A method for preparing automobile brake pad

Abstract

The present application provides a method for preparing an automobile brake pad, the method comprising the following steps: bonding a friction material on the surface of a steel back; the friction material comprises the following raw materials in parts by weight: 10 parts of fluorosilicon-modified phenolic resin, 10 to 20 parts of organic fiber, 5 to 10 parts of mineral fiber, 5 to 8 parts of graphite, 4 to 8 parts of modified graphene, 5 to 15 parts of silicon carbide and 10 to 30 parts of filler; the fluorosilicon-modified phenolic resin comprises the following raw materials in molar parts: 1 part of phenol, 1.5 to 2.5 parts of formaldehyde, 0.5 to 0.8 parts of aminopropyltriethoxysilane and 0.5 to 0.8 parts of 4-amino-3-fluoropyridine. The present application prepares an automobile brake pad with excellent performance by rationally matching the raw materials for preparing the friction material.

Description

Technical Field

[0001] The present application relates to the technical field of automobile manufacturing, and in particular to a method for preparing an automobile brake pad. Background Art

[0002] Friction materials are composed of three major categories: polymer binders, reinforcing fibers and friction performance regulators, as well as other compounding agents. They are made through a series of production and processing. They are widely used in various types of engineering machinery and equipment such as automobiles, trains, airplanes, and oil drilling rigs.

[0003] Automobile brake pads in related technologies usually use asbestos friction materials, semi-metallic friction materials or asbestos-free organic friction materials. As asbestos brake pads have unstable high-temperature friction performance, loud braking noise, short service life and strong carcinogenicity, they have been replaced by semi-metallic and asbestos-free organic friction materials. However, most semi-metallic and asbestos-free brake pads cannot fully adapt to complex and harsh braking conditions and higher environmental protection requirements, especially in high-speed, heavy-load braking conditions. Semi-metallic brake pads have loud braking noise, are easy to damage the mating parts, are easy to rust and easily cause friction performance degradation.

[0004] Excellent friction plate materials should have good friction coefficient and wear resistance, high elastic modulus, sufficient mechanical strength, high heat resistance, high thermal conductivity and heat capacity to ensure that the service life meets the design requirements, achieve miniaturization and lightweight of the system, and thus improve the maneuverability and reliability of the vehicle. Summary of the invention

[0005] The present application is made in view of the above problems, and its purpose is to provide a method for preparing a vehicle brake pad, comprising the following steps:

[0006] Bonding friction material to the steel backing surface;

[0007] The friction material comprises the following raw materials in parts by weight:

[0008] 10 parts of fluorine-silicon modified phenolic resin, 10 to 20 parts of organic fiber, 5 to 10 parts of mineral fiber, 5 to 8 parts of graphite, 4 to 8 parts of modified graphene, 5 to 15 parts of silicon carbide and 10 to 30 parts of filler;

[0009] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0010] 1 part of phenol, 1.5 to 2.5 parts of formaldehyde, 0.5 to 0.8 parts of aminopropyltriethoxysilane and 0.5 to 0.8 parts of 4-amino-3-fluoropyridine.

[0011] According to one of the technical solutions of the preparation method of the present application, at least the following beneficial effects are achieved:

[0012] The present application ensures that the advantages of various materials are fully utilized in the friction material by reasonably matching multiple components. Firstly, by reasonably matching mineral fibers and organic fibers, the fiber network of the friction material is improved, which has a synergistic reinforcement effect; by controlling the amount of graphite and modified graphene, the graphite and modified graphite are better dispersed in the friction material composition.

[0013] The modified graphene in the present application can be well combined with the surface of the substrate, dispersed evenly, and can be compounded with other components to improve the comprehensive performance of the automobile brake pad.

[0014] The present application adopts a composition of fluorosilicone-modified phenolic resin as a material adhesive, which can effectively increase the heat resistance and toughness of the resin, thereby improving the impact resistance, elastic modulus and heat resistance temperature of the automobile brake pad; at the same time, the fluorosilicone modification can also increase the water-proof performance of the friction material.

[0015] After fluorine modification, the surface free energy of phenolic resin will become lower, which is conducive to the full dispersion and combination of modified graphene and phenolic resin, and phenolic resin and modified graphene can form a stable interaction; it is conducive to the full dispersion of modified graphene, thereby improving the performance of friction materials.

[0016] The present application utilizes the synergistic effect between the raw material components and the reasonable configuration of the processing technology to effectively improve the damping of the brake pad at low temperatures and suppress the generation of noise; the water-isolating performance of the brake pad is significantly improved, effectively preventing coefficient fluctuations, dual corrosion and other problems caused by moisture.

[0017] According to some embodiments of the present application, the organic fiber includes at least one of aramid fiber or polyimide pulp.

[0018] Aramid is a reinforcing material for automobile brake pad friction materials.

[0019] The parameters of aramid are: the specific surface area of ​​aramid is 9m 2 / g~14m 2 / g, the length distribution of aramid is 0.8mm~1.6mm; aramid was purchased from Lanbang Industrial Fiber Co., Ltd.

[0020] According to some embodiments of the present application, the mineral fibers include basalt fibers.

[0021] Basalt mineral fiber has the characteristics of high modulus and good thermal vibration stability. The fiber network of the friction material is well improved through organic fiber and basalt fiber, which has a synergistic reinforcement effect. It can effectively reduce the high-temperature wear rate and ensure the braking strength, and also has a good shock absorption effect.

[0022] According to some embodiments of the present application, the graphite includes a first graphite and a second graphite;

[0023] The particle size of the first graphite is 300 μm to 800 μm;

[0024] The particle size of the second graphite is 30 μm to 80 μm;

[0025] The mass ratio of the first graphite to the second graphite is 1:2-3.

[0026] Graphite has a low friction coefficient and is a good friction-reducing material. It is porous and loose, has good adsorption, reduces the formation of friction pair resonance during braking operation, and has good sound absorption. The application strictly controls the ratio of the first graphite and the second graphite, and can better disperse the graphite in the friction material composition.

[0027] According to some embodiments of the present application, the modified graphene is fluorinated graphene.

[0028] According to some embodiments of the present application, the fluorine content of the fluorinated graphene is 50% to 70%.

[0029] According to some embodiments of the present application, the filler includes barium sulfate, barium carbonate or potassium hexatitanate.

[0030] Barium sulfate is a filler in the friction material of automobile brake pads.

[0031] The parameters of barium sulfate are: fineness: 0.045 mm less than or equal to 0.2%; oil absorption: 15 g to 25 g / 100 g; volatile matter at 105° C. less than or equal to 0.3%; barium sulfate was purchased from Shanxi Nanfeng Group Co., Ltd.

[0032] The parameters of potassium hexatitanate whiskers are: melting point: 1300℃~1350℃.

[0033] Potassium hexatitanate whiskers were purchased from Shanghai Yixi Industrial Co., Ltd. with the brand name M-300.

[0034] According to some embodiments of the present application, the method for preparing the friction material comprises the following steps:

[0035] Mixing the raw materials for preparing the friction material, hot pressing and heat treating the mixture;

[0036] The temperature of the hot pressing is 130°C to 180°C.

[0037] According to some embodiments of the present application, the hot pressing pressure is 30 MPa~55 MPa.

[0038] According to some embodiments of the present application, the hot pressing time is 4 min to 5 min.

[0039] According to some embodiments of the present application, the method for preparing the fluorosilicone-modified phenolic resin comprises the following steps:

[0040] Phenol, formaldehyde, aminopropyltriethoxysilane, 4-amino-3-fluoropyridine and a solvent are mixed and reacted.

[0041] According to some embodiments of the present application, the solvent includes toluene.

[0042] According to some embodiments of the present application, the reaction temperature is 100°C to 150°C.

[0043] According to some embodiments of the present application, the reaction time is 3h~4h.

[0044] According to some embodiments of the present application, the heat treatment time is 0.5h~20h.

[0045] According to some embodiments of the present application, the temperature of the heat treatment is 80°C~250°C.

[0046] According to some embodiments of the present application, the heat treatment is followed by grinding.

[0047] Grinding is a type of external machining, including flat grinding, grooving and chamfering. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0049] Obviously, the following descriptions are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in the field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0050] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter described in the claims.

[0051] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0052] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0053] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0054] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0055] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0056] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0057] Some of the raw material manufacturers and properties in this application are as follows:

[0058] Aramid fiber was purchased from Lanbang Industrial Fiber Co., Ltd.

[0059] Fluorinated graphene (modified graphene selected in Examples 1 to 5), Xianfeng Nano, No.: XF225; fluorine content: 53% to 65%; thickness: 5 nm to 10 nm; sheet diameter: 4 μm to 10 μm.

[0060] Barium sulfate was purchased from Shanxi Nanfeng Group Co., Ltd.

[0061] Potassium hexatitanate whiskers were purchased from Shanghai Yixi Industrial Co., Ltd. with the brand name M-300.

[0062] Example 1

[0063] This embodiment is a method for preparing a brake pad for an automobile, which comprises the following steps:

[0064] Bonding friction material to the steel backing surface;

[0065] The friction material comprises the following raw materials in parts by weight:

[0066] 10 parts of fluorine-silicon modified phenolic resin, 14 parts of organic fiber (aramid fiber), 8 parts of mineral fiber (basalt fiber), 7 parts of graphite, 5 parts of modified graphene (fluorinated graphene), 12 parts of silicon carbide (D50 is 100nm) and 25 parts of filler;

[0067] The graphite consists of a first graphite (D50 is 500 μm) and a second graphite (D50 is 50 μm), and the mass ratio of the first graphite to the second graphite is 1:2.5;

[0068] The filler consists of barium sulfate and potassium hexatitanate whiskers, and the mass ratio of the barium sulfate to the potassium hexatitanate whiskers is 1:1.

[0069] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0070] 1 part of phenol, 2.2 parts of formaldehyde, 0.6 parts of aminopropyltriethoxysilane and 0.7 parts of 4-amino-3-fluoropyridine.

[0071] The preparation method of the fluorine-silicon modified phenolic resin in this embodiment consists of the following steps:

[0072] Phenol, formaldehyde (added in the formaldehyde aqueous solution with a mass fraction of 37%), aminopropyltriethoxysilane, 4-amino-3-fluoropyridine and toluene (the volume ratio of phenol to toluene is 1:1) are mixed and heated to 120°C, refluxed to separate water, and refluxed at a constant temperature for 3 hours to obtain a modified phenolic resin.

[0073] The manufacturing method of the automobile brake pad friction material of this embodiment is as follows:

[0074] S1. Mixing the raw material components according to mass fraction;

[0075] S2, hot pressing the mixture after the mixing treatment in S1;

[0076] S3, curing the product after the hot pressing treatment in S2;

[0077] S4, grinding the brake pad friction material obtained after the curing treatment in S3.

[0078] The device for mixing in S1 is a high-speed mixer, wherein the mixing speed is 2900 rpm; the mixing time is 25 min; and the maximum mixing temperature is 50°C.

[0079] The device for hot pressing treatment in S2 is a 100-ton six-station hydraulic press, wherein the hot pressing temperature is: 150°C to 160°C for the upper mold, 140°C to 150°C for the middle mold, and 145°C to 155°C for the lower mold; the pressing pressure of the hot pressing is 40MPa, and the hot pressing time is 4min.

[0080] The device for heat treatment in S3 is a program-controlled heat treatment oven, wherein the temperature and time for heat treatment are:

[0081] (1) The room temperature (25°C) was raised to 80°C over 0.5 h and then kept at 90°C for 1 h;

[0082] (2) Raise the temperature from 90°C to 130°C over 0.5 h and keep the temperature at 130°C for 1 h;

[0083] (3) Raise the temperature from 130°C to 150°C over 1 hour and keep it at 150°C for 2 hours;

[0084] (4) Raise the temperature from 150°C to 190°C after 1 hour, and keep the temperature at 190°C for 2 hours;

[0085] (5) Raise the temperature from 190°C to 210°C after 1 h, and keep the temperature at 210°C for 2 h;

[0086] (6) Raise the temperature from 210°C to 230°C over 1 h and maintain the temperature at 230°C for 3 h.

[0087] Example 2

[0088] This embodiment is a method for preparing a brake pad for an automobile, which differs from Embodiment 1 in that:

[0089] The friction material comprises the following raw materials in parts by weight:

[0090] 10 parts of fluorine-silicon modified phenolic resin, 10 parts of organic fiber, 10 parts of mineral fiber, 5 parts of graphite, 8 parts of modified graphene, 5 parts of silicon carbide and 30 parts of filler;

[0091] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0092] 1 part of phenol, 2.5 parts of formaldehyde, 0.8 parts of aminopropyltriethoxysilane and 0.5 parts of 4-amino-3-fluoropyridine.

[0093] Example 3

[0094] This embodiment is a method for preparing a brake pad for an automobile, which differs from Embodiment 1 in that:

[0095] The friction material comprises the following raw materials in parts by weight:

[0096] 10 parts of fluorine-silicon modified phenolic resin, 20 parts of organic fiber, 5 parts of mineral fiber, 8 parts of graphite, 4 parts of modified graphene, 15 parts of silicon carbide and 30 parts of filler;

[0097] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0098] 1 part of phenol, 2.5 parts of formaldehyde, 0.5 parts of aminopropyltriethoxysilane and 0.8 parts of 4-amino-3-fluoropyridine.

[0099] Example 4

[0100] This embodiment is a method for preparing a brake pad for an automobile, which differs from Embodiment 1 in that:

[0101] The friction material comprises the following raw materials in parts by weight:

[0102] 10 parts of fluorine-silicon modified phenolic resin, 12 parts of organic fiber, 8 parts of mineral fiber, 6 parts of graphite, 5 parts of modified graphene, 10 parts of silicon carbide and 10 to 30 parts of filler;

[0103] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0104] 1 part of phenol, 2.5 parts of formaldehyde, 0.6 parts of aminopropyltriethoxysilane and 0.7 parts of 4-amino-3-fluoropyridine.

[0105] Example 5

[0106] This embodiment is a method for preparing a brake pad for an automobile, which differs from Embodiment 1 in that:

[0107] The friction material comprises the following raw materials in parts by weight:

[0108] 10 parts of fluorine-silicon modified phenolic resin, 10 parts of organic fiber, 5 parts of mineral fiber, 5 parts of graphite, 4 parts of modified graphene, 5 parts of silicon carbide and 30 parts of filler;

[0109] The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions:

[0110] 1 part of phenol, 2.5 parts of formaldehyde, 0.5 parts of aminopropyltriethoxysilane and 0.5 parts of 4-amino-3-fluoropyridine.

[0111] Comparative Example 1

[0112] This comparative example is a method for preparing a brake pad for an automobile, which differs from Example 5 in that:

[0113] The silicon-modified phenolic resin comprises the following raw materials in molar fractions:

[0114] 1 part of phenol, 2.5 parts of formaldehyde and 0.5 parts of aminopropyltriethoxysilane.

[0115] The preparation method of the fluorine-silicon modified phenolic resin in this comparative example consists of the following steps:

[0116] Phenol, formaldehyde (added in the formaldehyde aqueous solution with a mass fraction of 37%), aminopropyltriethoxysilane and toluene (the volume ratio of phenol to toluene is 1:1) are mixed and heated to 120°C, refluxed to separate water, and refluxed at a constant temperature for 3 hours to obtain a modified phenolic resin.

[0117] Comparative Example 2

[0118] This comparative example is a method for preparing a brake pad for an automobile, which differs from Example 5 in that:

[0119] The fluorine-modified phenolic resin comprises the following raw materials in molar fractions:

[0120] 1 part of phenol, 2.5 parts of formaldehyde and 0.5 parts of 4-amino-3-fluoropyridine.

[0121] The preparation method of the fluorine-modified phenolic resin in this comparative example consists of the following steps:

[0122] Phenol, formaldehyde (added in the formaldehyde aqueous solution with a mass fraction of 37%), 4-amino-3-fluoropyridine and toluene (the volume ratio of phenol to toluene is 1:1) are mixed and heated to 120°C, refluxed to separate water, and refluxed at a constant temperature for 3 hours to obtain a modified phenolic resin.

[0123] Comparative Example 3

[0124] This comparative example is a method for preparing a brake pad for an automobile, which differs from Example 5 in that:

[0125] The phenolic resin comprises the following raw materials in molar fractions:

[0126] 1 part phenol and 2.5 parts formaldehyde.

[0127] The preparation method of the phenolic resin in this comparative example consists of the following steps:

[0128] Phenol, formaldehyde (added in the formaldehyde aqueous solution with a mass fraction of 37%) and toluene (the volume ratio of phenol to toluene is 1:1) are mixed and heated to 120°C, refluxed to separate water, and refluxed at a constant temperature for 3 hours to obtain a modified phenolic resin.

[0129] Comparative Example 4

[0130] This comparative example is a method for preparing a brake pad for an automobile, which differs from Example 5 in that:

[0131] In this comparative example, fluorinated graphene is replaced by graphene (Xianfeng Nano, No.: XF021, graphene nanosheets 3nm~10 nm).

[0132] Comparative Example 5

[0133] This comparative example is a method for preparing a brake pad for an automobile, which differs from Example 5 in that:

[0134] The phenolic resin comprises the following raw materials in molar fractions:

[0135] 1 part phenol and 2.5 parts formaldehyde.

[0136] The preparation method of the phenolic resin in this comparative example consists of the following steps:

[0137] Phenol, formaldehyde (added in the formaldehyde aqueous solution with a mass fraction of 37%) and toluene (the volume ratio of phenol to toluene is 1:1) are mixed and heated to 120°C, refluxed to separate water, and refluxed at a constant temperature for 3 hours to obtain a modified phenolic resin.

[0138] In this comparative example, fluorinated graphene is replaced by graphene (Xianfeng Nano, No.: XF021, graphene nanosheets 3nm~10nm).

[0139] The automobile brake pad friction materials obtained in the examples and comparative examples were subjected to room temperature (25°C) / hot compression performance test-compression variable, the test standard was SAE J2468; the brake pads were subjected to friction performance drag test-weight wear rate using GB / T34007, and the test results are shown in Table 1.

[0140]

[0141] The difference between Comparative Example 1 and Example 5 is that the phenolic resin in Comparative Example 1 is a silicon-modified phenolic resin. After the fluorine modification of Comparative Example 1 is missing, the surface free energy of the phenolic resin becomes higher, which is not conducive to the full dispersion and combination of the modified graphene and the phenolic resin, thereby resulting in poor performance of the friction material.

[0142] The difference between Comparative Example 2 and Example 5 is that the phenolic resin in Comparative Example 2 is a fluorine-modified phenolic resin. After the silicon modification is missing in Comparative Example 2, it is difficult for the phenolic resin and the modified graphene to form a stable interaction; it is not conducive to the full dispersion of the modified graphene (silane can also form Si-O-Si and has excellent hydrophobicity. In the absence of silane, the above effect cannot be formed), resulting in poor performance of the friction material.

[0143] The difference between Comparative Example 3 and Example 5 is that the phenolic resin in Comparative Example 3 is not modified. After the fluorine modification is missing in Comparative Example 3, the surface free energy of the phenolic resin will become higher, which is not conducive to the full dispersion and combination of the modified graphene and the phenolic resin, and it is difficult for the phenolic resin and the modified graphene to form a stable interaction; it is not conducive to the full dispersion of the modified graphene (silane can also form Si-O-Si and has excellent hydrophobicity. In the absence of silane, the above effect cannot be formed), resulting in poor performance of the friction material.

[0144] The difference between Comparative Example 4 and Example 5 is that in Comparative Example 4, graphene is selected, and the graphene is not modified, which increases the difficulty of dispersion with the phenolic resin, resulting in poor performance of the friction material.

[0145] The difference between Comparative Example 5 and Example 5 is that in Comparative Example 5, graphene and phenolic resin are selected without modification and cannot form a low surface energy composite structure, resulting in poor performance of the friction material.

[0146] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing an automobile brake pad, characterized in that: The following steps are involved: Bonding friction material to the steel backing surface; The friction material comprises the following raw materials in parts by weight: 10 parts of fluorine-silicon modified phenolic resin, 10 to 20 parts of organic fiber, 5 to 10 parts of mineral fiber, 5 to 8 parts of graphite, 4 to 8 parts of modified graphene, 5 to 15 parts of silicon carbide and 10 to 30 parts of filler; The fluorine-silicon modified phenolic resin comprises the following raw materials in molar fractions: 1 part of phenol, 1.5 to 2.5 parts of formaldehyde, 0.5 to 0.8 parts of aminopropyltriethoxysilane and 0.5 to 0.8 parts of 4-amino-3-fluoropyridine; The organic fiber includes at least one of aramid fiber or polyimide pulp; The mineral fiber includes basalt fiber; the graphite includes a first graphite and a second graphite; The particle size of the first graphite is 300 μm to 800 μm; The particle size of the second graphite is 30 μm to 80 μm; The mass ratio of the first graphite to the second graphite is 1:2-3; The modified graphene is fluorinated graphene; The fluorine content of the fluorinated graphene is 50% to 70%; The filler includes barium sulfate, barium carbonate or potassium hexatitanate.

2. The preparation method according to claim 1, characterized in that: The method for preparing the friction material comprises the following steps: Mixing the raw materials for preparing the friction material, hot pressing and heat treating the mixture; The temperature of the hot pressing is 130°C to 180°C.

3. The preparation method according to claim 2, characterized in that: The hot pressing pressure is 30MPa~55Mpa.

4. The preparation method according to claim 2, characterized in that: The hot pressing time is 4 min to 5 min.

5. The preparation method according to claim 1, characterized in that: The preparation method of the fluorine-silicon modified phenolic resin comprises the following steps: Phenol, formaldehyde, aminopropyltriethoxysilane, 4-amino-3-fluoropyridine and a solvent are mixed and reacted.

6. The preparation method according to claim 2, characterized in that: The heat treatment is followed by grinding.

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