A high-performance brake pad composite material and its preparation method

Abstract

The present invention discloses a high-performance brake pad composite material and a preparation method thereof. The brake pad composite material is made of the following components by weight: 15-30 parts of cashew 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 cis-1,4-polybutadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder, and 1-4 parts of graphite powder. Its excellent wear resistance and heat dissipation performance significantly extend the service life and reduce the maintenance frequency. At the same time, the material has an excellent balance of strength and toughness, can withstand sudden impact loads, and can maintain a stable braking effect, greatly improving the driving safety of vehicles and meeting the increasingly stringent requirements of modern high-performance vehicles for the braking system.

Description

Technical Field

[0001] The present invention relates to the technical field of brake pads, and particularly 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 frictional force between the brake pads and the brake disc (or drum) to achieve vehicle deceleration or stop. An ideal brake friction material should have a stable friction coefficient, excellent wear resistance, good thermal stability, and appropriate thermal conductivity. At the same time, it also needs to consider performance requirements such as environmental protection and low noise.

[0003] Friction materials are usually complex mixtures composed of multiple components, including binders (resin matrices), reinforcing fibers, friction modifiers, and fillers, etc. Binders such as phenolic resins provide matrix support; reinforcing fibers such as basalt fibers and aramid fibers 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 interactions, and each component has a significant impact on the final performance.

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

[0005] However, traditional brake pads have multiple technical defects: one is the prominent problem of high-temperature attenuation, where the friction coefficient significantly decreases under continuous braking conditions, affecting braking reliability; the second is insufficient wear resistance and short service life; the third is difficulty in controlling noise and vibration; the fourth is the health hazard of traditional asbestos fibers, while alternative materials such as steel fibers and copper fibers face increasingly strict restrictions of environmental protection regulations. In addition, brake pads reinforced with metal fibers have good heat resistance but often cause excessive wear of the mating parts and increased braking noise.

[0006] During the working process, friction materials face complex friction interface phenomena, including friction film formation, thermal decay, wear mechanisms, etc. The quality of the friction film is crucial for the stability of the friction coefficient, while thermal decay caused by the deterioration of material properties at high temperatures is the main factor affecting braking reliability. In addition, different wear mechanisms (such as abrasive wear, adhesive wear, fatigue wear, etc.) have a significant impact on the material life and need to be controlled through material composition and structure 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 its preparation method; the mass fraction composition of the lining of the brake pad is as follows: 8-12 parts of basalt fiber, 10-16 parts of iron oxide black, 3-8 parts of hybrid 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 stone tar, 0.3-1.5 parts of inert powder substance, 1-4 parts of friction property regulator, 1-2.4 parts of release agent.

[0008] However, the untreated basalt fiber has poor interfacial compatibility with the organic resin matrix, insufficient bonding force, and it is difficult to exert its special functions in high-temperature friction environments. There is a lack of brake pad composite materials in the market 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-function modification or simple physical mixing methods are difficult to meet the requirements of high-performance brake pads. There is an urgent need to develop a new composite material system with multi-functional synergy and integrated structure and performance design to solve key technical problems such as high-temperature decay, short life and high noise, and to meet the increasingly stringent performance requirements of modern transportation vehicles for braking systems. Summary of the Invention

[0010] In order to solve the deficiencies of the existing technology, the purpose of the present invention is to provide a high-performance brake pad composite material and its preparation method. The high-performance brake pad composite material of the present invention exhibits excellent thermal stability and anti-decay ability under high-temperature, high-speed and high-load conditions, has a stable friction coefficient and low noise, and effectively solves the problem of unstable performance of traditional brake pads under harsh working conditions.

[0011] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0012] A high-performance brake pad composite material is made of the following components by weight: 15-30 parts of cashew 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 cis-1,4-polybutadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder, and 1-4 parts of graphite powder.

[0013] Preferably, the preparation method of the modified basalt fiber includes the following steps:

[0014] (1) Immerse the basalt fiber in hydrochloric acid solution, filter and wash until neutral, add it to the ethanol aqueous solution, add KH550, adjust the pH of the system, stir and react, filter, wash with alcohol and dry the product to obtain amino-functionalized fiber;

[0015] Amination of basalt fiber: The pretreatment process of immersing basalt fiber in hydrochloric acid solution can activate the silicon-oxygen structure on the fiber surface and generate more active silanol groups. Subsequently, in the ethanol aqueous solution, the three ethoxy groups of KH550 hydrolyze under the action of water molecules and pH adjustment, and are converted into silanol groups to undergo a condensation reaction with the hydroxyl groups on the surface of basalt fiber, forming stable Si-O-Si covalent bonds, so that aminopropyl groups are successfully connected to the surface of basalt fiber, realizing surface amination.

[0016] Preferably, in step (1), the concentration of hydrochloric acid is 3-10 wt%, 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 stirring reaction at 65-80 °C for 4-7 h.

[0017] Preferably, in step (1), the volume ratio of ethanol to deionized water in the ethanol aqueous solution is 8-9:1-2; the dosage ratio of basalt fiber, ethanol aqueous solution, and KH550 is 10 g:100-150 mL:1-4 g.

[0018] (2) Immerse the amino-functionalized fiber in DMF, add [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde and glacial acetic acid, stir and react, filter, wash and dry the product to obtain intermediate fiber;

[0019] Reaction of amino-functionalized fiber with dialdehyde: Under the catalysis of glacial acetic acid, acetic acid first protonates the carbonyl oxygen of one aldehyde group in dialdehyde, enhancing the electrophilicity of the carbon atom. Subsequently, the amino group on the surface of the amino-functionalized fiber acts as a nucleophile, attacking the activated aldehyde group carbon atom to form an intermediate. After proton transfer, a molecule of water is removed to form an imine bond. Each amino group on the surface of the amino-functionalized fiber can only react with one aldehyde group, so there is still another unreacted aldehyde group on the surface of the intermediate fiber after the reaction, and this aldehyde group will participate in the next reaction.

[0020] Preferably, in step (2), the dosage ratio of the aminated fiber, DMF, [1,1':4',1''-terphenyl]-4,4''-dialdehyde, and glacial acetic acid is 10 g: 100 - 120 mL: 2.4 - 6 g: 0.1 - 1 mL.

[0021] Preferably, in step (2), the stirring reaction conditions are stirring and reacting at 45 - 60 °C for 10 - 16 h.

[0022] (3) Immerse the intermediate fiber in DMSO, then add 4-phenyl-3-thiosemicarbazide and triethylamine, stir and react, filter, wash, and dry the product to obtain the modified basalt fiber.

[0023] Reaction of the intermediate fiber with thiosemicarbazide: Triethylamine deprotonates the amino group in 4-phenyl-3-thiosemicarbazide, enhancing its nucleophilicity. The nucleophilic group attacks the aldehyde carbon atom remaining on the surface of the intermediate fiber to form an intermediate. This intermediate eliminates 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 onto the surface of the basalt fiber. The selection of the alkaline condition not only facilitates 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 its surface.

[0024] Preferably, in step (3), the dosage 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.

[0025] Preferably, in step (3), the stirring reaction conditions are stirring and reacting at 60 - 75 °C for 12 - 18 h.

[0026] The present invention also claims to protect a method for preparing the high-performance brake pad composite material, comprising the following steps: mixing the components to obtain a mixture; hot-pressing the mixture to form a blank; curing, shaping, and assembling the blank to obtain the high-performance brake pad composite material.

[0027] Preferably, the pressing pressure per unit area for hot-pressing is 15 - 60 MPa, and the hot-pressing temperature is 140 - 170 °C; the curing temperature is 200 - 240 °C, and the time is 9 - 11 h.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The high-performance brake pad composite material of the present invention achieves excellent comprehensive performance through the synergistic effect of each component. The cashew shell oil modified phenolic resin, as the main base material, has good heat resistance and adhesiveness. At the same time, the cashew shell oil component endows the material with better toughness and elasticity; the bismaleimide resin supplements and improves the high-temperature stability and durability of the material; the modified basalt fiber not only enhances the mechanical strength of the material, but also its special structure 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 heat fade resistance of the material; cis-1,4-polybutadiene rubber increases the toughness of the material and reduces vibration and noise during braking; aramid pulp provides additional fiber reinforcement and 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.

[0030] 2. The present invention provides a modified basalt fiber. First, the treatment with KH550 coupling agent introduces amino functional groups, significantly enhancing the interfacial bonding force between the fiber and the phenolic resin matrix, reducing the interfacial debonding phenomenon, and at the same time increasing the surface roughness and strengthening the mechanical interlocking effect. Second, the introduction of [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde provides a rigid backbone structure, not only improving the mechanical strength of the composite material, but also its large molecular volume forming an effective physical barrier on the fiber surface, blocking the chemical substances that may cause fiber decomposition or oxidation through steric hindrance effect and protecting the internal structure from being damaged. In addition, the terphenyl structure changes the electron density distribution on the fiber surface, improving the overall chemical stability, and its polybenzene ring structure is not easily decomposed or deformed at high temperatures, significantly enhancing the heat resistance of the material under extreme conditions. Finally, the grafting of 4-phenyl-3-aminothiourea forms a functional layer containing thiourea groups on the fiber surface. On the one hand, it endows the material with excellent heat-resistant oxidation performance. 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 at the same time provides anti-corrosion properties to protect the material from chemical medium erosion. This multi-level surface modification strategy not only solves the problem of poor bonding between traditional basalt fiber and organic resin matrix, but also endows the fiber with new functional characteristics by introducing specific functional groups, making the modified basalt fiber a key reinforcing component of high-performance brake pad composite materials, comprehensively improving the wear resistance, thermal stability and friction performance stability of brake pads. Detailed implementation mode

[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the following provides a further detailed description of the present invention in conjunction with embodiments. Of course, the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Unless otherwise specified, the chemical reagents and materials in the present invention are all purchased through market channels or synthesized from raw materials purchased through market channels.

[0033] The cashew shell oil modified phenolic resin is purchased from Cardolite Corporation, with the model NX-5341;

[0034] The barium sulfate has a particle size of 200 - 325 mesh and is purchased from Shanxi Nanfeng Group Co., Ltd.;

[0035] The sepiolite is purchased from Shijiazhuang Leisheng Mineral Products Co., Ltd.;

[0036] The basalt fiber has a diameter of 12 μm and a length of 3 - 8 mm;

[0037] The bismaleimide resin has a melting point of 152 - 158 °C and an acid value of < 1.0 KOH mg / g;

[0038] The cis-1,4-polybutadiene rubber is purchased from Yanshan Petrochemical, with the model BR9000;

[0039] The silicon nitride is purchased from Hefei Guona Yuan New Materials Technology Co., Ltd., with d50 = 40 nm.

[0040] The aramid pulp is purchased from Changzhou Saibang New Materials Technology Co., Ltd., with the model HP300.

[0041] A preparation method of a high-performance brake pad composite material includes the following steps:

[0042] (1) Immerse 10 g of basalt fiber into 100 - 150 mL of 3 - 10 wt% hydrochloric acid solution for 1 - 2 h, filter and wash until neutral, add it 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 with alcohol and dry the product to obtain amino-functionalized fiber;

[0043] (2) Immerse 10 g of amino-functionalized fiber into 100 - 120 mL of DMF, add 2.4 - 6 g of [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde 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 intermediate fiber;

[0044] (3) Immerse 10 g of intermediate fiber into 100 - 120 mL of DMSO, then add 1 - 4 g of 4 - phenyl - 3 - aminothiourea 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;

[0045] (4) Mix 15 - 30 parts of cashew 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 cis - 1,4 - polybutadiene rubber, 3 - 9 parts of aramid pulp, 2 - 5 parts of sepiolite powder, and 1 - 4 parts of graphite powder to obtain a mixture; subject the mixture to hot - press molding at 15 - 60 MPa and 140 - 170 °C to obtain a blank; cure the blank at 200 - 240 °C for 9 - 11 h, and through shape processing and assembly, obtain the high - performance brake pad composite material.

[0046] The following is a further description of the present invention through specific examples.

[0047] Example 1

[0048] A preparation method of a high - performance brake pad composite material includes the following steps:

[0049] (1) Immerse 10 g of basalt fiber into 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add it to 150 mL of ethanol - aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 4 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 80 °C for 4 h, filter, wash with alcohol, and dry to obtain amino - modified fiber;

[0050] (2) Immerse 10 g of amino - modified fiber into 100 mL of DMF, add 6 g of [1,1':4',1'' - terphenyl] - 4,4'' - dialdehyde and 1 mL of glacial acetic acid, stir and react at 60 °C for 10 h, filter, wash, and dry the product to obtain intermediate fiber;

[0051] (3) Immerse 10 g of intermediate fiber into 100 mL of DMSO, then add 4 g of 4 - phenyl - 3 - aminothiourea and 1 mL of triethylamine, stir and react at 60 °C for 10 h, filter, wash, and dry the product to obtain modified basalt fiber;

[0052] (4) Mix 3000 g of cardanol-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 cis-butadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder to obtain a mixture; subject the mixture to hot pressing at 45 MPa and 150 °C to obtain a blank; cure the blank at 220 °C for 10 h, and after machining the shape and assembling, obtain the high-performance brake pad composite material.

[0053] Example 2

[0054] A preparation method of a high-performance brake pad composite material, comprising the following steps:

[0055] (1) Immerse 10 g of basalt fiber in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add it to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 3 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 75 °C for 5 h, filter, wash with alcohol and dry the product to obtain amino-functionalized fiber;

[0056] (2) Immerse 10 g of amino-functionalized fiber in 100 mL of DMF, add 4.8 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.7 mL of glacial acetic acid, stir and react at 55 °C for 12 h, filter, wash and dry the product to obtain intermediate fiber;

[0057] (3) Immerse 10 g of intermediate fiber in 100 mL of DMSO, then add 3 g of 4-phenyl-3-aminothiourea and 0.7 mL of triethylamine, stir and react at 55 °C for 12 h, filter, wash and dry the product to obtain modified basalt fiber;

[0058] (4) Mix 2500 g of cardanol-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 cis-butadiene rubber, 700 g of aramid pulp, 400 g of sepiolite powder, and 300 g of graphite powder to obtain a mixture; subject the mixture to hot pressing at 45 MPa and 150 °C to obtain a blank; cure the blank at 220 °C for 10 h, and after machining the shape and assembling, obtain the high-performance brake pad composite material.

[0059] Example 3

[0060] A preparation method of a high-performance brake pad composite material, comprising the following steps:

[0061] (1) Immerse 10 g of basalt fibers in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add them to 150 mL of an ethanol aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 2 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 70 °C for 6 h, filter, wash with alcohol, and dry the product to obtain amino-functionalized fibers;

[0062] (2) Immerse 10 g of amino-functionalized fibers in 100 mL of DMF, add 3.6 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.4 mL of glacial acetic acid, stir and react at 50 °C for 12 h, filter, wash, and dry the product to obtain intermediate fibers;

[0063] (3) Immerse 10 g of intermediate fibers in 100 mL of DMSO, then add 2 g of 4-phenyl-3-aminothiourea and 0.4 mL of triethylamine, stir and react at 50 °C for 12 h, filter, wash, and dry the product to obtain modified basalt fibers;

[0064] (4) Mix 2000 g of cashew shell oil-modified phenolic resin, 800 g of bismaleimide resin, 1000 g of modified basalt fibers, 600 g of barium sulfate, 600 g of silicon nitride, 700 g of zircon powder, 700 g of cis-butadiene rubber, 700 g of aramid pulp, 300 g of sepiolite powder, and 200 g of graphite powder to obtain a mixture; hot press the mixture at 45 MPa and 150 °C to obtain a blank; cure the blank at 220 °C for 10 h, and through shape processing and assembly, obtain the high-performance brake pad composite material.

[0065] Example 4

[0066] A preparation method of a high-performance brake pad composite material, comprising the following steps:

[0067] (1) Immerse 10 g of basalt fibers in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add them to 150 mL of an ethanol aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 1 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 65 °C for 7 h, filter, wash with alcohol, and dry the product to obtain amino-functionalized fibers;

[0068] (2) Immerse 10 g of amino-functionalized fibers in 100 mL of DMF, add 2.4 g of [1,1':4',1''-terphenyl]-4,4''-dicarboxaldehyde and 0.1 mL of glacial acetic acid, stir and react at 45 °C for 16 h, filter, wash, and dry the product to obtain intermediate fibers;

[0069] (3) Immerse 10 g of the intermediate fiber in 100 mL of DMSO, then add 1 g of 4-phenyl-3-thiosemicarbazide and 0.1 mL of triethylamine, and stir and react at 45 °C for 16 h. Filter, wash, and dry the product to obtain the modified basalt fiber;

[0070] (4) Mix 1500 g of cashew 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 cis-1,4-polybutadiene rubber, 300 g of aramid pulp, 200 g of sepiolite powder, and 100 g of graphite powder to obtain a mixture. Hot press the mixture at 45 MPa and 150 °C to obtain a blank. Cure the blank at 220 °C for 10 h, and through shape processing and assembly, obtain the high-performance brake pad composite material.

[0071] Comparative Example 1

[0072] A preparation method of a brake pad composite material includes the following steps:

[0073] (1) Immerse 10 g of basalt fiber in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add it to 150 mL of an ethanol aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 4 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 80 °C for 4 h, filter, wash with alcohol, and dry the product to obtain the amino-functionalized fiber;

[0074] (2) Immerse 10 g of the amino-functionalized fiber in 100 mL of DMF, add 6 g of [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde and 1 mL of glacial acetic acid, stir and react at 60 °C for 10 h, filter, wash, and dry the product to obtain the intermediate fiber;

[0075] (3) Mix 3000 g of cashew 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 cis-1,4-polybutadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder to obtain a mixture. Hot press the mixture at 45 MPa and 150 °C to obtain a blank. Cure the blank at 220 °C for 10 h, and through shape processing and assembly, obtain the brake pad composite material.

[0076] Comparative Example 2

[0077] A preparation method of a brake pad composite material includes the following steps:

[0078] (1)Immerse 10 g of basalt fibers in 150 mL of 5 wt% hydrochloric acid solution for 1.5 h, filter and wash until neutral, add them to 150 mL of ethanol aqueous solution (the volume ratio of ethanol to deionized water is 9:1), add 4 g of KH550, adjust the pH of the system to 4.5 with acetic acid, stir and react at 80 °C for 4 h, filter, wash with alcohol, and dry the product to obtain amino-functionalized fibers;

[0079] (2)Mix 3000 g of cashew shell oil-modified phenolic resin, 1200 g of bismaleimide resin, 1500 g of amino-functionalized fibers, 1000 g of barium sulfate, 1000 g of silicon nitride, 900 g of zircon powder, 900 g of cis-butadiene rubber, 900 g of aramid pulp, 500 g of sepiolite powder, and 400 g of graphite powder to obtain a mixture; hot press the mixture at 45 MPa and 150 °C to obtain a blank; cure the blank at 220 °C for 10 h, and after shape processing and assembly, obtain the brake pad composite material.

[0080] Perform performance tests on the brake pad composite materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2. Refer to GB / T 1033.1-2008 Plastics - Determination of the density of non-cellular plastics - Part 1: Immersion method, pyknometer method and titration method to test the density; refer to GB / T 5766-2023 Test method for Rockwell hardness of friction materials to test the hardness; refer to GB 3096-2008 Ambient noise quality standard and GB 22337-2008 Emission standard for social life environmental noise to test the noise, measure at a distance of 3.5 m and a height of 1.2 m from the ground, test each sample 5 times, and take the average value; refer to GB / T 22309-2023 Road vehicles - Brake linings - Test method for shear strength of disc brake pads and drum brake shoes assemblies to test the room temperature shear strength and the high temperature shear strength at 300 °C; refer to SAE J2522 Inertia dynamometer disc and drum brake effectiveness test procedure to test the friction performance. The specific data are shown in Table 1.

[0081] Table 1 Performance test results of brake pad composite materials

[0082]

[0083] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A high-performance brake pad composite material, characterized in that, It is made of the following components by weight parts: 15-30 parts of cashew 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 cis-1,4-polybutadiene rubber, 3-9 parts of aramid pulp, 2-5 parts of sepiolite powder, 1-4 parts of graphite powder; The preparation method of the modified basalt fiber includes the following steps: (1) Immerse the basalt fiber in hydrochloric acid solution, filter and wash it until neutral, add it to the ethanol aqueous solution, add KH550, adjust the pH of the system, stir and react, filter, wash with alcohol and dry the product to obtain amino-functionalized fiber; (2) Immerse the amino-functionalized fiber in DMF, add [1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde and glacial acetic acid, stir and react, filter, wash and dry the product to obtain intermediate fiber; (3) Immerse the intermediate fiber in DMSO, then add 4-phenyl-3-aminothiourea and triethylamine, stir and react, filter, wash and dry the product to obtain modified basalt fiber.

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

3. The high-performance brake pad composite material according to claim 1, 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 dosage ratio of basalt fiber, ethanol aqueous solution and KH550 is 10 g:100-150 mL:1-4 g.

4. The high-performance brake pad composite material according to claim 1, characterized in that, In step (2), the dosage ratio of amino-functionalized fiber, 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.

5. The high-performance brake pad composite material according to claim 1, wherein In step (2), the stirring reaction conditions are stirring reaction at 45-60 °C for 10-16 h.

6. The high-performance brake pad composite material according to claim 1, wherein In step (3), the dosage ratio of intermediate fiber, DMSO, 4-phenyl-3-aminothiourea and triethylamine is 10 g:100-120 mL:1-4 g:0.1-1 mL.

7. The high-performance brake pad composite material according to claim 1, wherein In step (3), the stirring reaction conditions are stirring reaction at 60-75 °C for 12-18 h.

8. A method for preparing a high-performance brake pad composite material according to any one of claims 1 to 7, characterized in that, It includes the following steps: mix the components to obtain a mixture; make a blank by hot pressing and molding; cure, shape process and assemble the blank to obtain the high-performance brake pad composite material.

9. The preparation method according to claim 8, characterized in that, The pressing pressure per unit area of hot pressing and molding is 15-60 MPa, and the temperature of hot pressing and molding is 140-170 °C; the curing temperature is 200-240 °C, and the time is 9-11 h.

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