PBT-PC composite material, preparation method and application thereof

Abstract

This invention relates to a PBT-PC composite material, its preparation method, and its applications. The PBT-PC composite material comprises PBT resin, PC resin, and an ester exchange inhibitor; the tetrahydrofuran content in the PBT resin is <1000 ppm; and the bisphenol A content in the PC resin is <100 ppm. By controlling the tetrahydrofuran content in the PBT resin and the residual bisphenol A monomer content in the PC resin, this invention enables the PBT-PC composite material to maintain good tensile strength after being held at high temperatures, thus providing a wider processing window in alloying production.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a PBT-PC composite material, its preparation method, and its application. Background Technology

[0002] Polycarbonate (PC) is a linear, nearly colorless, glassy amorphous polymer with advantages such as good impact strength, excellent electrical insulation, a wide operating temperature range, and good dimensional stability. It is one of the five major engineering plastics and a superior thermoplastic engineering plastic widely used in electronics, automotive, medical devices, aerospace, and other fields. However, PC molecules contain a large number of benzene rings, resulting in high molecular rigidity and steric hindrance. Consequently, its melting temperature is relatively high, its flow properties during processing are poor, and its products are prone to stress cracking, resulting in high residual stress, poor wear resistance, and notch sensitivity. These factors limit its application in production.

[0003] Polybutylene terephthalate (PBT) is a polyester engineering plastic with excellent overall performance. It possesses very good chemical stability, mechanical strength (such as toughness, fatigue resistance, and self-lubricating properties), electrical insulation properties, and thermal stability. It has a fast crystallization rate, enabling high-speed molding. It exhibits excellent solvent resistance, heat resistance, toughness, and abrasion resistance, as well as low water absorption, maintaining its various good properties even in humid environments. It also has good electrical insulation. However, its disadvantages include low notched impact strength and high molding shrinkage.

[0004] Therefore, blending PC and PBT can not only compensate for the shortcomings of PC such as high melt viscosity, poor flowability and poor solvent resistance, but also improve the defects of PBT such as low impact resistance. For example, CN113956643A discloses a chemically resistant, scratch-resistant, high-hardness PC / PBT composite material and its preparation method. By weight percentage, the composite material comprises the following components: 50-70% polycarbonate, 20-40% polybutylene terephthalate, 3-5% compatibilizer, 4-6% toughening agent, 0.3-0.5% lubricant, 0.2-0.3% transesterification accelerator, and 0.2-0.4% compounded antioxidant. The transesterification accelerator is a weakly basic metal oxide with a particle size greater than 8000 mesh. By using the transesterification accelerator, the transesterification reaction of PC / PBT is accelerated, improving the interfacial compatibility between the PC and PBT phases. The addition of the transesterification accelerator can effectively improve the rigidity, toughness, and pencil hardness of the material. The addition of both the compatibilizer and the toughening agent can improve the toughness and heat resistance of the material. Simultaneously, the use of a special high-hardness PC increases the surface hardness of the PCPBT alloy, improving the scratch resistance of the alloy material.

[0005] However, during the alloying process, the transesterification reaction between PBT and PC often leads to material defects and decreased product performance during injection molding, resulting in a short processing window for PBT-PC alloying. Therefore, there is an urgent need in this field to develop a PBT-PC composite material with a wider processing window that can maintain excellent mechanical properties even when held at the high temperatures of the extruder. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a PBT-PC composite material, its preparation method, and its application. By controlling the tetrahydrofuran content in PBT resin and the residual bisphenol A monomer content in PC resin, the PBT-PC composite material retains good tensile strength after being held at high temperatures, thus providing a wider processing window in alloying production.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a PBT-PC composite material comprising PBT resin, PC resin and an ester exchange inhibitor; wherein the content of tetrahydrofuran (THF) in the PBT resin is <1000ppm; and the content of bisphenol A in the PC resin is <100ppm.

[0009] The PBT-PC composite material provided by this invention limits the THF content in the PBT resin and the bisphenol A content in the PC resin. THF is a byproduct of PBT resin production, and bisphenol A is a raw material monomer of PC resin, remaining in the PC resin due to incomplete reaction. Both contents significantly affect product performance. This invention uses PBT resin with a THF content <1000ppm and PC resin with a bisphenol A content <100ppm to composite the material, resulting in a composite material that maintains excellent tensile strength after being held at high temperatures, has a wide processing window, and exhibits good application performance.

[0010] The tetrahydrofuran content in the PBT resin is <1000 ppm, for example, it can be 950 ppm, 900 ppm, 850 ppm, 800 ppm, 750 ppm, 700 ppm, 650 ppm, 600 ppm, 550 ppm, 500 ppm, 450 ppm, 400 ppm, 350 ppm, 300 ppm, 250 ppm, 200 ppm, 150 ppm, 100 ppm, 50 ppm, 30 ppm, 10 ppm, 5 ppm, 1 ppm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range. Based on purification cost considerations, the tetrahydrofuran content in the PBT resin is >10 ppm, more preferably 10–900 ppm, more preferably 100–600 ppm, and even more preferably 200–500 ppm.

[0011] In this invention, PBT resin with a specific tetrahydrofuran content can be obtained by purchasing commercially available products or by preparing them using conventional methods. For example, the method includes: adding commercially available PBT resin with a high tetrahydrofuran content to a solid-state apparatus and holding it at 180–200°C for 5–8 hours. By changing the temperature and time, PBT resin with different tetrahydrofuran contents can be obtained.

[0012] In this invention, the tetrahydrofuran content in PBT resin is tested using a static headspace method. The specific test method is as follows:

[0013] (1) Construction of THF standard curve

[0014] THF methanol solutions with concentrations of 0.010 g / L, 0.1 g / L, 1.0 g / L, 5.0 g / L, 10.0 g / L, 20.0 g / L, 50.0 g / L, and 100.0 g / L were prepared. The peak area of ​​THF in the THF methanol solutions of different concentrations was measured by static headspace analysis. A standard curve of THF was constructed with the peak area of ​​THF as the ordinate and the concentration of THF as the abscissa.

[0015] (2) Determination of THF content in PBT resin:

[0016] Accurately weigh approximately 1,2000 g of the sample to be tested and add it to a static headspace test vial. Measure the peak area of ​​THF in the PBT resin using the static headspace method. The THF content in the sample can be calculated based on the peak area of ​​THF in the PBT resin and the THF standard curve. The standard curve is calibrated using tetrahydrofuran / methanol solution.

[0017] The static headspace method test conditions are as follows:

[0018] Temperature: Heating chamber: 105℃; Metering loop: 135℃; Transmission line: 165℃.

[0019] Time: Sample vial equilibration: 120 minutes; Injection duration: 0.09 minutes; GC cycle: 30 minutes.

[0020] The instrument models and parameters used for static headspace analysis are as follows: Agilent Technologies 7697 Headspace Sampler; Agilent Technologies 7890 AGC System; Column: J&W 122-7032: 250℃: 30m×250μm×0.25μm; Injection: N2 pre-SS inlet; Ejection: FID pre-detector.

[0021] The bisphenol A content in the PC resin is <100 ppm, for example, it can be 95 ppm, 90 ppm, 85 ppm, 80 ppm, 70 ppm, 60 ppm, 50 ppm, 40 ppm, 30 ppm, 20 ppm, 15 ppm, 10 ppm, 5 ppm, 1 ppm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range. Based on purification cost considerations, the bisphenol A content in the PC resin is >1 ppm, more preferably 1-90 ppm, and particularly preferably 10-60 ppm.

[0022] In this invention, the PC resin with a specific bisphenol A content can be obtained commercially or prepared using conventional methods. For example, the method includes: placing a PC resin with a high bisphenol A content in a twin-screw extruder and extruding it at a temperature of 220–300°C and a vacuum of -0.05–-0.1 MPa. By changing the temperature and vacuum, PC resins with different bisphenol A contents can be obtained.

[0023] In this invention, high performance liquid chromatography (HPLC) is used to test the bisphenol A content in PC resin. The specific test method is as follows:

[0024] The BPA content was determined by high-performance liquid chromatography (HPLC). The instrument conditions and methods were as follows: HPLC instrument (equipped with a fluorescence detector); excitation wavelength: 227 nm; emission wavelength: 313 nm; chromatographic conditions: total flow rate 1 mL / min, column temperature oven 40℃, retention time 9.2 min; mobile phase A: methanol; mobile phase B: water; gradient elution: 0–8 min, 70% A; 8–10 min, 80% A; 10–12 min, 90% A; 12–13 min, 100% A. Preferably, the tetrahydrofuran content in the PBT resin was 11-999 ppm.

[0025] Preferably, the PBT-PC composite material comprises, by weight, 8-55 parts of PBT resin, 8-55 parts of PC resin, and 0.05-1 parts of transesterification inhibitor.

[0026] Preferably, the PBT-PC composite material comprises, by weight, 15-55 parts of PBT resin, 15-55 parts of PC resin, and 0.05-1 parts of transesterification inhibitor.

[0027] The PBT resin is 8-55 parts, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0028] The PC resin is 8-55 parts, for example, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0029] The transesterification inhibitor is 0.05-1 part, for example, 0.1 part, 0.2 part, 0.3 part, 0.5 part, 0.6 part or 0.8 part, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0030] The "parts" and "parts by weight" used in this invention are calculated based on solid content and do not include solvents, dispersants, etc.

[0031] This invention uses a specific amount of transesterification inhibitor in combination with other components to effectively control the transesterification reaction between PBT and PC, thus solving the problem of material defects and product performance degradation during injection molding.

[0032] Preferably, the mass ratio of PBT resin to PC resin is 1:(0.1-6.2), for example, it can be 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.2, 1:2.5, 1:3, 1:4, 1:4.5, 1:5 or 1:5.5, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but more preferably it is 1:(0.3-3).

[0033] This invention uses a specific ratio of PBT resin and PC resin to produce a PBT-PC composite material with a wider processing window and significantly improved strength, which can meet the performance requirements of more fields and broaden its application scope.

[0034] Preferably, the intrinsic viscosity of the PBT resin is greater than 0.8 dl / g, for example, it can be 0.9 dl / g, 1.0 dl / g, 1.1 dl / g, 1.2 dl / g, 1.3 dl / g, 1.4 dl / g, 1.5 dl / g, 1.8 dl / g or 2 dl / g, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0035] In this invention, the intrinsic viscosity is measured at 23°C in accordance with the standard GB / T 1632-1993 "Determination of Viscosity and Intrinsic Viscosity of Dilute Polymer Solutions".

[0036] Preferably, the melt flow index of the PC resin measured at 300℃ / 1.2kg is ≤25g / 10min, for example, it can be 22g / 10min, 20g / 10min, 15g / 10min, 10g / 10min, 9.5g / 10min, 9g / 10min, 8g / 10min, 7g / 10min, 6g / 10min or 5g / 10min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range. More preferably, it is ≤10g / 10min.

[0037] In this invention, the melt flow index is measured using a melt flow indexer according to the ASTM D1238-2010 standard at 300℃ / 1.2kg.

[0038] Preferably, the transesterification inhibitor comprises any one or a combination of at least two of zinc dihydrogen phosphate, sodium dihydrogen phosphate, or zinc hydrogen phosphate.

[0039] Preferably, the PBT-PC composite material further includes additives.

[0040] Preferably, the additives include any one or a combination of at least two of flame retardants, synergistic flame retardants, or toughening agents.

[0041] Preferably, the flame retardant is in the form of 8-15 parts by weight, for example, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts or 14 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0042] Preferably, the flame retardant includes any one or a combination of at least two of the following: brominated flame retardants, sulfonate flame retardants, or phosphorus flame retardants.

[0043] Preferably, the brominated flame retardant includes any one or a combination of at least two of brominated polycarbonate, brominated epoxy, polybrominated styrene, tetrabromobisphenol A, decabromodiphenyl ether, polydibromophenyl ether, or tetradecylbromodiphenoxybenzene.

[0044] Preferably, the sulfonate flame retardant is any one or a combination of at least two of potassium perfluorobutyl sulfonate, potassium benzenesulfonylbenzenesulfonate, or sodium 2,4,5-trichlorobenzenesulfonate.

[0045] Preferably, the phosphorus-based flame retardant includes any one or a combination of at least two of the following: aluminum hypophosphite, diethylaluminum hypophosphite, melamine polyphosphate, red phosphorus, ammonium polyphosphate, ammonium dihydrogen phosphate, triphenyl phosphate, tricresyl phosphate, tri(dibromopropyl) phosphate, or tri(β-chloroethyl) phosphate.

[0046] Preferably, the synergistic flame retardant is in the form of 1-5 parts by weight, for example, 1.5 parts, 2 parts, 3 parts, 4 parts or 4.5 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0047] Preferably, the synergistic flame retardant includes silane flame retardants and / or antimony-based flame retardants.

[0048] Preferably, the silane flame retardant includes any one or a combination of at least two of polysilane, polysiloxane, or polyorganosilicon silsesquioxane.

[0049] Preferably, the antimony-based flame retardant includes any one or a combination of at least two of antimony trioxide, colloidal antimony pentoxide, or sodium antimonate.

[0050] Preferably, the toughening agent is in the form of 3-15 parts by weight, for example, 4 parts, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts or 14 parts, and specific values ​​between the above-mentioned values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0051] Preferably, the toughening agent comprises any one or a combination of at least two of the following: ethylene-acrylate-glycidyl methacrylate copolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate copolymer, methacrylate-styrene-silicone copolymer, and methacrylate-styrene-butadiene copolymer.

[0052] The PBT-PC composite material provided by this invention can be supplemented with other additives according to actual needs. These other additives include any one or a combination of at least two of antioxidants, release agents, and anti-dripping agents.

[0053] Preferably, the antioxidant includes hindered phenolic antioxidants and / or phosphite antioxidants.

[0054] Preferably, the release agent comprises any one or a combination of at least two of the following: metal stearate, alkyl stearate, pentaerythritol stearate, paraffin wax, and lignite wax.

[0055] Preferably, the anti-dripping agent includes a polytetrafluoroethylene-based anti-dripping agent.

[0056] In a second aspect, the present invention provides a method for preparing the PBT-PC composite material as described in the first aspect, the method comprising the following steps:

[0057] PBT resin, PC resin, transesterification inhibitor and optional additives are mixed, extruded and granulated to obtain the PBT-PC composite material.

[0058] Preferably, the extrusion is carried out in a twin-screw extruder.

[0059] Preferably, the extrusion temperature is 150-300℃, for example, it can be 160℃, 170℃, 180℃, 200℃, 220℃, 250℃ or 280℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0060] Thirdly, the present invention provides an application of the PBT-PC composite material as described in the first aspect in the fields of electronics and electrical engineering, automotive industry, medical devices, or aerospace.

[0061] In this invention, the applications in electronics, automotive industry, medical devices, or aerospace include, for example, photovoltaic connectors, energy storage connectors, charging guns for new energy batteries, housings for disinfection guns, and battery pack housings for power tools.

[0062] Compared with the prior art, the present invention has at least the following beneficial effects:

[0063] This invention provides a PBT-PC composite material, comprising PBT resin, PC resin, flame retardant, synergistic flame retardant, toughening agent, and transesterification inhibitor. By using PBT resin with a specific tetrahydrofuran content and PC resin with a specific residual bisphenol A monomer content, and compounding it with other components, the tensile strength retention rate of the PBT-PC composite material after being held at 270°C for 10 minutes is above 80%, and it has a wide processing window of 230–300°C during alloying production. Detailed Implementation

[0064] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0065] In the following specific embodiments of the present invention, the materials involved are as follows:

[0066] 1) PBT resin

[0067] PBT-1: Tetrahydrofuran content 875ppm, intrinsic viscosity 0.86dl / g, obtained by feeding PBT-TH6082 into a solid phase apparatus and holding it at 180℃ for 5 hours.

[0068] PBT-2: Tetrahydrofuran content 490ppm, intrinsic viscosity 0.88dl / g; obtained by feeding PBT-1 into a solid phase apparatus and holding it at 185℃ for 5.5hr.

[0069] PBT-3: Tetrahydrofuran content is 385ppm, intrinsic viscosity is 0.89dl / g; PBT-1 is fed into a solid-state apparatus and held at 185℃ for 6 hours to obtain PBT-3.

[0070] PBT-4: Tetrahydrofuran content is 235ppm, intrinsic viscosity is 0.91dl / g; PBT-1 is fed into a solid phase apparatus and held at 190℃ for 6.5hr to obtain PBT-4.

[0071] PBT-5: Tetrahydrofuran content is 110ppm, intrinsic viscosity is 0.92dl / g; PBT-1 is fed into a solid phase apparatus and held at 195℃ for 6.5hr to obtain PBT-5.

[0072] PBT-6: Tetrahydrofuran content is 30ppm, intrinsic viscosity is 0.95dl / g; PBT-1 is fed into a solid-state apparatus and held at 200℃ for 7 hours to obtain PBT-6.

[0073] PBT-7: Tetrahydrofuran content is 380ppm, intrinsic viscosity is 1.28dl / g; PBT-GL236 (purchased from Yizheng Chemical Fiber Co., Ltd.) was fed into a solid phase apparatus and held at 180℃ for 5 hours to obtain PBT-GL236.

[0074] PBT-d1: PBT-TH6082, purchased from Tunhe, Lanshan, Xinjiang, with a tetrahydrofuran content of 1124ppm and an intrinsic viscosity of 0.83dl / g.

[0075] 2) PC resin

[0076] PC-d1: Bisphenol A content 120ppm, melt index 8.5g / 10min, LXZY1809-01H, purchased from Liaocheng Luxi Polycarbonate Co., Ltd.

[0077] PC-1: Bisphenol A content 72ppm, melt index 8.0g / 10min; PC-d1 is added to a twin-screw extruder and extruded at an extrusion temperature of 250℃ and a vacuum degree of -0.06MPa.

[0078] PC-2: Bisphenol A content 30ppm, melt index 6.2g / 10min; PC-d1 is added to a twin-screw extruder and extruded at an extrusion temperature of 280℃ and a vacuum of -0.08MPa to obtain the product.

[0079] PC-3: Bisphenol A content 6ppm, melt index 5.2g / 10min; PC-d1 is added to a twin-screw extruder and extruded at an extrusion temperature of 300℃ and a vacuum of -0.1MPa to obtain the product.

[0080] PC-4: Bisphenol A content 8ppm, melt index 20g / 10min. PC1300 22NP (purchased from LG Chem, Ltd.) was added to a twin-screw extruder and extruded at an extrusion temperature of 240℃ and a vacuum degree of -0.05MPa.

[0081] 3) Toughening agent

[0082] Ethylene-acrylate copolymer, 1400PN, purchased from Shanghai Zhuangjing Chemical Co., Ltd.

[0083] SOG-003 was purchased from Jia Yi Rong Polymer (Shanghai) Co., Ltd.

[0084] 4) Flame retardants

[0085] Brominated epoxy flame retardant: F-2100, purchased from Bromine Compounds Ltd.

[0086] Brominated polycarbonate flame retardant: FG-8500, purchased from Guangdong Pushi Trading Co., Ltd.

[0087] 5) Synergistic flame retardants

[0088] Antimony white: S-04N, purchased from Yiyang Shengli Materials Technology Co., Ltd.

[0089] Examples 1-17, Comparative Examples 1-3

[0090] A PBT-PC composite material, the types and amounts of each component are shown in Table 1 and Table 2, and the amount of each component is in "parts";

[0091] The PBT-PC composite material is prepared by the following method:

[0092] PBT resin, PC resin, flame retardant, synergistic flame retardant, toughening agent and transesterification inhibitor were mixed according to the proportions in Table 1 and Table 2 and fed into a twin-screw extruder. The mixture was extruded at 250°C and granulated to obtain the PBT-PC composite material, which was used to test the original tensile strength and notched impact strength.

[0093] PBT resin, PC resin, flame retardant, synergistic flame retardant, toughening agent and transesterification inhibitor were mixed according to the proportions in Tables 1 and 2 and fed into a twin-screw extruder. After being held at 270°C for 10 minutes, the mixture was extruded and granulated to obtain the PBT-PC composite material, which was used to test the tensile strength after being held at 270°C for 10 minutes.

[0094] The PBT-PC composite materials in the examples or comparative examples were tested as follows:

[0095] 1) Tensile strength:

[0096] The test was conducted according to the method specified in GB / T 1040.2-2022 "Determination of tensile properties of plastics - Part 2: Test conditions for molded and extruded plastics", with a test speed of 10 mm / min.

[0097] 2) Impact strength of cantilever beam with notch

[0098] The notched impact strength of the cantilever beam was determined in accordance with ISO 180 standard.

[0099] The test results are shown in Tables 1 and 2.

[0100] Table 1

[0101]

[0102]

[0103] Table 2

[0104]

[0105]

[0106] The test results show that the PBT-PC composite material provided by the present invention, by using PBT resin with a specific tetrahydrofuran content and PC resin with a specific residual bisphenol A monomer content, and compounding it with other components, enables the PBT-PC composite material to retain a tensile strength of more than 80% after being held at 270°C for 10 minutes, and has a wide processing window in alloying production.

[0107] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A PBT-PC composite material, characterized in that, The PBT-PC composite material comprises 8-55 parts of PBT resin, 8-55 parts of PC resin, and 0.05-1 parts of transesterification inhibitor; The tetrahydrofuran content in the PBT resin is 10~900ppm; The bisphenol A content in the PC resin is <100 ppm.

2. The PBT-PC composite material according to claim 1, characterized in that, By weight, the PBT-PC composite material comprises 15-55 parts of PBT resin, 15-55 parts of PC resin, and 0.05-1 parts of transesterification inhibitor.

3. The PBT-PC composite material according to claim 1, characterized in that, The PBT resin contains 100-600 ppm of tetrahydrofuran.

4. The PBT-PC composite material according to claim 1, characterized in that, The PBT resin contains 200-500 ppm of tetrahydrofuran.

5. The PBT-PC composite material according to claim 1, characterized in that, The bisphenol A content in the PC resin is 1~90 ppm.

6. The PBT-PC composite material according to claim 1, characterized in that, The bisphenol A content in the PC resin is 10~60 ppm.

7. The PBT-PC composite material according to claim 1, characterized in that, The transesterification inhibitor includes any one or a combination of at least two of zinc dihydrogen phosphate, sodium dihydrogen phosphate, or zinc hydrogen phosphate.

8. The PBT-PC composite material according to claim 1, characterized in that, The PBT-PC composite material also includes additives.

9. The PBT-PC composite material according to claim 8, characterized in that, The additives include any one or a combination of at least two of flame retardants, synergistic flame retardants, or toughening agents.

10. The PBT-PC composite material according to claim 9, characterized in that, The flame retardant is present in 8-15 parts by weight.

11. The PBT-PC composite material according to claim 9, characterized in that, The flame retardant includes any one or a combination of at least two of the following: brominated flame retardants, sulfonate flame retardants, or phosphorus flame retardants.

12. The PBT-PC composite material according to claim 11, characterized in that, The brominated flame retardant includes any one or a combination of at least two of the following: brominated polycarbonate, brominated epoxy, polybrominated styrene, tetrabromobisphenol A, decabromodiphenyl ether, polydibromophenyl ether, or tetradecylbromodiphenoxybenzene.

13. The PBT-PC composite material according to claim 11, characterized in that, The sulfonate flame retardant is any one or a combination of at least two of potassium perfluorobutyl sulfonate, potassium benzenesulfonylbenzenesulfonate, or sodium 2,4,5-trichlorobenzenesulfonate.

14. The PBT-PC composite material according to claim 11, characterized in that, The phosphorus-based flame retardant includes any one or a combination of at least two of the following: aluminum hypophosphite, diethylaluminum hypophosphite, melamine polyphosphate, red phosphorus, ammonium polyphosphate, ammonium dihydrogen phosphate, triphenyl phosphate, tricresyl phosphate, tri(dibromopropyl) phosphate, or tri(β-chloroethyl) phosphate.

15. The PBT-PC composite material according to claim 9, characterized in that, The synergistic flame retardant is present in parts by weight of 1-5 parts.

16. The PBT-PC composite material according to claim 9, characterized in that, The synergistic flame retardants include silane flame retardants and / or antimony-based flame retardants.

17. The PBT-PC composite material according to claim 16, characterized in that, The silane flame retardant includes any one or a combination of at least two of polysilane, polysiloxane, or polyorganosilicon silsesquioxane.

18. The PBT-PC composite material according to claim 16, characterized in that, The antimony-based flame retardant includes any one or a combination of at least two of antimony trioxide, colloidal antimony pentoxide, or sodium antimonate.

19. The PBT-PC composite material according to claim 9, characterized in that, The toughening agent is present in parts by weight of 3-15 parts.

20. The PBT-PC composite material according to claim 9, characterized in that, The toughening agent includes any one or a combination of at least two of the following: ethylene-acrylate-glycidyl methacrylate copolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate copolymer, methacrylate-styrene-silicone copolymer, and methacrylate-styrene-butadiene copolymer.

21. A method for preparing the PBT-PC composite material according to any one of claims 1-20, characterized in that, The preparation method includes the following steps: PBT resin, PC resin, transesterification inhibitor and optional additives are mixed, extruded and granulated to obtain the PBT-PC composite material.

22. The preparation method according to claim 21, characterized in that, The extrusion is carried out in a twin-screw extruder.

23. The preparation method according to claim 21, characterized in that, The extrusion temperature is 150-300℃.

24. The application of a PBT-PC composite material as described in any one of claims 1-20 in the electronics, automotive, medical device, or aerospace industries.

Images