Preparation method of high-strength flame-retardant polyester material

Abstract

To provide a preparation method of polyester materials, which mainly adopts a continuous step and performs molten state feeding and modification technology to reduce the waste of energy consumption due to repeated temperature rise and fall, so as to be more energy-saving.SOLUTION: A recycled release film is crushed, compacted and dried, and then melted, extruded and degassed. After filtration, a liquid viscosifying system is used for thickening. After that, the thickened film is melted and kneaded, modified with modifiers and extruded, and then pelletized and dehydrated to make the polyester material. Therein the modifiers include nucleating agents, flame retardants, antioxidants, rod-shaped filling reinforcements and compatibilizers.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a polyester material, and more particularly to a method for manufacturing a high-strength flame-retardant polyester material.

Background Art

[0002] In the existing technical field of the method for manufacturing a high-strength flame-retardant polyester material, the mixing and modification techniques mainly employ offline (non-continuous process) extrusion, mixing, and modification using a splitting process. More specifically, steps 1, 2, and 3 can be subdivided and carried out. In step 1, the recycled release film is pulverized, and after the pulverized film is compressed and dried, it is melted, extruded, and degassed. After filtration, granulation, and dehydration, low-viscosity PET recycled particles can be obtained. Then, step 2 is executed. In step 2, the low-viscosity PET recycled particles are subjected to solid-phase polymerization and mixed with an expanding agent to form medium-viscosity and high-viscosity PET recycled particles. Finally, step 3 is executed. In step 3, the medium- and high-viscosity PET recycled particles are melted, kneaded, extruded, modified using a modifier, and granulated and dehydrated to obtain a high-strength flame-retardant polyester material. That is, the method for manufacturing a high-strength flame-retardant polyester material mainly uses the splitting processes of steps 1, 2, and 3 to perform offline (non-continuous process) extrusion, mixing, and modification.

[0003] As environmental awareness is gradually emphasized, international brands have set an important goal of introducing low-carbon emission recycled materials into their products and are gradually shifting towards the trends of circular economy, energy conservation, and carbon reduction. However, the existing manufacturing method of high-strength flame-retardant polyester materials using a splitting process is inefficient and energy-consuming, and does not conform to the trend of global environmental protection such as plastic reduction and energy conservation.

[0004] Based on the above, developing a method for manufacturing a high-strength flame-retardant polyester material that improves production efficiency, reduces energy consumption, and thus conforms to the trend of global environmental protection such as plastic reduction and energy conservation is an important research theme currently required.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention mainly employs continuous processes, executes supply and modification technologies in a molten state, reduces the waste of energy consumption caused by repeated temperature increases and decreases, and provides a method for manufacturing a polyester material that is more energy-efficient.

Means for Solving the Problems

[0006] The present invention provides a method for manufacturing a polyester material, which is a continuous process and includes the following steps. The recycled release film is crushed, compressed, and dried, and then melted, extruded, and degassed. After filtration, it is thickened using a liquid thickening system. Then, it is melt-kneaded, modified with a modifier, extruded, granulated, and dehydrated to produce a polyester material. Here, the modifier includes a nucleating agent, a flame retardant, an antioxidant, a rod-shaped filling and strengthening material, and a compatibilizer.

[0007] In one embodiment of the present invention, the method for manufacturing a polyester material further includes removing the surface coating of the recycled release film using a film surface ceramic slurry removal technique before crushing, compressing, and drying the recycled release film.

[0008] In one embodiment of the present invention, the liquid thickening system is used to increase the intrinsic viscosity (IV) from a viscosity range of 0.5 dl / g to 0.62 dl / g to a viscosity range of 0.7 dl / g to 0.9 dl / g.

[0009] In one embodiment of the present invention, the temperature for crushing, compressing, and drying the recycled release film is 100°C to 160°C.

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

[0011] In one embodiment of the present invention, the melt-kneading temperature is 230°C to 275°C.

[0012] In one embodiment of the present invention, the temperature of modification and extrusion is 230°C to 280°C.

[0013] In one embodiment of the present invention, the nucleating agent includes an organic nucleating agent, an inorganic nucleating agent, or a mixture thereof.

[0014] In one embodiment of the present invention, the organic nucleating agent includes an organic sodium salt, and the organic sodium salt includes sodium benzoate, sodium montanate, or ethylene-methacrylic acid copolymer (EMAA).

[0015] In one embodiment of the present invention, the inorganic nucleating agent includes inorganic micro-nano powder, and the inorganic micro-nano powder includes talc, titanium dioxide, silica, or calcium carbonate.

[0016] In one embodiment of the present invention, the flame retardant includes a halogen-free flame retardant, and the halogen-free flame retardant includes a nitrogen-based flame retardant, a phosphorus-based flame retardant, or a composite mixture thereof.

[0017] In one embodiment of the present invention, the antioxidant includes a hindered phenol-based antioxidant, a phenol-based antioxidant, a phosphite-based antioxidant, a composite antioxidant, or a combination thereof.

[0018] In one embodiment of the present invention, the rod-shaped filling reinforcing material includes siloxane-modified glass fiber.

[0019] In one embodiment of the present invention, the compatibilizer includes ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), polyolefin elastomer graft glycidyl methacrylate (POE-g-GMA), polyethylene graft glycidyl methacrylate glyceride (PE-g-GMA), or a combination thereof.

[0020] In one embodiment of the present invention, based on the total weight of the polyester material, the addition amount of the nucleating agent is 0.5 wt% to 3 wt%, the addition amount of the flame retardant is 10 wt% to 18 wt%, the addition amount of the antioxidant is 0.1 wt% to 1 wt%, the addition amount of the rod-shaped filling reinforcing material is 25 wt% to 32 wt%, and the addition amount of the compatibilizer is 0.5 wt% to 5 wt%.

Effects of the Invention

[0021] Based on the above, the present invention mainly adopts a continuous process, implements a supply and modification technology in a molten state, reduces the waste of energy consumption due to repeated temperature increases and decreases, and provides a manufacturing method for a polyester material that is more energy-saving. Furthermore, the present invention improves the problems of slow crystallization rate, insufficient impact strength, and rigidity of the PET material through a mixing and modification technology. Therefore, it can be used for injection molding applications such as industrial connectors, fans, sports goods, battery cases, and casings of electrical appliances.

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative, and the present invention is not limited thereto.

[0023] Note that 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 specific numerical range includes any numerical value within that range and any smaller numerical range enclosed by any numerical value within that range, as if the specification had described any numerical value and any smaller numerical range within that range.

[0024] The present invention provides a method for manufacturing a polyester material, which is a continuous process and includes the following steps. First, use the ceramic slurry removal technology on the film surface to remove the surface coating of the recycled release film. Next, crush, compress, and dry the recycled release film, put it into a melt extruder for melting, extrusion, and degassing. After filtration, continuous on-line thickening is performed using a liquid thickening system. Then, melt and knead, modify with a modifier, extrude, granulate, and dehydrate to obtain a high-strength flame-retardant and environmentally friendly polyester material that meets the V0 grade standard in the UL 94 test (thickness: 1.2 mm).

[0025] In this embodiment, the liquid thickening system is used to increase the inherent viscosity (IV) from a viscosity range of 0.5 dl / g to 0.62 dl / g to a viscosity range of 0.7 dl / g to 0.9 dl / g. As a result, the mechanical properties, flame retardancy, and fluidity of the environmentally friendly recycled particles are equivalent to those of virgin particles.

[0026] In this embodiment, the temperature for crushing, compressing, and drying the recycled release film is, for example, 100°C to 160°C. The temperature for melting, extrusion, and degassing is, for example, 240°C to 280°C. The melt-kneading temperature is, for example, 230°C to 275°C. The temperature for modification and extrusion is, for example, 230°C to 280°C.

[0027] In this embodiment, the modifier may include a nucleating agent, a flame retardant, an antioxidant, a rod-shaped filler reinforcement, and a compatibilizer. Hereinafter, each of the above-described components will be described in detail.

[0028] Nucleating agent

[0029] In this embodiment, the nucleating agent may include an organic nucleating agent, an inorganic nucleating agent, or a mixture thereof. The organic nucleating agent includes an organic sodium salt, and the organic sodium salt includes sodium benzoate, sodium montanate, or ethylene-methacrylic acid copolymer (EMAA). The inorganic nucleating agent includes inorganic micro / nano powder, and the inorganic micro / nano powder includes talc, titanium dioxide, silica, or calcium carbonate. Based on the total weight of the polyester material, the addition amount of the nucleating agent is, for example, 0.5 wt% to 3 wt%. Preferably, the compound is composed of an organic nucleating agent and an inorganic nucleating agent. At this time, based on the total weight of the polyester material, the addition amount is, for example, 1 wt% to 2 wt%. By adding the nucleating agent, the crystallization and solidification rates of the PET material can be improved, thereby improving its processability.

[0030] Flame retardant

[0031] In this embodiment, in order to meet the RoHS and halogen-free requirements of the product, the flame retardant is a halogen-free flame retardant. The halogen-free flame retardant may include a nitrogen-based flame retardant, a phosphorus-based flame retardant, or a composite mixture thereof. The phosphorus-based flame retardant may include pentaerythritol bisphosphate melamine salt (MPP), ammonium polyphosphate (APP), toluene xylyl phosphate, or hypophosphite. The nitrogen-based flame retardant may include melamine cyanurate (MCA), melamine, etc. More specifically, the composite effect of hypophosphite and melamine cyanurate (MCA) is more excellent. The ratio of hypophosphite to melamine cyanurate (MCA) is, for example, 3:1 to 1:1. The addition amount of the flame retardant is, for example, 10 wt% to 18 wt% based on the total weight of the polyester material. The flame retardant can suppress the combustion of PET by carbonizing the surface and improve the flame retardancy.

[0032] Antioxidant

[0033] In this embodiment, the antioxidant may include a hindered phenolic antioxidant, a phenolic antioxidant, a mixed antioxidant, a phosphite antioxidant, a composite antioxidant, or a combination thereof. The addition amount of the antioxidant is, for example, 0.1 wt% to 1 wt% based on the total weight of the polyester material. The antioxidant can improve the heat resistance and processability of the material.

[0034] Rod-shaped filling and reinforcing material

[0035] In this embodiment, the rod-shaped filling and reinforcing material may include siloxane-modified glass fibers. The surface is modified with siloxane to improve compatibility. The diameter of the glass fiber is, for example, 10 μm to 13 μm, and the length of the chopped strand is 3 mm to 4 mm. The addition amount of the rod-shaped filling and reinforcing material is, for example, 25 wt% to 32 wt% based on the total weight of the polyester material. The rod-shaped filling and reinforcing material can effectively improve the impact strength and rigidity of the material, and the improvement effect of the physical properties is directly related to the dispersion degree of the rod-shaped filling and reinforcing material. Therefore, in order to improve the dispersibility of the rod-shaped filling and reinforcing material in PET, it is necessary to simultaneously introduce a compatibilizer grafted with GMA.

[0036] Compatibilizer

[0037] In this embodiment, the compatibilizer may include ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA), polyolefin elastomer graft glycidyl methacrylate (POE-g-GMA), polyethylene graft glycidyl methacrylate glyceride (PE-g-GMA), or a combination thereof. The addition amount of the compatibilizer is, for example, 0.5 wt% to 5 wt% based on the total weight of the polyester material. The compatibilizer can improve the compatibility between the rod-shaped filling and reinforcing material and the PET resin, and improve the material reinforcement effect.

[0038] Hereinafter, the above manufacturing method of the high-strength flame-retardant polyester material of the present invention will be described in detail by experimental examples. However, the following experimental examples do not limit the present invention.

[0039] Experimental Example

[0040] In order to prove that the manufacturing method of the polyester material proposed by the present invention can manufacture a high-strength flame-retardant and environmentally friendly polyester material and can improve the problems of flame-retardant characteristics, slow crystallization rate, insufficient impact strength, and rigidity, the following experimental examples were carried out in particular.

[0041] Test Method

[0042] Specific Gravity: ASTM D792

[0043] Tensile Strength, Elongation: ASTM D638

[0044] Flexural Strength, Flexural Modulus: ASTM D790

[0045] Flame Retardancy: UL94

[0046] Heat Deflection Temperature (HDT): ASTM D648

[0047] Material Property Evaluation PBT + 30% GF (glass fiber), unmodified PET, recycled PET + 30% GF (glass fiber), and industrial parts made of polyester materials manufactured by the manufacturing method of the present invention were tested according to the above test methods. The test results are shown in Table 1 below. Since the manufacturing method of the polyester material of the present invention has been described in detail above, it will not be described in detail here. The manufacturing conditions of the polyester material manufactured by the manufacturing method of the present invention described in Table 1 are as follows. Thickening was carried out using a liquid thickening system to increase the intrinsic viscosity (IV) to 0.8 dl / g. The recycled release film was crushed, compressed, and dried at 120°C. The temperature of melting, extrusion, and degassing was 255°C, the temperature of melting and kneading was 265°C, and the temperature of modification and extrusion was 270°C. The addition amount of the nucleating agent is 1.5 wt% based on the total weight of the polyester material, the addition amount of the flame retardant is 12 wt%, the addition amount of the antioxidant is 0.2 wt%, the addition amount of the rod-shaped filler reinforcing material is 30 wt%, and the addition amount of the compatibilizer is 2.5 wt%.

[0048] As can be seen from Table 1 below, the impact resistance, rigidity (flexural modulus), and flame retardancy of the unmodified PET material cannot meet the requirements of industrial parts products. Recycled PET + 30% glass fiber meets the physical property requirements of the parts but has no flame retardant effect. In contrast, the polyester material produced by the manufacturing method of the present invention and PBT + 30% glass fiber for industrial parts have flame retardancy and heat resistance, and at the same time have excellent mechanical properties, reaching the V0 grade in the UL 94 standard test (thickness: 1.2 mm). The problems of slow crystallization rate and insufficient strength have been improved by modifying with a crystallization nucleating agent and a rod-shaped filler reinforcing material.

[0049]

Table 1

[0050] In summary, the present invention mainly adopts a continuous process, reduces the waste of energy consumption caused by repeated temperature rise and fall, and provides a manufacturing method of a polyester material that is more energy-saving. In this way, the problems of low efficiency and high energy consumption in the divided process of the existing manufacturing method of high-strength flame-retardant polyester materials can be effectively improved. Furthermore, the present invention improves the problems of slow crystallization rate, insufficient impact strength and rigidity of the PET material through mixing and modification technology, so it can be used in injection molding applications such as industrial connectors, fans, sports goods, battery cases and casings of electrical appliances. On the other hand, in the present invention, a recycled release film is used as the PET raw material, and its mechanical properties, flame retardancy and fluidity are equivalent to those of virgin particles. Therefore, it can contribute to the global goals of plastic reduction and energy conservation.

Industrial Applicability

[0051] The manufacturing method of the polyester material of the present invention can be applied to injection molding applications such as industrial connectors, fans, sports goods, battery cases and casings of electrical appliances.

Claims

1. 1. A method for producing a polyester material which is a continuous process, comprising the steps of: grinding, compressing, and drying the recycled release film, and then melting, extruding, and degassing the recycled release film; thickening the mixture using a liquid thickening system after filtration; melting and kneading the polyester material, modifying the polyester material with a modifier including a nucleating agent, a flame retardant, an antioxidant, a rod-shaped filler reinforcing material and a compatibilizing agent, and extruding the polyester material, granulating the polyester material and dehydrating the polyester material; A method comprising:

2. Further comprising removing the surface coating of the recycled release film using a film surface ceramic slurry removal technique before grinding, compressing and drying the recycled release film; A method for producing the polyester material according to claim 1.

3. The liquid thickening system is used to increase the intrinsic viscosity (IV) from a viscosity range of 0.5 dl / g to 0.62 dl / g to a viscosity range of 0.7 dl / g to 0.9 dl / g. A method for producing the polyester material according to claim 1.

4. The crushing, compressing and drying temperature of the recycled release film is 100°C to 160°C; A method for producing the polyester material according to claim 1.

5. The melting, extrusion and degassing temperatures are between 240°C and 280°C. A method for producing the polyester material according to claim 1.

6. The melting and kneading temperature is 230°C to 275°C. A method for producing the polyester material according to claim 1.

7. The temperature of the modification and extrusion is 230°C to 280°C. A method for producing the polyester material according to claim 1.

8. The nucleating agent comprises an organic nucleating agent, an inorganic nucleating agent, or a mixture thereof. A method for producing the polyester material according to claim 1.

9. The organic nucleating agent comprises an organic sodium salt, the organic sodium salt comprising sodium benzoate, sodium montanate or ethylene-methacrylic acid copolymer (EMAA); A method for producing the polyester material according to claim 8.

10. The inorganic nucleating agent includes inorganic micro-nano powder, and the inorganic micro-nano powder includes talc, titanium dioxide, silica, or calcium carbonate. A method for producing the polyester material according to claim 8.

11. The flame retardant comprises a halogen-free flame retardant, the halogen-free flame retardant comprises a nitrogen-based flame retardant, a phosphorus-based flame retardant, or a composite mixture thereof; A method for producing the polyester material according to claim 1.

12. 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 polyester material according to claim 1.

13. The rod-shaped filler reinforcing material includes siloxane-modified glass fibers; A method for producing the polyester material according to claim 1.

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

15. Based on the total weight of the polyester material, the amount of the nucleating agent is 0.5 wt % to 3 wt %, the amount of the flame retardant is 10 wt % to 18 wt %, the amount of the antioxidant is 0.1 wt % to 1 wt %, the amount of the rod-shaped filler reinforcing material is 25 wt % to 32 wt %, and the amount of the compatibilizer is 0.5 wt % to 5 wt %. A method for producing the polyester material according to claim 1.

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