High-performance brake pad composite material and preparation method thereof

Abstract

The invention discloses a high-performance brake pad composite material and a preparation method thereof. The brake pad composite material is prepared from the following components in parts by weight: 15-30 parts of cashew nut shell oil modified phenolic resin, 6-12 parts of bismaleimide resin, 6-15 parts of modified basalt fiber, 4-10 parts of barium sulfate, 4-10 parts of silicon nitride, 6-9 parts of zircon powder, 3-9 parts of butadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder and 1-4 parts of graphite powder. According to the material, the service life is remarkably prolonged due to the excellent wear resistance and heat dissipation performance, the maintenance frequency is reduced, meanwhile, the material has excellent obdurability balance, burst impact loads can be borne, the stable braking effect can be kept, the vehicle driving safety is greatly improved, and the increasingly stringent requirements of modern high-performance vehicles for a braking system are met.

Description

Technical Field

[0001] The present invention relates to the technical field of brake pads, and in particular to a high-performance brake pad composite material and a preparation method thereof. Background Art

[0002] As a typical application of friction materials, brake pads are key components of vehicle braking systems, and their performance is directly related to driving safety. The working principle of brake pads is to convert kinetic energy into heat energy through the friction between the brake disc (or drum) to achieve vehicle deceleration or stopping. The ideal brake friction material should have a stable friction coefficient, excellent wear resistance, good thermal stability and appropriate thermal conductivity, while also taking into account environmental protection, low noise and other performance requirements.

[0003] Friction materials are usually a complex mixture of multiple components, including binders (resin matrix), reinforcing fibers, friction modifiers and fillers. Binders such as phenolic resin provide matrix support; reinforcing fibers such as basalt fiber and aramid fiber provide mechanical strength; friction modifiers such as graphite and alumina adjust the friction coefficient; fillers such as barium sulfate and zircon powder increase heat capacity and density. These components form high-performance friction materials through complex physical and chemical reactions, and each component has a significant impact on the final performance.

[0004] According to the different compositions, brake pads can be divided into asbestos-based, semi-metal-based, low-metal-based and non-asbestos organic-based types. Asbestos-based brake pads were once widely used due to their good heat resistance and friction properties, but they have been gradually eliminated due to the harm of asbestos to human health. Although semi-metal-based and low-metal-based brake pads have good heat resistance and braking performance, the metal components often lead to increased braking noise and excessive wear on the brake disc. Non-asbestos organic-based brake pads have become a current research hotspot due to their advantages such as environmental protection and low noise, but they still have shortcomings in high temperature performance.

[0005] However, traditional brake pads have many technical defects: first, the high temperature attenuation problem is prominent, and the friction coefficient drops significantly under continuous braking conditions, affecting the braking reliability; second, the wear resistance is insufficient and the service life is short; third, the noise and vibration control is difficult; fourth, the traditional asbestos fiber has health risks, and alternative materials such as steel fiber and copper fiber face increasingly stringent restrictions on environmental regulations. In addition, although metal fiber-reinforced brake pads have good heat resistance, they often cause excessive wear of the mating parts and increased braking noise.

[0006] Friction materials face complex friction interface phenomena during operation, including friction film formation, thermal attenuation, wear mechanisms, etc. The quality of the friction film is crucial to the stability of the friction coefficient, and thermal attenuation caused by material performance degradation at high temperatures is the main factor affecting brake reliability. In addition, different wear mechanisms (such as abrasive wear, adhesive wear, fatigue wear, etc.) have a significant impact on material life and need to be controlled through material composition and structural design.

[0007] In recent years, basalt fiber has attracted attention due to its excellent mechanical properties, heat resistance and environmental protection characteristics. CN107725649A discloses a friction-resistant brake pad and a preparation method thereof; the lining of the brake pad is composed of the following parts by mass: 8-12 parts of basalt fiber, 10-16 parts of black iron oxide, 3-8 parts of mixed fiber, 5-9 parts of calcium carbonate, 2-9 parts of bronze powder, 3-8 parts of calcium hydroxide, 1-7 parts of mica, 0.8-1.4 parts of zinc oxide, 0.9-1.2 parts of rock tar, 0.3-1.5 parts of inert powder material, 1-4 parts of friction performance regulator, and 1-2.4 parts of release agent.

[0008] However, the untreated basalt fiber has poor compatibility with the organic resin matrix interface, insufficient bonding strength, and is difficult to exert its special functions in high-temperature friction environments. The market lacks brake pad composite materials that can simultaneously meet multiple requirements such as high temperature resistance, stable friction coefficient, low noise and long life.

[0009] In the existing technology, single functional modification or simple physical mixing methods can no longer meet the requirements of high-performance brake pads. It is urgent to develop a new composite material system with multifunctional synergy and integrated structure and performance design to solve key technical problems such as high-temperature attenuation, short life, and high noise, and to meet the increasingly stringent performance requirements of modern vehicles for braking systems. Summary of the invention

[0010] In order to address the deficiencies in the prior art, the purpose of the present invention is to provide a high-performance brake pad composite material and a preparation method thereof. The high-performance brake pad composite material of the present invention exhibits excellent thermal stability and anti-fading ability under high temperature, high speed and high load conditions, with a stable friction coefficient and low noise, effectively solving the problem of unstable performance of traditional brake pads under harsh working conditions.

[0011] In order to achieve the above object, the present invention adopts the following technical solution: A high-performance brake pad composite material is prepared from the following components by weight: 15-30 parts of cashew nut shell oil modified phenolic resin, 6-12 parts of bismaleimide resin, 6-15 parts of modified basalt fiber, 4-10 parts of barium sulfate, 4-10 parts of silicon nitride, 6-9 parts of zircon powder, 3-9 parts of butadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder and 1-4 parts of graphite powder.

[0012] Preferably, the method for preparing the modified basalt fiber comprises the following steps: (1) Immerse the basalt fiber in a hydrochloric acid solution, filter, wash until neutral, add it to an ethanol aqueous solution, add KH550, adjust the pH of the system, stir the reaction, filter the product, wash with alcohol, and dry it to obtain an amino fiber; Amination of basalt fiber: The pretreatment process of basalt fiber immersed in hydrochloric acid solution can activate the silicon oxygen structure on the fiber surface and generate more active silanol groups. Then, in ethanol aqueous solution, the three ethoxy groups of KH550 are hydrolyzed under the action of water molecules and pH regulation, and converted into silanol groups to undergo condensation reaction with the hydroxyl groups on the surface of basalt fiber to form a stable Si-O-Si covalent bond, so that the surface of basalt fiber is successfully connected to aminopropyl group, realizing surface amination.

[0013] Preferably, in step (1), the concentration of hydrochloric acid is 3-10 wt %, and the immersion time is 1-2 h; the pH of the system is adjusted to 3.5-5 with acetic acid; and the stirring reaction conditions are 65-80 ° C. and stirring the reaction for 4-7 h.

[0014] Preferably, in step (1), the volume ratio of ethanol to deionized water in the ethanol aqueous solution is 8-9:1-2; and the dosage ratio of basalt fiber, ethanol aqueous solution, and KH550 is 10 g:100-150 mL:1-4 g.

[0015] (2) immersing the amino fiber in DMF, adding [1,1':4',1''-terphenyl]-4,4''-diformaldehyde and glacial acetic acid, stirring to react, filtering, washing, and drying the product to obtain an intermediate fiber; Reaction of aminated fiber with dialdehyde: Under the catalysis of glacial acetic acid, acetic acid first protonates one of the aldehyde carbonyl oxygens in diformaldehyde, enhancing the electrophilicity of the carbon atom. Subsequently, the amino group on the surface of the aminated fiber acts as a nucleophilic reagent to attack the activated aldehyde carbon atom to form an intermediate, which removes a molecule of water after proton transfer to form an imine bond. Each amino group on the surface of the aminated fiber can only react with one aldehyde group, so another unreacted aldehyde group is still retained on the surface of the intermediate fiber after the reaction, and this aldehyde group will participate in the next reaction.

[0016] Preferably, in step (2), the usage ratio of aminocellulose, DMF, [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde and glacial acetic acid is 10 g: 100-120 mL: 2.4-6 g: 0.1-1 mL.

[0017] Preferably, in step (2), the stirring reaction conditions are 45-60° C. and 10-16 h.

[0018] (3) The intermediate fiber is immersed in DMSO, and then 4-phenyl-3-thiosemicarbazide and triethylamine are added, and the reaction is stirred. The product is filtered, washed, and dried to obtain modified basalt fiber.

[0019] Reaction of intermediate fiber with thiosemicarbazide: triethylamine deprotonates the amino group in 4-phenyl-3-thiosemicarbazide, enhances its nucleophilicity, and nucleophilically attacks the aldehyde carbon atom remaining on the surface of the intermediate fiber to form an intermediate, which removes a molecule of water to form a second imine bond. In this reaction, the thiourea group in the 4-phenyl-3-thiosemicarbazide molecule remains intact and is successfully introduced into the surface of the basalt fiber. The selection of alkaline conditions is not only conducive to the reaction, but also protects the thiourea group from the acidic environment and avoids possible side reactions. The final product is a modified basalt fiber with a composite structure containing terphenyl and thiourea groups on the surface.

[0020] Preferably, in step (3), the usage ratio of the intermediate fiber, DMSO, 4-phenyl-3-thiosemicarbazide and triethylamine is 10 g: 100-120 mL: 1-4 g: 0.1-1 mL.

[0021] Preferably, in step (3), the stirring reaction conditions are 60-75° C. for 12-18 hours.

[0022] The present invention also claims protection for a method for preparing the high-performance brake pad composite material, comprising the following steps: mixing the components to obtain a mixture; forming the mixture into a blank by hot pressing; and curing, shaping, and assembling the blank to obtain the high-performance brake pad composite material.

[0023] Preferably, the pressing pressure per unit area of ​​the hot pressing molding is 15-60 MPa, the temperature of the hot pressing molding is 140-170° C.; the temperature of the curing is 200-240° C., and the time is 9-11 hours.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The high-performance brake pad composite material of the present invention achieves excellent comprehensive performance through the synergistic effect of each component. Cashew nut shell oil-modified phenolic resin as the main substrate has good heat resistance and adhesion, while the cashew nut shell oil component gives the material better toughness and elasticity; bismaleimide resin supplements and improves the high temperature stability and durability of the material; modified basalt fiber not only enhances the mechanical strength of the material, but its special structure also improves the friction coefficient and thermal stability; barium sulfate as a filler provides appropriate density and heat capacity, which is conducive to heat absorption and dispersion during braking; silicon nitride and zircon powder as hard fillers significantly improve the wear resistance and thermal decay resistance of the material; butadiene rubber increases the toughness of the material and reduces vibration and noise during braking; aramid pulp provides additional fiber reinforcement, improves the impact resistance and fatigue resistance of the material; graphite powder provides appropriate lubrication effect, and reduces surface wear during braking. The reasonable ratio of these components enables the brake pad to maintain stable friction performance and structural integrity under high temperature, high speed and high load conditions.

[0025] 2. The present invention provides a modified basalt fiber. First, the KH550 coupling agent treatment introduces amino functional groups, which significantly enhances the interfacial bonding between the fiber and the phenolic resin matrix, reduces the interfacial debonding phenomenon, and increases the surface roughness, thereby strengthening the mechanical interlocking effect. Secondly, the introduction of [1,1':4',1''-terphenyl]-4,4''-diformaldehyde provides a rigid skeleton structure, which not only improves the mechanical strength of the composite material, but also forms an effective physical barrier on the fiber surface by its large molecular volume, blocking the chemical substances that may cause the fiber to decompose or oxidize through the steric effect, and protecting the internal structure from being destroyed. In addition, the terphenyl structure changes the electron density distribution on the fiber surface, improves the overall chemical stability, and its polyphenyl ring structure is not easy to decompose or deform at high temperatures, which significantly enhances the heat resistance of the material under extreme conditions. Finally, the grafting of 4-phenyl-3-thiocarbamate forms a functional layer containing thiourea groups on the fiber surface, which, on the one hand, gives the material excellent heat-resistant oxidation performance, and on the other hand, the thiourea groups can be converted into a stable self-lubricating film during high-temperature friction, effectively stabilizing the friction coefficient and reducing material loss. The introduction of thiourea compounds also increases the toughness of the material, improves the impact resistance through its flexible structure, and provides anti-corrosion properties to protect the material from chemical media erosion. This multi-level surface modification strategy not only solves the problem of poor bonding between traditional basalt fibers and organic resin matrices, but also gives the fiber new functional properties by introducing specific functional groups, making the modified basalt fiber a key reinforcing component of high-performance brake pad composites, and comprehensively improving the wear resistance, thermal stability and friction performance stability of the brake pad. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0027] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased from commercial sources or synthesized from raw materials purchased from commercial sources.

[0028] Cashew nut shell liquid modified phenolic resin was purchased from Cardolite, model NX-5341; The particle size of barium sulfate was 200-325 mesh and was purchased from Shanxi Nanfeng Group Co., Ltd.; Sepiolite was purchased from Shijiazhuang Leisheng Mineral Products Co., Ltd.; The diameter of basalt fiber is 12 μm and the length is 3~8 mm; The melting point of bismaleimide resin is 152~158℃, and the acid value is <1.0 KOH mg / g; Butadiene rubber was purchased from Yanshan Petrochemical, model BR9000; Silicon nitride was purchased from Hefei Guonayuan New Material Technology Co., Ltd., d50 = 40 nm.

[0029] Aramid pulp was purchased from Changzhou Saibang New Material Technology Co., Ltd., model HP300.

[0030] A method for preparing a high-performance brake pad composite material comprises the following steps: (1) Immerse 10 g of basalt fiber in 100-150 mL of 3-10 wt% hydrochloric acid solution for 1-2 h, filter, wash until neutral, add to 100-150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 8-9:1-2), add 1-4 g of KH550, adjust the pH of the system to 3.5-5 with acetic acid, stir and react at 65-80 ° C for 4-7 h, filter, wash and dry the product to obtain amino fiber; (2) Immerse 10 g of the amino fiber in 100-120 mL of DMF, add 2.4-6 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.1-1 mL of glacial acetic acid, stir and react at 45-60 °C for 10-16 h, filter, wash and dry the product to obtain the intermediate fiber; (3) Immerse 10 g of the intermediate fiber in 100-120 mL of DMSO, then add 1-4 g of 4-phenyl-3-thiosemicarbazide and 0.1-1 mL of triethylamine, stir and react at 45-60 °C for 10-16 h, filter, wash and dry the product to obtain modified basalt fiber; (4) 15-30 parts of cashew nut shell oil modified phenolic resin, 6-12 parts of bismaleimide resin, 6-15 parts of modified basalt fiber, 4-10 parts of barium sulfate, 4-10 parts of silicon nitride, 6-9 parts of zircon powder, 3-9 parts of butadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder, and 1-4 parts of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 15-60 MPa and 140-170°C to obtain a blank; the blank is cured at 200-240°C for 9-11 hours, and the high-performance brake pad composite material is obtained after shape processing and assembly.

[0031] The present invention will be further described below through specific embodiments.

[0032] Example 1

[0033] A method for preparing a high-performance brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), 4 g of KH550 was added, the pH of the system was adjusted to 4.5 with acetic acid, stirred and reacted at 80 ° C for 4 h, the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 10 g of the amino-modified fiber was immersed in 100 mL of DMF, 6 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 1 mL of glacial acetic acid were added, and the reaction was stirred at 60°C for 10 h. The product was filtered, washed, and dried to obtain an intermediate fiber; (3) 10 g of the intermediate fiber was immersed in 100 mL of DMSO, and then 4 g of 4-phenyl-3-thiosemicarbazide and 1 mL of triethylamine were added, and the reaction was stirred at 60 ° C for 10 h. The product was filtered, washed, and dried to obtain modified basalt fiber; (4) 3000 g of cashew nut shell oil modified phenolic resin, 1200 g of bismaleimide resin, 1500 g of modified basalt fiber, 1000 g of barium sulfate, 1000 g of silicon nitride, 900 g of zircon powder, 900 g of butadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and the high-performance brake pad composite material is obtained after shape processing and assembly.

[0034] Example 2

[0035] A method for preparing a high-performance brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), 3 g of KH550 was added, the pH of the system was adjusted to 4.5 with acetic acid, stirred and reacted at 75 ° C for 5 h, the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 10 g of the amino-modified fiber was immersed in 100 mL of DMF, 4.8 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.7 mL of glacial acetic acid were added, and the reaction was stirred at 55 °C for 12 h. The product was filtered, washed, and dried to obtain an intermediate fiber; (3) 10 g of the intermediate fiber was immersed in 100 mL of DMSO, and then 3 g of 4-phenyl-3-thiosemicarbazide and 0.7 mL of triethylamine were added, and the reaction was stirred at 55 °C for 12 h. The product was filtered, washed, and dried to obtain modified basalt fiber; (4) 2500 g of cashew nut shell oil modified phenolic resin, 1000 g of bismaleimide resin, 1200 g of modified basalt fiber, 800 g of barium sulfate, 800 g of silicon nitride, 800 g of zircon powder, 700 g of butadiene rubber, 700 g of aramid pulp, 400 g of sepiolite powder, and 300 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and the high-performance brake pad composite material is obtained after shape processing and assembly.

[0036] Example 3

[0037] A method for preparing a high-performance brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), added 2 g of KH550, and the pH of the system was adjusted to 4.5 with acetic acid. The reaction was stirred at 70 ° C for 6 h, and the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 10 g of the amino fiber was immersed in 100 mL of DMF, 3.6 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.4 mL of glacial acetic acid were added, and the reaction was stirred at 50°C for 12 h. The product was filtered, washed, and dried to obtain an intermediate fiber; (3) 10 g of the intermediate fiber was immersed in 100 mL of DMSO, and then 2 g of 4-phenyl-3-thiosemicarbazide and 0.4 mL of triethylamine were added, and the reaction was stirred at 50 °C for 12 h. The product was filtered, washed, and dried to obtain modified basalt fiber; (4) 2000 g of cashew nut shell oil modified phenolic resin, 800 g of bismaleimide resin, 1000 g of modified basalt fiber, 600 g of barium sulfate, 600 g of silicon nitride, 700 g of zircon powder, 700 g of butadiene rubber, 700 g of aramid pulp, 300 g of sepiolite powder, and 200 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and the high-performance brake pad composite material is obtained by shape processing and assembly.

[0038] Example 4

[0039] A method for preparing a high-performance brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), 1 g of KH550 was added, the pH of the system was adjusted to 4.5 with acetic acid, stirred and reacted at 65 ° C for 7 h, the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 10 g of the amino-modified fiber was immersed in 100 mL of DMF, 2.4 g of [1,1':4',1''-terphenyl]-4,4''-diformaldehyde and 0.1 mL of glacial acetic acid were added, and the reaction was stirred at 45 °C for 16 h. The product was filtered, washed, and dried to obtain an intermediate fiber; (3) 10 g of the intermediate fiber was immersed in 100 mL of DMSO, and then 1 g of 4-phenyl-3-thiosemicarbazide and 0.1 mL of triethylamine were added, and the reaction was stirred at 45 °C for 16 h. The product was filtered, washed, and dried to obtain modified basalt fiber; (4) 1500 g of cashew nut shell oil modified phenolic resin, 600 g of bismaleimide resin, 600 g of modified basalt fiber, 400 g of barium sulfate, 400 g of silicon nitride, 600 g of zircon powder, 300 g of butadiene rubber, 300 g of aramid pulp, 200 g of sepiolite powder, and 100 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and the high-performance brake pad composite material is obtained after shape processing and assembly.

[0040] Comparative Example 1

[0041] A method for preparing a brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), 4 g of KH550 was added, the pH of the system was adjusted to 4.5 with acetic acid, stirred and reacted at 80 ° C for 4 h, the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 10 g of the amino-modified fiber was immersed in 100 mL of DMF, 6 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 1 mL of glacial acetic acid were added, and the reaction was stirred at 60°C for 10 h. The product was filtered, washed, and dried to obtain an intermediate fiber; (3) 3000 g of cashew nut shell oil-modified phenolic resin, 1200 g of bismaleimide resin, 1500 g of intermediate fiber, 1000 g of barium sulfate, 1000 g of silicon nitride, 900 g of zircon powder, 900 g of butadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and subjected to shape processing and assembly to obtain the brake pad composite material.

[0042] Comparative Example 2

[0043] A method for preparing a brake pad composite material comprises the following steps: (1) 10 g of basalt fiber was immersed in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filtered, washed until neutral, added to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water was 9:1), 4 g of KH550 was added, the pH of the system was adjusted to 4.5 with acetic acid, stirred and reacted at 80 ° C for 4 h, the product was filtered, washed with alcohol, and dried to obtain amino fiber; (2) 3000 g of cashew nut shell oil-modified phenolic resin, 1200 g of bismaleimide resin, 1500 g of amino fiber, 1000 g of barium sulfate, 1000 g of silicon nitride, 900 g of zircon powder, 900 g of butadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder are mixed to obtain a mixture; the mixture is hot-pressed at 45 MPa and 150° C. to obtain a blank; the blank is cured at 220° C. for 10 h, and the brake pad composite material is obtained after shape processing and assembly.

[0044] The performance tests were carried out on the brake pad composite materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2. The density was tested with reference to GB / T1033.1-2008 "Determination of Density of Plastic Non-foamed Plastics Part 1: Immersion Method, Liquid Pycnometer Method and Titration Method"; the hardness was tested with reference to GB / T 5766-2023 "Rockwell Hardness Test Method for Friction Materials"; the noise was tested with reference to GB 3096-2008 "Ambient Noise Quality Standard" and GB 22337-2008 "Social Living Environment Noise Emission Standard", with a measuring distance of 3.5m and a height of 1.2m from the ground. Each sample was tested 5 times and the average value was taken; the normal temperature shear strength and the high temperature shear strength at 300°C were tested with reference to GB / T 22309-2023 "Test Method for Shear Strength of Road Vehicle Brake Linings, Disc Brake Block Assemblies and Drum Brake Shoe Assemblies"; and the friction performance was tested with reference to SAE J2522 "Inertia Dynamometer Disc and Drum Brake Effectiveness Test Procedure". See Table 1 for specific data.

[0045] Table 1 Brake pad composite material performance test results

[0046] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-performance brake pad composite material, characterized in that: The invention is prepared from the following components by weight: 15-30 parts of cashew nut shell oil modified phenolic resin, 6-12 parts of bismaleimide resin, 6-15 parts of modified basalt fiber, 4-10 parts of barium sulfate, 4-10 parts of silicon nitride, 6-9 parts of zircon powder, 3-9 parts of butadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder and 1-4 parts of graphite powder.

2. The high performance brake pad composite material according to claim 1, characterized in that: The preparation method of the modified basalt fiber comprises the following steps: (1) Immerse the basalt fiber in a hydrochloric acid solution, filter, wash until neutral, add it to an ethanol aqueous solution, add KH550, adjust the pH of the system, stir the reaction, filter the product, wash with alcohol, and dry it to obtain an amino fiber; (2) immersing the amino fiber in DMF, adding [1,1':4',1''-terphenyl]-4,4''-diformaldehyde and glacial acetic acid, stirring to react, filtering, washing, and drying the product to obtain an intermediate fiber; (3) The intermediate fiber is immersed in DMSO, and then 4-phenyl-3-thiosemicarbazide and triethylamine are added, and the reaction is stirred. The product is filtered, washed, and dried to obtain modified basalt fiber.

3. The high performance brake pad composite material according to claim 2, characterized in that: In step (1), the concentration of hydrochloric acid is 3-10 wt %, and the immersion time is 1-2 h. The pH of the system is adjusted to 3.5-5 with acetic acid. The stirring reaction conditions are 65-80 ° C. and the stirring reaction is carried out for 4-7 h.

4. The high performance brake pad composite material according to claim 2, characterized in that: In step (1), the volume ratio of ethanol to deionized water in the ethanol aqueous solution is 8-9:1-2; the amount ratio of basalt fiber, ethanol aqueous solution and KH550 is 10 g:100-150 mL:1-4 g.

5. The high performance brake pad composite material according to claim 2, characterized in that: In step (2), the usage ratio of aminocellulose, DMF, [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde and glacial acetic acid is 10 g: 100-120 mL: 2.4-6 g: 0.1-1 mL.

6. The high performance brake pad composite material according to claim 2, characterized in that: In step (2), the stirring reaction conditions are 45-60° C. and 10-16 h.

7. The high performance brake pad composite material according to claim 2, characterized in that: In step (3), the usage ratio of the intermediate fiber, DMSO, 4-phenyl-3-thiosemicarbazide, and triethylamine is 10 g: 100-120 mL: 1-4 g: 0.1-1 mL.

8. The high performance brake pad composite material according to claim 2, characterized in that: In step (3), the stirring reaction conditions are 60-75° C. and 12-18 h.

9. A method for preparing a high-performance brake pad composite material according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components to obtain a mixture; forming the mixture into a blank by hot pressing; and curing, shaping and assembling the blank to obtain the high-performance brake pad composite material.

10. The preparation method according to claim 9, characterized in that: The pressing pressure per unit area of ​​hot pressing molding is 15~60MPa, and the temperature of hot pressing molding is 140~170℃; the curing temperature is 200~240℃, and the time is 9~11h.

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