Special impregnating compound for basalt fiber reinforced epoxy resin as well as preparation method and application of impregnating compound

Abstract

The invention discloses a special impregnating compound for basalt fiber reinforced epoxy resin as well as a preparation method and application of the special impregnating compound. Raw materials for forming the impregnating compound comprise the following components in percentage by mass: 0.4-0.8% of a silane coupling agent, a mixture of an epoxy silane coupling agent and an amino silane coupling agent, 8-16% of a film-forming agent, a film-forming agent selected from an epoxy resin emulsion, an epoxy equivalent of 400-1000g / equivalent, and the balance of water. The solid content is 20-50 wt%, the lubricant is 0.8-1.45%, the pH regulator is 0.08-0.16%, and the balance is water; and the solid content of the impregnating compound is 5-7wt%. The impregnating compound is specially used for basalt fiber reinforced epoxy resin, the problem of poor bonding property of basalt fiber and epoxy resin is well solved, and the mechanical property of a basalt fiber reinforced epoxy resin composite material can be improved.

Description

Technical Field

[0001] This invention relates to the field of basalt fiber impregnating agents. More specifically, it relates to a special impregnating agent for basalt fiber reinforced epoxy resin, its preparation method, and its application. Background Technology

[0002] Basalt fiber is a continuous fiber produced by melting basalt rock at a high temperature of approximately 1450℃ to 1500℃ and then drawing it at high speed through a platinum-rhodium alloy spinneret. Basalt fiber not only boasts high mechanical strength but also possesses excellent comprehensive properties such as high-temperature resistance, corrosion resistance, electrical insulation, and flame resistance. Furthermore, its production process requires no addition of new components and generates no wastewater, waste gas, waste residue, or toxic substances, making it a resource-saving and environmentally friendly material. It holds promise as a replacement for glass fiber as a reinforcement in composite materials, with applications in aerospace, construction, transportation, energy conservation and environmental protection, and petrochemical industries.

[0003] Epoxy resin is a class of polymers containing two or more epoxy groups in its molecule. It possesses numerous advantages, including easy curing, excellent mechanical properties, good insulation, low shrinkage, and good durability, making it one of the most commonly used resin materials. Composite materials using epoxy resin as the matrix and basalt fiber as the reinforcement are a promising material with applications in wind turbine blades, aircraft fuselages, vehicle and ship bodies, and building exteriors. In particular, it can serve as a primary raw material for large offshore wind turbine blades, leveraging its low cost, high performance, and ideal cleanliness to reduce blade manufacturing costs and meet national requirements for wind power development.

[0004] Basalt fiber possesses excellent mechanical properties, with tensile strength surpassing that of aramid and E-glass fiber, reaching a level comparable to S-glass fiber. However, the tensile strength of basalt fiber-reinforced epoxy resin composites is far lower than that of corresponding S-glass fiber and aramid products, only comparable to that of E-glass fiber products. This indicates that the superior mechanical properties of basalt fiber are not fully utilized in polymer-based composites.

[0005] In composite materials, besides the reinforcing phase and the matrix phase, there also exists an interfacial phase between the two phases. The polymer matrix acts as a medium, binding the fibers and giving them a specific shape, while the fibers are the main source of mechanical strength. In this case, the interface plays a crucial role in the mechanical properties of the composite material. An ideal interface can transmit stress, allowing the reinforcing phase to bear larger loads, thus improving the load-bearing capacity of the composite material. It can also inhibit crack propagation, enhance the toughness of the material, and disperse the heat energy from external impacts, improving impact resistance. In basalt fiber reinforced epoxy resin, the mechanical properties of basalt fibers are not fully realized because of the weak interfacial strength. Therefore, surface modification is necessary to enhance the strength of the two-phase interface. Currently, commonly used modification techniques include acid-base etching, plasma treatment, coupling agent modification, grafting nanoparticles, and sizing agent modification. Among these, sizing agent modification is the most frequently used method. This involves coating the fiber surface with a sizing agent coating composed of film-forming agents, coupling agents, lubricants, and antistatic agents. The multi-scale irregular surface caused by the sizing agent can enhance the interaction between basalt fiber and epoxy resin, and can also reduce stress concentration at surface defects by passivating crack tips, thereby improving the fiber's inherent strength. Currently, sizing agent raw material and formulation technology has become a key technology in the field of basalt fiber products and is one of the core competitive advantages for basalt fiber manufacturers to maintain sustainable development.

[0006] Some of the sizing agents that have been disclosed contain nano-silica particles. The formulation process is complicated and there is a problem of nanoparticle agglomeration, so the stability needs to be improved. In addition, both are general-purpose sizing agents and are not specifically for epoxy resins. Therefore, their modification effect needs to be further improved. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a special sizing agent for basalt fiber reinforced epoxy resin, its preparation method, and its application. This sizing agent is specifically designed for basalt fiber reinforced epoxy resin, effectively solving the problem of poor bonding between basalt fiber and epoxy resin, and can improve the mechanical properties of basalt fiber reinforced epoxy resin composites.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] On the one hand, the present invention provides a special sizing agent for basalt fiber reinforced epoxy resin, wherein the raw materials forming the sizing agent contain the following components by weight percentage:

[0010] 0.4-0.8% silane coupling agent, selected from a mixture of epoxy silane coupling agents and amino silane coupling agents;

[0011] 8-16% film-forming agent, selected from epoxy resin emulsion film-forming agents, with an epoxy equivalent of 400-1000 g / equivalent and a solid content of 20-50 wt%;

[0012] 0.8-1.45% lubricant;

[0013] 0.08-0.16% pH adjuster; and

[0014] The remaining water;

[0015] The solid content of the wetting agent is 5-7 wt%.

[0016] Furthermore, the epoxy equivalent of the epoxy resin emulsion film-forming agent includes, but is not limited to, 500-1000 g / equivalent, 500-800 g / equivalent, 700-1000 g / equivalent, 700-800 g / equivalent, 750 g / equivalent, etc.

[0017] Furthermore, the preparation of the epoxy resin emulsion film-forming agent includes the following steps:

[0018] Epoxy acrylate and deionized water are mixed at a mass ratio of 1:1 to 1:3 and stirred until the epoxy acrylate is completely dispersed to obtain a mixture.

[0019] Add the emulsifier (such as polyoxyethylene ethers or phosphates) to the mixture and continue stirring, wherein the mass of the emulsifier is 5-10% of the mass of the epoxy acrylate;

[0020] Using a high-shear mixer, the mixture is stirred at high speed for 5-15 minutes to form an emulsion, thus obtaining the epoxy resin emulsion film-forming agent.

[0021] Furthermore, during the preparation of this epoxy resin emulsion film-forming agent, the rotation speed can be gradually increased to ensure the formation of a uniform emulsion.

[0022] Furthermore, if necessary, the pH of the emulsion can be adjusted to 5-7 using acid or alkali to improve stability.

[0023] Further, cool the emulsion to room temperature and transfer it to a dry, cool container for storage, avoiding direct sunlight and moisture.

[0024] Further, the epoxy equivalent of the epoxy acrylate is 400-1000 g / equivalent. For example, the epoxy equivalent of the epoxy resin emulsion film-forming agent includes, but is not limited to, 500-1000 g / equivalent, 500-800 g / equivalent, 700-1000 g / equivalent, 700-800 g / equivalent, 750 g / equivalent, etc.

[0025] Furthermore, the silane coupling agent is a mixture of epoxy-based silane coupling agent and amino-based silane coupling agent at a mass ratio of 1:(3-7). By selecting the type and dosage of the silane coupling agent, the resulting wetting agent is more suitable for basalt fiber reinforced epoxy resin composites, and the resulting composite material has excellent mechanical properties (tensile strength, flexural strength, interlaminar shear strength, and interfacial shear strength, etc.).

[0026] Furthermore, the silane coupling agent is a mixture of an epoxy silane coupling agent and an amino silane coupling agent in a mass ratio of 1:(3-6), 1:(6-7), 1:(5-6), 1:3, 1:6, or 1:7.

[0027] Furthermore, the silane coupling agent is a mixture of an epoxy-based silane coupling agent and an amino-based silane coupling agent in a mass ratio of 1:6. In this case, the aforementioned effects are even better.

[0028] Furthermore, the epoxy silane coupling agent is selected from A187 and / or A1871.

[0029] Furthermore, the aminosilane is selected from polyamide silane.

[0030] Furthermore, the aminosilane coupling agent is selected from one or more of A1100, A1110, and A1120.

[0031] Furthermore, the lubricant is selected from a mixture of nonionic and cationic lubricants in a mass ratio of (12-15):1. The nonionic lubricant reduces friction between basalt fiber monofilaments, preventing fiber damage during production; the presence of the cationic lubricant further enhances the wear resistance of the basalt fibers, similarly protecting them from damage. By selecting the type and dosage of lubricant, the resulting impregnating agent is more suitable for basalt fiber reinforced epoxy resin composites, further improving the mechanical properties of the composite material (tensile strength, flexural strength, interlaminar shear strength, and interfacial shear strength, etc.). For example, the lubricant is selected from a mixture of nonionic and cationic lubricants in a mass ratio of (12-14):1, (12.5-13.5):1, 12.5:1, or 13.125:1.

[0032] Furthermore, the nonionic lubricant is selected from one or more of polyoxyethylene ether lubricants, amide lubricants, and ester lubricants.

[0033] Furthermore, the cationic lubricant is selected from polyoxyethylene amine salt lubricants and / or imidazoline lubricants.

[0034] In the technical solution of this invention, an epoxy resin film-forming agent with a specific epoxy equivalent can improve the compatibility between basalt fiber and epoxy resin. At the same time, it can effectively reduce stress concentration at surface defects by filling cracks, thereby improving the strength of the fiber. In addition, it also has the function of promoting monofilament bundling and avoiding fiber breakage and scattering.

[0035] Furthermore, the epoxy resin emulsion film-forming agent is an epoxy acrylate film-forming agent.

[0036] Furthermore, the preparation of the epoxy resin emulsion film-forming agent includes the following steps:

[0037] Epoxy acrylate and deionized water are mixed in a mass ratio of 1:1 to 1:3 and stirred until the resin is completely dispersed to obtain a mixture.

[0038] Add the emulsifier (polyoxyethylene ether or phosphate) to the mixture and continue stirring. The mass of the emulsifier is 5-10% of the mass of the epoxy acrylate.

[0039] Using a high-shear mixer, the mixture is stirred at high speed for 5-15 minutes to form an emulsion, thus obtaining the epoxy resin emulsion film-forming agent.

[0040] During the preparation of this epoxy resin emulsion film-forming agent, the rotation speed can be gradually increased to ensure the formation of a uniform emulsion.

[0041] If necessary, adjust the pH of the emulsion to 5-7 using acid or alkali to improve stability.

[0042] Cool the emulsion to room temperature and transfer it to a dry, cool container for storage, avoiding direct sunlight and moisture.

[0043] Furthermore, the pH adjuster is selected from a mixture of citric acid and boric acid in a mass ratio of 1:(0.8-1.2).

[0044] Furthermore, the pH adjuster is selected from a mixture of citric acid and boric acid in a mass ratio of 1:1.

[0045] Furthermore, the raw materials forming the wetting agent, by weight percentage, contain the following components:

[0046] 0.7% silane coupling agent, selected from a mixture of aminosilane coupling agent and epoxysilane coupling agent in a mass ratio of 6:1;

[0047] 13.6% film-forming agent;

[0048] 1.13% of the lubricant is selected from a mixture of nonionic and cationic lubricants in a mass ratio of 1.05:0.08;

[0049] 0.12% pH adjuster, selected from a 1:1 mass ratio of citric acid and boric acid; and

[0050] The remainder is water.

[0051] In another aspect, the present invention provides a method for preparing the wetting agent as described above, the method comprising the following steps:

[0052] Under the conditions of pH film-forming agent and water, epoxy silane coupling agent and amino silane coupling agent were hydrolyzed respectively to obtain hydrolyzed epoxy silane coupling agent and hydrolyzed amino silane coupling agent.

[0053] The film-forming agent and the lubricant were diluted with water to obtain aqueous solutions of the film-forming agent and the lubricant, respectively.

[0054] Hydrolyzed aminosilane coupling agent, aqueous solution of lubricant, aqueous solution of film-forming agent, pH adjuster, hydrolyzed epoxysilane coupling agent, and water are added sequentially to water and mixed to obtain the wetting agent.

[0055] Furthermore, the preparation method includes the following steps:

[0056] In the presence of citric acid and water, epoxy-based silane coupling agents and amino-based silane coupling agents were hydrolyzed respectively to obtain hydrolyzed epoxy-based silane coupling agents and hydrolyzed amino-based silane coupling agents.

[0057] The film-forming agent and the lubricant were diluted with water to obtain aqueous solutions of the film-forming agent and the lubricant, respectively.

[0058] Hydrolyzed aminosilane coupling agent, aqueous solution of lubricant, aqueous solution of film-forming agent, boric acid, hydrolyzed epoxysilane coupling agent, and the balance water are added sequentially to water and mixed well to obtain the wetting agent.

[0059] In another aspect, the present invention provides the use of the as-described impregnating agent in basalt fiber reinforced epoxy resin.

[0060] Furthermore, the application includes the following steps:

[0061] A sizing agent is coated on the surface of basalt fiber to obtain basalt fiber with a sizing agent coating on the surface;

[0062] The basalt fibers with a wetting agent coating on their surface are mixed with epoxy resin, heated and molded, and then cooled to room temperature to obtain a basalt fiber reinforced epoxy resin composite material.

[0063] Further, the coating wetting agent includes the following steps:

[0064] The sizing agent is coated onto the surface of the basalt fiber to form a sizing agent coating.

[0065] The basalt fiber coated with the sizing agent is mixed with epoxy resin solution, heated to form a mold, and cooled to room temperature to obtain a basalt fiber reinforced epoxy resin composite material.

[0066] Furthermore, the mass of the sizing agent is 0.8-1.2% of the mass of the basalt fiber.

[0067] Furthermore, in the composite material, the mass percentage of basalt fiber with the sizing agent coating is 50-70%, preferably 60%.

[0068] Furthermore, the molding method is a vacuum bag pressure assisted molding method.

[0069] Furthermore, the method for coating the basalt fiber surface with a sizing agent to form a sizing agent coating includes the following steps:

[0070] Basalt fibers are impregnated in a sizing agent for 5-12 seconds, and then cured in an oven at 80-120℃ for 1-3 hours.

[0071] The beneficial effects of this invention are as follows:

[0072] This invention provides a novel sizing agent. Compared with the prior art, basalt fibers treated with this sizing agent have better compatibility with epoxy resin, higher interfacial bonding strength, and the resulting basalt fiber reinforced epoxy resin has superior mechanical properties. In addition, the raw material components of this sizing agent are readily available, the preparation method is simple, the stability is good, and it can be produced on a large scale. Attached Figure Description

[0073] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0074] Figure 1 This illustrates an exemplary basalt fiber wetting agent coating process in an embodiment of the present invention.

[0075] Figure 2 SEM images of the fracture morphology of basalt fiber reinforced epoxy resin composites modified with a general sizing agent or the sizing agent of Example 1 at different magnifications are shown.

[0076] Figure 3 SEM images of the fracture morphology of short beam shear tests using either a general sizing agent or the sizing agent of Example 1 are shown at different magnifications. Detailed Implementation

[0077] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0078] Example 1

[0079] A basalt fiber reinforced epoxy resin sizing agent, based on a total weight of 100 kg, comprises the following components:

[0080] 0.7 kg of silane coupling agent, including 0.6 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.1 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%).

[0081] 13.6 kg of film-forming agent, selected from epoxy resin emulsion film-forming agent: epoxy acrylate film-forming agent, epoxy equivalent is 750 g / equivalent, solid content is 30 wt%;

[0082] 1.13 kg of lubricant, including 1.05 kg of nonionic lubricant (PEG400MONO (Emerest 2640), solid content 100 wt%) and 0.08 kg of cationic lubricant (polyoxyethylene amine salt, brand name Emery 6760L, solid content 65 wt%).

[0083] 0.12 kg of pH adjuster, comprising 0.06 kg of citric acid and 0.06 kg of boric acid; and

[0084] The remaining water.

[0085] The preparation of the above-mentioned film-forming agent includes the following steps:

[0086] Mix 100g of epoxy acrylate (epoxy equivalent of 750g / equivalent) with 150g of deionized water and stir gently for 5 minutes to ensure even dispersion;

[0087] Add 10g of polyoxyethylene ether (TWEEN 20) and continue stirring for 10 minutes until the emulsifier is completely dissolved;

[0088] Using a high-shear mixer, set the speed to 3000 rpm and stir for 15 minutes until a homogeneous emulsion is formed.

[0089] Adjust the pH of the emulsion to 6.5-7.0 using diluted sodium hydroxide or acetic acid;

[0090] Cool the emulsion to room temperature, then transfer it to a sealed container for storage, away from light and in a cool place.

[0091] The preparation method of this basalt fiber reinforced epoxy resin special impregnating agent includes the following steps:

[0092] (1) Add 0.05 kg of citric acid to 19.5 kg of purified water, mix well, and then slowly add 0.6 kg of polyamide silane while stirring. Stir for 30 min until the solution is clear.

[0093] (2) Add 0.01 kg of citric acid to 1.6 kg of purified water, mix well, and then slowly add 0.1 kg of γ-glycidoxypropyltrimethoxysilane while stirring. Stir for 20 min until the solution is clear.

[0094] (3) Measure 13.6 kg of epoxy resin emulsion film-forming agent, add 27.2 kg of purified water, stir thoroughly and mix evenly;

[0095] (4) Measure 1.05 kg of PEG400MONO, add 21 kg of purified water at 45°C, stir thoroughly and mix evenly;

[0096] (5) Measure 0.08 kg of polyoxyethylene amine salt, add 1.04 kg of pure water at 45°C, stir thoroughly and mix evenly;

[0097] (6) Add 10kg of purified water, hydrolyzed polyamide silane, diluted PEG400MONO, diluted polyoxyethylene amine salt, diluted epoxy resin emulsion film-forming agent, 0.06kg of boric acid, and hydrolyzed γ-glycidyl etheroxypropyltrimethoxysilane to the container in sequence, and finally add the remaining water to make the total weight reach 100kg.

[0098] Example 2

[0099] A basalt fiber reinforced epoxy resin sizing agent, based on a total weight of 100 kg, comprises the following components:

[0100] 0.8 kg of silane coupling agent, including 0.6 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.2 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%).

[0101] 13.6 kg of film-forming agent, selected from epoxy resin emulsion film-forming agent: epoxy acrylate film-forming agent, epoxy equivalent is 750 g / equivalent, solid content is 30 wt%;

[0102] 1.13 kg of lubricant, including 1.05 kg of nonionic lubricant (PEG400MONO (Emerest 2640), solid content 100 wt%) and 0.08 kg of cationic lubricant (polyoxyethylene amine salt, brand name Emery 6760L, solid content 65 wt%).

[0103] 0.16 kg of pH adjuster, comprising 0.08 kg of citric acid and 0.08 kg of boric acid; and

[0104] The remaining water.

[0105] The preparation method of this basalt fiber reinforced epoxy resin special impregnating agent includes the following steps:

[0106] (1) Add 0.05 kg of citric acid to 19.5 kg of purified water, mix well, and then slowly add 0.6 kg of polyamide silane while stirring. Stir for 30 min until the solution is clear.

[0107] (2) Add 0.03 kg of citric acid to 3.2 kg of purified water, mix well, and then slowly add 0.2 kg of γ-glycidoxypropyltrimethoxysilane while stirring. Stir for 20 min until the solution is clear.

[0108] (3) Measure 13.6 kg of epoxy resin emulsion film-forming agent, add 27.2 kg of purified water, stir thoroughly and mix evenly;

[0109] (4) Measure 1.05 kg of PEG400MONO, add 21 kg of purified water at 45°C, stir thoroughly and mix evenly;

[0110] (5) Measure 0.08 kg of polyoxyethylene amine salt, add 1.04 kg of pure water at 45°C, stir thoroughly and mix evenly;

[0111] (6) Add 10kg of purified water, hydrolyzed polyamide silane, diluted PEG400MONO, diluted polyoxyethylene amine salt, diluted epoxy resin emulsion film-forming agent, 0.08kg of boric acid, and hydrolyzed γ-glycidyl etheroxypropyltrimethoxysilane to the container in sequence, and finally add the remaining water to make the total weight reach 100kg.

[0112] Example 3

[0113] A basalt fiber reinforced epoxy resin sizing agent, based on a total weight of 100 kg, comprises the following components:

[0114] 0.8 kg of silane coupling agent, including 0.7 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.1 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%).

[0115] 13.6 kg of film-forming agent, selected from epoxy resin emulsion film-forming agent: epoxy acrylate film-forming agent, epoxy equivalent is 750 g / equivalent, solid content is 30 wt%;

[0116] 1.13 kg of lubricant, including 1.05 kg of nonionic lubricant (PEG400MONO (Emerest 2640), solid content 100 wt%) and 0.08 kg of cationic lubricant (polyoxyethylene amine salt, brand name Emery 6760L, solid content 65 wt%).

[0117] 0.16 kg of pH adjuster, comprising 0.08 kg of citric acid and 0.08 kg of boric acid; and

[0118] The remaining water.

[0119] The preparation method of this basalt fiber reinforced epoxy resin special impregnating agent includes the following steps:

[0120] (1) Add 0.07 kg of citric acid to 22.75 kg of purified water, mix well, and then slowly add 0.7 kg of polyamide silane while stirring. Stir for 30 min until the solution is clear.

[0121] (2) Add 0.01 kg of citric acid to 1.6 kg of purified water, mix well, and then slowly add 0.1 kg of γ-glycidoxypropyltrimethoxysilane while stirring. Stir for 20 min until the solution is clear.

[0122] (3) Measure 13.6 kg of epoxy resin emulsion film-forming agent, add 27.2 kg of purified water, stir thoroughly and mix evenly;

[0123] (4) Measure 1.05 kg of PEG400MONO, add 21 kg of purified water at 45°C, stir thoroughly and mix evenly;

[0124] (5) Measure 0.08 kg of polyoxyethylene amine salt, add 1.04 kg of pure water at 45°C, stir thoroughly and mix evenly;

[0125] (6) Add 10kg of purified water, hydrolyzed polyamide silane, diluted PEG400MONO, diluted polyoxyethylene amine salt, diluted epoxy resin emulsion film-forming agent, 0.08kg of boric acid, and hydrolyzed γ-glycidyl etheroxypropyltrimethoxysilane to the container in sequence, and finally add the remaining water to make the total weight reach 100kg.

[0126] Example 4

[0127] A basalt fiber reinforced epoxy resin sizing agent, based on a total weight of 100 kg, comprises the following components:

[0128] 0.7 kg of silane coupling agent, including 0.6 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.1 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%).

[0129] 13.1 kg of film-forming agent, selected from epoxy resin emulsion film-forming agent: epoxy acrylate film-forming agent, epoxy equivalent is 750 g / equivalent, solid content is 30 wt%;

[0130] 1.13 kg of lubricant, including 1.05 kg of nonionic lubricant (PEG400MONO (Emerest 2640), solid content 100 wt%) and 0.08 kg of cationic lubricant (polyoxyethylene amine salt, brand name Emery 6760L, solid content 65 wt%).

[0131] 0.12 kg of pH adjuster, comprising 0.06 kg of citric acid and 0.06 kg of boric acid; and

[0132] The remaining water.

[0133] The preparation method of this basalt fiber reinforced epoxy resin special impregnating agent includes the following steps:

[0134] (1) Add 0.05 kg of citric acid to 19.5 kg of purified water, mix well, and then slowly add 0.6 kg of polyamide silane while stirring. Stir for 30 min until the solution is clear.

[0135] (2) Add 0.01 kg of citric acid to 1.6 kg of purified water, mix well, and then slowly add 0.1 kg of γ-glycidoxypropyltrimethoxysilane while stirring. Stir for 20 min until the solution is clear.

[0136] (3) Measure 13.1 kg of epoxy resin emulsion film-forming agent, add 26.2 kg of purified water, stir thoroughly and mix evenly;

[0137] (4) Measure 1.05 kg of PEG400MONO, add 21 kg of purified water at 45°C, stir thoroughly and mix evenly;

[0138] (5) Measure 0.08 kg of polyoxyethylene amine salt, add 1.04 kg of pure water at 45°C, stir thoroughly and mix evenly;

[0139] (6) Add 10kg of purified water, hydrolyzed polyamide silane, diluted PEG400MONO, diluted polyoxyethylene amine salt, diluted epoxy resin emulsion film-forming agent, 0.06kg of boric acid, and hydrolyzed γ-glycidyl etheroxypropyltrimethoxysilane to the container in sequence, and finally add the remaining water to make the total weight reach 100kg.

[0140] Example 5

[0141] A basalt fiber reinforced epoxy resin sizing agent, based on a total weight of 100 kg, comprises the following components:

[0142] 0.7 kg of silane coupling agent, including 0.6 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.1 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%).

[0143] 13.6 kg of film-forming agent, selected from epoxy resin emulsion film-forming agents: epoxy acrylate film-forming agent, epoxy equivalent of 750 g / equivalent, solid content of 30 wt%;

[0144] 1.08 kg of lubricant, including 1.00 kg of nonionic lubricant (PEG400MONO (Emerest 2640), solid content 100 wt%) and 0.08 kg of cationic lubricant (polyoxyethylene amine salt, brand name Emery 6760L, solid content 65 wt%).

[0145] 0.12 kg of pH adjuster, comprising 0.06 kg of citric acid and 0.06 kg of boric acid; and

[0146] The remaining water.

[0147] The preparation method of this basalt fiber reinforced epoxy resin special impregnating agent includes the following steps:

[0148] (1) Add 0.05 kg of citric acid to 19.5 kg of purified water, mix well, and then slowly add 0.6 kg of polyamide silane while stirring. Stir for 30 min until the solution is clear.

[0149] (2) Add 0.01 kg of citric acid to 1.6 kg of purified water, mix well, and then slowly add 0.1 kg of γ-glycidoxypropyltrimethoxysilane while stirring. Stir for 20 min until the solution is clear.

[0150] (3) Measure 13.6 kg of epoxy resin emulsion film-forming agent, add 27.2 kg of purified water, stir thoroughly and mix evenly;

[0151] (4) Measure 1.00 kg of PEG400MONO, add 20 kg of purified water at 45℃, stir thoroughly and mix evenly;

[0152] (5) Measure 0.08 kg of polyoxyethylene amine salt, add 1.04 kg of pure water at 45°C, stir thoroughly and mix evenly;

[0153] (6) Add 10kg of purified water, hydrolyzed polyamide silane, diluted PEG400MONO, diluted polyoxyethylene amine salt, diluted epoxy resin emulsion film-forming agent, 0.06kg of boric acid, and hydrolyzed γ-glycidyl etheroxypropyltrimethoxysilane to the container in sequence, and finally add the remaining water to make the total weight reach 100kg.

[0154] Comparative Example 1

[0155] Repeat Example 1, except that the epoxy resin emulsion film-forming agent is replaced with an epoxy resin emulsion film-forming agent with an epoxy equivalent of 350 g / equivalent, while keeping the other conditions unchanged, to obtain the wetting agent.

[0156] Comparative Example 2

[0157] Example 1 was repeated, except that the silane coupling agent consisted of 0.62 kg of aminosilane coupling agent (polyamide silane, solid content of 65 wt%) and 0.08 kg of epoxysilane coupling agent (γ-glycidoxypropyltrimethoxysilane, solid content of 80 wt%), with the other conditions remaining unchanged, to obtain the wetting agent.

[0158] Applications of the impregnating agents prepared in the above embodiments and comparative examples in basalt fiber reinforced epoxy resins:

[0159] 1. Coat the surface of the basalt fiber with a sizing agent:

[0160] The sizing agent is placed in a sizing tank, and then basalt fiber bundles or basalt fiber unidirectional fabric wound on guide rollers are passed sequentially and uniformly through the sizing tank and oven to achieve sizing agent coating and curing. Finally, the fibers are wound and wound onto another guide roller to obtain basalt fibers or basalt fiber unidirectional fabrics with sizing agent coating. The residence time of the basalt fiber bundles or basalt fiber fabrics in the sizing tank is approximately 10 seconds, the oven temperature is 100℃, and the curing time is 2 hours. The specific process is as follows: Figure 1 As shown.

[0161] 2. Preparation and mechanical property testing of basalt fiber reinforced epoxy resin composites:

[0162] The reinforcing effect of the sizing agent was tested by measuring the mechanical strength of the basalt fiber reinforced epoxy resin composite material. The composite material was prepared using a vacuum bag compression molding method. The specific method is as follows:

[0163] 2.1 Preparation of adhesive solution:

[0164] Epoxy resin and amine curing agent are mixed at a mass ratio of 100:30. After stirring evenly, vacuum is applied at room temperature for 20 minutes. The total mass of the resin system is calculated based on the ratio of fiber cloth to resin of 1:1 to obtain epoxy resin solution. At the same time, 500g of resin is weighed out for each square meter of composite material to prevent insufficient resin and for touch-up application.

[0165] 2.2 Material Laying:

[0166] First, apply a layer of release agent to the aluminum alloy heating platform to facilitate subsequent demolding. Then, lay down the following layers in sequence: a lower layer of release cloth, a basalt fiber unidirectional cloth coated with a wetting agent (3 layers for tensile and dynamic thermomechanical samples, 30cm × 16cm in size; 13 layers for bending and shearing samples, 25cm × 10cm in size), an upper layer of release cloth, a flow guide net, and a vacuum bag. Install injection tubes and vacuum tubes at both ends, securing them with vacuum tape. The two rubber tubes should be placed between the two layers of release cloth. Furthermore, the vacuum tube opening should be wrapped with a breathable mesh to prevent blockage.

[0167] 2.3 Resin Introduction:

[0168] Secure the vacuum bag with vacuum tape to form a sealed system between the vacuum bag and the aluminum alloy heating stage. Turn on the vacuum pump, ensuring the system is leak-proof, and then introduce the epoxy resin solution. Once the resin has completely impregnated the fiber cloth and flowed into the vacuum tube, clamp the injection tube and the vacuum tube, heat to 80°C and maintain for 3 hours. Turn off the heating stage and allow the sample to cool naturally to room temperature before demolding to obtain a basalt fiber unidirectional cloth reinforced epoxy resin composite board. The mass fraction of the basalt fiber cloth is approximately 60%.

[0169] 2.4 Mechanical property testing:

[0170] The prepared basalt fiber reinforced epoxy resin composite board was mechanically processed into test strips of different sizes using a universal sample preparation machine.

[0171] (1) Tensile strength test

[0172] The tensile properties of the composite material were tested on a universal testing machine according to ISO 527. The specimen size was 250 mm × 15 mm × 1 mm. Reinforcing sheets were attached to both ends of the specimen using epoxy resin structural adhesive, and the specimen was cured in an oven at 50 °C for 1 hour. The tensile speed during the test was 5 mm·min. -1 .

[0173] (2) Bending strength test

[0174] The flexural properties of the composite material were tested on a universal testing machine according to ISO 178. The specimen size was 80 mm × 10 mm × 4 mm, the span was 64 mm, and the loading rate during the test was 10 mm·min. -1 .

[0175] (3) Interlaminar shear strength test

[0176] The shear properties of the composite material were tested on a universal testing machine according to ISO 14130. The specimen size was 40mm × 20mm × 4mm, the span was 20mm, and the loading rate was 10mm·min during the test. -1 .

[0177] (4) Characterization of fracture morphology

[0178] The fracture morphology of the specimens after bending or interlaminar shear tests was observed using a scanning electron microscope. The sample surface needs to be sputtered with gold before the test.

[0179] (5) Interfacial shear strength test

[0180] The interfacial shear strength of the basalt fiber-epoxy resin microcomposite material was tested using a micro-debonding test. First, test samples were prepared by fixing basalt fiber monofilaments straight onto a paper frame with a central perforation using 502 glue. Resin was prepared, and a needle tip was dipped into the resin and quickly slid it across the fiber monofilament. The resin contracted into small spheres under surface tension. The samples were then cured in an oven at 150°C for 4 hours.

[0181] After preparing the sample, clamp the paper frame in the fixture, adjust the cutter so that it just clamps the resin droplet, and then pull the fiber at a speed of 0.005 mm / s. -1 The fiber can pass through the clamp while the resin cannot, until the droplet slips. The maximum tensile force is recorded, and the interfacial shear strength is calculated.

[0182] Test results:

[0183] The mechanical properties of the sizing agents described in the above embodiments for modifying basalt fiber reinforced epoxy resin are shown in Table 1 below. Specifically, the general-purpose sizing agent refers to the commercially available sizing agent BF826M.

[0184] Table 1

[0185]

[0186] The results of the mechanical properties of the above-mentioned sizing agents used to modify basalt fiber reinforced epoxy resin are shown in Table 2 below.

[0187] Table 2

[0188]

[0189] Figure 2 (a) i ), (a ii The following are SEM images of the fracture morphology of the above-mentioned general-purpose sizing agent modified basalt fiber reinforced epoxy resin composite material at different magnifications in the bending test. Figure 2 (b) i (b) ii The images show SEM images of the fracture morphology of the sizing agent modified basalt fiber reinforced epoxy resin composite material in Example 1 above at different magnifications.

[0190] Figure 3 (a) i ), (a ii The following are SEM images of the fracture morphology of the short beam shear test of the above-mentioned general impregnating agent modified basalt fiber reinforced epoxy resin composite material at different magnifications: Figure 3 (b) i (b) ii The images show SEM images of the fracture morphology of the short beam shear test of the sizing agent modified basalt fiber reinforced epoxy resin composite material in Example 1 above, at different magnifications.

[0191] The SEM results show that the surface of basalt fibers modified with general-purpose sizing agents is relatively smooth, with gaps between the fibers and resin. In contrast, the surface of basalt fibers modified with special-purpose sizing agents has more resin residue, and the fibers and resin are more tightly bonded. This indicates that the modification effect of the special-purpose sizing agent is better, thus improving the interfacial strength.

[0192] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A special-purpose sizing agent for basalt fiber-reinforced epoxy resin, characterized by, The raw materials for forming the infiltrant include the following components by mass percentage: 0.4-0.8% silane coupling agent selected from a mixture of epoxy silane coupling agent and amino silane coupling agent; 8-16% film forming agent selected from epoxy resin emulsion film forming agent, epoxy equivalent weight of 400-1000 g / eq, solid content of 20-50 wt%; 0.8-1.45% lubricant; 0.08-0.16% pH regulator; and the balance being water. The solid content of the infiltrant is 5-7 wt%.

2. The sizing agent according to claim 1, characterized in that, The silane coupling agent is a mixture of epoxy silane coupling agent and amino silane coupling agent in a mass ratio of 1:(3-7).

3. The sizing agent according to claim 1, characterized in that, The silane coupling agent is a mixture of epoxy silane coupling agent and amino silane coupling agent in a mass ratio of 1:(5-6).

4. The impregnating agent according to any one of claims 1 to 3, characterized in that The epoxy silane coupling agent is selected from A187 and / or A1871; and / or The amino silane coupling agent is selected from one or more of A1100, A1110, A1120.

5. The sizing agent of claim 1, wherein The lubricant is selected from a mixture of non-ionic lubricant and cationic lubricant in a mass ratio of (12-15):1; Preferably, the non-ionic lubricant is selected from one or more of polyoxyethylene ether lubricant, amide lubricant and ester lubricant; Preferably, the cationic lubricant is selected from polyoxyethylene amine salt lubricant and / or imidazoline lubricant.

6. The sizing agent of claim 1, wherein The pH regulator is selected from a mixture of citric acid and boric acid in a mass ratio of 1:(0.8-1.2), preferably 1:

1.

7. The sizing agent of claim 1, wherein The raw materials for forming the infiltrant include the following components by mass percentage: 0.7% silane coupling agent selected from a mixture of amino silane coupling agent and epoxy silane coupling agent in a mass ratio of 6:1; 13.6% film forming agent; 1.13% lubricant selected from a mixture of non-ionic lubricant and cationic lubricant in a mass ratio of 1.05:0.08; 0.12% pH regulator selected from a mixture of citric acid and boric acid in a mass ratio of 1:1; and the balance being water.

8. The method of preparing an impregnation according to any one of claims 1 to 7, characterized in that, The steps include: hydrolyzing the epoxy silane coupling agent and the amino silane coupling agent respectively in the presence of pH film forming agent and water to obtain hydrolyzed epoxy silane coupling agent and hydrolyzed amino silane coupling agent; diluting the film forming agent and the lubricant respectively with water to obtain aqueous solution of film forming agent and aqueous solution of lubricant; adding the hydrolyzed amino silane coupling agent, the aqueous solution of lubricant, the aqueous solution of film forming agent, the balance of pH regulator, the hydrolyzed epoxy silane coupling agent and the balance of water to water in sequence, and mixing to obtain the infiltrant.

9. Use of the infiltrant of any one of claims 1-7 in basalt fiber reinforced epoxy resin.

10. Use according to claim 9, characterized in that, The use includes the following steps: coating the infiltrant on the surface of the basalt fiber to form an infiltrant coating; mixing the basalt fiber with the infiltrant coating and epoxy resin glue solution, heating to form, and cooling to room temperature to obtain basalt fiber reinforced epoxy resin composite material; Preferably, the mass of the infiltrant is 0.8-1.2% of the mass of the basalt fiber. Preferably, in the composite material, the mass percentage of basalt fiber to which the sizing agent coating is formed is 50-70%.

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