Glass fiber impregnating compound, low-dielectric glass fiber and cyanate ester resin-based wave-transparent composite material
By compounding low-molecular-weight epoxy emulsions and high-molecular-weight epoxy emulsions, and combining them with low-molecular-weight polypropylene emulsions, lubricants, and silane coupling agents, the compatibility problem between glass fiber impregnating agents and cyanate ester resin matrices was solved, thereby improving the mechanical and wave transmission properties of the composite material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-04-07
AI Technical Summary
Existing glass fiber impregnating agents are difficult to achieve good compatibility and interfacial bonding strength with cyanate ester resin matrices, which affects the performance of composite materials.
Low molecular weight epoxy emulsion and high molecular weight epoxy emulsion are used as film-forming agents, combined with low molecular weight polypropylene emulsion, lubricant and silane coupling agent to form a dense network structure, which enhances the bonding performance between glass fiber and cyanate ester resin.
Good compatibility and interfacial bonding strength between low dielectric glass fiber and cyanate ester resin matrix were achieved, improving the mechanical properties and wave transmission properties of the composite material.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of glass fiber sizing agent, in particular to a glass fiber sizing agent, low dielectric glass fiber and cyanate ester resin-based wave-transparent composite material. BACKGROUND
[0002] Low dielectric glass fiber is a special glass composition with boron trioxide (B2O3) and borosilicate as main components, which has the core characteristics of low dielectric constant and extremely low thermal expansion coefficient. Its dielectric properties make the material widely used as insulation layer material in optical cable structure, and the low thermal expansion property is applied to the field of electronic circuit board which needs to withstand temperature changes. At present, the material has formed large-scale application in the field of electrical component packaging.
[0003] Sizing agent is a kind of glass fiber surface treatment agent. After the glass fiber flows out of the bushing, it usually needs to be treated with aqueous sizing agent to give the glass fiber good textile processing performance, mechanical properties required by composite materials and other customized properties. Different sizing agents give different properties to glass fibers, and various yarns for spinning and weaving must have good spinning performance and good compatibility with resin matrix to meet the needs of various products. Therefore, it is crucial to develop a sizing agent suitable for high-performance glass fiber and its composite materials. SUMMARY
[0004] In view of one or more technical problems in the prior art, the present application provides a glass fiber sizing agent, low dielectric glass fiber and cyanate ester resin-based wave-transparent composite material. The sizing agent provided by the present application has good compatibility and interfacial bonding strength with the cyanate ester resin matrix.
[0005] In a first aspect, the present application provides a glass fiber sizing agent, which comprises the following components in mass fraction: 35-50 parts of low molecular weight epoxy emulsion, the molecular weight of the epoxy resin in the low molecular weight epoxy emulsion being 400-600; 5-15 parts of high molecular weight epoxy emulsion, the molecular weight of the epoxy resin in the high molecular weight epoxy emulsion being 5000-8000; 5-10 parts of low molecular weight polypropylene emulsion, the molecular weight of the polypropylene in the low molecular weight polypropylene emulsion being 2000-3000; 20-25 parts of lubricant; 15-20 parts of silane coupling agent, the silane coupling agent comprising a main silane coupling agent and an auxiliary silane coupling agent, the main silane coupling agent being a benzyl silane coupling agent, and the auxiliary silane coupling agent being an unsaturated silane coupling agent; 0.1-0.3 parts of graphene.
[0006] Preferably, the epoxy resin in the low molecular weight epoxy emulsion and the high molecular weight epoxy emulsion is bisphenol A type epoxy resin.
[0007] Preferably, the glass fiber sizing agent further comprises a pH regulator for adjusting the pH of the glass fiber sizing agent to 5~7. The pH regulator is preferably an organic acid, preferably one or more of acetic acid, formic acid, succinic acid, boric acid, citric acid.
[0008] Preferably, the lubricant comprises an ester lubricant and a mineral oil lubricant. The mass ratio of the ester lubricant to the mineral oil lubricant is 1~3.5:1.
[0009] Preferably, the mass ratio of the benzyl silane coupling agent to the unsaturated silane coupling agent is 1~8:1.
[0010] Preferably, the number of layers of the graphene is less than 5.
[0011] Preferably, the solid content of the glass fiber sizing agent is 5~6%.
[0012] The present application provides, in a second aspect, a low dielectric glass fiber, which is obtained by drying the low dielectric glass fiber filaments coated with the sizing agent of the first aspect.
[0013] Preferably, the drying process comprises placing the low dielectric glass fiber filaments coated with the sizing agent in a dry environment for 8~12h, then drying at 75~85℃ for 60~90min, then drying at 100~110℃ for 160~180min, and finally drying at 115~125℃ for 160~180min.
[0014] The present application provides, in a third aspect, a cyanate ester resin-based wave-transparent composite material, which is obtained by compounding the low dielectric glass fiber of the second aspect and a cyanate ester resin matrix.
[0015] Compared with the prior art, the present application has at least the following beneficial effects: The present application provides an infiltrating agent, which selects a low molecular weight epoxy resin emulsion as a main film forming agent, and a high molecular weight epoxy resin emulsion as an auxiliary film forming agent. The low molecular weight epoxy resin emulsion forms a flexible film layer, which can effectively guarantee the flexibility of the glass fiber and reduce the rigidity of the fiber itself. The addition of a low-dosage high molecular weight epoxy resin emulsion can improve the elasticity of the film layer. Through the use of the above two kinds of epoxy resin emulsions, the glass fiber can be endowed with excellent bending resistance and wear resistance, and the comprehensive mechanical properties and use performance of the fiber can be optimized. At the same time, the two film forming agents can be cross-linked and interlaced with each other to form a relatively dense network structure, thereby improving the performance of the glass fiber. In addition, the high molecular weight epoxy resin has weak polarity, which can effectively reduce static electricity in the production process and prevent graphene from agglomerating. The low molecular weight polypropylene emulsion can better absorb graphene, reduce the dispersion movement of graphene during emulsification and dispersion and the preparation of the infiltrating agent, reduce the self-aggregation of graphene sheets, ensure the uniform distribution of graphene sheets on the surface of the fiber, and also improve the bonding degree of the surface of the infiltrating agent and the cyanate ester resin matrix. As a bridge of the system, the silane coupling agent enhances the bonding performance of the resin-interface-glass fiber through hydrogen bonding and π-π interfacial interaction, thereby ensuring the wave transmission performance of the composite material and improving the mechanical properties of the composite material. The present application selects specific film forming agents, polypropylene emulsions, lubricants and silane coupling agents, which can effectively avoid the agglomeration and self-aggregation of graphene without pretreatment of graphene, realize the uniform dispersion of graphene, and obtain an infiltrating agent with good compatibility and interfacial bonding strength with the cyanate ester resin.
[0016] The low dielectric glass fiber treated by the infiltrating agent provided by the present application has good compatibility and interfacial bonding strength with the cyanate ester resin matrix. During the compounding process of the low dielectric glass fiber treated by the infiltrating agent and the cyanate ester resin, the benzene ring structure of the main coupling agent (benzyl silane coupling agent) can form π-π bonding with the cyclic structure generated during the heating compounding process of the cyanate ester resin, thereby improving the compatibility and interfacial bonding strength of the glass fiber and the cyanate ester resin matrix. In addition, while the main coupling agent (benzyl silane coupling agent) on the surface of the glass fiber forms a connection with the resin matrix, the auxiliary coupling agent (unsaturated silane coupling agent) is grafted with the unsaturated active groups of the resin and the film forming agent to form a network connection, thereby further improving the interfacial performance and mechanical properties of the composite material. The two-dimensional graphene uniformly distributed on the surface of the glass fiber can further form π-π bonding with the benzene ring structure of the main coupling agent and the cyclic structure generated by the cyanate ester resin, thereby densifying the interface. At the same time, the nanoscale graphene can interact with the cyanate ester matrix molecules at the interface of the composite material, thereby increasing the wettability of the resin on the surface of the glass fiber and further enhancing the interfacial bonding strength of the composite material.
[0017] The low-polarity infiltrant treated low-dielectric glass fiber containing two-dimensional graphene sheets provided by the application and the cyanate resin composite material obtained by compounding the low-dielectric glass fiber with a cyanate resin have excellent mechanical properties and wave-transmitting properties. DETAILED DESCRIPTION
[0018] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the technical solutions in the embodiments of the present application for a clear and complete description. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0019] The present application provides a glass fiber infiltrant in a first aspect, the glass fiber infiltrant comprises the following components in mass fraction: Low molecular weight epoxy emulsion 35~50 parts, the molecular weight of epoxy resin in the low molecular weight epoxy emulsion is 400~600; High molecular weight epoxy emulsion 5~15 parts, the molecular weight of epoxy resin in the high molecular weight epoxy emulsion is 5000~8000; Low molecular weight polypropylene emulsion 5~10 parts, the molecular weight of polypropylene in the low molecular weight polypropylene emulsion is 2000~3000; Lubricant 20~25 parts; Silane coupling agent 15~20 parts, the silane coupling agent comprises main silane coupling agent and auxiliary silane coupling agent, the main silane coupling agent is benzyl silane coupling agent, and the auxiliary silane coupling agent is unsaturated silane coupling agent; Graphene 0.1~0.3 parts.
[0020] The infiltrant provided by the present application selects a low molecular weight epoxy resin emulsion as a main film-forming agent, and simultaneously matches a high molecular weight epoxy resin emulsion as an auxiliary film-forming agent. The low molecular weight epoxy resin emulsion forms a flexible film layer, which can effectively guarantee the flexibility of the glass fiber and reduce the rigidity of the fiber itself; the addition of a low-dosage high molecular weight epoxy resin emulsion can realize the improvement of the elasticity of the film layer. The matching use of the two kinds of epoxy resin emulsions can synergistically give the glass fiber more excellent bending resistance and wear resistance, and realize the optimization of the comprehensive mechanical properties and use performance of the fiber. Meanwhile, the two kinds of film-forming agents can cross-link and interlace with each other to form a relatively dense network structure, thereby improving the performance of the glass fiber. In addition, the high molecular weight epoxy resin has weak polarity, which can effectively reduce static electricity in the production process and prevent the agglomeration of graphene while providing coating performance. The low molecular weight polypropylene emulsion can better absorb graphene, reduce the dispersion movement of graphene in the emulsification and dispersion and the embedding process of the infiltrant, reduce the generation of the self-aggregation phenomenon of graphene sheets, guarantee the uniform distribution of the graphene sheets on the surface of the fiber, and also can improve the bonding degree of the surface of the infiltrant and the cyanate ester resin matrix. The silane coupling agent acts as a bridge of the system, enhances the bonding performance of the resin-interface-glass fiber through hydrogen bonding and π-π interfacial interaction, guarantees the wave transmission performance of the composite material, and improves the mechanical properties of the composite material. The present application selects specific film-forming agents, polypropylene emulsions, lubricants and silane coupling agents, and can effectively avoid the agglomeration and self-aggregation of graphene without pretreatment of graphene, realize the uniform dispersion of graphene, and obtain an infiltrant with good compatibility and interfacial bonding strength with the cyanate ester resin.
[0021] According to some preferred embodiments, the epoxy resin in the low molecular weight epoxy emulsion and the high molecular weight epoxy emulsion is a bisphenol A type epoxy resin.
[0022] According to some preferred embodiments, the glass fiber infiltrant further comprises a pH adjusting agent for adjusting the pH of the glass fiber infiltrant to 5-7. The pH adjusting agent is preferably an organic acid, preferably one or more of acetic acid, formic acid, succinic acid, boric acid, citric acid.
[0023] Since the silane coupling agent needs to be hydrolyzed under certain pH conditions, the prepared infiltrant needs to be stored and used under certain pH conditions, and the pH value is generally controlled in an acidic environment of 5-7.
[0024] According to some preferred embodiments, the lubricant comprises an ester lubricant and a mineral oil lubricant. The mass ratio of the ester lubricant to the mineral oil lubricant is 1-3.5:1 (for example, it can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1 or 3.5:1).
[0025] Because a single ester-based lubricant cannot meet the performance requirements of fibers during textile processes such as unwinding, doubling, and weaving, some preferred embodiments of this invention employ two lubricants to lubricate the glass fiber surface in both wet (during the drawing process) and dry (during unwinding and weaving) states, reducing fuzz formation, minimizing wear, and improving fiber abrasion resistance. Ester-based lubricants can reduce graphene aggregation and lubricate the glass fiber surface during unwinding and doubling, thus enhancing fiber performance. Mineral oil lubricants lubricate the glass fiber surface during weaving, further improving fiber performance.
[0026] According to some preferred embodiments, the mass ratio of the benzyl silane coupling agent to the unsaturated silane coupling agent is 1 to 8:1 (for example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1). The benzyl silane coupling agent is preferably A-1127, and the silane coupling agent is preferably A-174.
[0027] According to some preferred embodiments, the number of graphene layers is less than 5.
[0028] According to some preferred embodiments, the solid content of the glass fiber impregnating agent is 5-6%.
[0029] According to some preferred embodiments, the solid content of the low molecular weight epoxy emulsion is 45-55 wt%; The high molecular weight epoxy emulsion has a solid content of 45-55 wt%. The solid content of the low molecular weight polypropylene emulsion is 35-45 wt%; and / or The solid content of the grease lubricant is 45-55 wt%. The solid content of the nonionic lubricant is 35~45wt%.
[0030] Considering the poor shear resistance of graphene emulsions and the need for continuous stirring during use, graphene may easily aggregate on the surface of some wetting agents, preventing uniform dispersion and thus failing to achieve its intended purpose. Therefore, in some preferred embodiments of this invention, graphene is pretreated before being mixed with other components. The pretreatment process includes: 1) mixing a surfactant, a high molecular weight epoxy resin emulsion, and water for pre-emulsification to obtain a pre-emulsion; 2) mixing graphene and a low molecular weight epoxy emulsion and ultrasonically dispersing to obtain a dispersion; the amount of low molecular weight epoxy emulsion is 0.3~0.7 wt% of the total mass of the wetting agent; 3) emulsifying the dispersion with the pre-emulsion to obtain a graphene powder dispersion emulsion; the stirring speed during emulsification is controlled at 1000~3000 rpm. This pretreatment reduces graphene aggregation in the wetting agent, achieving uniform dispersion of graphene.
[0031] Furthermore, the inventors discovered that, due to the specific selection of the film-forming agent, polypropylene emulsion, lubricant, and silane coupling agent in this invention, directly mixing the low molecular weight epoxy emulsion, high molecular weight epoxy emulsion, low molecular weight polypropylene emulsion, lubricant, silane coupling agent, and graphene effectively avoids graphene agglomeration and self-agglomeration without the need for graphene pretreatment, thus achieving uniform dispersion of graphene and obtaining a uniformly dispersed graphene sizing agent. Therefore, in some preferred embodiments of this invention, the sizing agent is prepared by directly mixing the low molecular weight epoxy emulsion, high molecular weight epoxy emulsion, low molecular weight polypropylene emulsion, lubricant, silane coupling agent, and graphene, resulting in a simpler process.
[0032] In a second aspect, the present invention provides a low-dielectric glass fiber, which is obtained by drying low-dielectric glass fiber precursor coated with the sizing agent described in the first aspect.
[0033] The low-dielectric glass fiber treated with the sizing agent provided by this invention exhibits good compatibility and interfacial bonding strength with the cyanate ester resin matrix. During the composite process of the sizing agent-treated low-dielectric glass fiber and the cyanate ester resin, the benzyl ring structure of the main coupling agent (benzyl silane coupling agent) can form π-π bonds with the ring structure generated during the heating and composite process of the cyanate ester resin, thereby improving the compatibility and interfacial bonding strength between the glass fiber and the cyanate ester resin matrix. Furthermore, while the main coupling agent (benzyl silane coupling agent) on the glass fiber surface forms a connection with the resin matrix, the auxiliary coupling agent (unsaturated silane coupling agent) grafts onto the unsaturated active groups of the resin and film-forming agent, forming a network connection, thus improving the interfacial and mechanical properties of the composite material. The uniformly distributed two-dimensional graphene on the surface of glass fiber can further form π-π bonds with the benzene ring structure of the main coupling agent and the ring structure generated by the cyanate resin, thereby densifying the interface. At the same time, the nanoscale graphene can interact with the cyanate matrix molecules at the interface of the composite material, increasing the wettability of the resin on the surface of the glass fiber and further enhancing the interfacial bonding strength of the composite material.
[0034] According to some preferred embodiments, the drying process includes placing the low-dielectric glass fiber precursor coated with a wetting agent in a dry environment for 8 to 12 hours, then drying it at 75 to 85°C for 60 to 90 minutes, then drying it at 100 to 110°C for 160 to 180 minutes, and finally drying it at 115 to 125°C for 160 to 180 minutes.
[0035] Glass fiber precursors coated with sizing agents must be dried in an oven before subsequent processing to ensure that the film-forming agent is evenly spread on the fiber surface. The drying process involves four stages: storage in a dry environment for 8–12 hours, followed by drying at 75–85°C for 60–90 minutes, then at 100–110°C for 160–180 minutes, and finally at 115–125°C for 160–180 minutes. This dry storage and low-temperature pre-drying process prevents small molecules from escaping with moisture and forming aggregates on the outer layer of the precursor.
[0036] In a third aspect, the present invention provides a cyanate ester resin-based microwave-transparent composite material, which is obtained by combining the low dielectric glass fiber and the cyanate ester resin matrix described in the second aspect.
[0037] The cyanate ester resin-based wave-transparent composite material provided by the present invention, which is a low-dielectric glass fiber treated with a low-polarity sizing agent containing two-dimensional graphene sheets and combined with cyanate ester resin, has both excellent mechanical properties and wave-transparent properties.
[0038] Graphene is composed of carbon atoms separated by sp. 2Hybridized monolayer two-dimensional materials, where each carbon atom forms three covalent bonds arranged in a hexagonal pattern, construct a tightly packed two-dimensional honeycomb structure, exhibiting excellent physical properties in mechanics, electricity, and optics. Furthermore, graphene is a novel electromagnetic wave absorbing material with advantages such as high dielectric loss and low density, exhibiting strong electromagnetic wave attenuation characteristics. Compared to traditional absorbing materials, graphene can selectively absorb and reflect electromagnetic waves, simultaneously meeting the new requirements for electromagnetic radiation protection materials to be "thin, wide, light, and strong," and possessing good environmental adaptability. However, as an electromagnetic protection material, graphene's non-magnetic nature and poor impedance matching limit its applications. Cyanate ester resin (CE) is a thermosetting polymer with a higher mechanical storage modulus than EP and good heat resistance. Its low dielectric properties are particularly prominent, and its dielectric properties exhibit unique stability to changes in temperature and electromagnetic wave frequency. Research has been conducted on composite materials with wideband transmission and high transmittance in this system. Therefore, this invention introduces graphene into a low-polarity glass fiber sizing agent, and then combines the sizing agent-treated low-dielectric glass fiber with cyanate ester resin to prepare a cyanate ester resin-based wave-transparent composite material.
[0039] In some preferred embodiments of the present invention, the preparation method of the cyanate ester resin-based microwave transparent composite material includes: using low dielectric glass fiber to make a hollow fabric, then impregnating the hollow fabric with cyanate ester resin, and then curing and demolding to obtain the cyanate ester resin-based microwave transparent composite material.
[0040] In some preferred embodiments of the present invention, the hollow fabric is an integrally layered hollow fabric, with the internal fibers arranged in a three-dimensional interwoven pattern. The warp yarns of the hollow fabric are wavy, the weft yarns are straight, and the pile warp is in a figure-eight shape, and the structure is cyclical. It should be noted that the hollow fabric of the present invention is not limited to the above structure and can be adjusted according to actual needs.
[0041] In some specific embodiments of the present invention, the preparation method of cyanate ester resin-based microwave transparent composite material includes: laying low dielectric fiber hollow fabric on the surface of a mold, then starting a cyanate ester resin flow program to fully impregnate the low dielectric fiber hollow fabric with cyanate ester resin, and finally, performing heat treatment according to a pre-set curing process program. After curing is completed, the material is demolded to obtain the cyanate ester resin-based microwave transparent composite material.
[0042] To more clearly illustrate the technical solution and advantages of the present invention, the present invention will be further described below in conjunction with the embodiments. However, the scope of protection of the present invention is not limited to the following embodiments.
[0043] In the following examples, the low molecular weight epoxy emulsion used was NBR-210-50G bisphenol A type epoxy emulsion from Nanjing Glass Fiber Research and Design Institute Co., Ltd., with an effective content of 50wt%; the high molecular weight epoxy emulsion used was EP834 high molecular weight epoxy emulsion from Macquarie Corporation, with an effective content of 50wt%; the low molecular weight polypropylene emulsion used was PP2-01 from Macquarie Corporation, with an effective content of 40wt%. The main silane coupling agent (benzyl silane coupling agent) A-1127 and the auxiliary coupling agent (unsaturated silane coupling agent) A-174 were both provided by Momentive, with an effective content of 99wt%; the ester lubricant was provided by Nanjing Glass Fiber Research and Design Institute Co., Ltd., trade name NBR-2090, with an effective content of 50wt%; the mineral oil lubricant was provided by Guangzhou Kekai Co., Ltd., trade name 7440, with an effective content of 40wt%; and the graphene powder was ZHF-6 type reinforced graphene from Xiamen Zhuohaofeng Co., Ltd. It should be noted that the above-mentioned substances are only for better illustrating the technical method of the present invention, and are not intended to limit it. Each component includes, but is not limited to, the above-mentioned substances.
[0044] Example 1 This embodiment provides a low-dielectric glass fiber impregnating agent in the first aspect, which is obtained by mixing low molecular weight epoxy emulsion, high molecular weight epoxy emulsion, low molecular weight polypropylene emulsion, lubricant (including mineral oil lubricant and ester lubricant), silane coupling agent (main silane coupling agent and auxiliary silane coupling agent), and graphene. The amount of each substance is detailed in Table 1, where the amount of each substance is by mass.
[0045] In a second aspect, this embodiment provides a low-dielectric glass fiber obtained by drying low-dielectric glass fiber precursors coated with the above-mentioned sizing agent (first storing in a dry environment for 24 hours, then drying at 80°C for 90 minutes, at 105°C for 180 minutes, and at 120°C for 180 minutes).
[0046] This embodiment provides a cyanate ester resin-based wave-transparent composite material in a third aspect, which is obtained by impregnating a hollow fabric made of the above-mentioned low dielectric glass fiber with cyanate ester resin, followed by curing and demolding.
[0047] Examples 2-5 and Comparative Examples 1-4 are basically the same as Example 1, except that the composition of the wetting agent is slightly different, as shown in Table 1. The amount of each substance in the table is by mass.
[0048] Table 1. Amounts of each component in the wetting agents of the various embodiments and comparative examples of the present invention The performance data of each embodiment and comparative example of the present invention are shown in Table 2, and the specific test methods are as follows: Fiber performance testing: Combustible content (LOI): According to GB / T9914.2 Test methods for reinforced products Part 2: Determination of combustible content of glass fiber.
[0049] Fiber tensile strength: According to GB / T7690.3 Test methods for reinforcing yarns Part 3: Determination of breaking strength and elongation at break of glass fibers.
[0050] Hairiness: Includes the weight of all hairs generated during friction between the untwisted roving and the abrasion-resistant device, measured in milligrams. The sample is broken by rubbing at multiple points with various friction materials and angles at a constant bending rate, and the hairiness is measured after the process is completed.
[0051] Stiffness test method: The stiffness test is conducted according to the national standard GB / T7690.4-2001.
[0052] Composite material performance testing: Tensile strength: The tensile strength performance of the fiber was tested according to the national standard GB / T20310-2006.
[0053] Flat compressive strength: The flat compressive strength performance of the integral layered hollow fabric was tested in accordance with the national standard GB / T 1453-2022.
[0054] Transmittance test: The transmittance test was conducted in accordance with the national military standard GJB7954-2012.
[0055] Reflectivity test: The reflectivity test was conducted in accordance with the national military standard GJB 2038A-2011.
[0056] Table 2. Performance data of low-dielectric fibers and composite materials in various embodiments and comparative examples of the present invention. As shown in Table 2, the cyanate ester resin-based wave-transparent composite material obtained by combining lubricant-treated low dielectric glass fiber with cyanate ester resin provided in the embodiments of the present invention has both excellent mechanical properties (tensile strength greater than 1785 MPa, compressive strength greater than 8.5 MPa) and wave-transparent properties (wave transmittance greater than 90% in the range of 2~18 GHz, reflectivity less than -5 dB in the range of 14~18 GHz).
[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A glass fiber impregnating agent, characterized in that, The glass fiber impregnating agent comprises the following components in parts by weight: 35-50 parts of low molecular weight epoxy emulsion, wherein the molecular weight of the epoxy resin in the low molecular weight epoxy emulsion is 400-600; 5-15 parts of high molecular weight epoxy emulsion, wherein the molecular weight of the epoxy resin in the high molecular weight epoxy emulsion is 8000-10000; 5-10 parts of low molecular weight polypropylene emulsion, wherein the molecular weight of the polypropylene in the low molecular weight polypropylene emulsion is 2000-3000; 20-25 parts of lubricant; 15-20 parts of silane coupling agent, wherein the silane coupling agent includes a primary silane coupling agent and an auxiliary silane coupling agent, wherein the primary silane coupling agent is a benzyl silane coupling agent, and the auxiliary silane coupling agent is an unsaturated silane coupling agent; and 0.1-0.3 parts of graphene.
2. The glass fiber impregnating agent according to claim 1, characterized in that, The epoxy resin in the low molecular weight epoxy emulsion and the high molecular weight epoxy emulsion is bisphenol A type epoxy resin.
3. The glass fiber impregnating agent according to claim 1, characterized in that, The glass fiber impregnating agent also includes a pH adjuster for adjusting the pH of the glass fiber impregnating agent to 5-7; The pH adjuster is preferably an organic acid, and more preferably one or more of acetic acid, formic acid, succinic acid, boric acid, and citric acid.
4. The glass fiber impregnating agent according to claim 1, characterized in that, The lubricant includes ester-based lubricants and mineral oil-based lubricants; The mass ratio of the ester lubricant to the mineral oil lubricant is 1~3.5:
1.
5. The glass fiber impregnating agent according to claim 1, characterized in that, The mass ratio of the benzyl silane coupling agent to the unsaturated silane coupling agent is 1~8:
1.
6. The glass fiber impregnating agent according to claim 1, characterized in that, The graphene has fewer than 5 layers.
7. The glass fiber impregnating agent according to claim 1, characterized in that, The solid content of the glass fiber impregnating agent is 5-6%.
8. A low-dielectric glass fiber, characterized in that, It is obtained by drying low-dielectric glass fiber precursor coated with the glass fiber sizing agent according to any one of claims 1 to 7.
9. The low-dielectric glass fiber according to claim 8, characterized in that, The drying process includes placing the low-dielectric glass fiber precursor coated with a wetting agent in a dry environment for 8-12 hours, then drying it at 75-85°C for 60-90 minutes, then drying it at 100-110°C for 160-180 minutes, and finally drying it at 115-125°C for 160-180 minutes.
10. A cyanate ester resin-based microwave-transparent composite material, characterized in that, It is obtained by combining the low dielectric glass fiber and cyanate ester resin matrix as described in any one of claims 8-9.