Preparation method for 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 manufacturing a polyester composition, and particularly to a method for manufacturing an impact-resistant polyester composition.

Background Art

[0002] In response to carbon reduction and ESG policies of companies in various countries, the trend of a circular economy and plastic recycling is gradually advancing in the market. By introducing recycled materials with low carbon emissions and environmental friendliness without affecting mechanical performance and processability, it contributes to achieving the global goals of carbon emission reduction and energy conservation. In the development of low-carbon materials, in addition to using recycled materials to reduce carbon emissions, production in low-carbon processes is also a focus of future development.

[0003] In existing manufacturing methods for modifying impact-resistant polyester materials from recycled materials, mainly a splitting process is adopted. In each process, it is necessary to raise the temperature, melt, increase the viscosity, and then cool and granulate. Repeatedly raising and lowering the temperature results in waste and loss of energy and an increase in carbon emissions. Therefore, this is an inefficient and energy-consuming manufacturing method. More specifically, for example, Process 1, Process 2, and Process 3 can be subdivided and carried out. In Process 1, the recycled release film is pulverized, the pulverized film is compressed and dried, and then melted, extruded, and degassed. After filtration, reverse strip water cooling, granulation, and dehydration, low-viscosity PET recycled particles can be obtained. Then, Process 2 is executed. In Process 2, the low-viscosity PET recycled particles are subjected to solid-phase polymerization to form high-viscosity PET recycled particles. Finally, Process 3 is executed. In Process 3, the high-viscosity PET recycled particles are mixed and modified with a modifier using a twin-screw, the reverse strip is water-cooled, cut and granulated, and dehydrated to obtain an impact-resistant polyester material.

[0004] From the above, developing a method for manufacturing an impact-resistant polyester composition to respond to the trend of global environmental protection such as plastic reduction and energy conservation, and to improve production efficiency and reduce energy consumption has become an important research issue currently required.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a method for manufacturing an impact-resistant polyester composition. By modification through continuous processes, the impact strength of the 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 extrusion plates that require high impact resistance, such as casings, suitcases, and food trays.

Means for Solving the Problems

[0006] The present invention provides a method for manufacturing an impact-resistant polyester composition, which is a continuous process and includes the following step A. 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 melt-kneaded and modified and extruded with a modifier. The modifier includes an impact-resistant modifier, a compatibilizer, an antioxidant, and a lubricant. After water-cooling the plastic strip, it is granulated and dehydrated to produce an impact-resistant polyester composition.

[0007] In one embodiment of the present invention, the method for manufacturing an impact-resistant polyester composition further includes 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 temperature for melting, extruding, and degassing is 240°C to 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 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 includes 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 includes an ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), a polyolefin elastomer grafted glycidyl methacrylate (POE-g-GMA), a polyethylene grafted glycidyl methacrylate (PE-g-GMA), or a combination thereof.

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

[0017] In one embodiment of the present invention, the lubricant includes 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 the recycled PET resin is 70 wt% to 92 wt%, the content of the impact-resistant 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%.

Effects of the Invention

[0019] Based on the above, the present invention provides a method for manufacturing an impact-resistant polyester composition. By continuous process modification, the impact strength of the 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 of injection-molded products and extruded plates that require high impact resistance, such as casings, suitcases, and food trays. Furthermore, the present invention mainly employs continuous molten state supply and modification. In this way, compared with the divided processes of the prior art, energy waste and an increase in carbon emissions can be avoided. Therefore, the manufacturing method of the present invention is efficient and more energy-saving.

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative, and the present invention is not limited thereto.

[0021] In addition, in this specification, the range of "from one value to another value" is a general expression for avoiding listing all values within that range. Therefore, the description of a specific numerical range includes any numerical value within that range and a smaller numerical range surrounded by any numerical value within that range, as if any numerical value and a smaller numerical range were described in the specification.

[0022] The present invention provides a method for manufacturing an impact-resistant polyester composition, which is a continuous process and includes the following steps. First, the surface coating of the 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 melt-kneaded, modified with a modifier, and extruded. The modifier includes an impact-resistant modifier, a compatibilizer, an antioxidant, and a lubricant. After the plastic strip is water-cooled, it is granulated and dehydrated to produce an impact-resistant polyester composition.

[0023] In this embodiment, to avoid affecting the hue and properties of the PET recycled particles, the surface coating of the recycled release film is removed and recovered. Furthermore, using a liquid thickening system, the inherent viscosity (IV) is increased 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. And in order to improve the strength and processability of the material or impart functionality (such as impact resistance) during use of the material, functional modification is performed, so it can be used in high-value products such as injection molding and extrusion molding.

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

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

[0026] In this embodiment, the impact modifier may include a polyolefin elastomer. As the compatibilizer, it 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. As the antioxidant, it may include a hindered phenolic antioxidant, a phenolic antioxidant, a mixed antioxidant, a phosphite antioxidant, a composite antioxidant, or a combination thereof. As the lubricant, it may include a stearate, a polyethylene wax, a siloxane modifier, and a fluororesin. Through the modification of compatibility, the adjustment of viscosity, and the mixing and dispersion technology, the compatibility between the polyolefin elastomer and the polyester material is improved. After adjustment, 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, the polyester material has the characteristics of high impact strength, high rigidity, low density, and easy processing, and the 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 the recycled PET resin is, for example, 70 wt% to 92 wt%, and the content of the impact modifier is, for example, 5 wt% to 15 wt%. The content of the compatibilizer is, for example, 2 wt% to 15 wt%. The content of the antioxidant is, for example, 0.1 wt% to 1 wt%. The content of the lubricant is, for example, 0.1 wt% to 1 wt%.

[0028] In summary, based on the above, the present invention provides a method for manufacturing an impact-resistant polyester composition. By continuous process modification, the impact strength of the 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 mainly employs continuous molten state supply and modification. In this way, compared with the segmented processes of the prior art, waste of energy and increase in carbon emissions can be avoided. As a result, the manufacturing method of the present invention is efficient and more energy-saving. On the other hand, the continuous process of the present invention can reduce the loss of molecular weight or IV of the material due to repeated temperature rise and fall, and can improve the impact resistance of the impact-resistant modified particles. (Continuous process of the present invention: 56.2 kg-cm / cm, conventional segmented process: 43.0 kg-cm / cm). In addition to reducing the yield loss of the segmented process, since all the continuous processes of the present invention are completed under high-temperature melting, the energy consumption due to repeated temperature rise and fall can be avoided.

Industrial Applicability

[0029] The method for manufacturing an impact-resistant polyester composition of the present invention can be applied to injection molded products 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 the steps of: Grinding, compressing, and drying a recycled release film containing recycled PET resin, and then melting, extruding, and degassing the recycled release film; thickening the mixture using a liquid thickening system after filtration; melting, kneading, modifying and extruding a plastic strip with a modifier including an impact modifier, a compatibilizer, an antioxidant and a lubricant, and then cooling the plastic strip with water, granulating and dehydrating the plastic strip to produce an impact resistant polyester composition; The method includes:

2. The recycled release film is crushed, compressed, and dried, and the surface coating of the recycled release film is removed and recovered. A method for producing the impact resistant polyester composition according to claim 1.

3. The crushing, compressing and drying temperature of 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 melting, extrusion and degassing temperatures are between 240°C and 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 rubber 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 phenol-based antioxidant, a phenol-based antioxidant, a phosphite-based 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.