High-dielectric low-loss polyphenyl ether composite material as well as preparation method and application thereof

Abstract

The invention provides a high-dielectric and low-loss polyphenyl ether composite material as well as a preparation method and application thereof. The high-dielectric and low-loss polyphenyl ether composite material comprises the following components in parts by weight: 10-55 parts of polyphenyl ether; 14 to 25 parts of polystyrene; 15 to 70 parts of modified titanium dioxide; 0.1 to 0.5 part of an antioxidant; 0.3 to 1.0 part of a lubricant; 3-8 parts of a toughening agent; wherein titanium dioxide is subjected to surface modification treatment to obtain modified titanium dioxide, the titanium dioxide is rutile type titanium dioxide, and a preparation method of the modified titanium dioxide comprises the following steps: adding titanium dioxide into a high-speed mixer, adding a silane coupling agent in a low-speed stirring process, stirring for a certain time, adding fumed silica, and stirring for a certain time to obtain a mixture; continuously stirring, sufficiently and uniformly mixing, adding barium titanate, and sufficiently mixing to obtain the modified titanium dioxide.

Description

Technical Field

[0001] This invention belongs to the field of polyphenylene ether materials technology, specifically relating to a high dielectric, low loss polyphenylene ether composite material, its preparation method, and its application. Background Technology

[0002] Antenna elements are a crucial component of wireless communication systems, converting electromagnetic waves into current or voltage signals and transmitting them to receivers or transmitters. They are a key component for realizing wireless communication, including 5G communication. In this process, the material of the antenna element plays a vital role in its performance.

[0003] Common microwave antenna elements are typically made of ceramic materials with excellent dielectric properties, characterized by high dielectric strength, low loss, and good stability, which can improve antenna performance and operating frequency range. However, their manufacturing process is relatively complex, involves high density, and is costly, making it difficult to meet the current market demand for low-cost, high-performance, and easily manufactured, mass-producible materials.

[0004] Therefore, polymer materials with low dielectric constants and dielectric losses can be selected for use in low-frequency antenna elements. Miniaturization of antenna elements can be achieved through high-dielectric-constant, low-loss materials. High dielectric properties significantly increase the charge storage capacity per unit volume, while low-loss properties reduce losses during transmission. Therefore, for small-sized microwave antenna elements, modification of polymers is necessary to meet their performance requirements.

[0005] The team's preliminary research found that mixing titanium dioxide with resin can effectively improve the dielectric constant of the resin. However, the density difference between titanium dioxide and resin is relatively large during the processing, making it easy to separate during mixing. In addition, the high viscosity of titanium dioxide makes it difficult to feed, which is not conducive to subsequent processing and molding, and greatly affects the practicality of the formula. Therefore, it is necessary to modify titanium dioxide to improve its processability.

[0006] In view of this, improving the processing technology of titanium dioxide to facilitate subsequent processing is an urgent problem to be solved. Specifically, this is achieved by modifying titanium dioxide to improve its processability. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to solve the problem in the prior art that the large density difference between titanium dioxide and resin makes it easy to separate during the mixing process, leading to processing difficulties, and to provide a high dielectric, low loss polyphenylene ether composite material, its preparation method and application.

[0008] To achieve the above objectives, the present invention proposes the following technical solution: Firstly, a high-dielectric, low-loss polyphenylene ether composite material is proposed, comprising the following components in parts by weight: Polyphenylene oxide: 10-55 parts; polystyrene: 14-25 parts; modified titanium dioxide: 15-70 parts; antioxidant: 0.1-0.5 parts; lubricant: 0.3-1.0 parts; toughening agent: 3-8 parts; The process involves surface modification of titanium dioxide to obtain modified titanium dioxide, wherein the titanium dioxide is rutile titanium dioxide, and the preparation method of the modified titanium dioxide includes: The titanium dioxide was added to a high-speed mixer, and a silane coupling agent was added during low-speed stirring. After stirring for a certain period of time, fumed silica was added. After continuous stirring and thorough mixing, barium titanate was added. After thorough mixing, the modified titanium dioxide was obtained.

[0009] Furthermore, the preparation method of the modified titanium dioxide includes: The titanium dioxide is added to a high-speed mixer, and while stirring at 40-60 °C and 50-150 r / min, 0.1%-0.3% of the silane coupling agent (by weight of the titanium dioxide) is added. After stirring for 3-10 min, 0.3%-1.0% of the fumed silica (by weight of the titanium dioxide) is added. The mixture is stirred for 5-10 min at 80-100 °C and 200-300 r / min until fully mixed. Then, 3%-8% of the barium titanate (by weight of the titanium dioxide) is added. The mixture is stirred for 3-8 min at 40-60 °C and 100-200 r / min to obtain the modified titanium dioxide.

[0010] Furthermore, the silane coupling agent is at least one of aminosilane, epoxysilane, or vinylsilane; The specific surface area of ​​the fumed silica is 150~300 m². 2 / g; The barium titanate has a particle size D50 of 0.5~5.0 μm.

[0011] Secondly, a method for preparing a high-dielectric, low-loss polyphenylene ether composite material is proposed, comprising the following steps: S1. After the polyphenylene ether, polystyrene, antioxidant, lubricant and toughening agent are mixed evenly by a high-speed mixer, they are added to the first loss-in-weight scale for precise measurement and then continuously fed into the main feed port of the twin-screw extruder. S2. Surface modification treatment is performed on titanium dioxide to obtain modified titanium dioxide; S3. After the modified titanium dioxide is accurately measured by adding it to the second loss-in-weight scale, it is continuously added to the side feed port of the twin-screw extruder. S4. All components are melt-extruded and blended in the twin-screw extruder, then cooled, drawn, and pelletized to obtain the high-dielectric, low-loss polyphenylene ether composite material.

[0012] Furthermore, the polyphenylene ether comprises one or more polyphenylene ethers with an intrinsic viscosity of 0.2~0.45 dL / g; The polystyrene comprises one or more types of high-impact polystyrene, and the polybutadiene rubber content in the high-impact polystyrene is 5-15 wt%. The antioxidant includes one or more of hindered phenolic antioxidants and phosphite antioxidants; the lubricant includes one or more of pentaerythritol tetrastearate, polyethylene wax, silicone masterbatch, EBS or TAF. The toughening agent comprises one or more of SEBS or SBS, and the styrene content of the SEBS and / or the SBS is 20-40 wt%.

[0013] Furthermore, in S1 and S3, The measurement accuracy of both the first loss-in-weight scale and the second loss-in-weight scale is controlled within ±0.5%. The first loss-in-weight scale and the second loss-in-weight scale are linked and controlled by a central control system. The feeding mass ratio of the first loss-in-weight scale and the second loss-in-weight scale remains constant. The fluctuation deviation of the feeding mass ratio of the first loss-in-weight scale and the second loss-in-weight scale is controlled within ±1.0%. The feeding rate control range of the second loss-in-weight weigher is 40~100 kg / h.

[0014] Furthermore, in S3, The second loss-in-weight scale is a twin-screw loss-in-weight scale, which is used to accurately measure and transport the modified titanium dioxide. The surfaces of the second loss-in-weight balance that come into contact with the modified titanium dioxide are at least partially coated with a fluorine-containing coating; The fluorine-containing coating area includes the inside of the hopper of the second loss-in-weight scale and the feeding screw; The fluorinated coating is at least one of polytetrafluoroethylene, perfluoroalkoxyalkane, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer; The thickness of the fluorine-containing coating is 25~50 μm.

[0015] Furthermore, in S3, The side feed port is located after the melt plasticizing section of the twin-screw extruder.

[0016] Furthermore, in S4, The twin-screw extruder has a screw length-to-diameter ratio of 40:1 to 48:1; the twin-screw extruder has a processing temperature of 240 to 270 ℃ and a rotation speed of 300 to 500 rpm.

[0017] Thirdly, the application of the aforementioned high-dielectric, low-loss polyphenylene ether composite material in the fabrication of antenna oscillators is proposed.

[0018] The beneficial effects of this invention are: This invention selects polyphenylene ether (PPE) with low dielectric loss as the base material and rutile titanium dioxide with low relative density and high dielectric properties. On the one hand, it uses rutile titanium dioxide as a dielectric modifier to adjust the dielectric properties of PPE. By adjusting the ratio of rutile titanium dioxide to PPE, the dielectric constant of the material can be orderly regulated within a certain range. On the other hand, by utilizing the synergistic effect of rutile titanium dioxide and PPE, the dielectric constant of the modified material is significantly improved while maintaining its dielectric loss as much as possible, specifically, the dielectric loss is ≤ 0.0015. This gives the modified material the characteristics of high dielectric and low dielectric loss, which can be applied to communication components, including but not limited to microwave antenna vibrators.

[0019] In addition, this invention modifies titanium dioxide. On the one hand, fumed silica is used to form a chemical reaction with the surface of titanium dioxide through the action of a silane coupling agent to obtain titanium dioxide coated with fumed silica. Then, a small amount of barium titanate ceramic powder is fully mixed with the titanium dioxide coated with fumed silica. The barium titanate physically isolates the titanium dioxide particles, further reducing the stickiness of the titanium dioxide and facilitating the feeding of titanium dioxide.

[0020] On the other hand, feeding the modified titanium dioxide separately through a twin-screw loss-in-weight feeder has better forced conveying capacity and more stable discharge effect. At the same time, the hopper of the second loss-in-weight feeder and the contact surfaces of the feed screw with the modified titanium dioxide are coated with a fluorine-containing coating. This works in synergy with the twin-screw loss-in-weight feeder to prevent problems such as adhesion, bridging and poor flow of the modified titanium dioxide during the feeding process, thus greatly improving its processing performance.

[0021] This invention feeds the remaining components of the polyphenylene ether composite material and modified titanium dioxide separately using a loss-in-weight weighing system, achieving precise metering and conveying of the material components. Simultaneously, the modified titanium dioxide is added through the side feed port of a twin-screw extruder, which is located after the melting and plasticizing section of the twin-screw extruder. The modified titanium dioxide is added after the matrix has melted, located in the fourth zone of the twin-screw extruder, avoiding material accumulation caused by simultaneous addition from the main feed port with the main material. This ensures that the modified titanium dioxide can be fully mixed and dispersed evenly with the resin, forming a good interfacial bond with the resin, and significantly improving processability.

[0022] In summary, this invention significantly improves the uniform dispersion and processability of titanium dioxide in the system by first modifying rutile titanium dioxide, then feeding it separately and combining it with other components to form modified polyphenylene ether. This solves the stratification problem in the processing of titanium dioxide in the prior art, namely the stratification problem caused by the large difference between the density of titanium dioxide and the density of resin, as well as the processing difficulties and material inconsistencies caused by the high viscosity of titanium dioxide making it difficult to feed. It ensures the consistency of the product, the preparation process is simple, the operation is controllable, and the product quality is uniform and stable.

[0023] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described 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. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0025] The terms "comprising" or "including" or similar words used in the patent application specification and claims of this invention mean that the elements or objects preceding "comprising" or "including" encompass the features, integrals, steps, operations, elements and / or components listed after "comprising" or "including", and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0026] The terms "first," "second," and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components.

[0027] Typically, antenna elements can be made from polymers with low dielectric constant and low dielectric loss, such as polyphenylene ether, polystyrene, and polyolefin materials. High-dielectric ceramic powders are used to modify these polymers to impart high dielectric properties to the materials, such as titanium dioxide, alumina, calcium titanate, and barium titanate.

[0028] Among them, alumina has limited effect on improving dielectric constant; calcium titanate system is prone to discoloration, affecting product stability; barium titanate has a high density, so even if the antenna vibrator is miniaturized, its weight has not been reduced.

[0029] Titanium dioxide, commonly used as a white pigment in plastic products, primarily enhances the whiteness and gloss of these products. Its density is approximately 4 g / cm³. 3 Its density is approximately the same as that of calcium titanate, but much lower than that of barium titanate (6 g / cm³). 3 Furthermore, rutile titanium dioxide has a high dielectric constant, which can effectively improve the dielectric constant of the material. However, its density difference with that of the resin is relatively large, making it prone to stratification during mixing. In addition, the high viscosity of titanium dioxide presents problems such as difficulty in feeding, which is not conducive to subsequent processing and molding.

[0030] Unless otherwise stated, the abbreviations used in this invention have the following meanings: In this invention, PPO refers to polyphenylene oxide, and HIPS refers to high-impact polystyrene. PTFE refers to polytetrafluoroethylene; PFA refers to perfluoroalkoxyalkane; PVDF refers to polyvinylidene fluoride; ETFE refers to ethylene-tetrafluoroethylene copolymer.

[0031] This invention discloses a method for preparing a high-dielectric, low-loss polyphenylene ether composite material, comprising the following steps: S1. Weigh 10-55 parts by weight of polyphenylene ether, 14-25 parts by weight of polystyrene, 0.1-0.5 parts by weight of antioxidant, 0.3-1.0 parts by weight of lubricant, and 3-8 parts by weight of toughening agent. Mix the above components evenly with a high-speed mixer and add them to the first loss-in-weight scale for precise measurement. Then, continuously add them to the main feed port of the twin-screw extruder.

[0032] S2. Add titanium dioxide to a high-speed mixer and stir at 40-60 ℃ and 50-150 r / min. Add 0.1%-0.3% of silane coupling agent by weight of titanium dioxide and stir continuously for 3-10 min. Then add 0.3%-1.0% of fumed silica by weight of titanium dioxide and stir continuously at 80-100 ℃ and 200-300 r / min for 5-10 min. After mixing thoroughly, add 3%-8% of barium titanate by weight of titanium dioxide and mix thoroughly at 40-60 ℃ and 100-200 r / min for 3-8 min to obtain modified titanium dioxide.

[0033] S3. Weigh 15-70 parts by weight of modified titanium dioxide, add the modified titanium dioxide to the second loss-in-weight scale for precise measurement, and then continuously add it to the side feed port of the twin-screw extruder.

[0034] S4. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300~500 rpm. Melt extrusion and blend all components in the twin-screw extruder, then cool, traction and pelletize to obtain a high dielectric and low loss polyphenylene ether composite material.

[0035] Preferably, in step S2, titanium dioxide is added to a high-speed mixer, and while stirring at 100 r / min and 50 °C, 0.1% of the mass of the titanium dioxide is added as a silane coupling agent. After stirring continuously at 50 °C for 5 min, 0.5% of the mass of the titanium dioxide is added as fumed silica. After stirring continuously at 80 °C and 200 r / min for 10 min, and after being thoroughly mixed, 5% of the mass of the titanium dioxide is added as barium titanate. After being thoroughly mixed at 50 °C and 150 r / min for 5 min, modified titanium dioxide is obtained.

[0036] Specifically, the surface coating of the modified titanium dioxide includes an inorganic coating layer and an organic coating layer. The inorganic coating layer includes silicon dioxide and barium titanate, and the organic coating layer is a silane coupling agent. The inorganic coating layer is coated on the outside of the organic coating layer. The inorganic coating layer provides weather resistance and chemical stability, while the organic coating layer can improve the compatibility and dispersibility of titanium dioxide with external polymers.

[0037] Based on the quality of titanium dioxide, the coating amount of the organic coating layer is 0.1%, and the coating amount of the inorganic coating layer is 5.5%, of which the coating amount of silicon dioxide is 0.5% and the coating amount of barium titanate is 5%.

[0038] The modified titanium dioxide mentioned above uses rutile titanium dioxide with a dielectric constant of 114. The surface is coated with gaseous silica through the action of silane coupling agent. In addition, it is mixed with a small amount of barium titanate to obtain a homogeneous titanium dioxide mixture. Compared with the single titanium dioxide system, the modified titanium dioxide has better fluidity and is easier to feed and accurately add materials.

[0039] Furthermore, the first and second loss-in-weight scales are linked and controlled by a central control system to keep the feed mass ratio of the first and second loss-in-weight scales constant.

[0040] Specifically, the fluctuation deviation of the feeding mass ratio of the first loss-in-weight weigher and the second loss-in-weight weigher is controlled within ±1.0%, ensuring the coordination and stability of the feeding system during processing.

[0041] The metering accuracy of both the first and second loss-in-weight balances is controlled within ±0.5%, ensuring the fluidity of modified titanium dioxide during processing, making it easier to achieve high-precision metering and improve processing results.

[0042] Specifically, a twin-screw loss-in-weight balance is used as the second loss-in-weight balance to accurately measure and convey modified titanium dioxide. The feeding rate of the second loss-in-weight balance is controlled within the range of 40~100 kg / h. At least part of the surface of the second loss-in-weight balance that comes into contact with the modified titanium dioxide is coated with a fluorine-containing coating.

[0043] The fluorine-containing coating area includes the inside of the hopper and the feeding screw of the second loss-in-weight scale. The coating area can be adjusted according to the actual use to ensure that the area where the modified titanium dioxide comes into contact with the second loss-in-weight scale is coated with a fluorine-containing coating to ensure its fluidity and prevent sticking.

[0044] The fluorinated coating is at least one of polytetrafluoroethylene, perfluoroalkoxyalkane, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer; the thickness of the fluorinated coating is 25~50 μm.

[0045] Preferably, the fluorinated coating is polytetrafluoroethylene; the thickness of the fluorinated coating is 30 μm.

[0046] Specifically, the extremely low surface area of ​​the fluorine coating makes it difficult for titanium dioxide particles to adhere to the screw and hopper surfaces, fundamentally solving the "bridging" and "rat hole" problems caused by material adhesion. This ensures the smooth and uniform flow of modified titanium dioxide material. At the same time, setting an appropriate fluorine coating thickness avoids problems such as discontinuous coating due to insufficient thickness and weakened adhesion between the coating and the metal substrate due to excessive thickness, resulting in blistering, cracking, or peeling. This ensures that the fluorine coating forms a continuous, non-porous barrier, ensuring stable, energy-saving, and continuous unloading of modified titanium dioxide material. It also provides a stable and reliable weight signal for the control system, greatly improving the instantaneous flow rate and cumulative measurement accuracy of the loss-in-weight scale.

[0047] Furthermore, the length-to-diameter ratio of the screw in the twin-screw extruder is 40:1 to 48:1.

[0048] Furthermore, the side feed port is located after the melting and plasticizing section of the twin-screw extruder. The purpose is to add the modified titanium dioxide in the fourth zone of the twin-screw extruder, avoiding the accumulation of material caused by adding it from the main feed port at the same time as the main material. At the same time, it ensures that the modified titanium dioxide can be fully mixed and dispersed evenly with the resin, and can form a good interfacial bond with the resin.

[0049] Another embodiment of the present invention discloses a high dielectric and low loss polyphenylene ether composite material prepared by the above method, the dielectric constant of which can be controlled within a certain range and the dielectric loss ≤ 0.0015. Then, the high dielectric and low loss polyphenylene ether composite material provided by the present invention is used to make an antenna vibrator, which has high dielectric constant and low dielectric loss performance, as well as high stability, non-discoloration, low density and lightweight characteristics.

[0050] The high-dielectric, low-loss polyphenylene ether composite material obtained by this invention can be directly injection molded to obtain antenna vibrators. The whole process is simple and easy to control, the molding is simple, and the consistency is high. It is suitable for industrial mass production and can be applied to communication technology components, including but not limited to antenna vibrators, as well as other related fields that require high-dielectric and low-loss materials.

[0051] The high-dielectric, low-loss polyphenylene ether composite material and its preparation method disclosed in this invention will be further described in detail below with reference to specific embodiments. Unless otherwise specified, the instruments and reagents used in the embodiments are all commercially available, and the specific product models and other information are as follows: Polyphenylene oxide (PPO) includes one or more types of polyphenylene oxide with an intrinsic viscosity of 0.2 to 0.45 dL / g.

[0052] In this embodiment, the PPO product model is PPO ZM035, with an intrinsic viscosity of 0.35 dL / g. The intrinsic viscosity test method is ASTM D2857, and the test is conducted at 25 °C. Using low-viscosity polyphenylene ether is beneficial for improving the material's processing fluidity.

[0053] High-impact polystyrene, abbreviated as HIPS, contains 5-15 wt% polybutadiene rubber. In this embodiment, the HIPS product model is HIPS 476L, the melt flow rate is 5 g / 10 min, the melt flow rate test method is ASTM D1238, and the test conditions are 200℃ and 5 kg. By using high-impact polystyrene with a polybutadiene rubber content of 5~15wt%, the material's fluidity and a certain degree of toughness are ensured.

[0054] The titanium dioxide is rutile titanium dioxide with a particle size of 0.1~0.3 μm, a dielectric constant of 100~130, a dispersibility of 6.0~7.0, and a volatile content of ≤0.3% at 105℃. The dispersibility test method is ASTM D1210, and the volatile content test method at 105℃ is ASTM D280.

[0055] In this embodiment, the titanium dioxide product is R103 titanium dioxide. This type of titanium dioxide has a dense structure, good stability, high dielectric constant, and good resistance to yellowing. It has a higher dielectric constant than anatase titanium dioxide.

[0056] The silane coupling agent is at least one of aminosilane, epoxysilane, or vinylsilane.

[0057] In this embodiment, the silane coupling agent is product model KH-570, which specifically includes two types of functional groups. One is the organic functional group methacryloyloxy, which can participate in free radical copolymerization reactions and form chemical bonds or physical entanglement with the organic matrix, thereby improving the bonding strength. The other is the silanoxy group trimethoxysilyl, which can react with the hydroxyl groups on the surface of inorganic materials such as sericite to form a strong bond, ensuring good interfacial bonding for titanium dioxide.

[0058] Fumed silica, with a specific surface area of ​​150~300 m² 2 / g.

[0059] In this embodiment, the fumed silica product is Wacker H20, with a specific surface area of ​​170~230 m². 2 / g, ensuring that it can effectively prevent agglomeration and improve the overall flowability of titanium dioxide.

[0060] Barium titanate with a particle size D50 of 0.5~5.0 μm.

[0061] In this embodiment, the barium titanate product model is BT-501, and the particle size D50 is 1~3 μm. The median diameter of the particle size distribution determines the dispersibility and dielectric properties of barium titanate in the composite material, ensuring the uniform dispersion of titanium dioxide particles.

[0062] Antioxidants, including one or more of hindered phenolic antioxidants and phosphite antioxidants.

[0063] In this embodiment, antioxidant 168 and antioxidant 1010 are compounded in a 1:1 ratio. The Chinese name of antioxidant 168 is tris[2,4-di-tert-butylphenyl]phosphite, which is a phosphite antioxidant and its CAS registration number is 31570-04-4. The Chinese name of antioxidant 1010 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], which is a hindered phenolic antioxidant and has a CAS registry number of 6683-19-8.

[0064] Lubricants, including one or more of pentaerythritol tetrastearate, polyethylene wax, silicone masterbatch, EBS or TAF.

[0065] In this embodiment, the lubricant used is pentaerythritol stearate, product model PETS-AP.

[0066] Toughening agents, including one or more of SEBS or SBS, wherein the styrene content of SEBS and / or SBS is 20 to 40 wt%.

[0067] In this embodiment, the toughening agent used is SEBS, product model SEBS 6151, with a styrene content of 32 wt%. By using medium- to low-molecular-weight SEBS with a styrene content of ≤35 wt%, it is beneficial to improve the toughness and flowability of the material, improve the compatibility between rutile titanium dioxide and organic materials, make the modified titanium dioxide easier to process, and further reduce dielectric loss.

[0068] The first loss-in-weight scale uses a conventional loss-in-weight scale.

[0069] The second loss-in-weight feeder, in this embodiment, is a twin-screw loss-in-weight feeder, model LG-LW-GNT38, with a metering accuracy of ±0.5% and a feeding rate control range of 40~100 kg / h. Automatic feeding is implemented using machine control, and the bulk density of the modified titanium dioxide is 0.6 g / cm³. 3 The instrument is equipped with Mettler Toledo weighing sensors and digital modules, a square weighing platform, a spherical hopper with horizontal stirring, a 120 L symmetrical metering hopper, an automatic feeding hopper with vertical stirring, a universal screw interface, and SUS304 stainless steel for all parts in contact with materials, including the inside of the hopper and the feeding screw area, and is coated with a PTFE coating with a thickness of 30 μm.

[0070] Example 1 A method for preparing a high-dielectric, low-loss polyphenylene ether composite material: S1. Weigh 34.5 parts by weight of polyphenylene ether, 25 parts by weight of polystyrene, 0.2 parts by weight of antioxidant, 0.3 parts by weight of lubricant and 3 parts by weight of toughening agent. Mix the above components evenly through a high-speed mixer and add them to the first loss-in-weight scale for precise measurement. Then, continuously add them to the main feed port of the twin-screw extruder.

[0071] S2. Add titanium dioxide to a high-speed mixer. While stirring at 100 r / min and 50 ℃, add 0.1% of the titanium dioxide mass as a silane coupling agent. After stirring continuously at 50 ℃ for 5 min, add 0.5% of the titanium dioxide mass as fumed silica. Stir continuously at 80 ℃ and 200 r / min for 10 min. After mixing thoroughly, add 5% of the titanium dioxide mass as barium titanate. After mixing thoroughly at 50 ℃ and 150 r / min for 5 min, the modified titanium dioxide is obtained.

[0072] S3. Weigh 40 parts by weight of titanium dioxide, add the modified titanium dioxide to the second loss-in-weight scale for precise measurement, and then continuously add it to the side feed port of the twin-screw extruder.

[0073] S4. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300 rpm. Melt extrusion and blend all components in the twin-screw extruder, then cool, traction and pelletize to obtain a high dielectric and low loss polyphenylene ether composite material.

[0074] Example 2 A method for preparing a high-dielectric, low-loss polyphenylene ether composite material: S1. Weigh 27.2 parts by weight of polyphenylene ether, 17 parts by weight of polystyrene, 0.3 parts by weight of antioxidant, 0.5 parts by weight of lubricant and 5 parts by weight of toughening agent. Mix the above components evenly with a high-speed mixer and add them to the first loss-in-weight scale for precise measurement. Then, continuously add them to the main feed port of the twin-screw extruder.

[0075] S2. Add titanium dioxide to a high-speed mixer. While stirring at 100 r / min and 50 ℃, add 0.1% of the titanium dioxide mass as a silane coupling agent. After stirring continuously at 50 ℃ for 5 min, add 0.5% of the titanium dioxide mass as fumed silica. Stir continuously at 80 ℃ and 200 r / min for 10 min. After mixing thoroughly, add 5% of the titanium dioxide mass as barium titanate. After mixing thoroughly at 50 ℃ and 150 r / min for 5 min, the modified titanium dioxide is obtained.

[0076] S3. Weigh 50 parts by weight of titanium dioxide, add the modified titanium dioxide to the second loss-in-weight scale for precise measurement, and then continuously add it to the side feed port of the twin-screw extruder.

[0077] S4. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300 rpm. Melt extrusion and blend all components in the twin-screw extruder, then cool, traction and pelletize to obtain a high dielectric and low loss polyphenylene ether composite material.

[0078] The main difference between Example 2 and Example 1 is that: 50 parts by weight of modified titanium dioxide are weighed; 27.2 parts by weight of polyphenylene ether, 17 parts by weight of polystyrene, 0.3 parts by weight of antioxidant, 0.5 parts by weight of lubricant, and 5 parts by weight of toughening agent are weighed and mixed with modified titanium dioxide to make a high dielectric and low loss material.

[0079] Example 3 A method for preparing a high-dielectric, low-loss polyphenylene ether composite material: S1. Weigh 16 parts by weight of polyphenylene ether, 15 parts by weight of polystyrene, 0.4 parts by weight of antioxidant, 0.6 parts by weight of lubricant and 8 parts by weight of toughening agent. Mix the above components evenly through a high-speed mixer and add them to the first loss-in-weight scale for precise measurement. Then, continuously add them to the main feed port of the twin-screw extruder.

[0080] S2. Add titanium dioxide to a high-speed mixer. While stirring at 100 r / min and 50 ℃, add 0.1% of the titanium dioxide mass as a silane coupling agent. After stirring continuously at 50 ℃ for 5 min, add 0.5% of the titanium dioxide mass as fumed silica. Stir continuously at 80 ℃ and 200 r / min for 10 min. After mixing thoroughly, add 5% of the titanium dioxide mass as barium titanate. After mixing thoroughly at 50 ℃ and 150 r / min for 5 min, the modified titanium dioxide is obtained.

[0081] S3. Weigh 60 parts by weight of titanium dioxide, add the modified titanium dioxide to the second loss-in-weight scale for precise measurement, and then continuously add it to the side feed port of the twin-screw extruder.

[0082] S4. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300 rpm. Melt extrusion and blend all components in the twin-screw extruder, then cool, traction and pelletize to obtain a high dielectric and low loss polyphenylene ether composite material.

[0083] The main difference between Example 3 and Example 1 is that: 60 parts by weight of modified titanium dioxide are weighed; 16 parts by weight of polyphenylene ether, 15 parts by weight of polystyrene, 0.4 parts by weight of antioxidant, 0.6 parts by weight of lubricant, and 8 parts by weight of toughening agent are weighed and mixed with modified titanium dioxide to make a high dielectric and low loss material.

[0084] Comparative Example 1 A method for preparing a high-dielectric, low-loss polyphenylene ether composite material: Weigh out 34.5 parts by weight of polyphenylene ether, 22 parts by weight of polystyrene, 0.2 parts by weight of antioxidant, 0.3 parts by weight of lubricant, 3 parts by weight of toughening agent, and 40 parts by weight of titanium dioxide. Mix the above components evenly using a high-speed mixer and then directly add them into a twin-screw extruder. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300 rpm. Melt-extrude and blend all components in the twin-screw extruder, followed by cooling, traction, and pelletizing to obtain a high-dielectric, low-loss polyphenylene ether composite material.

[0085] The difference between Comparative Example 1 and Example 1 is that the titanium dioxide was not modified or fed separately, but was directly mixed with other components and fed together.

[0086] Comparative Example 2 A method for preparing a high dielectric, low loss polyphenylene ether composite material, the difference between Comparative Example 2 and Example 2 is that the modified titanium dioxide is replaced with unmodified titanium dioxide.

[0087] Comparative Example 3 A method for preparing a high-dielectric, low-loss polyphenylene ether composite material: S1. Add titanium dioxide to a high-speed mixer. While stirring at 100 r / min and 50 ℃, add 0.1% of the mass of titanium dioxide as a silane coupling agent. After stirring continuously at 50 ℃ for 5 min, add 0.5% of the mass of titanium dioxide as fumed silica. Stir continuously at 80 ℃ and 200 r / min for 10 min. After mixing thoroughly, add 5% of the mass of titanium dioxide as barium titanate. After mixing thoroughly at 50 ℃ and 150 r / min for 5 min, the modified titanium dioxide is obtained.

[0088] S2. Weigh 60 parts by weight of modified titanium dioxide, 16 parts by weight of polyphenylene ether, 15 parts by weight of polystyrene, 0.4 parts by weight of antioxidant, 0.6 parts by weight of lubricant and 8 parts by weight of toughening agent, mix the above components evenly through a high-speed mixer and then add them directly into a twin-screw extruder.

[0089] S3. Set the processing temperature of the twin-screw extruder to 240~270 ℃ and the rotation speed to 300 rpm. Melt extrusion and blend all components in the twin-screw extruder, then cool, traction and pelletize to obtain a high dielectric and low loss polyphenylene ether composite material.

[0090] The difference between Comparative Example 3 and Example 3 is that the modified titanium dioxide was not added separately, but was mixed evenly with the other components and then added together.

[0091] The composition and dosage of the high dielectric and low loss polyphenylene ether composite materials prepared in Examples 1-3 and Comparative Examples 1-3 are summarized in Tables 1 and 2, respectively.

[0092] Table 1. Weight ratio of each component in Examples 1-3 Component Name Example 1 Example 2 Example 3 PPO 34.5 27.2 16 HIPS 22 17 15 toughening agent 3 5 8 antioxidants 0.2 0.3 0.4 lubricant 0.3 0.5 0.6 Modified titanium dioxide 40 50 60 Table 2. Weight proportions of each component in Comparative Examples 1-3 Component Name Comparative Example 1 Comparative Example 2 Comparative Example 3 PPO 34.5 27.2 16 HIPS 22 17 15 toughening agent 3 5 8 antioxidants 0.2 0.3 0.4 lubricant 0.3 0.5 0.6 Modified titanium dioxide —— —— 60 Titanium dioxide 40 50 ——

[0093] To better verify the performance of the high-dielectric, low-loss materials obtained in the above embodiments and comparative examples, the materials prepared in the comparative examples and embodiments were subjected to performance testing. The granules prepared in Examples 1-3 and Comparative Examples 1-3 were dried at 120 °C for 3 hours, injection molded, and made into standard samples for density and dielectric properties testing. For each dielectric property test, 5 samples were tested, and the variance of the dielectric constant was calculated. All the above performance indicators were tested using known methods in the prior art. The specific test methods are as follows: Dielectric constant test: ASTM D150, test conditions: 23±1 °C, 50±5 % RH, test frequency: 1GHz, sample size: 150 mm x 125 mm x 2 mm; Dielectric loss test: ASTM D150, test conditions: 23±1 °C, 50±5 % RH, test frequency: 1 GHz, sample size: 150 mm x 125 mm x 2 mm.

[0094] The specific test results of Examples 1-3 and Comparative Examples 1-3 are shown in Tables 3 and 4, respectively.

[0095] Table 3. Performance test results of Examples 1-3 Test metrics Example 1 Example 2 Example 3 Dielectric constant Dk 3.8 5.1 6.3 Dielectric loss Df 0.0011 0.0012 0.0015 Dielectric constant variance 0.001 0.001 0.001 Table 4. Performance test results of Comparative Examples 1-3 Test metrics Comparative Example 1 Comparative Example 2 Comparative Example 3 Dielectric constant Dk / / 6.0 Dielectric loss Df / / 0.0015 Dielectric constant variance / / 0.003 Comparative Example 1 failed to produce a composite material because the filler and resin separated; Comparative Example 2 failed to produce a composite material because the titanium dioxide adhered to the inner wall of the loss-in-weight scale, making material feeding difficult.

[0096] As can be seen from the above results, this invention uses low-dielectric-loss polyphenylene ether as the base material and rutile titanium dioxide with high dielectric properties as the dielectric modifier. Surface physical and chemical modifications are performed on the titanium dioxide, solving problems such as difficulty in feeding titanium dioxide and its tendency to stick to the wall, thus ensuring the uniformity and stability of the material quality. By adjusting the ratio of rutile titanium dioxide to polyphenylene ether, the dielectric constant of the material can be orderly controlled within a certain range, and the dielectric loss is ≤0.0015.

[0097] As can be seen from Example 1 and Comparative Example 1 and the corresponding test results, in Comparative Example 1, titanium dioxide was mixed with resin and fed together without any modification treatment or separation from other components. This resulted in severe problems of filler and resin separation and filler adhesion to the wall, leading to experimental failure.

[0098] As can be seen from Example 2 and Comparative Example 2 and the corresponding test results, although titanium dioxide was fed separately in Comparative Example 2, it still had a certain degree of stickiness because it was not modified. It was very easy to stick to the wall of the weight loss scale, and the particles were not easy to flow and feed, which also led to the failure of the experiment.

[0099] The results of Example 3 and Comparative Example 3 and their corresponding test results show that the composite material made by blending the modified titanium dioxide with resin in Comparative Example 3 has reduced the wall adhesion problem due to the modification of titanium dioxide, but it still has the problem of delamination, resulting in relatively large fluctuations in dielectric constant. The variance of dielectric constant is significantly greater than that of the composite material made by blending the modified titanium dioxide alone in Example 3, indicating that the product processing is not stable.

[0100] In summary, the preparation method adopted in this invention is more conducive to the uniform dispersion of titanium dioxide in the system and is easier to process and mold. It solves the layering problem caused by the large difference between its density and the resin density, and ensures the consistency of the product.

[0101] The comprehensive data shows that the technical solution has achieved the expected results, namely, the preparation of a polyphenylene ether composite material with high dielectric constant, low dielectric loss, high stability, resistance to discoloration, and easy processing and molding.

[0102] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

[0103] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. Technical details not described in detail in this invention can all be implemented using any existing technology in the art. In particular, all technical features not described in detail in this invention can be implemented using any existing technology.

Claims

1. A high-dielectric, low-loss polyphenylene ether composite material, characterized in that, The high-dielectric, low-loss polyphenylene ether composite material comprises the following components in parts by weight: Polyphenylene oxide: 10-55 parts; polystyrene: 14-25 parts; modified titanium dioxide: 15-70 parts; antioxidant: 0.1-0.5 parts; Lubricant: 0.3~1.0 parts; Toughening agent: 3~8 parts; The process involves surface modification of titanium dioxide to obtain modified titanium dioxide, wherein the titanium dioxide is rutile titanium dioxide, and the preparation method of the modified titanium dioxide includes: The titanium dioxide was added to a high-speed mixer, and a silane coupling agent was added during low-speed stirring. After stirring for a certain period of time, fumed silica was added. After continuous stirring and thorough mixing, barium titanate was added. After thorough mixing, the modified titanium dioxide was obtained.

2. The high-dielectric, low-loss polyphenylene ether composite material according to claim 1, characterized in that, The method for preparing the modified titanium dioxide includes: The titanium dioxide is added to a high-speed mixer, and while stirring at 40-60 °C and 50-150 r / min, 0.1%-0.3% of the silane coupling agent (by weight of the titanium dioxide) is added. After stirring for 3-10 min, 0.3%-1.0% of the fumed silica (by weight of the titanium dioxide) is added. The mixture is stirred for 5-10 min at 80-100 °C and 200-300 r / min until fully mixed. Then, 3%-8% of the barium titanate (by weight of the titanium dioxide) is added. The mixture is stirred for 3-8 min at 40-60 °C and 100-200 r / min to obtain the modified titanium dioxide.

3. The high-dielectric, low-loss polyphenylene ether composite material according to claim 2, characterized in that, The silane coupling agent is at least one of aminosilane, epoxysilane or vinylsilane; The specific surface area of ​​the fumed silica is 150~300 m². 2 / g; The barium titanate has a particle size D50 of 0.5~5.0 μm.

4. A method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to any one of claims 1-3, characterized in that, Includes the following steps: S1. After the polyphenylene ether, polystyrene, antioxidant, lubricant and toughening agent are mixed evenly by a high-speed mixer, they are added to the first loss-in-weight scale for precise measurement and then continuously fed into the main feed port of the twin-screw extruder. S2. Surface modification treatment is performed on titanium dioxide to obtain modified titanium dioxide; S3. After the modified titanium dioxide is accurately measured by adding it to the second loss-in-weight scale, it is continuously added to the side feed port of the twin-screw extruder. S4. All components are melt-extruded and blended in the twin-screw extruder, then cooled, drawn, and pelletized to obtain the high-dielectric, low-loss polyphenylene ether composite material.

5. The method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to claim 4, characterized in that, The polyphenylene ether comprises one or more of polyphenylene ethers with an intrinsic viscosity of 0.2 to 0.45 dL / g; The polystyrene comprises one or more types of high-impact polystyrene, and the polybutadiene rubber content in the high-impact polystyrene is 5-15 wt%. The antioxidant includes one or more of hindered phenolic antioxidants and phosphite antioxidants; the lubricant includes one or more of pentaerythritol tetrastearate, polyethylene wax, silicone masterbatch, EBS or TAF. The toughening agent comprises one or more of SEBS or SBS, and the styrene content of the SEBS and / or the SBS is 20-40 wt%.

6. The method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to claim 4, characterized in that, In S1 and S3, The measurement accuracy of both the first loss-in-weight scale and the second loss-in-weight scale is controlled within ±0.5%. The first loss-in-weight scale and the second loss-in-weight scale are linked and controlled by a central control system. The feeding mass ratio of the first loss-in-weight scale and the second loss-in-weight scale remains constant. The fluctuation deviation of the feeding mass ratio of the first loss-in-weight scale and the second loss-in-weight scale is controlled within ±1.0%. The feeding rate control range of the second loss-in-weight weigher is 40~100 kg / h.

7. The method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to claim 6, characterized in that, In S3, The second loss-in-weight scale is a twin-screw loss-in-weight scale, which is used to accurately measure and transport the modified titanium dioxide. The surfaces of the second loss-in-weight balance that come into contact with the modified titanium dioxide are at least partially coated with a fluorine-containing coating; The fluorine-containing coating area includes the inside of the hopper of the second loss-in-weight scale and the feeding screw; The fluorine-containing coating is at least one of polytetrafluoroethylene, perfluoroalkoxyalkane, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer; The thickness of the fluorine-containing coating is 25~50 μm.

8. The method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to claim 4, characterized in that, In S3, The side feed port is located after the melt plasticizing section of the twin-screw extruder.

9. The method for preparing a high-dielectric, low-loss polyphenylene ether composite material according to claim 4, characterized in that, In S4, The twin-screw extruder has a screw length-to-diameter ratio of 40:1 to 48:1; the twin-screw extruder has a processing temperature of 240 to 270 ℃ and a rotation speed of 300 to 500 rpm.

10. The application of a high-dielectric, low-loss polyphenylene ether composite material as described in any one of claims 1-3 in the fabrication of an antenna vibrator, or the application of a high-dielectric, low-loss polyphenylene ether composite material prepared by the method described in any one of claims 4-9 in the fabrication of an antenna vibrator.