pellets to which the crystallization inhibitor has been added in the adding step into second pellets; a molding step of molding a resin molded product by injection blow molding using the second pellets processed in the second pellet processing step; A method for recycling used PET film.

2. The used PET film contains at least PET and a silicone resin, 2. The method for recycling used PET film according to claim 1, wherein in the ceramic removing step, the ceramic adhering to the surface is mechanically removed while leaving the silicone resin.

3. The method further includes a cleaning step, which is performed between the removing step and the flake processing step, of cleaning the surface of the used PET film from which the ceramics have been mechanically removed in the removing step; The used PET film used in the flake processing step is the used PET film whose surface has been cleaned.

3. A method for recycling used PET film according to claim 1 or claim 2.

4. A method for recycling used PET film having ceramics attached to its surface, comprising the steps of: a removing step of mechanically removing the ceramics adhering to the surface of the used PET film from the used PET film; a flake processing step of processing the used PET film into flakes after the ceramics attached to the surface have been removed in the removing step; an adding step of adding a crystallization inhibitor to the flakes produced in the flake processing step; a pellet processing step of processing the flakes to which the crystallization inhibitor has been added in the adding step into pellets; a molding step of molding a resin molded product by injection blow molding using the pellets processed in the pellet processing step; A method for recycling used PET film.

5. The used PET film contains at least PET and a silicone resin, 5. The method for recycling used PET film according to claim 4, wherein in the ceramic removing step, the ceramic adhering to the surface is mechanically removed while leaving the silicone resin.

6. The method further includes a cleaning step, which is performed between the removing step and the flake processing step, of cleaning the surface of the used PET film from which the ceramics have been mechanically removed in the removing step; The used PET film used in the flake processing step is the used PET film whose surface has been cleaned. The method for recycling used PET film according to claim 4 or 5.

7. A pellet manufactured using a used PET film having ceramics attached to its surface, The ceramics adhering to the surface of the used PET film are mechanically removed from the used PET film; The used PET film after the ceramics attached to the surface are removed is processed into flakes; the flakes are processed into first pellets; A crystallization inhibitor is added to the first pellet; Pellets produced by processing the first pellets to which the crystallization inhibitor has been added.

8. The pellet according to claim 7 , wherein the used PET film contains at least PET and a silicone resin, and when the ceramics attached to the surface are mechanically removed, the silicone resin remains.

9. 8. The pellets of claim 7, wherein the surface of the post-consumer PET film from which the ceramics have been mechanically removed is washed after the ceramics adhering to the surface have been mechanically removed and before the post-consumer PET film is processed into the flakes.

10. A pellet manufactured using a used PET film having ceramics attached to its surface, The ceramics adhering to the surface of the used PET film are mechanically removed from the used PET film; The used PET film after the ceramics attached to the surface are removed is processed into flakes; A crystallization inhibitor is added to the flakes; Pellets are produced by processing the flakes to which the crystallization inhibitor has been added.

11. The pellet according to claim 10, wherein the used PET film contains at least PET and a silicone resin, and when the ceramics attached to the surface are mechanically removed, the silicone resin remains.

12. 11. The pellets of claim 10, wherein the surface of the post-consumer PET film from which the ceramic has been mechanically removed is washed after the ceramic adhering to the surface has been mechanically removed and before the post-consumer PET film is processed into the flakes.

13. A resin molded product molded by injection blow molding using the pellet according to any one of claims 7 to 12.

14. 14. The resin molded product according to claim 13, wherein the resin molded product is a sliding part, molded by the injection blow molding using the pellet according to claim 8 or 11.

15. The resin molded product according to claim 14, wherein the sliding part is a sliding part of an image forming apparatus.

Images