Low-dielectric polyphenyl ether composite material, preparation method and application thereof

Abstract

The application discloses a kind of low dielectric polyphenyl ether composite material and preparation method and application, specifically related to high polymer material technical field, by the following mass content components: non-functional polyphenyl ether 15%-45%; Polyphenyl sulfide 15%-55%; Grafting modified ABS 8%-25%; Core-shell structure inorganic filler 15%-35%; Compound compatilizer 0.5%-3%; Mercapto silane coupling agent 0.1%-0.8%; Composite antioxidant 0.15%-0.25%.The core-shell structure inorganic filler of silica coated boron nitride in the application, solve the problem that traditional pure boron nitride filler is poor in compatibility with resin matrix, easy to agglomerate, break through the limitation that traditional polyphenyl ether composite material is difficult to realize low dielectric characteristics and good filler dispersibility simultaneously, rely on the combination of core-shell structure inorganic filler and compound compatilizer, give composite material excellent extreme environmental stability, for the wide temperature fluctuation working condition that 5G equipment may face, the dielectric properties of material always remain stable, break through the technical bottleneck that mechanical property and heat resistance of low dielectric material generally exist.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a low-dielectric polyphenylene ether composite material, its preparation method, and its application. Background Technology

[0002] As 5G communication technology moves towards the millimeter-wave band, its core components, such as millimeter-wave antenna elements and key structural components of 5G communication equipment, face stringent requirements for material performance: they must simultaneously possess low dielectric constant Dk and low dielectric loss Df to reduce high-frequency signal attenuation and ensure signal transmission efficiency; they must have sufficient mechanical strength to meet structural load-bearing requirements and prevent deformation or damage to components during assembly and use; they must possess excellent high-temperature resistance to withstand the heat generated by long-term equipment operation; and they must maintain stable dielectric properties over a wide temperature range, such as from -40℃ outdoors to 85℃ inside the equipment, to prevent signal distortion caused by temperature fluctuations.

[0003] When adapting to the above-mentioned 5G application requirements, existing technologies often use inorganic fillers such as boron nitride (BN) to improve the dielectric properties of polyphenylene ether (PPE) composite materials. However, pure BN fillers have poor compatibility with resin matrices such as PPE and PPE sulfide, and are prone to agglomeration. This not only makes it difficult to reduce the dielectric constant and dielectric loss of the material to the low level required for 5G high-frequency scenarios, but also destroys the continuity of the resin matrix, resulting in a significant decrease in the mechanical strength of the material, and making it impossible to simultaneously meet the requirements of dielectric performance and structural strength.

[0004] Existing composite materials mostly use a single type of compatibilizer, which can only initially improve the compatibility between some resins. It cannot simultaneously achieve efficient compatibility between multiple resin components and tight interfacial bonding between inorganic fillers and resin matrix. This leads to the formation of interfacial defects inside the material, which on the one hand exacerbates dielectric loss and on the other hand reduces the heat resistance of the material, making the material prone to dimensional deformation in high-temperature environments and unable to adapt to the long-term high-temperature operation conditions of 5G equipment.

[0005] Furthermore, it has poor dielectric stability over a wide temperature range and insufficient environmental adaptability. 5G equipment often needs to operate in environments with large temperature fluctuations, such as low outdoor temperatures and high internal temperatures. However, existing polyphenylene ether composite materials have poor compatibility between components and uneven filler dispersion. When the temperature changes, the interfacial stress inside the material is prone to change, resulting in large fluctuations in the dielectric constant. This will cause distortion during high-frequency signal transmission, affect the communication stability of 5G equipment, and make it difficult to meet the usage requirements under complex working conditions. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a low dielectric polyphenylene ether composite material, its preparation method and application, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a low-dielectric polyphenylene ether composite material, composed of the following components by mass content:

[0008] Nonfunctionalized polyphenylene ether 15%-45%;

[0009] Polyphenylene sulfide 15%-55%;

[0010] Graft-modified ABS 8%-25%;

[0011] Core-shell structured inorganic filler: 15%-35%;

[0012] Compound compatibilizer 0.5%-3%;

[0013] Thiosilane coupling agent 0.1%-0.8%;

[0014] Compound antioxidant 0.15%-0.25%;

[0015] The grafted modified ABS is glycidyl methacrylate grafted modified ABS, with a glycidyl methacrylate grafting rate of 0.8%-1.2%, and the mass content of butadiene segments in the ABS is 21%-23%.

[0016] The core-shell inorganic filler is a core-shell particle coated with boron nitride in silica, wherein the mass ratio of the core layer BN to the shell layer SiO2 is 1:2 to 1:4.

[0017] Preferably, the particle size of the BN core in the core-shell inorganic filler is 1μm-3μm, and the coating thickness of the SiO2 shell is 50nm-100nm.

[0018] Preferably, the polyphenylene sulfide has a crystallinity greater than 65%; the nonfunctionalized polyphenylene sulfide has a molecular weight of 22,000-24,000.

[0019] Preferably, the mercaptosilane coupling agent is γ-mercaptopropyltriethoxysilane; the composite antioxidant is prepared by compounding antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0020] Preferably, the compound compatibilizer is prepared by compounding a copolymer of ethylene and glycidyl methacrylate with bisphenol A bis(diphenyl) phosphate in a mass ratio of 2:1 to 3:1.

[0021] A method for preparing the polyphenylene ether composite material as described above is also provided, comprising the following steps:

[0022] S1: Pretreatment of filler: The core-shell structured inorganic filler and 0.5%-1.2% of the mercaptosilane coupling agent by mass are stirred in a high-speed mixer at 80℃-90℃ for 30-45 minutes to obtain pretreated filler;

[0023] S2: Pre-blending, the grafted modified ABS and the polyphenylene sulfide are pre-blended in an internal mixer at 260℃-280℃ for 5 minutes to 8 minutes at a mass ratio of 1:2 to 1:3 to obtain a pre-blended product;

[0024] S3: Melt blending and granulation: The pretreated filler, the pre-blended material, the nonfunctionalized polyphenylene ether, the compatibilizer and the composite antioxidant are added to a twin-screw extruder, and the mixture is melt-extruded, water-cooled and pelletized to obtain the polyphenylene ether composite material.

[0025] Preferably, the twin-screw extruder has a length-to-diameter ratio of 40:1, and the torque during the melt extrusion process is controlled at 55%-95%.

[0026] Preferably, the barrel temperature of the twin-screw extruder in S3 is set as follows: Zone 1 80℃-210℃, Zone 2 250℃-300℃, Zones 3 to 10 280℃-305℃, and the die head 290℃-315℃; the screw speed is 360RPM-400RPM.

[0027] The temperature setting and screw speed are coordinated to ensure that the epoxy groups in the grafted modified ABS react in a controlled manner with the compound compatibilizer and the polyphenylene sulfide terminal groups, while preventing damage to the shell layer of the core-shell structure inorganic filler.

[0028] An application of the polyphenylene ether composite material described above in the preparation of 5G millimeter-wave antenna vibrators.

[0029] An application of a polyphenylene ether composite material as described above in the manufacture of 5G communication equipment.

[0030] The technical effects and advantages of this invention are as follows:

[0031] 1. The core-shell structure of boron nitride inorganic filler coated with silica solves the problems of poor compatibility and easy agglomeration of traditional pure boron nitride filler with resin matrix. The core-shell structure can achieve uniform dispersion of inorganic filler in resin. Combined with the synergistic effect of compound compatibilizer, the dielectric properties of composite material are greatly optimized, effectively reducing signal loss during signal transmission. It breaks through the limitation of traditional polyphenylene ether composite material that is difficult to achieve low dielectric properties and good filler dispersion at the same time, and provides a solution for the demand for low signal loss materials in the 5G communication field.

[0032] 2. By relying on the combination of core-shell structure inorganic filler and compound compatibilizer, the composite material is endowed with excellent extreme environmental stability. For the wide temperature fluctuation conditions that 5G equipment may face, the dielectric properties of the material remain stable, which fundamentally avoids the signal distortion problem caused by temperature changes. This stability comes from the strengthening effect of the core-shell structure on the bonding between the filler and the resin interface, and the improvement of the compatibilizer on the compatibility of resin components. It breaks the dilemma of traditional materials in balancing environmental adaptability and dielectric properties, and can be perfectly adapted to complex application scenarios such as outdoor and equipment interiors.

[0033] 3. Through precise component matching and preparation process design, the technical bottleneck of insufficient mechanical properties and heat resistance, which are common in low dielectric materials, has been overcome. The core-shell structure inorganic filler not only optimizes dielectric properties but also significantly enhances the structural load-bearing capacity of the material. The compound compatibilizer further improves the interfacial bonding strength between the resin matrix and the filler, while ensuring the high temperature resistance of the material. Through the synergistic performance of low dielectric, high strength and high heat resistance, the composite material can not only meet the structural load-bearing requirements of components such as 5G millimeter-wave antenna vibrators, but also withstand the high temperature environment of long-term equipment operation, successfully solving the contradiction that traditional materials have to make trade-offs under multiple performance requirements. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This invention relates to a low-dielectric polyphenylene ether composite material, its preparation method, and its application. By using a specific ratio of nonfunctionalized polyphenylene ether, polyphenylene sulfide, grafted modified ABS, core-shell structured inorganic filler, and compounded additives, combined with a precise preparation process, the material possesses low dielectric constant, low dielectric loss, high strength, and high temperature resistance, making it suitable for 5G millimeter-wave antenna vibrators and communication equipment.

[0036] Raw material preparation:

[0037] Nonfunctionalized polyphenylene ether: Example 1 uses an industrial-grade product with a molecular weight of 22,000, Example 2 uses a molecular weight of 23,000, and Example 3 uses a molecular weight of 24,000. The product is Mitsubishi Chemical PPO 640.

[0038] Polyphenylene sulfide: Example 1 uses linear polyphenylene sulfide with a crystallinity of 68%, Example 2 uses linear polyphenylene sulfide with a crystallinity of 70%, and Example 3 uses linear polyphenylene sulfide with a crystallinity of 72%, the model is Polyplastics PPS 1140A6.

[0039] Graft-modified ABS: ABS grafted with glycidyl methacrylate (GMA), wherein the GMA grafting rates were 0.8% in Example 1, 1.0% in Example 2, and 1.2% in Example 3, as determined by titration. The mass content of butadiene segments in the ABS substrate was 22% by quantitative analysis using infrared spectroscopy. The substrate model was Chi Mei Industrial ABS 757.

[0040] Core-shell structured inorganic filler: This filler consists of core-shell particles of boron nitride (BN) coated with silicon dioxide (SiO2). It can be prepared using the chemical vapor deposition method described below. By controlling the initial particle size of the BN core and the deposition time of SiO2, the core-shell structure and mass ratio can be adjusted.

[0041] Example 1: The mass ratio of BN core to SiO2 shell is 1:2; the particle size D50 of the BN core material is about 1.0 μm, and after coating, the thickness of the SiO2 shell is about 110 nm.

[0042] Example 2: The mass ratio of BN core to SiO2 shell is 1:3; the particle size D50 of the BN core material used is about 2.0 μm, and after coating, the thickness of the SiO2 shell is about 105 nm.

[0043] Example 3: The mass ratio of BN core to SiO2 shell is 1:4; the particle size D50 of the BN core material used is about 3.0 μm, and after coating, the thickness of the SiO2 shell is about 100 nm.

[0044] The particle size of BN cores was determined using a laser particle size analyzer, and the SiO2 shell coating thickness was observed using a transmission electron microscope. The purity of the BN used was ≥99.5%, and the purity of the SiO2 used was ≥99.8%.

[0045] The silica-coated boron nitride core-shell structure inorganic fillers of the present invention can all be prepared by the following general chemical vapor deposition method. The method is illustrated by taking the filler prepared in Example 2 (BN core D50=2.0μm, target shell thickness about 105nm) as an example. The fillers required in other examples can be obtained by adjusting the core parameters.

[0046] Raw material preparation: Weigh 100g of boron nitride powder with a particle size D50 of 2.0μm and a purity of 99.5% and place it in a fluidized bed vapor deposition furnace.

[0047] Pretreatment: Under a nitrogen atmosphere, the furnace body is heated to 500°C and held for 30 minutes to remove moisture and impurities adsorbed on the surface of the BN powder.

[0048] SiO2 coating:

[0049] a. Stabilize the furnace temperature at 400℃.

[0050] b. Tetraethoxysilane (TEOS) was used as a silicon source precursor and carried into the fluidized bed reactor by nitrogen gas at a flow rate of 5 L / min.

[0051] c. Simultaneously, water vapor is introduced into the reactor as a reactant at a flow rate of 0.1 mL / min.

[0052] d. Deposition was carried out by controlling the reaction time; for the filler in Example 2, the reaction time was controlled to be 120 minutes.

[0053] Post-processing: After the reaction is complete, the mixture is cooled to room temperature under nitrogen protection, and the powder is removed to obtain the target core-shell filler.

[0054] Parameter adjustments for different implementations:

[0055] To obtain the filler material of Example 1 (BN core D50=1.0μm, target shell thickness about 110nm): BN core material with D50 of 1.0μm can be selected, and the deposition time is appropriately extended to about 130 minutes to obtain a relatively thicker SiO2 shell layer.

[0056] To obtain the filler material of Example 3 (BN core D50=3.0μm, target shell thickness about 100nm): BN core material with D50 of 3.0μm can be selected, and the deposition time can be appropriately shortened to about 110 minutes to obtain a relatively thin SiO2 shell layer.

[0057] Note: The coating thickness can be initially controlled by the relationship between reaction time and thickness, and finally verified by transmission electron microscopy (TEM). Those skilled in the art can adjust the deposition time through conventional experiments based on the above general method according to the core particle size and shell thickness of the target filler, and thus prepare the core-shell fillers of different specifications required in the various embodiments of the present invention.

[0058] The compound compatibilizer is composed of ethylene-glycidyl methacrylate copolymer, model Arkema AX8900, and bisphenol A bis(diphenyl phosphate) BDP, model DaBa Chemical CR-741.

[0059] Example 1: The mass ratio of EGMA to BDP is 2:1;

[0060] Example 2: The mass ratio of EGMA to BDP was 2.5:1;

[0061] Example 3: The mass ratio of EGMA to BDP is 3:1.

[0062] Mercaptosilane coupling agent: γ-mercaptopropyltriethoxysilane, model: Wuhan University Organosilicon KH-580.

[0063] The compound antioxidant is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1; wherein antioxidant 1010 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and antioxidant 168 is tris[2,4-di-tert-butylphenyl] phosphite.

[0064] Example 1

[0065] The formula, by weight percentage, consists of: 21.25% nonfunctionalized polyphenylene ether with a molecular weight of 22,000, 47.25% polyphenylene sulfide with a crystallinity of 68%, 15.75% grafted modified ABS with a GMA grafting rate of 0.8%, 15% core-shell structured inorganic filler with a BN:SiO2 ratio of 1:2, 0.5% composite compatibilizer with a EGMA:BDP ratio of 2:1, 0.1% γ-mercaptopropyltriethoxysilane, and 0.15% composite antioxidant with a ratio of 1010:168 of 1:1.

[0066] Preparation steps:

[0067] S1: Pretreatment of packing material: Weigh the core-shell structure inorganic packing material, add 0.5% of its mass of γ-mercaptopropyltriethoxysilane to it, place it in a high-speed mixer, and stir at 80°C for 30 minutes to obtain the pretreated packing material.

[0068] S2: Pre-blending: Grafted modified ABS and polyphenylene sulfide are added to a mixer at a mass ratio of 1:3. The ratio of the two in the formula is 15.75%:47.25%=1:3, which is consistent with the pre-blending ratio. The mixture is pre-blended at 260°C for 5 minutes to obtain the pre-blended product.

[0069] S3: Melt Blending and Granulation: Pretreated fillers, pre-blended materials, non-functionalized polyphenylene ether, compound compatibilizer and composite antioxidant are mixed according to the formula ratio and then added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The parameters are set as follows: barrel zone 1 temperature 150℃, zone 2 temperature 280℃, zone 3 to 10 temperature 300℃, die head temperature 300℃; screw speed 380RPM, torque controlled at 60%. After melt extrusion, water cooling and pelletizing, polyphenylene ether composite material is obtained.

[0070] Example 2

[0071] The formula, by weight percentage, is as follows: 30% nonfunctionalized polyphenylene ether with a molecular weight of 23,000, 30.21% polyphenylene sulfide with a crystallinity of 70%, 12.08% grafted modified ABS with a GMA grafting rate of 1.0%, 25% core-shell structured inorganic filler with BN:SiO2=1:3, 2% compound compatibilizer with EGMA:BDP=2.5:1, 0.5% γ-mercaptopropyltriethoxysilane, and 0.2% composite antioxidant with a ratio of 1010:168=1:1.

[0072] Preparation steps:

[0073] S1: Pretreatment of packing material: Weigh the core-shell structure inorganic packing material, add 0.8% of its mass of γ-mercaptopropyltriethoxysilane to it, place it in a high-speed mixer, and stir at 85°C for 40 minutes to obtain the pretreated packing material.

[0074] S2: Pre-blending: Grafted modified ABS and polyphenylene sulfide are added to a mixer and pre-blended at 270°C for 6 minutes to obtain a pre-blended product.

[0075] S3: Melt Blending and Granulation: Pretreated fillers, pre-blended materials, non-functionalized polyphenylene ether, compound compatibilizer and composite antioxidant are mixed according to the formula ratio and then added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The parameters are set as follows: barrel zone 1 temperature 150℃, zone 2 temperature 280℃, zone 3 to 10 temperature 300℃, die head temperature 300℃; screw speed 380RPM, torque controlled at 60%. After melt extrusion, water cooling and pelletizing, polyphenylene ether composite material is obtained.

[0076] Example 3

[0077] The formula, by weight percentage, is as follows: 35% nonfunctionalized polyphenylene ether with a molecular weight of 24,000, 17.3% polyphenylene sulfide with a crystallinity of 72%, 8.65% grafted modified ABS with a GMA grafting rate of 1.2%, 35% core-shell structured inorganic filler with BN:SiO2=1:4, 3% compound compatibilizer with EGMA:BDP=3:1, 0.8% γ-mercaptopropyltriethoxysilane, and 0.25% composite antioxidant with a ratio of 1010:168=1:1.

[0078] Preparation steps:

[0079] S1: Pretreatment of packing material: Weigh the core-shell structure inorganic packing material, add 1.2% of its mass of γ-mercaptopropyltriethoxysilane to it, place it in a high-speed mixer, and stir at 90°C for 45 minutes to obtain the pretreated packing material.

[0080] S2: Pre-blending: Grafted modified ABS and polyphenylene sulfide are added to a mixer and pre-blended at 280°C for 8 minutes to obtain a pre-blended product.

[0081] S3: Melt Blending and Granulation: Pretreated fillers, pre-blended materials, non-functionalized polyphenylene ether, compound compatibilizer and composite antioxidant are mixed according to the formula ratio and then added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The parameters are set as follows: barrel zone 1 temperature 150℃, zone 2 temperature 280℃, zone 3 to 10 temperature 300℃, die head temperature 300℃; screw speed 380RPM, torque controlled at 60%. After melt extrusion, water cooling and pelletizing, polyphenylene ether composite material is obtained.

[0082] Comparative Example 1: The formulation, by mass percentage, consists of: 30% nonfunctionalized polyphenylene ether with a molecular weight of 23000, 30.21% polyphenylene sulfide with a crystallinity of 70%, 12.08% grafted modified ABS with a GMA grafting rate of 1.0%, 25% pure BN particles with a particle size of 2μm and no SiO2 coating, 2% EGMA:BDP compatibilizer with a ratio of 2.5:1, 0.5% γ-mercaptopropyltriethoxysilane, and 0.2% composite antioxidant with a ratio of 1010:168 = 1:1.

[0083] The sum of the above components is 100%.

[0084] Preparation steps:

[0085] S1: Filler pretreatment: Weigh pure BN particles that are not coated with SiO2, add 0.8% of γ-mercaptopropyltriethoxysilane by mass to them, place them in a high-speed mixer, and stir at 85°C for 40 minutes to obtain pretreated filler.

[0086] S2: Pre-blending: Grafted modified ABS and polyphenylene sulfide are added to a mixer and pre-blended at 270°C for 6 minutes to obtain a pre-blended product.

[0087] S3: Melt Blending and Granulation: Pretreated fillers, pre-blended materials, non-functionalized polyphenylene ether, compound compatibilizer and composite antioxidant are mixed according to the formula ratio and then added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The parameters are set as follows: barrel zone 1 temperature 150℃, zone 2 temperature 280℃, zone 3 to 10 temperature 300℃, die head temperature 300℃; screw speed 380RPM, torque controlled at 60%. After melt extrusion, water cooling and pelletizing, polyphenylene ether composite material is obtained.

[0088] Comparative Example 2:

[0089] The formula, by weight percentage, is as follows: 32% nonfunctionalized polyphenylene ether with a molecular weight of 23,000, 30.21% polyphenylene sulfide with a crystallinity of 70%, 12.09% grafted modified ABS with a GMA grafting rate of 1.0%, 25% core-shell structured inorganic filler with a BN:SiO2 ratio of 1:3, 0.5% γ-mercaptopropyltriethoxysilane, and 0.2% composite antioxidant with a ratio of 1010:168 = 1:1.

[0090] The total of the above components is 100%. The only difference from Example 2 is that it does not contain a compound compatibilizer, that is, the content of the compound compatibilizer is 0%. The types and parameters of other raw materials are exactly the same as those in Example 2.

[0091] Preparation steps:

[0092] S1: Pretreatment of packing material: Weigh the core-shell structure inorganic packing material, add 0.8% of its mass of γ-mercaptopropyltriethoxysilane to it, stir at 85℃ for 40 minutes to obtain the pretreated packing material;

[0093] S2: Pre-blending: Grafted modified ABS and polyphenylene sulfide are added to a mixer at a mass ratio of 1:2.5 and pre-blended at 270°C for 6 minutes to obtain a pre-blended product;

[0094] S3: Melt blending and granulation: The pretreated filler, pre-blended material, non-functionalized polyphenylene ether and composite antioxidant are mixed according to the formula ratio and then added to a twin-screw extruder with a length-to-diameter ratio of 40:1. The barrel temperature is set to 150°C in zone 1, 280°C in zone 2, 300°C in zones 3 to 10, and 300°C in the die head. The screw speed is 380 RPM and the torque is controlled at 60%. After melt extrusion, water cooling and pelletizing, the composite material is obtained.

[0095] test:

[0096] Dielectric performance testing: Refer to GB / T1409-2006, test frequency 10GHz, room temperature 25℃, focus on verifying the material's signal transmission capability, low Dk, low Df.

[0097] Mechanical performance testing: tensile strength according to GB / T1040.2-2006, flexural strength according to GB / T9341-2008, to verify the structural bearing capacity.

[0098] Heat resistance test: Heat distortion temperature (HDT) is measured according to GB / T1634.2-2004 to verify dimensional stability at high temperatures.

[0099] Dielectric temperature stability test: Referencing GB / T12636-1990, the temperature range is -40℃ to 85℃, covering the extreme operating conditions of 5G equipment, testing the fluctuation of dielectric performance, and verifying environmental adaptability.

[0100] Test Project unit Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Dielectric constant (10 GHz, 25 ° C) - 2.4 2.3 2.5 3.1 2.8 Dielectric loss (10GHz, 25℃) - 0.0025 0.0022 0.0026 0.0045 0.0038 Tensile strength MPa 85 92 88 65 70 Heat distortion temperature (1.82 MPa) ℃ 260 275 270 230 240 Rate of change of dielectric constant % ±1.2 ±0.8 ±1.0 ±3.5 ±2.8

[0101] This invention achieves three major performance breakthroughs in composite materials through the synergistic design of core-shell structured inorganic filler SiO2 coating BN and compound compatibilizer;

[0102] Superior dielectric properties: dielectric constant ≤2.5, dielectric loss ≤0.0026, far below the basic requirements of 5G materials Dk≤3.0, Df≤0.005, reducing signal transmission attenuation rate in the 10GHz band and solving the problem of high signal loss in traditional materials;

[0103] Stable in extreme environments: The dielectric constant changes by only ±0.8% to ±1.2% within the temperature range of -40℃ to 85℃, avoiding 5G signal distortion caused by temperature fluctuations and adapting to complex working conditions such as outdoor and equipment interiors;

[0104] Excellent in both structure and heat resistance: tensile strength of 85-92MPa and heat distortion temperature of 260-275℃, which not only meets the structural load-bearing requirements of the antenna vibrator, but also can withstand the high temperature of long-term operation of the equipment, solving the problem of poor mechanical / heat resistance of low dielectric materials;

[0105] By comparing with the comparative example, the necessity of core-shell structure filler is shown. After removing the SiO2 coating, the dielectric constant increased from 2.3 to 3.1, and the tensile strength decreased from 92MPa to 65MPa. The reason is that pure BN has poor compatibility with resin and is prone to agglomeration, while the SiO2 shell can achieve uniform dispersion of filler. This is a low dielectric constant and high strength synergy that conventional pure BN filler cannot achieve.

[0106] Comparative Example 2 and Example 2 demonstrate the necessity of the compound compatibilizer. After removing the compound compatibilizer, the dielectric loss increased from 0.0022 to 0.0038, and the heat distortion temperature decreased from 275°C to 240°C. This was because the lack of synergy between EGMA and BDP led to the failure of the interfacial bonding between the resin components and the filler and the resin.

[0107] In summary, this invention, through the creative combination of core-shell filler and composite compatibilizer, breaks through the technical bottleneck of polyphenylene ether composite materials where low dielectric constant, high strength, heat resistance, and stability are mutually exclusive, providing a high-performance material for 5G millimeter-wave antenna vibrators and communication equipment.

[0108] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low dielectric polyphenylene ether composite material, characterized by: It consists of the following components by mass content: Nonfunctionalized polyphenylene ether 15%-45%; Polyphenylene sulfide 15%-55%; Graft-modified ABS 8%-25%; Core-shell structured inorganic filler: 15%-35%; The compound compatibilizer is 0.5%-3%, wherein the compound compatibilizer is compounded with ethylene-glycidyl methacrylate copolymer and bisphenol A bisdiphenyl phosphate in a mass ratio of 2:1 to 3:1; Thiol-silane coupling agent 0.1%-0.8%; Compound antioxidant 0.15%-0.25%; The grafted modified ABS is glycidyl methacrylate grafted modified ABS, with a glycidyl methacrylate grafting rate of 0.8%-1.2%, and the mass content of butadiene segments in the ABS is 21%-23%. The core-shell inorganic filler is a core-shell particle coated with boron nitride and silicon dioxide, wherein the mass ratio of the core layer BN to the shell layer SiO2 is 1:2 to 1:

4.

2. The low dielectric polyphenylene ether composite of claim 1, wherein: The core-shell inorganic filler has a BN core with a particle size of 1μm-3μm and a SiO2 shell coating thickness of 100nm.

3. The low dielectric polyphenylene ether composite of claim 1, wherein: The polyphenylene sulfide has a crystallinity greater than 65%; the nonfunctionalized polyphenylene sulfide has a molecular weight of 22,000-24,000.

4. The low dielectric polyphenylene ether composite of claim 1, wherein: The mercaptosilane coupling agent is γ-mercaptopropyltriethoxysilane; the composite antioxidant is composed of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:

1.

5. The low dielectric polyphenylene ether composite of claim 1, wherein: The compound compatibilizer is composed of a copolymer of ethylene and glycidyl methacrylate and bisphenol A bis(diphenyl) phosphate in a mass ratio of 2:1 to 3:

1.

6. A method for preparing the low-dielectric polyphenylene ether composite material as described in claims 1-5, comprising the following steps: S1: Pretreatment of filler: The core-shell structured inorganic filler and 0.5%-1.2% of the mercaptosilane coupling agent by mass are stirred in a high-speed mixer at 80℃-90℃ for 30-45 minutes to obtain pretreated filler; S2: Pre-blending, the grafted modified ABS and the polyphenylene sulfide are pre-blended in a mixer at 260℃-280℃ for 5 minutes to 8 minutes at a mass ratio of 1:2 to 1:3 to obtain a pre-blended product; S3: Melt blending and granulation: The pretreated filler, the pre-blended material, the nonfunctionalized polyphenylene ether, the compatibilizer and the composite antioxidant are added to a twin-screw extruder, and the mixture is melt-extruded, water-cooled and pelletized to obtain the polyphenylene ether composite material.

7. A method of manufacture according to claim 6, wherein: The twin-screw extruder has a length-to-diameter ratio of 40:1, and the torque during the melt extrusion process is controlled between 55% and 95%.

8. The method of claim 6, wherein: The barrel temperature of the twin-screw extruder in S3 is set as follows: Zone 1 80℃-210℃, Zone 2 250℃-300℃, Zones 3 to 10 280℃-305℃, and the die head 290℃-315℃; the screw speed is 360RPM-400RPM. The temperature setting and screw speed are coordinated to ensure that the epoxy groups in the grafted modified ABS react in a controlled manner with the compound compatibilizer and the polyphenylene sulfide terminal groups, while preventing damage to the shell layer of the core-shell structure inorganic filler.

9. The application of a low-dielectric polyphenylene ether composite material as described in any one of claims 1 to 5 in the preparation of a 5G millimeter-wave antenna vibrator.

10. The application of a low-dielectric polyphenylene ether composite material as described in any one of claims 1 to 5 in the manufacture of 5G communication equipment.