Method for producing impact-resistant polyester composition

Abstract

To provide a continuous preparation method for a polyester composition having significantly improved impact resistance.SOLUTION: The present invention provides a preparation method for an impact-resistant polyester composition, which is a continuous process and includes the following steps. A recycled release film is crushed, compacted and dried, and then melted, extruded and degassed. The recycled release film contains a recycled PET resin. After filtration, a liquid viscosifying system is used for thickening. Next, it is melted and kneaded, modified with a modifier and extruded. Examples of the modifier include impact modifiers, compatibilizers, antioxidants and lubricants. After the rubber strips are cooled with water, they are pelletized and dehydrated to produce the impact-resistant polyester composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a polyester composition, and more particularly to a method for producing an impact-resistant polyester composition. [Background technology]

[0002] In response to carbon reduction and ESG policies of companies around the world, the circular economy and plastic recycling are gradually gaining momentum in the market. The introduction of environmentally friendly recycled materials with low carbon emissions without affecting mechanical performance or processability will contribute to achieving global goals of carbon emission reduction and energy conservation. In addition to using recycled materials to reduce carbon emissions, production using low-carbon processes is also a focus of future development.

[0003] Existing manufacturing methods for modifying impact-resistant polyester materials from recycled materials primarily involve separate processes. Each process requires increasing the temperature, melting, and viscosity, followed by cooling and granulation. Repeated temperature cycles result in energy waste and loss, resulting in increased carbon emissions. This process is therefore inefficient and energy-intensive. More specifically, for example, processes 1, 2, and 3 can be subdivided. In process 1, recycled release film is crushed, compressed, dried, melted, extruded, and degassed. Low-viscosity recycled PET particles are obtained after filtering, rubber strip water cooling, granulation, and dehydration. Next, process 2 is carried out. In process 2, the low-viscosity recycled PET particles are solid-state polymerized to form high-viscosity recycled PET particles. Finally, process 3 is carried out. In process 3, the high-viscosity recycled PET particles are mixed and modified using a twin-screw mixer. The rubber strip is then water-cooled, cut into granules, and dehydrated to produce impact-resistant polyester material.

[0004] In light of the above, in response to the global environmental protection trend of reducing plastics and saving energy, it is currently an important research topic to develop a method for producing an impact-resistant polyester composition that will improve production efficiency and reduce energy consumption. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a method for producing impact-resistant polyester compositions. Through continuous process modification, the impact strength of PET materials can be significantly improved from 3.6 kg-cm / cm to 56.2 kg-cm / cm. Therefore, this composition can replace ABS, PC, and PP in injection-molded products and extruded panels that require high impact resistance, such as casings, suitcases, and food trays. [Means for solving the problem]

[0006] The present invention provides a continuous process for producing an impact-resistant polyester composition, including the following step A. Recycled release film is crushed, compressed, and dried, then melted, extruded, and degassed. The recycled release film contains recycled PET resin. After filtration, it is thickened using a liquid thickening system. The resulting material is then melted, kneaded, modified with a modifier, and extruded. The modifier includes an impact modifier, a compatibilizer, an antioxidant, and a lubricant. The plastic strip is water-cooled, granulated, and dehydrated to produce the impact-resistant polyester composition.

[0007] In one embodiment of the present invention, the method for producing an impact resistant polyester composition further comprises removing and recovering the surface coating of the recycled release film before crushing, compressing, and drying the recycled release film.

[0008] In one embodiment of the present invention, the temperature for crushing, compressing and drying the recycled release film is 70°C to 120°C.

[0009] In one embodiment of the present invention, the melting, extrusion and degassing temperatures are between 240°C and 290°C.

[0010] In one embodiment of the present invention, the melting and kneading temperature is 240°C to 280°C.

[0011] In one embodiment of the present invention, the temperature for the modification and extrusion is 250°C to 275°C.

[0012] In one embodiment of the present invention, the water cooling temperature of the plastic strip is 40°C to 80°C.

[0013] In one embodiment of the present invention, the impact modifier comprises a polyolefin elastomer.

[0014] In one embodiment of the present invention, the polyolefin elastomer has a dispersed particle size of 0.5 μm to 1.2 μm in the impact resistant polyester composition.

[0015] In one embodiment of the present invention, the compatibilizer comprises ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), polyolefin elastomer grafted glycidyl methacrylate (POE-g-GMA), polyethylene grafted glycidyl methacrylate (PE-g-GMA), or a combination thereof.

[0016] In one embodiment of the present invention, the antioxidant includes a hindered phenolic antioxidant, a phenolic antioxidant, a phosphite antioxidant, a complex antioxidant, or a combination thereof.

[0017] In one embodiment of the present invention, the lubricant comprises a stearate, a polyethylene wax, a siloxane modifier, or a fluororesin.

[0018] In one embodiment of the present invention, based on the total weight of the impact-resistant polyester composition, the content of recycled PET resin is 70 wt% to 92 wt%, the content of impact modifier is 5 wt% to 15 wt%, the content of compatibilizer is 2 wt% to 15 wt%, the content of antioxidant is 0.1 wt% to 1 wt%, and the content of lubricant is 0.1 wt% to 1 wt%. [Effects of the Invention]

[0019] Based on the above, the present invention provides a method for producing impact-resistant polyester compositions. Through continuous process modification, the impact strength of PET materials can be significantly improved from 3.6 kg-cm / cm to 56.2 kg-cm / cm. Therefore, it can replace ABS, PC, and PP in injection-molded products and extruded plates that require high impact resistance, such as casings, suitcases, and food trays. Furthermore, the present invention primarily employs continuous molten state feeding and modification. In this way, energy waste and increased carbon emissions are avoided compared to the conventional split process. Therefore, the production method of the present invention is efficient and more energy-saving. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail, but these embodiments are merely examples and the present invention is not limited to these.

[0021] In this specification, the range "from one value to another value" is a general expression to avoid listing all values ​​within that range. Therefore, the description of a particular numerical range includes any numerical value within that numerical range and any smaller numerical range enclosed by any numerical value within that numerical range, just as if that arbitrary numerical value and smaller numerical range were described in the specification.

[0022] The present invention provides a continuous process for producing an impact-resistant polyester composition, including the following steps: First, the surface coating of recycled release film is removed and recovered. Next, the recycled release film is crushed, compressed, and dried, and then melted, extruded, and degassed. The recycled release film contains recycled PET resin. After filtration, it is thickened using a liquid thickening system. Next, it is melted and kneaded, modified with modifiers, and extruded. The modifiers include impact modifiers, compatibilizers, antioxidants, and lubricants. The plastic strip is water-cooled, granulated, and dehydrated to produce the impact-resistant polyester composition.

[0023] In this embodiment, the surface coating of the recycled release film is removed and recovered to avoid affecting the color and properties of the recycled PET particles. Furthermore, a liquid thickening system is used to increase the intrinsic viscosity (IV) from a viscosity range of 0.58 dL / g to 0.65 dL / g to a viscosity range of 0.70 dL / g to 0.86 dL / g. Functional modifications are then performed to improve the strength and processability of the material and to impart functionality (such as impact resistance) during use, allowing it to be used in high-value products such as injection molding and extrusion molding.

[0024] In this embodiment, the temperatures for crushing, compressing, and drying the recycled release film are, for example, 70°C to 120°C. The temperatures for melting, extruding, and degassing are, for example, 240°C to 290°C. The temperature for melting and kneading is, for example, 240°C to 280°C. The temperature for modifying and extruding is, for example, 250°C to 275°C. The water cooling temperature for the plastic strip is, for example, 40°C to 80°C.

[0025] In this embodiment, the modifier includes an impact modifier, a compatibilizer, an antioxidant, and a lubricant. Each of the above-mentioned components will be described in detail below.

[0026] In this embodiment, the impact modifier may include a polyolefin elastomer. The compatibilizer may include ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), polyolefin elastomer-grafted glycidyl methacrylate (POE-g-GMA), polyethylene-grafted glycidyl methacrylate (PE-g-GMA), or a combination thereof. The antioxidant may include a hindered phenol-based antioxidant, a phenol-based antioxidant, a mixed antioxidant, a phosphite-based antioxidant, a composite antioxidant, or a combination thereof. The lubricant may include a stearate, a polyethylene wax, a siloxane modifier, or a fluorine-based resin. The compatibility between the polyolefin elastomer and the polyester material is improved by compatibility modification, viscosity adjustment, and mixing and dispersion techniques. After preparation, the dispersed particle size of the polyolefin elastomer in the impact-resistant polyester composition is, for example, 0.5 μm to 1.2 μm. Therefore, polyester materials have the characteristics of high impact strength, high rigidity, low density, and easy processing, and their impact strength can reach 56.2 kg-cm / cm.

[0027] In this embodiment, based on the total weight of the impact-resistant polyester composition, the content of recycled PET resin is, for example, 70 wt% to 92 wt%, the content of impact resistance modifier is, for example, 5 wt% to 15 wt%, the content of compatibilizer is, for example, 2 wt% to 15 wt%, the content of antioxidant is, for example, 0.1 wt% to 1 wt%, and the content of lubricant is, for example, 0.1 wt% to 1 wt%.

[0028] In summary, based on the above, the present invention provides a method for producing impact-resistant polyester compositions. Through continuous process modification, the impact strength of PET material can be significantly improved from 3.6 kg-cm / cm to 56.2 kg-cm / cm. Therefore, it can replace ABS, PC, and PP in injection-molded products and extruded plates that require high impact resistance, such as casings, suitcases, and food trays. Furthermore, the present invention primarily employs continuous molten state feeding and modification. In this way, energy waste and increased carbon emissions are avoided compared with the prior art segmentation process. As a result, the production method of the present invention is efficient and more energy-saving. Meanwhile, the continuous process of the present invention can reduce the molecular weight or IV loss of the material due to repeated temperature increases and decreases, thereby improving the impact resistance of the impact-modified particles. (Continuous process of the present invention: 56.2 kg-cm / cm; conventional segmentation process: 43.0 kg-cm / cm). In addition to reducing yield loss in the segmentation process, the continuous process of the present invention is completed entirely under high-temperature melt conditions, thereby avoiding the energy consumption caused by repeated temperature increases and decreases. [Industrial Applicability]

[0029] The process for producing an impact-resistant polyester composition of the present invention can be applied to injection-molded articles and extruded plates that require high impact resistance, such as casings, suitcases, and food trays.

Claims

1. 1. A method for producing an impact resistant polyester composition which is a continuous process, comprising: Crushing, compressing, and drying a recycled release film containing recycled PET resin, and then melting, extruding, and degassing the recycled release film; thickening the mixture to increase the intrinsic viscosity (IV) from a viscosity range of 0.58 dL / g to 0.65 dL / g to a viscosity range of 0.70 dL / g to 0.86 dL / g after filtration; melting and kneading a plastic strip with a modifier containing an impact modifier, a compatibilizer, an antioxidant, and a lubricant; extruding the modified plastic strip; water-cooling the plastic strip, granulating the plastic strip, and dehydrating the plastic strip to produce an impact-resistant polyester composition; A method comprising:

2. The method further comprises removing and recovering the surface coating of the recycled release film before crushing, compressing, and drying the recycled release film; A method for producing the impact-resistant polyester composition according to claim 1.

3. The temperature for crushing, compressing and drying the recycled release film is 70°C to 120°C. A method for producing the impact-resistant polyester composition according to claim 1.

4. The temperature of melting, extrusion and degassing is 240°C to 290°C; A method for producing the impact-resistant polyester composition according to claim 1.

5. The melting and kneading temperature is 240°C to 280°C. A method for producing the impact-resistant polyester composition according to claim 1.

6. The temperature of the modification and extrusion is 250°C to 275°C. A method for producing the impact-resistant polyester composition according to claim 1.

7. The water cooling temperature of the plastic strip is 40°C to 80°C; A method for producing the impact-resistant polyester composition according to claim 1.

8. The impact modifier comprises a polyolefin elastomer. A method for producing the impact-resistant polyester composition according to claim 1.

9. The polyolefin elastomer has a dispersed particle size of 0.5 μm to 1.2 μm in the impact-resistant polyester composition. A method for producing the impact-resistant polyester composition according to claim 8.

10. The compatibilizer comprises ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), polyolefin elastomer grafted glycidyl methacrylate (POE-g-GMA), polyethylene grafted glycidyl methacrylate (PE-g-GMA), or a combination thereof; A method for producing the impact-resistant polyester composition according to claim 1.

11. The antioxidant includes a hindered phenolic antioxidant, a phenolic antioxidant, a phosphite antioxidant, a complex antioxidant, or a combination thereof. A method for producing the impact-resistant polyester composition according to claim 1.

12. The lubricant comprises a stearate, a polyethylene wax, a siloxane modifier, or a fluororesin. A method for producing the impact-resistant polyester composition according to claim 1.

13. Based on the total weight of the impact-resistant polyester composition, the content of the recycled PET resin is 70 wt % to 92 wt %, the content of the impact resistance modifier is 5 wt % to 15 wt %, the content of the compatibilizer is 2 wt % to 15 wt %, the content of the antioxidant is 0.1 wt % to 1 wt %, and the content of the lubricant is 0.1 wt % to 1 wt %. A method for producing the impact-resistant polyester composition according to claim 1.