Epoxy resin for carbon fiber part prepreg, preparation method and prepreg

Abstract

The invention provides epoxy resin for a carbon fiber part prepreg, a preparation method of the epoxy resin and the prepreg. The epoxy resin comprises epoxy resin, silicon powder, beta-type silicon carbide whiskers, a curing agent, benzoic acid, butyl glycidyl ether and a coupling agent. In order to better adjust the comprehensive performance of a component, high-purity silicon powder and beta-type silicon carbide whiskers are added into a resin system, the comprehensive mechanical performance of the carbon fiber component prepreg is comprehensively improved, the wear resistance and mechanical performance of a composite material can be remarkably improved, the wear resistance and damping performance of the material are improved, and the service life of the material is prolonged. And the compression strength is improved to 1800 to 2400 MPa from the original 1200 MPa.

Description

Technical Field

[0001] The present invention belongs to the technical field of epoxy resins and relates to an epoxy resin for carbon fiber component prepregs, and in particular to an epoxy resin for carbon fiber component prepregs that comprehensively improves the comprehensive mechanical properties of the carbon fiber component prepregs and can significantly improve the wear resistance and mechanical properties of composite materials, as well as a preparation method and prepreg. Background Art

[0002] The basic components of epoxy resin currently used in carbon fiber component prepregs mainly include epoxy resin matrix (Epoxy Resin) and curing agent (Hardener), and sometimes accelerators, diluents and other functional additives are added.

[0003] The epoxy resin formula used in carbon fiber rim prepreg is usually proprietary. The approximate proportions of the components are as follows: epoxy resin matrix: 50%-70%, curing agent: 30%-50%, accelerator: 1%-3%, diluent: 5%-10%.

[0004] Most carbon fiber prepregs currently used in the market use conventional epoxy resin as the matrix material. While these materials possess certain mechanical properties, they still leave much room for improvement in terms of tensile strength, compressive strength, interlaminar shear strength, and in-plane shear strength. Furthermore, epoxy resin itself is somewhat brittle, making it more likely to break rather than deform when subjected to external forces. Conventional epoxy resin formulations struggle to meet the comprehensive performance requirements of high-performance carbon fiber components, especially when used in extreme environments.

[0005] To overcome the limitations of existing technologies, researchers have been exploring new epoxy resin formulations, hoping to achieve composite materials with even better performance by adjusting the proportions of the various components and adding specific functional additives. However, existing solutions often improve performance in one area at the expense of others, failing to achieve comprehensive optimization and overall improvement. Summary of the Invention

[0006] In response to the deficiencies in the prior art, the present invention proposes an epoxy resin for carbon fiber component prepreg, a preparation method, and a prepreg. The purpose is to comprehensively improve the comprehensive mechanical properties of the carbon fiber component prepreg by optimizing the formula composition and introducing functional additives such as silicon powder and β-silicon carbide whiskers, thereby significantly improving the wear resistance and mechanical properties of the composite material.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention first provides an epoxy resin for carbon fiber component prepreg. The epoxy resin comprises, by weight, 55-70 parts of epoxy resin, 10-25 parts of silicon powder, 10-15 parts of beta-type silicon carbide whiskers and 14.5-22.8 parts of auxiliary agents. The auxiliary agents include a curing agent, an accelerator, a diluent and a coupling agent.

[0009] As a preferred solution of the present invention, the auxiliary agent comprises, by weight, 10-15 parts of modified anhydride curing agent, 3-5 parts of accelerator, 1-2 parts of diluent and 0.5-0.8 parts of silane coupling agent.

[0010] As a preferred embodiment of the present invention, the β-silicon carbide whiskers are pretreated, and the pretreatment comprises the following steps:

[0011] a) Ductile iron treatment;

[0012] b) preparing an acid solution;

[0013] c) immersing the β-silicon carbide whiskers after spherical graphite in an acid solution;

[0014] d) multiple cleanings;

[0015] e) The cleaned β-silicon carbide whiskers are dried and set aside.

[0016] As a preferred embodiment of the present invention, in step a), the spherical ink time is 6 hours; in step b), the acid solution is a 5% hydrochloric acid solution; in step c), the soaking time is ≥ 24 hours; in step e), the drying temperature is 100°C.

[0017] As a preferred embodiment of the present invention, the epoxy resin is E20 bisphenol A epoxy resin.

[0018] As a preferred embodiment of the present invention, the curing agent is a modified acid anhydride.

[0019] As a preferred embodiment of the present invention, the accelerator is benzoic acid and the diluent is butyl glycidyl ether.

[0020] The present invention also provides a method for preparing the epoxy resin for the carbon fiber component prepreg, the preparation method comprising the following steps:

[0021] 1) Weigh epoxy resin, silicon powder, β-silicon carbide whiskers, curing agent, benzoic acid, butyl glycidyl ether, and coupling agent for later use;

[0022] 2) Whisker pretreatment;

[0023] 3) stirring and mixing the epoxy resin and the coupling agent, adding silicon powder and the β-silicon carbide whiskers obtained in step 2), stirring and mixing to obtain a resin system;

[0024] 4) adding a curing agent to the resin system obtained in step 3), stirring and mixing uniformly, then adding benzoic acid and butyl glycidyl ether, stirring and mixing uniformly, and then kneading and vacuum degassing;

[0025] 5) injecting the degassed material from step 4) into a mold and performing a heat curing treatment;

[0026] 6) The cured resin in step 5) is cooled to room temperature, crushed, sieved, and dried to obtain epoxy resin particles for carbon fiber component prepreg.

[0027] As a preferred embodiment of the present invention, in step 4), the resin system after adding the curing agent is stirred and mixed uniformly, then dried and crushed, and then benzoic acid is added, stirred and mixed uniformly, and dried and crushed again, and finally butyl glycidyl ether is added, stirred and mixed uniformly, and then kneaded and vacuum degassed.

[0028] Finally, the present invention provides a carbon fiber component prepreg prepared by impregnating the above-mentioned epoxy resin into carbon fiber.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1) The present invention achieves a comprehensive improvement in the mechanical properties of carbon fiber component prepregs through careful design and optimization of the epoxy resin formula.

[0031] 2) The present invention adds an appropriate amount of high-purity silicon powder and β-silicon carbide whiskers, which significantly improves the mechanical properties of the product, including tensile strength and stiffness, which are crucial for carbon fiber components subjected to high stress conditions and can effectively extend their service life.

[0032] 3) The addition of appropriate amounts of silicon powder and β-silicon carbide whiskers not only improves the material's wear resistance and shock absorption properties, but also increases its compressive strength from the original 1200 MPa to 1800-2400 MPa. This demonstrates that the improved material exhibits greater resistance to pressure, making it suitable for applications requiring high loads. The improved flexural strength also makes the material less susceptible to deformation and damage when subjected to bending moments, maintaining its structural integrity.

[0033] 4) The present invention not only achieves significant progress in single mechanical properties, but more importantly, it achieves a comprehensive improvement in comprehensive performance, so that carbon fiber component prepregs can better adapt to various complex working conditions in practical applications and meet the stringent requirements of high-end fields such as high-performance sports equipment and aerospace. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] The present invention provides an epoxy resin for carbon fiber component prepreg, a preparation method, and the prepreg. The purpose is to comprehensively improve the comprehensive mechanical properties of the carbon fiber component prepreg by optimizing the formula composition and introducing functional additives such as silicon powder and β-type silicon carbide whiskers, thereby significantly improving the wear resistance and mechanical properties of the composite material.

[0036] For applications such as carbon fiber self-propelled components that require light weight and high strength, the present invention selects epoxy resin as the base resin, selects bisphenol A epoxy resin, modified acid anhydride as the curing agent, and benzoic acid as the accelerator to help accelerate the curing reaction; butyl glycidyl ether is selected as the diluent, which has a lower viscosity and can effectively reduce the viscosity of the resin system while participating in the curing reaction; in order to better adjust the comprehensive performance of the components, high-purity silicon powder and β-type silicon carbide whiskers are added to the resin system. Both contain the same silicon element and have good compatibility and adaptability. Among them, high-purity silicon powder as an inorganic filler can form a stable network structure in the cured resin, thereby enhancing the material's resistance to wear and scratches; and β-type silicon carbide whiskers have very high strength and elastic modulus. Adding them to the resin can significantly improve the mechanical properties of the composite material, especially tensile strength and rigidity.

[0037] Furthermore, to evenly disperse the high-purity silicon powder and β-silicon carbide whiskers in the resin system, a silane coupling agent is used as a dispersant to achieve optimal dispersion. Silane coupling agents act as a bridge between the inorganic filler and the organic polymer, improving the interfacial bonding between the two and thus enhancing the filler's dispersion in the matrix. Silane coupling agents can reduce van der Waals forces between the whiskers, reducing agglomeration and thus improving dispersibility. By forming chemical bonds, they strengthen the interfacial bonding between the whiskers and the polymer matrix, enhancing the overall performance of the composite material. All of the above raw materials undergo rigorous screening and pretreatment to remove impurities and ensure the purity of the final product.

[0038] In the present invention, the epoxy resin was purchased from Laizhou Baichen Insulation Material Co., Ltd., and the model was E20 bisphenol A type epoxy resin solid 601.

[0039] Silica powder was purchased from Gansu Yuyang New Materials Co., Ltd., with a model of silica powder (microsilica powder) of 96%.

[0040] β-SiC whiskers were purchased from Bisley New Materials (Suzhou) Co., Ltd., model SFC.

[0041] The modified anhydride curing agent was purchased from Hubei Maidehao Biotechnology Co., Ltd.

[0042] Methylbenzoic acid was purchased from Guangzhou Yulong Chemical Co., Ltd.

[0043] Butyl glycidyl ether was purchased from Shanghai Hongzhuang Chemical Technology Co., Ltd.

[0044] KH-550 silane coupling agent was purchased from Kangjin New Material Technology Co., Ltd.

[0045] Example 1

[0046] The epoxy resin for carbon fiber component prepreg provided in this embodiment comprises, by weight, 60 parts of bisphenol A epoxy resin, 10 parts of silicon powder, 15 parts of β-silicon carbide whiskers, 10 parts of modified anhydride curing agent, 3 parts of methyl benzoic acid, 1.5 parts of butyl glycidyl ether, and 0.5 parts of KH-550 silane coupling agent.

[0047] Prepared by the following method:

[0048] (1) Raw material preparation: Prepare the required resin, high-purity silicon powder, β-silicon carbide whiskers, and other additives. Weigh each ingredient according to the formula to ensure the correct ratio.

[0049] (2) Whisker pretreatment:

[0050] 1. Ball milling: placing the whiskers in a ball mill for long-term mechanical grinding helps break up whisker agglomerations and improve their dispersion.

[0051] 2. Prepare acid solution: Prepare 5% hydrochloric acid solution.

[0052] 3. Soaking treatment: Soak the whiskers in hydrochloric acid solution for not less than 24 hours.

[0053] 4. Cleaning: After soaking, the whiskers need to be rinsed with deionized water several times to remove residual acid.

[0054] 5. Drying: Finally, the cleaned whiskers are dried in a drying oven, and the processed whiskers are weighed for later use.

[0055] (3) Premixing stage: Mix bisphenol A epoxy resin and silane coupling agent in proportion and use high-speed stirring equipment to ensure that the two materials are fully in contact and evenly dispersed.

[0056] (4) Adding high-purity silicon powder and β-silicon carbide whiskers: Add the weighed β-silicon carbide whiskers and silicon powder to the premixed resin system. Use a high-speed stirring device to mix the above materials evenly to form a uniformly dispersed system. The post-addition of β-silicon carbide whiskers can promote the adsorption of the silane coupling agent during the mixing process with the resin.

[0057] (5) Adding curing agent: Add curing agent modified anhydride to the above resin mixture in proportion, and use a mechanical stirrer to stir to ensure that the curing agent is evenly dispersed in the resin system. At the same time, care should be taken to avoid introducing too many bubbles during stirring.

[0058] (6) Addition of functional additives: Benzoic acid and butyl glycidyl ether are then added in proportion. Each additive needs to be dried and crushed before being added to ensure its uniform distribution in the system. Functional additives should be classified and added gradually. After each additive is added, it should be fully stirred to ensure that each additive is evenly dispersed in the resin system.

[0059] (7) Mixing and degassing: After all raw materials are fully mixed, vacuum degassing treatment is performed to eliminate bubbles that may be generated during the mixing process and ensure the density of the final material.

[0060] (8) Molding and curing: The degassed material is injected into the mold and placed in a curing oven for thermal curing.

[0061] (9) Cooling: Cool the cured resin to room temperature to prevent the resin from decomposing due to high temperature.

[0062] (10) Crushing: Use crushing equipment to break the solidified resin into small particles for subsequent processing.

[0063] (11) Screening: Resin particles of different particle sizes are classified through screening equipment to meet different application requirements.

[0064] (12) Drying: Place the sieved resin particles in a drying oven to remove moisture and other volatile substances, thereby improving the stability and shelf life of the resin.

[0065] Finally, a carbon fiber component prepreg is prepared by using the epoxy resin.

[0066] Comparative Example 1

[0067] The epoxy resin provided in this comparative example comprises, by weight, 60 parts of bisphenol A epoxy resin, 25 parts of silicon powder, 10 parts of modified anhydride curing agent, 3 parts of methyl benzoic acid, 1.5 parts of butyl glycidyl ether, and 0.5 parts of KH-550 silane coupling agent.

[0068] Prepared by the following method:

[0069] (1) Raw material preparation: Prepare the required resin, high-purity silicon powder, β-silicon carbide whiskers, and other additives. Weigh each ingredient according to the formula to ensure the correct ratio.

[0070] (2) Whisker pretreatment:

[0071] 1. Ball milling: placing the whiskers in a ball mill for long-term mechanical grinding helps break up whisker agglomerations and improve their dispersion.

[0072] 2. Prepare acid solution: Prepare 5% hydrochloric acid solution.

[0073] 3. Soaking treatment: Soak the whiskers in hydrochloric acid solution for not less than 24 hours.

[0074] 4. Cleaning: After soaking, the whiskers need to be rinsed with deionized water several times to remove residual acid.

[0075] 5. Drying: Finally, the cleaned whiskers are dried in a drying oven, and the processed whiskers are weighed for later use.

[0076] (3) Premixing stage: Mix bisphenol A epoxy resin and silane coupling agent in proportion and use high-speed stirring equipment to ensure that the two materials are fully in contact and evenly dispersed.

[0077] (4) Adding high-purity silicon powder and β-silicon carbide whiskers: Add the weighed β-silicon carbide whiskers and silicon powder to the premixed resin system. Use a high-speed stirring device to mix the above materials evenly to form a uniformly dispersed system. The post-addition of β-silicon carbide whiskers can promote the adsorption of the silane coupling agent during the mixing process with the resin.

[0078] (5) Adding curing agent: Add curing agent modified anhydride to the above resin mixture in proportion, and use a mechanical stirrer to stir to ensure that the curing agent is evenly dispersed in the resin system. At the same time, care should be taken to avoid introducing too many bubbles during stirring.

[0079] (6) Addition of functional additives: Benzoic acid and butyl glycidyl ether are then added in proportion. Each additive needs to be dried and crushed before being added to ensure its uniform distribution in the system. Functional additives should be classified and added gradually. After each additive is added, it should be fully stirred to ensure that each additive is evenly dispersed in the resin system.

[0080] (7) Mixing and degassing: After all raw materials are fully mixed, vacuum degassing treatment is performed to eliminate bubbles that may be generated during the mixing process and ensure the density of the final material.

[0081] (8) Molding and curing: The degassed material is injected into the mold and placed in a curing oven for thermal curing.

[0082] (9) Cooling: Cool the cured resin to room temperature to prevent the resin from decomposing due to high temperature.

[0083] (10) Crushing: Use crushing equipment to break the solidified resin into small particles for subsequent processing.

[0084] (11) Screening: Resin particles of different particle sizes are classified through screening equipment to meet different application requirements.

[0085] (12) Drying: Place the sieved resin particles in a drying oven to remove moisture and other volatile substances, thereby improving the stability and shelf life of the resin.

[0086] Finally, a carbon fiber component prepreg is prepared by using the epoxy resin.

[0087] Comparative Example 2

[0088] The epoxy resin provided in this comparative example comprises, by weight, 60 parts of bisphenol A epoxy resin, 25 parts of β-silicon carbide whiskers, 10 parts of modified anhydride curing agent, 3 parts of methyl benzoic acid, 1.5 parts of butyl glycidyl ether, and 0.5 parts of KH-550 silane coupling agent.

[0089] Prepared by the following method:

[0090] (1) Raw material preparation: Prepare the required resin, high-purity silicon powder, β-silicon carbide whiskers, and other additives. Weigh each ingredient according to the formula to ensure the correct ratio.

[0091] (2) Whisker pretreatment:

[0092] 1. Ball milling: placing the whiskers in a ball mill for long-term mechanical grinding helps break up whisker agglomerations and improve their dispersion.

[0093] 2. Prepare acid solution: Prepare 5% hydrochloric acid solution.

[0094] 3. Soaking treatment: Soak the whiskers in hydrochloric acid solution for not less than 24 hours.

[0095] 4. Cleaning: After soaking, the whiskers need to be rinsed with deionized water several times to remove residual acid.

[0096] 5. Drying: Finally, the cleaned whiskers are dried in a drying oven, and the processed whiskers are weighed for later use.

[0097] (3) Premixing stage: Mix bisphenol A epoxy resin and silane coupling agent in proportion and use high-speed stirring equipment to ensure that the two materials are fully in contact and evenly dispersed.

[0098] (4) Adding high-purity silicon powder and β-silicon carbide whiskers: Add the weighed β-silicon carbide whiskers and silicon powder to the premixed resin system. Use a high-speed stirring device to mix the above materials evenly to form a uniformly dispersed system. The post-addition of β-silicon carbide whiskers can promote the adsorption of the silane coupling agent during the mixing process with the resin.

[0099] (5) Adding curing agent: Add curing agent modified anhydride to the above resin mixture in proportion, and use a mechanical stirrer to stir to ensure that the curing agent is evenly dispersed in the resin system. At the same time, care should be taken to avoid introducing too many bubbles during stirring.

[0100] (6) Addition of functional additives: Benzoic acid and butyl glycidyl ether are then added in proportion. Each additive needs to be dried and crushed before being added to ensure its uniform distribution in the system. Functional additives should be classified and added gradually. After each additive is added, it should be fully stirred to ensure that each additive is evenly dispersed in the resin system.

[0101] (7) Mixing and degassing: After all raw materials are fully mixed, vacuum degassing treatment is performed to eliminate bubbles that may be generated during the mixing process and ensure the density of the final material.

[0102] (8) Molding and curing: The degassed material is injected into the mold and placed in a curing oven for thermal curing.

[0103] (9) Cooling: Cool the cured resin to room temperature to prevent the resin from decomposing due to high temperature.

[0104] (10) Crushing: Use crushing equipment to break the solidified resin into small particles for subsequent processing.

[0105] (11) Screening: Resin particles of different particle sizes are classified through screening equipment to meet different application requirements.

[0106] (12) Drying: Place the sieved resin particles in a drying oven to remove moisture and other volatile substances, thereby improving the stability and shelf life of the resin.

[0107] Finally, a carbon fiber component prepreg is prepared by using the epoxy resin.

[0108] In Comparative Example 3, a carbon fiber component prepreg was prepared by using a traditional epoxy resin.

[0109] The carbon fiber component prepreg prepared in Example 1 and the carbon fiber component prepregs of Comparative Examples 1-3 were tested for their tensile strength, compressive strength, flexural strength, wear resistance and damping coefficient. The results are shown in Table 1.

[0110] Table 1. Performance data

[0111]

[0112] As can be seen from Table 1, the present invention adds an appropriate amount of high-purity silicon powder and β-silicon carbide whiskers, which significantly improves the mechanical properties of the product, including tensile strength and stiffness, which are crucial for carbon fiber components subjected to high stress conditions and can effectively extend their service life.

[0113] The addition of appropriate amounts of silicon powder and β-silicon carbide whiskers not only improves the material's wear resistance and shock absorption properties, but also increases its compressive strength from the original 1200 MPa to 1800-2400 MPa. This demonstrates that the improved material exhibits greater resistance to pressure, making it suitable for applications requiring high loads. Increased flexural strength also reduces deformation and damage when subjected to bending moments, maintaining structural integrity.

[0114] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An epoxy resin for carbon fiber component prepreg, characterized in that: The epoxy resin comprises, by weight, 55-70 parts of epoxy resin, 10-25 parts of silicon powder, 10-15 parts of beta-type silicon carbide whiskers and 14.5-22.8 parts of auxiliary agents, wherein the auxiliary agents include a curing agent, an accelerator, a diluent and a coupling agent.

2. The epoxy resin for carbon fiber component prepreg according to claim 1, characterized in that: The auxiliary agent comprises 10-15 parts of curing agent, 3-5 parts of accelerator, 1-2 parts of diluent and 0.5-0.8 parts of coupling agent in parts by weight.

3. The epoxy resin for carbon fiber component prepreg according to claim 1, characterized in that: The β-silicon carbide whiskers are pretreated, and the pretreatment comprises the following steps: a) Ductile iron treatment; b) preparing an acid solution; c) immersing the β-silicon carbide whiskers after spherical graphite in an acid solution; d) multiple cleanings; e) The cleaned β-silicon carbide whiskers are dried and set aside.

4. The epoxy resin for carbon fiber component prepreg according to claim 3, characterized in that: In step a), the spherical ink time is 6 hours; in step b), the acid solution is a hydrochloric acid solution with a concentration of 5%; in step c), the soaking time is ≥ 24 hours; in step e), the drying temperature is 100°C.

5. The epoxy resin for carbon fiber component prepreg according to claim 1, characterized in that: The epoxy resin is E20 bisphenol A type epoxy resin.

6. The epoxy resin for carbon fiber component prepreg according to claim 1, characterized in that: The curing agent is a modified acid anhydride.

7. The epoxy resin for carbon fiber component prepreg according to any one of claims 1 to 6, characterized in that: The accelerator is benzoic acid and the diluent is butyl glycidyl ether.

8. A method for preparing an epoxy resin for carbon fiber component prepreg according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: 1) Weigh epoxy resin, silicon powder, β-silicon carbide whiskers, curing agent, benzoic acid, butyl glycidyl ether, and coupling agent for later use; 2) Whisker pretreatment; 3) stirring and mixing the epoxy resin and the coupling agent, adding silicon powder and the β-silicon carbide whiskers obtained in step 2), stirring and mixing to obtain a resin system; 4) adding a curing agent to the resin system obtained in step 3), stirring and mixing uniformly, then adding benzoic acid and butyl glycidyl ether, stirring and mixing uniformly, and then kneading and vacuum degassing; 5) injecting the degassed material from step 4) into a mold and performing a heat curing treatment; 6) The cured resin in step 5) is cooled to room temperature, crushed, sieved, and dried to obtain epoxy resin particles for carbon fiber component prepreg.

9. The method for preparing an epoxy resin for carbon fiber component prepreg according to claim 8, characterized in that: In step 4), the resin system after adding the curing agent is stirred and mixed uniformly, then dried and crushed, and then benzoic acid is added, stirred and mixed uniformly, and dried and crushed again, and finally butyl glycidyl ether is added, stirred and mixed uniformly, and then kneaded and vacuum degassed.

10. A carbon fiber component prepreg, characterized in that: The carbon fiber component prepreg is prepared by impregnating carbon fiber with the epoxy resin described in any one of claims 1 to 7 or the epoxy resin obtained by the preparation method described in any one of claims 8 to 9.

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