PC / ABS alloy material for low-pressure injection coating and preparation method thereof

Abstract

The application discloses a PC / ABS alloy material capable of being used for low-pressure injection coating and a preparation method thereof, and relates to the technical field of automobile accessory manufacturing. The PC / ABS alloy material is prepared from the following raw materials: PC resin, ABS resin, a compatibilizer, a flow modifier, a toughening agent, a heat stabilizer, an antioxidant, a dispersant and pigments. The PC resin and the ABS resin are dried respectively to a water content of less than 0.2%; then, the compatibilizer, the flow modifier, the toughening agent, the heat stabilizer, the antioxidant, the dispersant and the pigments are put into a high-speed mixer together with the PC resin and the ABS resin to be uniformly mixed; and finally, the mixture is put into an extruder to be extruded, cooled, dried, cut into particles and homogenized. The PC / ABS alloy material prepared by the application has the advantages of good toughness, good heat resistance, high fluidity and low viscosity, and can be used for the low-pressure injection coating process, so that the problem that the PC / ABS material prepared by the prior art cannot meet the requirements of the low-pressure injection coating process can be solved.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing technology, and in particular to an automotive interior material and its preparation method. Background Technology

[0002] With the rapid development of the automotive industry and the continuous improvement of the material needs of drivers and passengers, users have placed higher demands on the aesthetics and comfort of car interiors. Therefore, more and more automotive products are using fabrics and artificial leather to cover pillar trim panels to enhance the aesthetics and comfort of the interior and improve its sensory quality.

[0003] Currently, the main processes for covering column panels with fabric or artificial leather include traditional hand-wrapping and low-pressure injection molding. Among them, low-pressure injection molding has advantages over traditional hand-wrapping, such as higher production efficiency, environmental friendliness, and better consistency, and has a promising application prospect.

[0004] Low-pressure injection molding is a process that injects encapsulation material into a mold at very low injection pressure and allows it to solidify rapidly (5s-50s). Artificial leather or knitted fabric is first added to the injection molding process, simultaneously completing the composite injection molding between the surface material and the skeleton material. Due to the special properties of artificial leather or knitted fabric, the injection pressure (1.5bar-40bar), injection speed, and injection temperature (<230℃) are required. This necessitates that the encapsulation material used has high flowability and low viscosity at 230℃, while also ensuring certain strength, rigidity, toughness, and heat resistance. Currently, most encapsulation materials for automotive interiors use polypropylene. However, some components require materials with higher strength and rigidity, thus necessitating the use of PC / ABS materials. However, conventional PC / ABS materials, due to their high processing temperature, poor flowability, and high viscosity, cannot meet the requirements of the aforementioned low-pressure injection molding encapsulation process.

[0005] For example, Chinese patent application number CN202110942633.4, entitled "A High-Flowability, High-Impact, Low-Pressure Thin-Wall Injection Molding PC / ABS Material," discloses a material prepared from the following parts by weight: 20-40 parts PC material, 50-70 parts ABS material, 5-15 parts toughening agent, 2-8 parts compatibilizer, 0.2-1 part lubricant, and 0.2-0.6 parts antioxidant. This material possesses both ultra-high flowability and high notched impact strength, making it suitable for thin-walled parts requiring high material toughness. Low pressure and low speed during injection molding reduce impact on the mold's inner wall, protecting the mold cavity and extending its service life. However, the use of medium-viscosity PC, high-melt-viscosity heat-resistant ABS, and maleic anhydride graft compatibilizer all affect the alloy material's processing performance. Therefore, although the resulting PC / ABS material has high flowability, its processing temperature and flowability are difficult to meet the requirements of low-pressure, low-speed overmolding injection molding processes.

[0006] Chinese patent CN202110396130 discloses a composite material suitable for in-mold injection molding and its preparation method. The composite material includes the following raw materials: polycarbonate, carbonate-organosiloxane copolymer, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, toughening agent, flame retardant, anti-dripping agent, antioxidant, lubricant, and glass fiber. This improves the mechanical properties of the composite material, and its high fluidity makes it suitable for low-temperature in-mold injection molding. Injection molding can be performed at a temperature of 230℃, allowing for low-temperature, low-pressure injection molding and preventing wrinkles, deformation, and pattern bleeds in decorative sheets. While the prepared material can be used for low-temperature, low-pressure injection molding, the added flame retardant, anti-dripping agent, and glass fiber affect the fluidity of the alloy material and can cause separation when coating artificial leather or knitted fabrics, especially during the injection molding coating process, where the glass fiber can easily puncture the artificial leather. Summary of the Invention

[0007] This invention provides a PC / ABS alloy material that can be used for low-pressure injection molding coating and its preparation method. The PC / ABS alloy material has the advantages of good toughness, good heat resistance, high fluidity and low viscosity. It can be used in low-pressure injection molding coating process, thereby overcoming the problem that the PC / ABS materials prepared by the above-mentioned prior art cannot meet the requirements of low-pressure injection molding coating process.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is a PC / ABS alloy material that can be used for low-pressure injection molding coating: It is prepared from the following parts by weight of raw materials: 30 to 70 parts of PC resin; 30 to 60 parts of ABS resin; Compatibilizer 3 to 8 parts; 3 to 15 parts of flow modifier; 3 to 8 parts toughening agent; Heat stabilizer 1 to 5 parts; Antioxidant 0.2 to 1 part; 1 to 5 parts of dispersant; 1 to 3 parts pigment; The PC resin is characterized by low viscosity, a weight-average molecular weight of 8000 mol to 21000 mol, produced by the phosgene method, and a melt index ≥20 g / 10 min at 300°C and 1.2 kg. The ABS resin has a melt flow index ≥30g / 10min when tested at 220℃ and 10kg. The compatibilizer is a styrene-acrylate copolymer. The flow modifier is a low molecular weight styrene-acrylonitrile copolymer. The toughening agent is: methyl methacrylate-butadiene-styrene core-shell copolymer; The heat stabilizer is: phenylmaleimide-maleic anhydride-styrene copolymer; The dispersant is N,N-ethylenebis-stearamide.

[0009] More specific technical solutions than those described above could also include: The antioxidants, hindered phenolic antioxidants, thioesters, and phosphite antioxidants are compounded in a mass ratio of 1:1:2.

[0010] Furthermore, the pigment is a black masterbatch with a content of 50% and a PE carrier.

[0011] Furthermore, the weight proportions of each raw material are as follows: 35 parts of PC resin; 55 parts of ABS resin; Compatibilizer 4 parts; 4 parts of flow modifier; 5 parts toughening agent; 5 parts heat stabilizer; Antioxidant 0.4 parts; 2 parts dispersant; 1 part pigment.

[0012] The second technical solution adopted in this invention is a method for preparing any of the PC / ABS alloy materials that can be used for low-pressure injection molding as described above: Its preparation method includes the following steps: (1) First, dry the PC resin and ABS resin in the raw materials to a moisture content of less than 0.2% and set aside for later use; (2) Then, according to the proportion, put the compatibilizer, flow modifier, toughening agent, heat stabilizer, antioxidant, dispersant, pigment, and PC resin and ABS resin after drying in step (1) into the high-speed mixer and mix them evenly. (3) The mixture obtained in step (2) is put into an extruder, extruded, cooled, dried, pelletized and homogenized.

[0013] A more specific technical solution to the above technical solution may be: the extruder is a dual-vacuum co-rotating twin-screw extruder with a screw diameter of 61.8 mm.

[0014] Furthermore, the specific extrusion process is as follows: the screw temperature is 210℃~230℃, the main screw speed is 400r / min~500r / min, and the feeder frequency is 10Hz~15Hz.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. This invention utilizes low-viscosity, high-flow PC resin and ABS resin as the main base materials, and then uses flow modifiers, compatibilizers, toughening agents, heat stabilizers and dispersants to compound them. The modification and preparation process is simple, and the prepared PC / ABS alloy material meets the requirements of low-temperature and low-pressure injection molding coating process for artificial leather or knitted fabrics.

[0016] 2. In this invention, the addition of the toughening agent—methyl methacrylate-butadiene-styrene core-shell copolymer—significantly improves the toughness of the PC / ABS alloy material, but simultaneously reduces its flowability and heat resistance. The addition of the flow modifier—low molecular weight styrene-acrylonitrile copolymer—and the dispersant—hexamethylene bis-stearamide combination—greatly improves the material's flowability and reduces the viscosity of the PC / ABS alloy, but simultaneously reduces the notched impact resistance and heat resistance of the PC / ABS alloy material. The addition of the compatibilizer—styrene-acrylate copolymer—can… Improving the overall performance of PC / ABS alloy materials without affecting processing fluidity; the heat stabilizer—a copolymer of phenylmaleimide-maleic anhydride-styrene—may effectively maintain the heat resistance temperature of PC / ABS alloys to meet the requirements of automotive interior working conditions, but at the same time, it will lead to a decrease in the fluidity and toughness of PC / ABS alloy materials; while the present invention utilizes the complementary and synergistic effects between the above components to combine them, so that the resulting product—PC / ABS alloy material—possesses excellent comprehensive properties such as good toughness, good heat resistance, high fluidity, and low viscosity, thereby meeting the requirements of low-pressure injection molding overmolding process.

[0017] 3. Furthermore, in this invention, the specific chemical composition of the added components such as compatibilizers, flow modifiers, toughening agents, heat stabilizers, antioxidants, and dispersants is not arbitrarily selected, nor is the combination between them arbitrarily selected. For example, if the compatibilizer added is not the styrene-acrylate copolymer compatibilizer selected in this invention, but a maleic anhydride-grafted compatibilizer, although it can improve the physical and mechanical properties of the PC / ABS alloy material, it will reduce the processing fluidity. If an appropriate amount of compatibilizer is not added, the alloy material has poor compatibility and the overall performance is severely reduced. However, if the styrene-acrylate copolymer compatibilizer selected in this invention is added, the overall performance of the PC / ABS alloy material can be improved without affecting the processing fluidity. Detailed Implementation

[0018] The invention will be further described in detail below with reference to examples; In the following embodiments, some of the materials used are as follows: 1. PC: Low viscosity, weight average molecular weight 8000-21000mol, produced by phosgene method, melt index ≥20g / 10min tested at 300℃ and 1.2kg (Luxi Chemical 1920T). 2. ABS: Melt flow index ≥30g / 10min at 220℃ and 10kg (Zhenjiang Chimei PA-757K); 3. Compatibilizer: Styrene-acrylate copolymer, HPC-3128 (Jia Yi Rong); 4. Flow modifier: Low molecular weight styrene-acrylonitrile copolymer (SAN), EMI 200 (Jia Yi Rong); 5. Toughening agent: Methyl methacrylate-butadiene-styrene core-shell copolymer (MBS), M-701 (Kanebuchi Chemical, Japan); 6. Heat stabilizer: Phenyl maleimide-maleic anhydride-styrene copolymer, DENKA-IP N (Denka Chemicals, Japan); 7. Antioxidants: Hindered phenolic antioxidants: Thioesters: Phosphite antioxidants are compounded in a mass ratio of 1:1:2, including Irganox 1076, Irganox PS802FL, and Irgafos 168 (BASF). 8. Dispersants: N,N-ethylene bis-stearamide (EBS), EB-FF (Kao Corporation, Japan); 9. Pigment: Black masterbatch, 50% content, PE carrier masterbatch, PE2718 (Cabot Corporation, USA).

[0019] According to the material ratios provided in Tables 1 and 2, a PC / ABS alloy material suitable for low-pressure injection molding overmolding is prepared using the following steps: (1) First, dry the PC resin in the raw materials at 110℃ and the ABS resin at 90℃ for more than 4 hours to make their moisture content less than 0.2% and set aside for later use; (2) Then, according to the proportion, put the compatibilizer, flow modifier, toughening agent, heat stabilizer, antioxidant, dispersant, pigment, and PC resin and ABS resin after drying in step (1) into a high-speed mixer and mix for 5 min to 10 min to make them evenly mixed. (3) The mixture obtained in step (2) is placed into a double vacuum co-rotating twin-screw extruder with a screw diameter of 61.8 mm. The specific extrusion process is as follows: the screw temperature is 210℃~230℃, the main screw speed is 400r / min~500r / min, the feeder frequency is 10Hz~15Hz, and the finished product is obtained after extrusion, cooling, drying, pelletizing, homogenization and other processes.

[0020] Table 1 .

[0021] Table 2 .

[0022] Note: The compatibilizer KT-5 in Table 2 refers to PS-g-MAH (PS grafted maleic anhydride), with a grafting rate ≥4%, KT-5 (Shenyang Ketong).

[0023] Performance testing methods: The granules prepared according to the above proportions were injection molded and then subjected to the following performance tests: 1. Density: Tested according to the standard in GB 1033.1-2008, using method A, with a sample size of 80×10×4mm; 2. The notched impact strength of the cantilever beam was tested according to GB / T 1843-2008 standard, with a specimen size of 80×10×4mm and a type A notch. 3. The heat distortion temperature test shall be conducted in accordance with GB / T 1634.2-2019 standard. The sample size is 80×10×4mm, the load is 0.46MPa, and the sample shall be laid flat. 4. Tensile property testing was conducted according to GB / T 1040.2-2018 standard, with a sample size of 170×10×4mm and a tensile speed of 50mm / min. 5. Bending performance test shall be conducted in accordance with GB / T 9341-2008 standard, with sample size of 80×10×4mm, bending speed of 2mm / min, and span of 64mm. 6. The melt flow index test shall be conducted in accordance with Method A of GB / T 3682-2000. The test conditions are: temperature 260℃ and load 5Kg.

[0024] The test results are shown in Tables 3 and 4 below: Table 3 .

[0025] Table 4 .

[0026] It should be noted that the above embodiments are used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PC / ABS alloy material that can be used for low-pressure injection molding coating, characterized in that... It is prepared from the following parts by weight of raw materials: 30 to 70 parts of PC resin; 30 to 60 parts of ABS resin; Compatibilizer 3 to 8 parts; 3 to 15 parts of flow modifier; 3 to 8 parts toughening agent; Heat stabilizer 1 to 5 parts; Antioxidant 0.2 to 1 part; 1 to 5 parts of dispersant; 1 to 3 parts pigment; The PC resin is characterized by low viscosity, a weight-average molecular weight of 8000 mol to 21000 mol, produced by the phosgene method, and a melt index ≥20 g / 10 min at 300°C and 1.2 kg. The ABS resin has a melt flow index ≥30g / 10min when tested at 220℃ and 10kg. The compatibilizer is a styrene-acrylate copolymer. The flow modifier is a low molecular weight styrene-acrylonitrile copolymer. The toughening agent is: methyl methacrylate-butadiene-styrene core-shell copolymer; The heat stabilizer is: phenylmaleimide-maleic anhydride-styrene copolymer; The dispersant is N,N-ethylenebis-stearamide.

2. The PC / ABS alloy material for low-pressure injection molding coating as described in claim 1, characterized in that: The antioxidants, hindered phenolic antioxidants, thioesters, and phosphite antioxidants are compounded in a mass ratio of 1:1:

2.

3. A PC / ABS alloy material for low-pressure injection molding coating as described in claim 1 or 2, characterized in that: The pigment is a black masterbatch with a content of 50% and a PE carrier.

4. A PC / ABS alloy material for low-pressure injection molding coating as described in claim 3, characterized in that... The weight proportions of each raw material are as follows: 35 parts of PC resin; 55 parts of ABS resin; Compatibilizer 4 parts; 4 parts of flow modifier; 5 parts toughening agent; 5 parts heat stabilizer; Antioxidant 0.4 parts; 2 parts dispersant; 1 part pigment.

5. A method for preparing PC / ABS alloy materials that can be used for low-pressure injection molding coating, characterized in that: The following parts by weight of raw materials are used: 30 to 70 parts of PC resin; 30 to 60 parts of ABS resin; Compatibilizer 3 to 8 parts; 3 to 15 parts of flow modifier; 3 to 8 parts toughening agent; Heat stabilizer 1 to 5 parts; Antioxidant 0.2 to 1 part; 1 to 5 parts of dispersant; 1 to 3 parts pigment; The PC resin is characterized by low viscosity, a weight-average molecular weight of 8000 mol to 21000 mol, produced by the phosgene method, and a melt index ≥20 g / 10 min at 300°C and 1.2 kg. The ABS resin has a melt flow index ≥30g / 10min when tested at 220℃ and 10kg. The compatibilizer is a styrene-acrylate copolymer. The flow modifier is a low molecular weight styrene-acrylonitrile copolymer. The toughening agent is: methyl methacrylate-butadiene-styrene core-shell copolymer; The heat stabilizer is: phenylmaleimide-maleic anhydride-styrene copolymer; The dispersant is N,N-ethylenebisstearamide; Its preparation method includes the following steps: (1) First, dry the PC resin and ABS resin in the raw materials to a moisture content of less than 0.2% and set aside for later use; (2) Then, according to the proportion, put the compatibilizer, flow modifier, toughening agent, heat stabilizer, antioxidant, dispersant, pigment, and PC resin and ABS resin after drying in step (1) into the high-speed mixer and mix them evenly. (3) The mixture obtained in step (2) is put into an extruder, extruded, cooled, dried, pelletized and homogenized.

6. A method for preparing a PC / ABS alloy material suitable for low-pressure injection molding coating according to claim 5, characterized in that: The antioxidants, hindered phenolic antioxidants, thioesters, and phosphite antioxidants are compounded in a mass ratio of 1:1:

2.

7. A method for preparing a PC / ABS alloy material suitable for low-pressure injection molding coating according to claim 5 or 6, characterized in that: The pigment is a black masterbatch with a content of 50% and a PE carrier.

8. A method for preparing a PC / ABS alloy material suitable for low-pressure injection molding coating according to claim 7, characterized in that... The weight proportions of each raw material are as follows: 35 parts of PC resin; 55 parts of ABS resin; Compatibilizer 4 parts; 4 parts of flow modifier; 5 parts toughening agent; 5 parts heat stabilizer; Antioxidant 0.4 parts; 2 parts dispersant; 1 part pigment.

9. A method for preparing a PC / ABS alloy material suitable for low-pressure injection molding coating according to claim 8, characterized in that: The extruder is a dual-vacuum co-rotating twin-screw extruder with a screw diameter of 61.8 mm.

10. A method for preparing a PC / ABS alloy material suitable for low-pressure injection molding coating according to claim 9, characterized in that: The specific extrusion process is as follows: the screw temperature is 210℃~230℃, the main screw speed is 400r / min~500r / min, and the feeder frequency is 10Hz~15Hz.