Method for preparing polyester modification material from 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 treating recycled release films, and in particular to a method for preparing polyester modified materials from recycled release films. [Background technology]

[0002] Release films are made by applying a release agent to polyester (e.g., polyethylene terephthalate (PET)) films to make the surface of the release film separable and to separate viscous substances. They are widely used in packaging, laminates, circuit boards, adhesive products, insulating products, etc. In response to the carbon reduction and environmental protection, social responsibility, and environmental, social, and governance (ESG) policies of global companies, the market is gradually leaning toward a circular economy and reuse of plastic recycling. Under the premise that processability is not affected, the introduction of environmentally friendly recycled materials with low carbon emissions can achieve the goal of global plastic reduction and energy saving. Therefore, by recycling the polyester material in the release film and forming functional modified materials for reuse, the carbon reduction policy of the company is properly adhered to and the application value of recycled polyester materials is also improved. Summary of the Invention [Problem to be solved by the invention]

[0003] At present, the method of preparing polyester modified materials from recycled release film is carried out through a step-by-step manufacturing process, which generally includes a first-step process of grinding, melting, and extruding the material to produce solid ester particles, a second-step process of increasing the temperature of the solid ester particles to carry out solid polymerization to form high-viscosity ester particles, and a third-step process of melting and modifying the high-viscosity polyester particles at high temperatures. However, the repeated temperature increase and decrease procedures significantly increase energy consumption, making it impossible to effectively reduce carbon emissions.

[0004] In light of the above, an important issue in current research is to develop a method that can effectively reduce the carbon emissions during the preparation of polyester modified materials from recycled release films. [Means for solving the problem]

[0005] The present invention provides a method for preparing polyester modified materials from recycled release films, which can reduce carbon emissions.

[0006] The method for preparing a polyester modified material from a recycled release film of the present invention includes successively carrying out the following steps at an elevated temperature: subjecting the recycled release film to a first melt treatment to form a low viscosity polyester; subjecting the low viscosity polyester to a polymerization treatment to form a high viscosity polyester; and adding a modifier to the high viscosity polyester and subjecting it to a second melt treatment to form a polyester modified material.

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

[0008] In one embodiment of the present invention, the temperature of the first melt 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, the method further comprises subjecting the recycled release film to a surface coating release treatment prior to the first melt treatment.

[0011] In one embodiment of the invention, the method further comprises filtering the low viscosity polyester after the first melt processing.

[0012] In one embodiment of the invention, the polymerization process includes performing a 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 invention, the modifiers include glass fibers, flame retardants, reinforcing agents, nucleating agents, weathering modifiers, antioxidants, and / or lubricants.

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

[0016] In one embodiment of the invention, the high viscosity polyester comprises polyethylene terephthalate of 99% or greater purity.

[0017] In one embodiment of the invention, the method further comprises subjecting the polyester modified material to a granulation process after the second melt processing to form polyester modified particles. Effect of the Invention

[0018] As described above, the method for preparing polyester modified materials from recycled release films enables polymerization and modification treatments to be carried out in a continuous molten state at a stable high temperature, which can prevent energy consumption caused by repeated temperature increases and decreases, and can effectively reduce carbon emissions. [Brief description of the drawings]

[0019] [Figure 1] 1 is a flow chart illustrating a method for preparing polyester modified materials from recycled release films according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0021] In the present specification, ranges expressed as "from one value to another value" are summary expressions to avoid listing every value in this specification one by one. Thus, the description of a particular numerical range covers any numerical value within that numerical range and smaller numerical ranges defined by any numerical value within that numerical range, and is equivalent to specifying that numerical value and the smaller numerical range.

[0022] FIG. 1 is a flow chart 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 crushed to obtain a crushed 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 Nanya Plastics Co., Ltd. In some embodiments, the recycled release film may include a polyester substrate and a coating or slurry (e.g., a ceramic coating or slurry) applied to the surface of the polyester substrate. In some embodiments, the polyester substrate may include polyethylene terephthalate (PET). In some embodiments, the coating or slurry applied to the surface of the polyester substrate may include a release agent or a ceramic slurry. In some embodiments, the release agent may include a silicone release agent and / or a fluorine release agent. In some embodiments, the coating or slurry on the surface of the recycled release film may be pre-peeled before crushing the recycled release film to avoid affecting the color and properties of the polyester modified material to be subsequently produced.

[0023] For example, the shredding of the release film can be accomplished by physical methods, i.e., by mechanically shredding or mechanically cutting the recycled release film to form shredded film, or by forming shredded recycled material. That is, the shredded recycled material can be smaller in size than the recycled release film. For example, the recycled release film can be in flake or film form, and the shredded recycled material can be in block, fine flake, powder, or granule form.

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

[0025] Then, steps 130 to 160 can be performed continuously at high temperature. In this way, it is possible to prevent a large amount of energy consumption caused by repeated temperature increase and decrease. 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, the compressed and dried ground film may be subjected to a first melting process in advance in step 130 to form a low-viscosity polyester. In some embodiments, the first melting process is performed at a temperature of about 240°C to 290°C, for example, 260°C, 270°C, or 280°C. For example, the shredded recycled material is melted through a melting and extrusion step to form a low-viscosity polyester. The shredded recycled material may be, for example, placed in an extrusion device. The extrusion device may include, for example, a single screw extruder (SSE), a twin screw extruder (TSE), or other similar screw extruder. The extrusion device may melt the shredded recycled material to form a molten low-viscosity polyester. In this embodiment, the shredded recycled material in the extrusion device may be heated to about 240°C to 290°C. That is, the temperature of the first melting process may be about 240°C to 290°C. In some embodiments, the duration of the first melt treatment is about 2 minutes to 10 minutes, such as 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, such as 0.53 dL / g, 0.57 dL / g, or 0.6 dL / g.

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

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

[0029] In some embodiments, an air pressure decompression step can be performed on the low-viscosity polyester disposed in the extrusion device to allow air in the ground recycled material (e.g., air between the ground recycled material in slice, powder, or particle form) to be more easily evacuated and / or allow volatile substances in the ground recycled material to be more easily evacuated. Thus, the intrinsic viscosity of the low-viscosity polyester can be increased. In some embodiments, the air pressure decompression step can reduce the air pressure to 1 mbar to 6 mbar, e.g., 2 mbar, 3 mbar, or 5 mbar, and the duration of the air pressure decompression step can be 15 minutes to 60 minutes, e.g., 20 minutes, 35 minutes, or 50 minutes.

[0030] In one embodiment, the low viscosity polyester disposed in the extrusion apparatus can be heated to about 260° C.-270° C. and the air pressure can be reduced to about 5 mbar. The time to heat to this temperature and reduce to this air pressure can be about 15 minutes to 20 minutes. As a result, if the intrinsic viscosity of the low viscosity polyester is about 0.5 dL / g, the intrinsic viscosity of the resulting high viscosity polyester can be about 0.72 dL / g.

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

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

[0033] In some embodiments, when the polyester substrate of the recycled release film comprises polyethylene terephthalate (PET), the high viscosity polyester comprises polyethylene terephthalate of 99% or greater purity, although the invention is not so limited.

[0034] Next, in step 160, a modifier is added to the high-viscosity polyester to perform a secondary melting process, and the high-viscosity polyester can be modified to form various functional polyester modified materials. In some embodiments, the modifier includes glass fiber, flame retardant, reinforcing agent, nucleating agent, weathering modifier, antioxidant, and / or lubricant. In some embodiments, the temperature of the secondary melting process is about 240°C to 275°C, such as 250°C, 260°C, or 270°C. In some embodiments, the time of the secondary melting process is 1 minute to 10 minutes, such as 3 minutes, 5 minutes, or 7 minutes.

[0035] For example, the extruder used for the secondary melt processing extrusion modification may be 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 is not specified in detail.

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

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

[0038] The functional polyester modified material may then be subjected to a granulation process to form functional polyester modified particles at step 170. In some embodiments, the granulation process includes extruding the polyester modified material into a strip, cooling and hardening 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 that adheres to the polyester modified particles during granulation.

[0039] As described above, the method for preparing polyester modified material from recycled release film of the present invention includes polymerization and modification treatment in continuous molten state, and maintains stable high temperature during the treatment.Compared with the traditional stepwise manufacturing process that repeats temperature rise and fall, it can save more energy, so that it can effectively reduce carbon dioxide emissions, and thereby improve the application value of recycled polyester material. [Industrial Applicability]

[0040] The method of preparing polyester modified materials from recycled release films of the present invention is applicable to packaging, laminates, circuit boards, adhesive products, insulating products, and the like. [Explanation of symbols]

[0041] 100 ways 110~170 steps

Claims

1. 1. A method for preparing a polyester modified material from recycled release film, comprising: performing a first melt treatment on the recycled release film to form a low viscosity polyester; subjecting the low-viscosity polyester to a polymerization process to form a high-viscosity polyester, the viscosity of the high-viscosity polyester being greater than the viscosity of the low-viscosity polyester; adding a modifier to the high viscosity polyester and performing a second melt processing to form the polyester modified material; continuously at an elevated temperature.

2. 2. The method of claim 1, wherein the elevated temperature is between 230°C and 300°C.

3. 2. The method of claim 1, wherein the temperature of the first melt processing is from 240°C to 290°C.

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

5. The method of claim 1 , further comprising performing a surface coating strip on the recycled release film prior to the first melt treatment.

6. 10. The method of claim 1 further comprising filtering the low viscosity polyester after the first melt processing.

7. The method of claim 1 , wherein the polymerization process comprises performing liquid thickening.

8. 2. The method of claim 1, wherein the intrinsic viscosity of the high viscosity polyester is from 0.7 dL / g to 0.86 dL / g.

9. The method of claim 1 , wherein the modifier comprises glass fiber, a flame retardant, a reinforcing agent, a nucleating agent, a weathering modifier, an antioxidant, and / or a lubricant.

10. 2. The method of claim 1, wherein the temperature of the second melt processing is from 240°C to 275°C.

11. 2. The method of claim 1, wherein the high viscosity polyester comprises polyethylene terephthalate of 99% or greater purity.

12. 10. The method of claim 1, further comprising subjecting the polyester modified material to a granulation process after the second melt process to form polyester modified particles.

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