Method for preparing a polyester modified material from a recycled release film

Abstract

PURPOSE: To provide a method for preparing polyester modified materials from recycled release films that can reduce carbon emissions.SOLUTION: A method for preparing polyester modification materials from recycled release films includes performing the following steps in succession at elevated temperatures. First melt processing is performed on the recycled release films to form low viscosity polyester. Polymerization processing is performed on the low viscosity polyester to form high viscosity polyester. The viscosity of the high viscosity polyester is greater than that of the low viscosity polyester. A modifier is added to the high viscosity polyester, and second melt processing is performed to form a polyester modified material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for processing a recycled release film, and particularly to a method for preparing a polyester modified material from a recycled release film.

Background Art

[0002] A release film is obtained by applying a release agent to a polyester (e.g., polyethylene terephthalate (PET)) film to make the surface of the release film separable for separating viscous substances, and is widely applied to packaging, laminating, circuit boards, adhesive products, insulation products, etc. In response to the global corporate carbon reduction, environmental protection, social responsibility, and environmental, social, and governance (ESG) policies, the market is gradually tilting towards a circular economy and the reuse of plastic recycling. On the premise that the processability is not affected, by introducing environmentally friendly recycled materials with low carbon emissions, it is possible to achieve the global goals of plastic reduction and energy conservation. Therefore, by recycling the polyester material in the release film, forming and reusing a functional modified material, the corporate carbon reduction policy can be properly observed, and the application value of the recycled polyester material can also be improved.

Summary of the Invention

Problems to be Solved by the Invention

[0003] At present, the method for preparing a polyester modified material from a recycled release film is carried out through a step-by-step manufacturing process. Generally, it includes a first-step process of producing solid ester particles by pulverizing, melting, and extruding the material, a second-step process of raising the temperature of the solid ester particles to carry out solid-state polymerization to form high-viscosity ester particles, and a third-step process of melting and modifying the high-viscosity polyester particles at a high temperature. However, the repeated temperature increase and decrease procedures significantly increase the energy consumption, so the carbon emissions cannot be effectively reduced.

[0004] From the above, an important issue in current research is to develop a method that can effectively reduce the carbon emissions when preparing a polyester modified material from a recycled release film.

Means for Solving the Problem

[0005] The present invention provides a method for preparing a polyester modified material from a recycled release film that can reduce carbon emissions.

[0006] The method for preparing a polyester modified material from the recycled release film of the present invention includes continuously performing the following steps at a high temperature. A first melting treatment is performed on the recycled release film to form a low-viscosity polyester. A polymerization treatment is performed on the low-viscosity polyester to form a high-viscosity polyester. The viscosity of the high-viscosity polyester is greater than that of the low-viscosity polyester. A modifier is added to the high-viscosity polyester to perform a second melting treatment to form a polyester modified material.

[0007] In one embodiment of the present invention, the high temperature is 230°C to 300°C.

[0008] In one embodiment of the present invention, the temperature of the first melting treatment is 240°C to 290°C.

[0009] In one embodiment of the present invention, the intrinsic viscosity of the low-viscosity polyester is 0.5 dL / g to 0.62 dL / g.

[0010] In one embodiment of the present invention, this method further includes performing a surface coating peeling treatment on the recycled release film before the first melting treatment.

[0011] In one embodiment of the present invention, this method further includes filtering the low-viscosity polyester after the first melting treatment.

[0012] In one embodiment of the present invention, the polymerization treatment includes performing liquid thickening.

[0013] In one embodiment of the present invention, the intrinsic viscosity of the high-viscosity polyester is 0.7 dL / g to 0.86 dL / g.

[0014] In one embodiment of the present invention, the modifier includes glass fiber, flame retardant, strengthening agent, nucleating agent, weather resistance modifier, antioxidant, and / or lubricant.

[0015] In one embodiment of the present invention, the temperature of the second melting treatment is 240°C to 275°C.

[0016] In one embodiment of the present invention, the high-viscosity polyester includes polyethylene terephthalate with a purity of 99% or more.

[0017] In one embodiment of the present invention, this method further includes performing a granulation treatment on the polyester modification material after the second melting treatment to form polyester modified particles.

Advantages of the Invention

[0018] As described above, the method for preparing a polyester modified material from a recyclable release film enables polymerization and modification treatments to be carried out in a stable continuous molten state at a high temperature, thus preventing energy consumption due to repeated temperature rises and falls, and furthermore, effectively reducing carbon emissions.

Brief Description of the Drawings

[0019]

Figure 1

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are exemplary and do not limit the scope of the present invention.

[0021] In this text, the range indicated by "from a certain numerical value to another numerical value" is a general expression for avoiding listing all numerical values one by one in this specification. Therefore, the description of a specific numerical range covers any numerical value within that numerical range and a relatively small numerical range defined by any numerical value within that numerical range, and is equivalent to the fact that those numerical values and the relatively small numerical range are specified.

[0022] FIG. 1 is a flowchart showing a method 100 for preparing a polyester modified material from a recycled release film according to one embodiment of the present invention. Referring to FIG. 1, first, in step 110, the obtained recycled release film can be pulverized to obtain a pulverized film. In some embodiments, the recycled release film may be derived from a circuit board, a protective film for an optical product, a release film for a multilayer ceramic capacitor, and a release film for a ceramic substrate. In some embodiments, the recycled release film may be a release film manufactured by Nan Ya Plastics Corporation. In some embodiments, the recycled release film can include a polyester base material and a coating or slurry (e.g., a ceramic coating or slurry) applied to the surface of the polyester base material. In some embodiments, the polyester base material can include polyethylene terephthalate (PET). In some embodiments, the coating or slurry applied to the surface of the polyester base material can include a release agent or a ceramic slurry. In some embodiments, the release agent can include a silicone release agent and / or a fluorine release agent. In some embodiments, before pulverizing the recycled release film, the coating or slurry on the surface of the recycled release film can be peeled off in advance so as not to affect the hue and properties of the polyester modified material generated later.

[0023] For example, the pulverization of the release film can be performed by a physical method, that is, by mechanically pulverizing or mechanically cutting the recycled release film to form a pulverized film, or by forming shredded recycled materials. That is, the shredded recycled materials may be smaller in size than the recycled release film. For example, the recycled release film may be in the form of flakes or a film, and the shredded recycled materials may be in the form of blocks, fine flakes, powders, or granules.

[0024] Next, the crushed film produced by crushing the recycled release film in step 120 can be compressed and dried. Drying is performed to prevent moisture from causing excessive deterioration during the recycling manufacturing process of the polyester. Further drying of the shredded recycled material may be performed by heating or a low-pressure arrangement, but the present invention is not limited thereto. As another example, the treatment for the aforementioned crushed film can include a corresponding compression treatment, but the present invention is not limited thereto. The compression treatment can reduce the volume of the shredded recycled material when performing the first melting treatment and improve the efficiency of the manufacturing process.

[0025] Thereafter, steps 130 to 160 can be continuously performed at a high temperature. By doing so, a large amount of energy consumption caused by repeated temperature rises and falls can be prevented. In some embodiments, the high temperature is about 230°C to 300°C, for example, 230°C to 290°C, 240°C to 300°C, or 240°C to 290°C, but the present invention is not limited thereto. In some embodiments, the high temperature is about 250°C to 270°C, 255°C to 275°C, or 260°C to 280°C. In some embodiments, the high temperature is about 245°C, 265°C, or 285°C.

[0026] In some embodiments, in step 130, a first melting treatment can be performed on the compressed and dried pulverized film to form a low-viscosity polyester. In some embodiments, the first melting treatment is performed at a temperature of about 240°C to 290°C, for example, 260°C, 270°C, or 280°C. For example, the recycled material shredded through the melting and extrusion steps is melted to form a low-viscosity polyester. The shredded recycled material can be put into, for example, an extrusion device. The extrusion device can include, for example, a single screw extruder (SSE), a twin screw extruder (TSE), or other similar screw extruders. The extrusion device can melt the shredded recycled material to form a low-viscosity polyester in a molten state. In this embodiment, the shredded recycled material in the extrusion device can be heated to about 240°C to 290°C. That is, the temperature of the first melting treatment can be about 240°C to 290°C. In some embodiments, the duration of the first melting treatment is about 2 minutes to 10 minutes, for example, 4 minutes, 6 minutes, or 8 minutes. In some embodiments, the intrinsic viscosity of the low-viscosity polyester is about 0.5 dL / g to 0.62 dL / g, for example, 0.53 dL / g, 0.57 dL / g, or 0.6 dL / g.

[0027] Next, in step 140, the molten low-viscosity polyester can be filtered through a filter mesh to remove solid impurities from the low-viscosity polyester. In some embodiments, the filtration can be performed at a temperature of about 240°C to 290°C.

[0028] Next, in step 150, by performing a polymerization process on the low-viscosity polyester to form a high-viscosity polyester, the viscosity of the high-viscosity polyester can be made greater than the viscosity of the low-viscosity polyester. In some embodiments, the polymerization process includes performing liquid thickening of the low-viscosity polyester within an extrusion device. In some embodiments, the intrinsic viscosity of the high-viscosity polyester is from about 0.7 dL / g to 0.86 dL / g, for example, 0.75 dL / g, 0.8 dL / g, or 0.85 dL / g. For example, in the present embodiment, the low-viscosity polyester within the extrusion device can be heated to about 240°C to 290°C, and the heating time can be about 15 minutes to 60 minutes, for example, 25 minutes, 40 minutes, or 55 minutes. Thus, the intrinsic viscosity of the low-viscosity polyester can be increased.

[0029] In some embodiments, by performing an air pressure reduction step on the low-viscosity polyester disposed within the extrusion device, air (for example, air between the shredded recycled materials in the form of slices, powders, or particles) within the shredded recycled material can be more easily discharged, and / or volatile substances within the shredded recycled material can be more easily discharged. Thus, the intrinsic viscosity of the low-viscosity polyester can be increased. In some embodiments, the air pressure reduction step can reduce the air pressure to 1 mbar to 6 mbar, for example, 2 mbar, 3 mbar, or 5 mbar, and the duration of the air pressure reduction step can be 15 minutes to 60 minutes, for example, 20 minutes, 35 minutes, or 50 minutes.

[0030] In one embodiment, the low-viscosity polyester disposed within the extrusion device can be heated to about 260°C to 270°C, and the air pressure can be reduced to about 5 mbar. The time for heating to this temperature and reducing the air pressure to this level can be about 15 minutes to 20 minutes. As a result, when the intrinsic viscosity of the low-viscosity polyester is about 0.5 dL / g, the intrinsic viscosity of the produced high-viscosity polyester can be about 0.72 dL / g.

[0031] In one embodiment, the low-viscosity polyester disposed within the extrusion device can be heated to about 260°C to 270°C, and the air pressure can be reduced to about 5 mbar. The time to heat to this temperature and reduce the air pressure to this level may be about 30 minutes to 40 minutes. As a result, when the intrinsic viscosity of the low-viscosity polyester is about 0.5 dL / g, the intrinsic viscosity of the produced high-viscosity polyester may be about 0.85 dL / g.

[0032] In one embodiment, the low-viscosity polyester disposed within the extrusion device can be heated to about 260°C to 270°C, and the air pressure can be reduced to 2 mbar. The time to heat to this temperature and reduce the air pressure to this level may be about 30 minutes to 40 minutes. As a result, when the intrinsic viscosity of the low-viscosity polyester is 0.5 dL / g, the intrinsic viscosity of the produced high-viscosity polyester may be about 0.75 dL / g.

[0033] In some embodiments, when the polyester base material of the recyclable release film contains polyethylene terephthalate (PET), the high-viscosity polyester contains polyethylene terephthalate with a purity of 99% or more, but the present invention is not limited thereto.

[0034] Next, in step 160, various functional polyester modification materials can be formed by adding a modifier to the high-viscosity polyester and performing a secondary melting treatment to modify the high-viscosity polyester. In some embodiments, the modifier includes glass fiber, flame retardant, strengthening agent, nucleating agent, weather resistance modifier, antioxidant, and / or lubricant. In some embodiments, the temperature of the secondary melting treatment is about 240°C to 275°C, for example, 250°C, 260°C, or 270°C. In some embodiments, the time of the secondary melting treatment is 1 minute to 10 minutes, for example, 3 minutes, 5 minutes, or 7 minutes.

[0035] For example, the extruder used for the extrusion modification of the secondary melting process is a commercially available twin-screw extruder (TSE) or other similar screw extruder, but the present invention is not limited thereto. In the present invention, the structure and / or operation of the commercially available extruder are not specified in detail.

[0036] In one embodiment, at least one feeding device (e.g., a side feeder) can be attached to the extruder. The feeding device may be a loss-in-weight feeder equipped with a loss-in-weight meter. The feeding device may be a conventional commercially available device and / or optional additional parts. That is, each component of the polyester mixture may be mixed before or during feeding, or may be fed to the extruder by different feeding devices and mixed within the extruder. In some embodiments, the extruder can be connected to an air extraction system. The air extraction system can include a conventional air extraction pump and a corresponding air pipeline. The extruder can be vented up by the air extraction system or the vent-up efficiency can be improved.

[0037] In some embodiments, when the modifier is glass fiber, an impact-resistant glass fiber reinforced polyester modified material can be produced. In some embodiments, when the modifier is a flame retardant, a flame-retardant polyester modified material can be produced. In some embodiments, when the modifier is a strengthening agent, a high-viscosity polyester modified material for profile extrusion can be produced. In some embodiments, when the modifier is a lubricant, a polyester modified material with better peeling performance can be produced. In some embodiments, when the modifier is polycarbonate (PC) or acrylonitrile butadiene styrene (ABS) resin, or a compatible modifier, a polyester alloy modified material can be produced. In some embodiments, when the modifier is a nucleating agent, a weather resistance modifier, or an antioxidant, a polyester modified material having nucleation performance, weather resistance, or antioxidant performance, respectively, can be produced.

[0038] Thereafter, in step 170, a granulation process can be performed on the functional polyester modified material to form functional polyester modified particles. In some embodiments, the granulation process includes extruding the polyester modified material into a strip, cooling and curing the strip in a bath tank, and granulating with a cutter to form polyester modified particles. In some embodiments, a dehydration process may be performed during the granulation process to remove moisture adhering to the polyester modified particles during granulation.

[0039] As described above, the method for preparing a polyester modified material from the recycled release film of the present invention includes polymerization and modification processes in a continuous molten state, and a stable high temperature is maintained during the process. Compared with the conventional step-by-step manufacturing process in which the temperature rises and falls repeatedly, more energy can be saved, so the carbon dioxide emissions can be effectively reduced, thereby improving the application value of the recycled polyester material.

Industrial Applicability

[0040] The method for preparing a polyester modified material from the recyclable release film of the present invention is applicable to packaging, laminates, circuit boards, adhesive products, insulation products, etc.

Explanation of Signs

[0041] 100 Method 110~170 Steps

Claims

1. A method for preparing a polyester modified material from a recycled release film, comprising: performing a first melting treatment on the recycled release film to form a low-viscosity polyester; performing a polymerization treatment on the low-viscosity polyester to form a high-viscosity polyester, wherein the viscosity of the high-viscosity polyester is greater than that of the low-viscosity polyester; adding a modifier to the high-viscosity polyester and performing a second melting treatment to form the polyester modified material; continuously performing the above steps at a high temperature; the polymerization treatment includes performing liquid thickening, and the liquid thickening includes heating at an air pressure of 2 to 5 mbar at 260 to 270 °C for 15 to 40 minutes to increase the intrinsic viscosity from 0.5 dL / g to 0.72 to 0.85 dL / g.

2. The method according to claim 1, wherein the high temperature is 230 °C to 300 °C.

3. The method according to claim 1, wherein the temperature of the first melting treatment is 240 °C to 290 °C.

4. The method according to claim 1, wherein the intrinsic viscosity of the low-viscosity polyester is 0.5 dL / g to 0.62 dL / g.

5. The method according to claim 1, further comprising performing surface coating peeling on the recycled release film before the first melting treatment.

6. The method according to claim 1, further comprising filtering the low-viscosity polyester after the first melting treatment.

7. The method according to claim 1, wherein the intrinsic viscosity of the high-viscosity polyester is 0.7 dL / g to 0.86 dL / g.

8. The method according to claim 1, wherein the modifier includes glass fiber, flame retardant, strengthening agent, nucleating agent, weather resistance modifier, antioxidant, and / or lubricant.

9. The method according to claim 1, wherein the temperature of the second melting treatment is 240 °C to 275 °C.

10. The method according to claim 1, wherein the high-viscosity polyester includes polyethylene terephthalate with a purity of 99% or more.

11. The method according to claim 1, further comprising performing granulation treatment on the polyester modified material after the second melting treatment to form polyester modified particles.

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