Organic synthetic friction material, brake pad / brake shoe and preparation method of brake pad / brake shoe

Abstract

The invention discloses an organic synthetic friction material, a brake pad / brake shoe and a preparation method of the brake pad / brake shoe, belongs to the field of train braking, and aims at solving the problem that an existing organic synthetic brake pad is poor in heat resistance in the braking process of a high-speed train provided with a carbon ceramic disc. The organic friction material is prepared from the following materials: a matrix, a matrix reinforcing component and a friction adjusting component, wherein the matrix comprises epoxy resin, a toughening agent, nitrile rubber powder and peroxide, the matrix reinforcing component comprises organic montmorillonite, zinc methacrylate and carbon nanotubes, and the friction adjusting component comprises aluminum oxide ceramic particles, copper sulfide and brucite. The organic synthetic friction material disclosed by the invention can meet the working condition that the operation speed of a train equipped with a carbon ceramic disc is 250km / h or above, and can be used for train braking of the train equipped with the carbon ceramic disc in high-speed operation. The invention further discloses a brake pad / brake shoe and a preparation method thereof.

Description

Technical Field

[0001] The invention relates to an organic synthetic friction material, a brake pad / brake shoe and a preparation method thereof, and relates to the technical field of train braking. Background Art

[0002] Due to the low thermal conductivity of carbon ceramic discs, the heat generated by trains equipped with carbon ceramic discs during braking is almost entirely absorbed by the friction material, and the friction surface temperature is much higher than that of ordinary steel discs or iron discs, which in turn increases the wear rate of organic synthetic friction materials, reduces the performance of the matrix at high temperatures, reduces the adhesion to friction particles, and leads to unstable friction coefficients. Therefore, trains equipped with carbon ceramic discs have extremely high requirements for the heat resistance of brake pads. Currently, the friction materials that can be compatible with carbon ceramic discs on the test bench are mainly carbon-carbon composite materials and powder metallurgy materials. The matrix of traditional organic synthetic materials is mainly rubber and resin, and the temperature resistance is lower than 450°C. Even if the rubber is reinforced by traditional reinforcing agents such as carbon black, the reinforcement effect cannot cope with the requirements of rapid temperature rise. Therefore, there is an urgent need for a brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains. Summary of the invention

[0003] The purpose of the present invention is to provide an organic synthetic friction material, a brake pad / brake shoe and a preparation method thereof to address the drawbacks of the prior art, so as to solve the problem of poor heat resistance of the existing organic synthetic brake pad during the braking process of a high-speed train equipped with a carbon ceramic disc.

[0004] The problem of the present invention is achieved by the following technical solutions:

[0005] In a first aspect, the present invention discloses an organic friction material, which is prepared from the following materials, including: a matrix, wherein the matrix includes epoxy resin, a toughening agent, nitrile rubber powder and peroxide; a matrix reinforcing component, wherein the matrix reinforcing component includes organic montmorillonite, zinc methacrylate and carbon nanotubes; and a friction adjusting component, wherein the friction adjusting component includes alumina ceramic particles, copper sulfide and brucite.

[0006] Compared with the prior art, among the raw material components of the friction material of the present invention, the cured epoxy resin and nitrile rubber powder have good wear resistance and high temperature resistance, which is helpful to improve the wear resistance and heat resistance of the friction material; the peroxide can promote the cross-linking reaction between the nitrile rubber molecules to form a cross-linked network structure, which is helpful to enhance the wear resistance of the friction material; the toughening agent is added to the epoxy resin to form a microscopic elastic phase or particle dispersion system in the epoxy resin, which can improve the impact resistance of the present invention, and the toughening agent can reduce the glass transition temperature of the material while improving the toughness, so that the flexibility of the material molecular chain is increased, which is helpful to improve the wear resistance and heat resistance of the friction material, and further helps to improve the overall performance and stability of the friction material.

[0007] In addition, the friction material of the present invention uses zinc methacrylate, which has good heat resistance and aging resistance. In the peroxide vulcanization process, zinc methacrylate is polymerized by "in-situ polymerization method". In this process, zinc methacrylate dissolves and diffuses while polymerizing under the action of peroxide, increasing the number of cross-linking bonds, and finally achieving nano-level dispersion, which has a good reinforcing effect on nitrile rubber and is beneficial to improving the mechanical properties, wear resistance and aging resistance of the friction material; carbon nanotubes can form a network structure or a fibrous structure in the nitrile rubber matrix, increasing the cohesion and toughness of the material. The nano-level layered structure of organic montmorillonite can form a network in the friction material, which is beneficial to enhancing the strength and rigidity of the material, and the layered structure can also absorb and disperse heat, so that the organic synthetic material has a good gas barrier property, which is beneficial to increasing the flame retardant property of the friction material.

[0008] The alumina ceramic particles used in the present invention have excellent high temperature resistance and will not be significantly deformed or cracked. Their high hardness can provide effective braking performance and reduce the wear rate. The alumina ceramic particles have good thermal conductivity and can prevent the brake pad from overheating during the train braking process. Copper sulfide has good stability at high temperatures. Adding it to the brake pad can improve the thermal stability of the brake pad. It also has good lubrication properties and can fill the gaps in the friction material to reduce the wear rate of the material. The flaky structure of brucite is conducive to high temperature lubrication, which can slow down the temperature rise of the friction surface, extend the service life of the brake pad, and help stabilize the high temperature friction performance of the brake pad.

[0009] Due to the mutual cooperation or reaction between the various components of the friction material, the heat resistance and matrix strength of the organic synthetic friction material are effectively improved, which can meet the requirements of brake pads / brake shoes that can still maintain good heat resistance during the braking process of high-speed trains.

[0010] Furthermore, the organic synthetic friction material is prepared by including the following components in parts by weight: 6 to 12 parts of epoxy resin, 0.4 to 0.6 parts of toughening agent, 8 to 20 parts of nitrile rubber powder, 1 to 2 parts of peroxide, 1 to 2 parts of organic montmorillonite, 0.5 to 1.5 parts of zinc methacrylate, 1 to 3 parts of carbon nanotubes, 2 to 6 parts of alumina ceramic particles, 2 to 4 parts of copper sulfide, and 2 to 6 parts of brucite.

[0011] Furthermore, the matrix reinforcement component further comprises steel fibers; and / or,

[0012] The friction adjustment component also includes any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, ferrochrome powder, and diatomaceous earth.

[0013] Furthermore, the matrix reinforcement component further includes the following components in parts by weight: 18 to 35 parts of steel fiber, and / or,

[0014] The friction adjustment component also includes the following components in parts by weight: 2 to 4 parts of silicon carbide, 6 to 12 parts of granular graphite, 2 to 4 parts of antimony sulfide, 6 to 9 parts of mica hematite powder, 6 to 10 parts of ferrochrome powder, and 2 to 5 parts of diatomaceous earth.

[0015] In a second aspect, the present invention further discloses a method for preparing an organic synthetic friction material, which is used to prepare the above-mentioned organic synthetic friction material, comprising the following steps:

[0016] The epoxy resin, toughening agent, nitrile rubber powder, peroxide, organic montmorillonite and zinc methacrylate are fully mixed to obtain a premix A;

[0017] The obtained premix A is subjected to pressure kneading to obtain a mixture B, the kneading time is 2 to 4 minutes, and the kneading pressure is 6 to 8 kPa;

[0018] Adding carbon nanotubes into the mixture B and performing pressure kneading to obtain a mixture C, wherein the kneading time is 4 to 6 minutes and the kneading pressure is 6 to 8 kPa;

[0019] Alumina ceramic particles, copper sulfide and brucite are put into the mixture C for pressure kneading to obtain a mixture D, the kneading time is 4 to 6 minutes, the kneading pressure is 6 to 7 kPa, and the kneading temperature is 90° C. to 110° C.;

[0020] The mixture D is cooled to below 30° C., crushed and sieved using a crusher to obtain an organic synthetic friction material.

[0021] Compared with the prior art, when the organic synthetic friction material is prepared by the above preparation method, the various components of the material are evenly distributed by mixing and granulating, and then pressed at a specified pressure and time. During the pressing process, the various components cooperate with each other and are not easy to segregate, which can improve the strength, wear resistance and heat resistance of the organic synthetic friction material. The heat resistance and matrix strength of the organic synthetic friction material prepared by the present invention can meet the requirements of the brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains.

[0022] Furthermore, steel fibers are added into the mixture B for pressurized mixing; and / or,

[0023] Any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, ferrochrome powder and diatomaceous earth are added into the mixture C for pressure kneading.

[0024] In a third aspect, the present invention further discloses a brake pad / brake shoe, comprising:

[0025] Steel back;

[0026] The organic synthetic friction material as described above is fixed on a steel back.

[0027] Compared with the prior art, the brake pad / brake shoe of the present invention will not have obvious attenuation of mechanical properties during rapid heating when friction braking is performed with a carbon ceramic disc. The matrix has strong tolerance and can firmly fix the abrasive that affects the friction coefficient, stabilize the friction coefficient, and reduce the wear rate. It can meet the requirement of maintaining good heat resistance of the brake pad / brake shoe during the braking process of high-speed trains.

[0028] In a fourth aspect, the present invention further discloses a method for preparing a brake pad / brake shoe, which is used to prepare the above-mentioned brake pad / brake shoe, comprising the following steps:

[0029] Pressing the organic synthetic friction material and the steel back together to obtain a cold blank;

[0030] The cold blank is heat treated to obtain a brake pad / brake shoe.

[0031] Compared with the prior art, when the brake pad is prepared by the above preparation method, the organic synthetic friction material is pressed together with the steel backing, which requires fewer process steps and equipment, and improves production efficiency. Heat treatment can change the organizational structure of the brake pad, so that it has higher hardness and strength, improves the wear resistance of the brake pad, and can eliminate the voids inside the material, increase the heat resistance of the brake pad, and can meet the requirements of the brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains.

[0032] Furthermore, the organic synthetic friction material is pressed together with the steel backing by cold pressing.

[0033] Further, the cold embryo is subjected to heat treatment including:

[0034] Performing a first heat treatment on the cold embryo, wherein the temperature of the first heat treatment is room temperature to 110° C., the heating time is 1 to 2 hours, and the heat preservation time is 2 to 4 hours;

[0035] Performing a second heat treatment on the cold embryo, wherein the temperature of the second heat treatment is 110° C. to 160° C., the heating time is 2 to 3 hours, and the heat preservation time is 1 to 3 hours;

[0036] The cold embryo is subjected to a third heat treatment, wherein the temperature of the third heat treatment is 160° C. to 190° C., the heating time is 1 to 2 hours, and the heat preservation time is 2 to 5 hours;

[0037] The cold embryo is subjected to a fourth heat treatment, wherein the temperature of the fourth heat treatment is 190° C. to 220° C., the temperature is raised for 1 to 2 hours, and the temperature is kept for 1 to 3 hours. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] In the prior art, due to the low thermal conductivity of carbon ceramic discs, the heat generated by braking can only be absorbed by the brake pads, making the friction surface temperature much higher than that of ordinary steel discs or iron discs, which in turn leads to an increase in the wear rate of organic synthetic friction materials. The performance of the matrix also decreases at high temperatures, and the adhesion to the friction particles decreases, resulting in an unstable friction coefficient. Therefore, the mechanical properties and wear rate of the brake pads are extremely high. At present, the friction materials that can be compatible with carbon ceramic discs on the test bench are mainly carbon-carbon composite materials and powder metallurgy materials. The matrix of traditional organic synthetic materials is mainly rubber and resin, and the temperature resistance is lower than 450°C. Even if the rubber is reinforced by traditional reinforcing agents such as carbon black, the reinforcement effect cannot meet the requirements of rapid temperature rise.

[0040] In view of this problem, the present invention provides an organic friction material for a carbon ceramic disc, a brake pad / brake shoe and a preparation method thereof.

[0041] In a first aspect, an embodiment of the present invention provides an organic synthetic friction material suitable for a carbon ceramic disc, which is prepared from the following materials, including: a matrix, wherein the matrix includes epoxy resin, a toughening agent, nitrile rubber powder and peroxide; a matrix reinforcement component, wherein the matrix reinforcement component includes organic montmorillonite, zinc methacrylate and carbon nanotubes; and a friction adjustment component, wherein the friction adjustment component includes alumina ceramic particles, copper sulfide and brucite.

[0042] By adopting the above technical scheme, epoxy resin is used in the above embodiment instead of the commonly used phenolic resin. The epoxy resin has good strength, wear resistance and high temperature resistance after curing, which can make the friction material have higher wear resistance and durability, and can maintain stable performance in a high temperature environment without being easily deformed or hot-melted, meeting the high temperature resistance requirements of the brake pad in high-speed braking of trains; the toughening agent can form a microscopic elastic phase or particle dispersion system in the epoxy resin, which can improve the impact resistance of the present invention, and the toughening agent can reduce the glass transition temperature of the material while improving the toughness, so that the flexibility of the material molecular chain is increased, which helps to improve Impact resistance and fatigue resistance of friction materials; Nitrile rubber powder has excellent elasticity and flexibility. Adding it to the brake pad material can enhance the elasticity and flexibility of the friction material, thereby improving the wear resistance and durability of the brake pad. Nitrile rubber powder can provide good high temperature resistance and increase the high temperature resistance of the friction material. Peroxide can promote the cross-linking reaction of nitrile rubber molecules to form a cross-linked network structure, which helps to improve the wear resistance and heat resistance of the friction material. Peroxide has good thermal stability and can maintain the stable performance of the friction material at high temperatures, thereby helping to improve the overall performance and stability of the friction material.

[0043] In addition, the friction material in the embodiment of the present invention uses zinc methacrylate instead of the traditional rubber reinforcing agent carbon black, which has better heat resistance and aging resistance. In the peroxide vulcanization process, zinc methacrylate is polymerized by "in-situ polymerization method", dissolving and diffusing while polymerizing under the action of peroxide, and finally achieving nano-scale dispersion. In the polymerization process, the number of cross-linking bonds between rubber molecules is increased, thereby increasing the cross-linking density and strength of the nitrile rubber matrix, and further improving the wear resistance and aging resistance of the friction material. The nano-scale dispersion of zinc methacrylate avoids the agglomeration and aggregation of particles, which helps to improve the uniformity and stability of the friction material; carbon nanotubes can form a network structure or a fibrous structure in the nitrile rubber matrix, which increases the cohesion and toughness of the material, thereby improving the tear resistance of the nitrile rubber and reducing the wear rate. The nano-level layered structure of organic montmorillonite can form a network in the friction material, enhance the strength and stiffness of the material, and help improve the tensile strength and tear resistance of the friction material. The layered structure of organic montmorillonite can absorb and disperse heat, so that the organic synthetic material has better gas barrier properties, increase the flame retardant properties of the friction material, reduce the matrix loss caused by high-temperature burning, and thus ensure the friction and wear performance, which can significantly improve the tensile strength and tear strength of nitrile rubber.

[0044] The alumina ceramic particles used in the embodiment of the present invention can remain stable at 2000°C, have excellent high temperature resistance, and will not be significantly deformed or cracked. Their high hardness can provide effective braking performance and reduce wear rate. Their low thermal expansion coefficient can also reduce the cracking of friction materials at high temperatures. In addition, the alumina ceramic particles have good thermal conductivity. Adding them to the brake pad can improve the thermal conductivity of the brake pad, help to quickly conduct the heat generated during friction to the surrounding environment, avoid overheating of the brake pad and improve its working efficiency and stability. Copper sulfide has good stability at high temperatures. Adding it to the brake pad can improve the thermal stability of the brake pad, slow down the temperature rise of the friction surface, and reduce the risk of thermal damage caused by friction. It also has good lubrication properties and can fill the gaps in the friction material and reduce the wear rate of the material. After brucite releases water at high temperature, it forms magnesium oxide and has good high temperature resistance. Adding brucite to the brake pad can improve its thermal stability, slow down the temperature rise of the friction surface, and extend the service life of the brake pad. Its flaky structure also helps high temperature lubrication, which is beneficial to stabilize the high temperature friction performance of the brake pad.

[0045] Due to the mutual cooperation or reaction between the various components of the friction material, the heat resistance and matrix strength of the organic synthetic friction material are effectively improved, which can meet the requirements of brake pads / brake shoes that can still maintain good heat resistance during the braking process of high-speed trains.

[0046] In some possible implementations, the organic synthetic friction material is prepared by including the following components in parts by weight: 6 to 12 parts of epoxy resin, 0.4 to 0.6 parts of toughening agent, 8 to 20 parts of nitrile rubber powder, 1 to 2 parts of peroxide, 1 to 2 parts of organic montmorillonite, 0.5 to 1.5 parts of zinc methacrylate, 1 to 3 parts of carbon nanotubes, 2 to 6 parts of alumina ceramic particles, 2 to 4 parts of copper sulfide, and 2 to 6 parts of brucite.

[0047] By adopting the above technical scheme, by limiting the specific proportions of the above components, the various components of the friction material can better cooperate or react with each other, thereby improving the heat resistance and mechanical strength of the organic synthetic friction material, and making the organic synthetic friction material with a specific composition have excellent heat resistance.

[0048] Further, in combination with the above embodiments, the matrix reinforcement component in the embodiments of the present invention further comprises steel fibers. For example, the matrix reinforcement component in the embodiments of the present invention comprises 18 to 35 parts of steel fibers.

[0049] By adopting the above technical solution, steel fibers are added to the matrix reinforcement component. Since the steel fibers have good thermal conductivity, it helps to improve the thermal conductivity of the brake pad and more effectively dissipate the heat generated during braking, thereby increasing the thermal shock resistance of the organic synthetic material.

[0050] Further, in combination with the above embodiments, the friction adjustment component in the embodiment of the present invention also includes any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, chromium iron powder, and diatomaceous earth. For example, the friction adjustment component includes the following components in parts by weight: 2 to 4 parts of silicon carbide, 6 to 12 parts of granular graphite, 2 to 4 parts of antimony sulfide, 6 to 9 parts of mica hematite powder, 6 to 10 parts of chromium iron powder, and 2 to 5 parts of diatomaceous earth.

[0051] By adopting the above technical scheme, silicon carbide is added to the friction adjustment component, which has the characteristics of extremely high hardness and good wear resistance, and can increase the hardness and wear resistance of organic synthetic materials and improve friction performance. The melting point of silicon carbide is 2700°C. Adding it to the material can make the material have good stability and high temperature resistance; granular graphite has good lubrication performance and can fill the gaps in organic synthetic materials and reduce the wear rate of the material; antimony sulfide can reduce the combustion performance of the material and improve the flame retardant performance of the material; mica hematite powder and ferrochrome powder have high hardness and wear resistance, and adding them to the brake pad can enhance the wear resistance of its surface, and mica hematite powder has good thermal conductivity, which can effectively conduct the heat generated during braking to the surrounding environment, which helps to reduce the temperature of the braking system, reduce thermal attenuation during braking, and improve braking performance and stability; diatomaceous earth has good thermal stability and high temperature resistance, which can help improve the heat resistance of the brake pad and reduce the influence of high temperature generated by braking friction on braking performance. By further limiting the composition and ratio of organic synthetic friction materials, it is possible to ensure that the brake pads provide a stable friction coefficient during braking and avoid performance fluctuations caused by temperature changes. This makes the organic synthetic friction materials under specific composition have excellent heat resistance and can meet the requirements of brake pads / brake shoes that can maintain good heat resistance during the braking process of high-speed trains.

[0052] In a second aspect, an embodiment of the present invention further discloses a method for preparing an organic synthetic friction material, which is used to prepare the above-mentioned organic synthetic friction material, comprising the following steps:

[0053] The epoxy resin, toughening agent, nitrile rubber powder, peroxide, organic montmorillonite and zinc methacrylate are fully mixed to obtain a premix A;

[0054] The obtained premix A is subjected to pressure kneading to obtain a mixture B, the kneading time is 2 to 4 minutes, and the kneading pressure is 6 to 8 kPa;

[0055] Adding carbon nanotubes into mixture B and performing pressure kneading to obtain mixture C, wherein the kneading time is 4 to 6 minutes and the kneading pressure is 6 to 8 kPa;

[0056] Alumina ceramic particles, copper sulfide and brucite are put into mixture C for pressure kneading to obtain mixture D, the kneading time is 4 to 6 minutes, the kneading pressure is 6 to 7 kPa, and the kneading temperature is 90° C. to 110° C.;

[0057] The mixture D was cooled to below 30° C., crushed and sieved using a crusher to obtain an organic synthetic friction material.

[0058] When the organic synthetic friction material is prepared by the above technical solution and the above preparation method, the base material is fully mixed, and then the base reinforcing component and the friction adjusting component are added to perform pressure reduction and internal kneading to make the components uniformly distributed, and then the components are pressed at a specified pressure and time. During the pressing process, the components cooperate with each other and are not easy to segregate, which reduces the dislocation of the holes inside the material, and can improve the strength, wear resistance and heat resistance of the organic synthetic friction material. The heat resistance and base strength of the organic synthetic friction material prepared by the present invention can meet the requirements of the brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains.

[0059] Furthermore, the mixing machine used in the embodiment provided by the present invention is a horizontal mixer, and circulating water is provided between the inner and outer walls of the horizontal mixer during the mixing process, the temperature of the circulating water is 20°C to 35°C, and the mixing time is 10-15 minutes. Premixing can ensure that all ingredients are evenly distributed during the mixing process, effectively increase the rate of chemical reactions, and help improve the wear resistance and thermal stability of organic synthetic materials, thereby improving the heat resistance of brake pads / brake shoes.

[0060] Furthermore, in combination with the above-mentioned embodiment, the embodiment of the present invention also adds steel fibers into the mixture B for pressurized mixing.

[0061] Furthermore, in combination with the above embodiments, the embodiments of the present invention further add any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, ferrochrome powder, and diatomaceous earth into the mixture C for pressurized kneading.

[0062] In the above embodiments, steel fiber and mica hematite powder have good thermal conductivity. Adding steel fiber and mica hematite powder to the material can improve the thermal conductivity of the brake pad, which is beneficial to the heat generated during braking, thereby increasing the heat shock resistance of the friction material; adding silicon carbide to the material can increase the hardness, wear resistance and high temperature resistance of the friction material, so that the friction material has good stability and high temperature resistance; granular graphite has good lubrication properties and can fill the gaps in the friction material to reduce the wear rate of the material; antimony sulfide can reduce the combustion performance of the material and improve the flame retardant performance of the material; mica hematite powder and ferrochrome powder have high hardness and wear resistance, and adding them to the brake pad can enhance the wear resistance of its surface; diatomaceous earth has good thermal stability and high temperature resistance. Adding diatomaceous earth to the material can help improve the heat resistance of the brake pad and reduce the impact of high temperature generated by braking friction on the braking performance.

[0063] Further, in combination with the above embodiments, the internal mixing equipment used in the embodiments of the present invention are all internal mixers.

[0064] Further, in combination with the above embodiments, the mesh particle size used in the embodiments of the present invention can be 3 mm to 6 mm. Specifically, the mesh particle size can be selected to be 3 mm, 4 mm, 5 mm or 6 mm. The organic friction material within this particle size range can promote more uniform mixing of the materials, ensure that other components are evenly dispersed throughout the material, and increase the service life of the product.

[0065] In a third aspect, an embodiment of the present invention further provides a brake pad / brake shoe, comprising an organic friction material and a steel back, wherein the organic friction material for the carbon ceramic disc is fixed on the steel back. The connection relationship between the steel back and the friction material is no longer limited in detail, and conventional means such as mechanical fixing can be used for fixed connection.

[0066] By adopting the above technical scheme, the brake pad / brake shoe of the present invention uses the organic friction material in the above invention embodiment, and under the combined action of the various components of the organic friction material, friction braking is performed when the train is running at high speed. The mechanical properties of the brake pad / brake shoe of the present invention will not be significantly attenuated during the rapid heating process, the matrix has strong tolerance, can firmly fix the abrasive that affects the friction coefficient, stabilize the friction coefficient, and reduce the wear rate, and can meet the requirements of the brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains.

[0067] In a fourth aspect, an embodiment of the present invention further provides a method for preparing a brake pad / brake shoe, which is used to prepare the above-mentioned brake pad / brake shoe, comprising the following steps:

[0068] The organic synthetic friction material is pressed together with the steel back to obtain a cold blank;

[0069] The cold blank is heat treated to obtain the brake pad / brake shoe.

[0070] When the above technical solution and the above preparation method are used to prepare the brake pad, the organic synthetic friction material is pressed together with the steel back, which requires fewer process steps and equipment, thereby reducing the manufacturing cost and improving the production efficiency, and is suitable for industrial production. Heat treatment can change the organizational structure of the brake pad, promote the curing and cross-linking reaction of the resin, make the material of each part of the brake pad more uniform, make it obtain higher hardness and strength, improve the wear resistance of the brake pad, and eliminate the voids inside the material, increase the heat resistance of the brake pad, and can meet the requirements of the brake pad / brake shoe that can still maintain good heat resistance during the braking process of high-speed trains.

[0071] Further, in combination with the above embodiment, the method of cold pressing is used to press the organic synthetic friction material and the steel back together. For example, the cold pressing pressure can be selected to be 4000-6500N / cm 2 Specifically, the cold pressing pressure can be selected as 4000N / cm 2 、5000N / cm 2 、5500N / cm 2 、6000N / cm 2 or 6500N / cm 2 Etc. The holding time is 30s. At room temperature, cold pressing can optimize the microstructure and grain morphology of the material by controlling the pressure, improve the strength, hardness and wear resistance of the material, thereby improving its performance. Cold pressing is an efficient manufacturing process that can mass-produce high-quality parts or products in a short time and improve manufacturing efficiency.

[0072] Further, in combination with the above embodiment, the embodiment of the present invention heat treats the cold embryo including:

[0073] The cold embryo is subjected to a first heat treatment, wherein the temperature of the first heat treatment is room temperature to 110° C., the heating time is 1 to 2 hours, and the heat preservation time is 2 to 4 hours;

[0074] The cold embryo is subjected to a second heat treatment, the temperature of the second heat treatment is 110°C to 160°C, the heating time is 2 to 3 hours, and the heat preservation time is 1 to 3 hours;

[0075] The cold embryo is subjected to a third heat treatment, the temperature of the third heat treatment is 160°C to 190°C, the heating time is 1 to 2 hours, and the heat preservation time is 2 to 5 hours;

[0076] The cold embryo is subjected to the fourth heat treatment, the temperature of the fourth heat treatment is 190°C to 220°C, the temperature is raised for 1 to 2 hours, and the temperature is kept for 1 to 3 hours.

[0077] The heat treatment method of the preparation method of the brake shoe / brake pad of the present invention is a segmented heat treatment, which can promote the curing reaction of the resin, improve the heat resistance of the friction material under the condition of high-speed braking of the train, and help the friction material maintain stable friction performance and mechanical strength under the condition of train braking. By performing continuous heat treatment steps at different temperatures, the curing process of the resin can be gradually completed, ensuring that the final product has a stable chemical structure and good performance, and extending the service life of the product.

[0078] The organic synthetic friction material and brake pad / brake shoe provided by the present invention are further described in detail in conjunction with the embodiments. The following embodiments are merely explanations of the present invention, not limitations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The test methods used in the following embodiments are conventional methods unless otherwise specified; the raw materials used in the following implementation methods are commercially available raw materials unless otherwise specified, and the selection of physical properties of each raw material can be referenced as follows:

[0079] The epoxy resin can be DYD-128, the toughening agent can be any one of Qishi toughening agent, styrene-butadiene rubber, nitrile rubber and polyamide resin containing unsaturated bonds and amide groups, the nitrile rubber powder can be hydrogenated nitrile rubber powder, the peroxide can be any one of dicumyl peroxide (DCP), dialkyl peroxide, diacyl peroxide and peroxyester, the organic montmorillonite is nano-grade, and the zinc methacrylate is of ordinary grade on the market. The material and specific shape of the steel back can be determined according to actual use requirements. The steel back material is preferably Q235 steel, which is formed by stamping and bending a cold-rolled plate with a thickness of 1-5 mm.

[0080] The length of the carbon nanotubes is 75 μm-150 μm.

[0081] The alumina ceramic particles are 10 mesh and the purity is above 99.5%.

[0082] The fiber length of brucite is 1mm-3mm.

[0083] Copper sulfate should be of 325 mesh grade.

[0084] It should be noted that the selection of the above raw materials is only for illustration and is not a limitation on the performance of the raw materials. Raw materials that meet the performance requirements can be selected according to actual needs.

[0085] Example 1

[0086] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 5 mm; the organic synthetic friction material and the steel back are rolled together.

[0087] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 7 parts of epoxy resin, 0.5 parts of toughening agent QS-C, 15 parts of nitrile rubber powder, 1 part of dicumyl peroxide, 1.5 parts of organic montmorillonite, 1.5 parts of zinc methacrylate, 2 parts of carbon nanotubes, 6 parts of alumina ceramic particles, 4 parts of copper sulfide, and 4 parts of brucite.

[0088] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0089] S1. 7 parts of epoxy resin, 0.5 parts of toughening agent QS-C, 15 parts of nitrile rubber powder, 1 part of dicumyl peroxide, 1.5 parts of organic montmorillonite and 1.5 parts of zinc methacrylate are put into a horizontal mixer and mixed thoroughly. During the mixing process, circulating water is provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 35°C and the mixing time is 10 min, and obtain premix A;

[0090] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 2 min, the mixing pressure is 7 kPa;

[0091] S3, adding 2 parts of carbon nanotubes into mixture B and kneading them under pressure to obtain mixture C, and the kneading time is 4 min, the mixing pressure is 7 kPa;

[0092] S4, 6 parts of alumina ceramic particles, 4 parts of copper sulfide and 4 parts of brucite are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 7 kPa, and the mixing temperature is 90 °C;

[0093] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 6 mm sieve to obtain an organic synthetic friction material;

[0094] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 4000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0095] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0096] The above heat treatment adopts segmented heating, and the temperature control parameters of the segmented heating process are as follows:

[0097] Table 1 Temperature gradient table

[0098]

[0099]

[0100] Example 2

[0101] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 1 mm; the organic synthetic friction material and the steel back are rolled together.

[0102] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 11 parts of epoxy resin, 0.6 parts of toughening agent QS-C, 10 parts of nitrile rubber powder, 1.5 parts of dicumyl peroxide, 2 parts of organic montmorillonite, 1 part of zinc methacrylate, 1.5 parts of carbon nanotubes, 3 parts of alumina ceramic particles, 3 parts of copper sulfide, and 5 parts of brucite.

[0103] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0104] S1. Put 11 parts of epoxy resin, 0.6 parts of toughening agent QS-C, 10 parts of nitrile rubber powder, 1.5 parts of dicumyl peroxide, 2 parts of organic montmorillonite and 1 part of zinc methacrylate into a horizontal mixer and mix them thoroughly. During the mixing process, circulating water should be provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 20°C and the mixing time is 12 min, and obtain premix A;

[0105] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 3 min, the mixing pressure is 6 kPa;

[0106] S3, adding 1.5 parts of carbon nanotubes into mixture B and kneading under pressure to obtain mixture C, and the kneading time is 5 min, the mixing pressure is 6 kPa;

[0107] S4, 3 parts of alumina ceramic particles, 3 parts of copper sulfide and 5 parts of brucite are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 6 kPa, and the mixing temperature is 110 °C;

[0108] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 3 mm sieve to obtain an organic synthetic friction material;

[0109] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 6500N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0110] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0111] The above heat treatment adopts segmented heating, and the temperature control parameters of the segmented heating process are as follows:

[0112] Table 2 Temperature gradient table

[0113] Temperature(℃) Heating time (h) Insulation time (h) Room temperature~110 2 4 110～160 3 3 160～190 2 5 190～220 2 1

[0114] Example 3

[0115] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 1 mm; the organic synthetic friction material and the steel back are rolled together.

[0116] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 10 parts of epoxy resin, 0.4 parts of toughening agent QS-C, 18 parts of nitrile rubber powder, 2 parts of diisopropylbenzene peroxide, 1 part of organic montmorillonite, 1.2 parts of zinc methacrylate, 2.5 parts of carbon nanotubes, 4 parts of alumina ceramic particles, 2 parts of copper sulfide, and 3 parts of brucite.

[0117] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0118] S1. Put 10 parts of epoxy resin, 0.4 parts of toughening agent QS-C, 18 parts of nitrile rubber powder, 2 parts of dicumyl peroxide, 1 part of organic montmorillonite and 1.2 parts of zinc methacrylate into a horizontal mixer and mix them thoroughly. During the mixing process, circulating water should be provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 23°C and the mixing time is 15 min, and obtain premix A;

[0119] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 4 min, the mixing pressure is 8 kPa;

[0120] S3, adding 2.5 parts of carbon nanotubes into mixture B and kneading under pressure to obtain mixture C, and the kneading time is 6 min, the mixing pressure is 8 kPa;

[0121] S4, 4 parts of alumina ceramic particles, 2 parts of copper sulfide and 3 parts of brucite are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 6.5 kPa, and the mixing temperature is 105 °C;

[0122] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 5 mm sieve to obtain an organic synthetic friction material;

[0123] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 5000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0124] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0125] The above heat treatment adopts segmented heating, and the temperature control parameters of the segmented heating process are as follows:

[0126] Table 3 Temperature gradient table

[0127] Temperature(℃) Heating time (h) Insulation time (h) Room temperature~110 1.5 1.5 110～160 2.5 2 160～190 1.5 4 190～220 1.5 2

[0128] Example 4

[0129] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 3 mm; the organic synthetic friction material and the steel back are rolled together.

[0130] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 9 parts of epoxy resin DYD-128, 0.4 parts of toughening agent QS-C, 17 parts of hydrogenated nitrile rubber powder, 1 part of diisopropylbenzene peroxide, 1.5 parts of organic montmorillonite, 0.8 parts of zinc methacrylate, 2.7 parts of carbon nanotubes, 2.5 parts of 10-mesh alumina ceramic particles, 3 parts of 325-mesh copper sulfide, 2 parts of brucite, and 28 parts of steel fiber.

[0131] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0132] S1. 9 parts of epoxy resin DYD-128, 0.4 parts of toughening agent QS-C, 17 parts of hydrogenated nitrile rubber powder, 1 part of dicumyl peroxide, 1.5 parts of organic montmorillonite and 0.8 parts of zinc methacrylate are put into a horizontal mixer and fully mixed. During the mixing process, circulating water is provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 30° C. and the mixing time is 13 min to obtain premix A.

[0133] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 4 min, 7Pa;

[0134] S3, 1 part 2.7 parts of carbon nanotubes and 28 parts of steel fibers are put into mixture B for pressure kneading to obtain mixture C, and the kneading time is 4 min, the mixing pressure is 7 kPa;

[0135] S4, 2.5 parts of 10-mesh alumina ceramic particles, 3 parts of 325-mesh copper sulfide, and 2 parts of brucite are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 7 kPa, and the mixing temperature is 95 °C;

[0136] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 4 mm sieve to obtain an organic synthetic friction material;

[0137] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 4000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0138] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0139] The above heat treatment adopts staged heating, and the temperature control parameters of the staged heating process are the same as those in Example 1.

[0140] Example 5

[0141] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 2 mm; the organic synthetic friction material and the steel back are rolled together.

[0142] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 12 parts of epoxy resin DYD-128, 0.5 parts of Qishi toughening agent, 12 parts of hydrogenated nitrile rubber powder, 1 part of peroxide, 2 parts of organic montmorillonite, 0.5 parts of zinc methacrylate, 1 part of carbon nanotubes, 5.5 parts of 10-mesh alumina ceramic particles, 3 parts of 325-mesh copper sulfide, 3 parts of brucite, 25 parts of steel fiber, and 3 parts of silicon carbide.

[0143] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0144] S1. Put 12 parts of epoxy resin DYD-128, 0.5 parts of toughening agent QS-C, 12 parts of hydrogenated nitrile rubber powder, 1 part of benzoyl peroxide, 2 parts of organic montmorillonite and 0.5 parts of zinc methacrylate into a horizontal mixer and mix them thoroughly. During the mixing process, circulating water should be provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 28°C and the mixing time is 14 min, and obtain premix A;

[0145] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 3 min, the mixing pressure is 6 kPa;

[0146] S3, 1 part of carbon nanotubes and 25 parts of steel fibers are put into mixture B for pressure kneading to obtain mixture C, and the kneading time is 4 min, the mixing pressure is 6 kPa;

[0147] S4, 5.5 parts of 10-mesh alumina ceramic particles, 3 parts of silicon carbide, 3 parts of 325-mesh copper sulfide and 3 parts of brucite are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 6.5 kPa, and the mixing temperature is 100 °C;

[0148] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 6 mm sieve to obtain an organic synthetic friction material;

[0149] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 4000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0150] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0151] The above heat treatment adopts staged heating, and the temperature control parameters of the staged heating process are the same as those in Example 1.

[0152] Example 6

[0153] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 4 mm; the organic synthetic friction material and the steel back are rolled together.

[0154] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 11 parts of epoxy resin DYD-128, 0.5 parts of Qishi toughening agent, 9 parts of hydrogenated nitrile rubber powder, 1 part of peroxide, 1.2 parts of organic montmorillonite, 1.4 parts of zinc methacrylate, 2.4 parts of carbon nanotubes, 3 parts of 10-mesh alumina ceramic particles, 2.5 parts of 325-mesh copper sulfide, 2.5 parts of brucite, 34 parts of steel fiber, 2 parts of silicon carbide, 7 parts of granular graphite, 2 parts of antimony sulfide, 8.5 parts of mica hematite powder, 6.5 parts of ferrochrome powder and 2 parts of diatomaceous earth.

[0155] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0156] S1. 11 parts of epoxy resin DYD-128, 0.5 parts of Qishi toughening agent QS-C, 9 parts of hydrogenated nitrile rubber powder, 1 part of tert-butyl hydroperoxide, 1.2 parts of organic montmorillonite and 1.4 parts of zinc methacrylate are put into a horizontal mixer and fully mixed. During the mixing process, circulating water is provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 25° C. and the mixing time is 10 min to obtain premix A.

[0157] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 3 min, the mixing pressure is 8 kPa;

[0158] S3, 2.4 parts of carbon nanotubes and 34 parts of steel fibers were added to the mixture B for pressure kneading to obtain a mixture C. The kneading time was 5 min, the mixing pressure is 8 kPa;

[0159] S4, 3 parts of 10-mesh alumina ceramic particles, 2.5 parts of 325-mesh copper sulfide, 2.5 parts of grade brucite, 2 parts of silicon carbide, 7 parts of granular graphite, 2 parts of antimony sulfide, 8.5 parts of mica hematite powder, 6.5 parts of ferrochrome powder and 2 parts of diatomaceous earth are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 7 kPa, and the mixing temperature is 100 °C;

[0160] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 3 mm sieve to obtain an organic synthetic friction material;

[0161] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 6500N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0162] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0163] The above heat treatment adopts staged heating, and the temperature control parameters of the staged heating process are the same as those in Example 2.

[0164] Example 7

[0165] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 5 mm; the organic synthetic friction material and the steel back are rolled together.

[0166] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 6 parts of epoxy resin DYD-128, 0.5 parts of Qishi toughening agent, 19 parts of hydrogenated nitrile rubber powder, 1.5 parts of peroxide, 1.1 parts of organic montmorillonite, 0.8 parts of zinc methacrylate, 1.3 parts of carbon nanotubes, 2 parts of 10-mesh alumina ceramic particles, 3 parts of 325-mesh copper sulfide, 4 parts of brucite, 18 parts of steel fiber, 4 parts of silicon carbide, 11 parts of granular graphite, 3.5 parts of antimony sulfide, 7 parts of mica hematite powder, 9 parts of ferrochrome powder and 4 parts of diatomaceous earth.

[0167] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0168] S1. 6 parts of epoxy resin DYD-128, 0.5 parts of Qishi toughening agent QS-C, 19 parts of hydrogenated nitrile rubber powder, 1.5 parts of ethyl acetyl peroxide, 1.1 parts of organic montmorillonite and 0.8 parts of zinc methacrylate are put into a horizontal mixer and fully mixed. During the mixing process, circulating water is provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 29° C. and the mixing time is 14 min to obtain premix A.

[0169] S2, the premix A obtained in step S1 is pressurized and kneaded to obtain a mixture B, and the kneading time is 2 min, the mixing pressure is 7 kPa;

[0170] S3, 1.3 parts of carbon nanotubes and 18 parts of steel fibers were added to the mixture B for pressure kneading to obtain a mixture C. The kneading time was 5 min, the mixing pressure is 6 kPa;

[0171] S4, 2 parts of 10-mesh alumina ceramic particles, 3 parts of 325-mesh copper sulfide, 4 parts of brucite, 4 parts of silicon carbide, 11 parts of granular graphite, 3.5 parts of antimony sulfide, 7 parts of mica hematite powder, 9 parts of ferrochrome powder and 4 parts of diatomaceous earth are put into the mixture C for pressure kneading to obtain a mixture D, and the kneading time is 6 min, the mixing pressure is 6.5 kPa, and the mixing temperature is 105 °C;

[0172] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 5 mm sieve to obtain an organic synthetic friction material;

[0173] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 5000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0174] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0175] The above heat treatment adopts staged heating, and the temperature control parameters of the staged heating process are the same as those in Example 3.

[0176] Example 8

[0177] The embodiment of the present invention provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the steel back is made of Q235 steel and is formed by stamping and bending a cold-rolled plate with a thickness of 5 mm; the organic synthetic friction material and the steel back are rolled together.

[0178] The organic synthetic friction material is prepared from the following materials, which are measured by weight: 8 parts of epoxy resin, 0.5 parts of Qishi toughening agent QS-C, 15 parts of nitrile rubber powder, 1.5 parts of diisopropylbenzene peroxide, 30 parts of steel fiber, 1.5 parts of organic montmorillonite, 1.5 parts of zinc methacrylate, 2 parts of carbon nanotubes, 4 parts of silicon carbide, 4 parts of alumina ceramic particles, 4 parts of copper sulfide, 4 parts of brucite, 4 parts of granular graphite, 3 parts of antimony sulfide, 6 parts of mica hematite powder, 8 parts of ferrochrome powder and 3 parts of diatomaceous earth.

[0179] The method for preparing a brake pad / brake shoe in an embodiment of the present invention comprises the following steps:

[0180] S1. 8 parts of epoxy resin, 0.5 parts of Qishi toughening agent QS-C, 15 parts of nitrile rubber powder, 1.5 parts of dicumyl peroxide, 30 parts of steel fiber, 1.5 parts of organic montmorillonite and 1.5 parts of zinc methacrylate are put into a horizontal mixer and fully mixed. During the mixing process, circulating water is provided between the inner and outer walls of the horizontal mixer. The circulating water temperature is 27° C. and the mixing time is 15 min to obtain premix A.

[0181] S2, pressurizing and kneading the premix A obtained in step S1 to obtain a mixture B, wherein the kneading time is 2 min and the kneading pressure is 8 kPa;

[0182] S3, adding 2 parts of carbon nanotubes and 30 parts of steel fibers into mixture B for pressurized banburying to obtain mixture C, the banburying time is 4 minutes, and the banburying pressure is 8 kPa;

[0183] S4, 4 parts of alumina ceramic particles, 4 parts of silicon carbide, 4 parts of copper sulfide, 4 parts of brucite, 4 parts of granular graphite, 3 parts of antimony sulfide, 6 parts of mica hematite powder, 8 parts of ferrochrome powder and 3 parts of diatomaceous earth are put into the mixture C for pressure mixing to obtain a mixture D, the mixing time is 6 min, the mixing pressure is 6.5 kPa, and the mixing temperature is 100 ° C;

[0184] S5, naturally cooling the mixture D to below 30° C., crushing and sieving using a 5 mm sieve to obtain an organic synthetic friction material;

[0185] S6. Cold press the organic synthetic friction material and the steel back together at room temperature, and set the pressure to 5000N / cm 2 , keep the pressure for 30s to obtain a cold embryo;

[0186] S7. Heat-treat the cold blank to obtain a brake pad / brake shoe.

[0187] The above heat treatment adopts staged heating, and the temperature control parameters of the staged heating process are the same as those in Example 3.

[0188] The present invention is further described below by using comparative examples.

[0189] Comparative Example 1

[0190] This comparative example provides a brake shoe / brake pad, comprising an organic synthetic friction material and a steel back, wherein the organic synthetic friction material and the steel back are rolled together.

[0191] The organic synthetic friction material is prepared from the following materials, which are calculated by weight: 15 parts of nitrile rubber, 40 parts of steel fiber, 10 parts of glass fiber, 20 parts of phenolic resin, 8 parts of calcium carbonate, 8 parts of petroleum coke, 10 parts of barium sulfate, 2 parts of granular graphite and 1 part of insoluble sulfur.

[0192] The preparation method of the brake shoe / brake pad in this comparative example is basically the same as the preparation method in Example 1.

[0193] Comparative Example 2

[0194] The raw material composition and preparation method of Comparative Example 2 are basically the same as those of Example 8, except that phenolic resin is used instead of epoxy resin in the preparation step S1, and the other amounts remain unchanged.

[0195] Comparative Example 3

[0196] The raw material composition and preparation method of Comparative Example 3 are basically the same as those of Example 8, except that an equal amount of styrene-butadiene rubber is used in the production step S1 to replace the nitrile rubber powder, and the other amounts remain unchanged.

[0197] Comparative Example 4

[0198] The raw material composition and preparation method of Comparative Example 4 are basically the same as those of Example 8, except that an equal amount of carbon black is used in place of zinc methacrylate in the preparation step S1, and the other amounts remain unchanged.

[0199] Comparative Example 5

[0200] The raw material composition and preparation method of Comparative Example 5 are basically the same as those of Example 8, except that an equal amount of granular graphite is used to replace carbon nanotubes in the preparation step S3, and the other amounts remain unchanged.

[0201] Comparative Example 6

[0202] The raw material composition and preparation method of Comparative Example 6 are basically the same as those of Example 8, with the difference being that an equal amount of alumina is used in the preparation step S4 to replace the alumina ceramic particles, and the other amounts remain unchanged.

[0203] Comparative Example 7

[0204] The raw material composition and preparation method of Comparative Example 7 are basically the same as those of Example 8, except that an equal amount of zinc sulfide is used in the preparation step S4 to replace copper sulfide, and the other amounts remain unchanged.

[0205] Comparative Example 8

[0206] The raw material composition and preparation method of Comparative Example 8 are basically the same as those of Example 8, except that an equal amount of magnesium carbonate is used in place of brucite in the preparation step S4, and the other amounts remain unchanged.

[0207] Comparative Example 9

[0208] The raw material composition and preparation method of Comparative Example 9 are basically the same as those of Example 8, except that an equal amount of natural montmorillonite is used to replace the organic montmorillonite in the preparation step S1, and the other amounts remain unchanged.

[0209] Comparative Example 10

[0210] The raw material composition and preparation method of Comparative Example 10 are basically the same as those of Example 8, except that an equal amount of epoxy resin is used in the production step S1 to replace the nitrile rubber powder, and the other amounts remain unchanged.

[0211] Comparative Example 11

[0212] The raw material composition and preparation method of Comparative Example 11 are basically the same as those of Example 8, except that an equal amount of ammonium persulfate is used in place of peroxide in the preparation step S1, and the other amounts remain unchanged.

[0213] Performance Testing

[0214] The friction and wear performance of the brake pads prepared in the above Example 1 and other comparative examples was tested with reference to "UIC541-3-2010 Braking - Disc Braking and Its Application - General Provisions for Brake Pad Acceptance" using a LINK 7200 inertial friction and wear test bench. It should be noted that in the following test results, the determination of the friction coefficient is carried out at a certain speed and braking pressure. This test method dynamically simulates the actual working conditions of the vehicle during braking, and obtains the friction coefficient by measuring the friction torque. After the test is completed, the wear amount is calculated based on the weight loss and braking energy. The friction coefficient is shown in Table 1, and the wear amount is shown in Table 2:

[0215] Table 1 Comparison of friction coefficient

[0216]

[0217]

[0218]

[0219] Note: "-" means that the sample cannot be completed at this speed due to material damage, and no test results are obtained

[0220] Table 2 Comparison of friction coefficient

[0221] Sample name <![CDATA[Wear rate (MJ / cm 3 )]]> Example 1 0.826 Example 2 0.635 Example 3 0.408 Example 4 0.632 Example 5 0.521 Example 6 0.815 Example 7 0.726 Example 8 0.653 Comparative Example 1 2.352 Comparative Example 2 1.986 Comparative Example 3 1.235 Comparative Example 4 1.325 Comparative Example 5 0.986 Comparative Example 6 0.985 Comparative Example 7 1.137 Comparative Example 8 1.254 Comparative Example 9 0.762 Comparative Example 10 1.325 Comparative Example 11 1.985

[0222] It can be seen from the above test results that the brake pad / brake shoe of the present invention, when matched with a carbon-ceramic disc for friction and wear tests, can effectively resist the degradation of matrix performance caused by high temperature, maintain a relatively stable friction coefficient, at least meet the emergency braking test of 250km / h, and the wear amount is significantly reduced compared to other organic synthetic brake pads.

[0223] 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 changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An organic synthetic friction material, characterized in that: The method is prepared by the following materials, including: A matrix, wherein the matrix comprises epoxy resin, toughening agent, nitrile rubber powder and peroxide; A matrix reinforcement component, wherein the matrix reinforcement component includes organic montmorillonite, zinc methacrylate and carbon nanotubes; A friction adjusting component comprising alumina ceramic particles, copper sulfide and brucite.

2. The organic synthetic friction material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 6 to 12 parts of epoxy resin, 0.4 to 0.6 parts of toughening agent, 8 to 20 parts of nitrile rubber powder, 1 to 2 parts of peroxide, 1 to 2 parts of organic montmorillonite, 0.5 to 1.5 parts of zinc methacrylate, 1 to 3 parts of carbon nanotubes, 2 to 6 parts of alumina ceramic particles, 2 to 4 parts of copper sulfide and 2 to 6 parts of brucite.

3. The organic synthetic friction material according to claim 1 or 2, characterized in that: The matrix reinforcement component further comprises steel fibers; and / or, The friction adjustment component also includes any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, ferrochrome powder, and diatomaceous earth.

4. The organic synthetic friction material according to claim 3, characterized in that: The matrix reinforcement component also includes the following components in parts by weight: 18 to 35 parts of steel fiber, and / or, The friction adjustment component also includes the following components in parts by weight: 2 to 4 parts of silicon carbide, 6 to 12 parts of granular graphite, 2 to 4 parts of antimony sulfide, 6 to 9 parts of mica hematite powder, 6 to 10 parts of ferrochrome powder, and 2 to 5 parts of diatomaceous earth.

5. A method for preparing an organic synthetic friction material, applied to the organic synthetic friction material according to any one of claims 1 to 4, characterized in that: The following steps are involved: The epoxy resin, toughening agent, nitrile rubber powder, peroxide, organic montmorillonite and zinc methacrylate are fully mixed to obtain a premix A; The obtained premix A is subjected to pressure kneading to obtain a mixture B, the kneading time is 2 to 4 minutes, and the kneading pressure is 6 to 8 kPa; Adding carbon nanotubes into the mixture B and performing pressure kneading to obtain a mixture C, wherein the kneading time is 4 to 6 minutes and the kneading pressure is 6 to 8 kPa; Alumina ceramic particles, copper sulfide and brucite are put into the mixture C for pressure kneading to obtain a mixture D, the kneading time is 4 to 6 minutes, the kneading pressure is 6 to 7 kPa, and the kneading temperature is 90° C. to 110° C.; The mixture D was cooled to below 30° C., crushed and sieved using a crusher to obtain an organic synthetic friction material.

6. The method for preparing an organic synthetic friction material according to claim 5, characterized in that: Also adding steel fibers into the mixture B for pressurized mixing; and / or, Any one or more of silicon carbide, granular graphite, antimony sulfide, mica hematite powder, ferrochrome powder and diatomaceous earth are added into the mixture C for pressure kneading.

7. A brake pad / brake shoe, characterized in that: include: Steel back; The organic synthetic friction material according to any one of claims 1 to 4, wherein the organic synthetic friction material is fixed on a steel back.

8. A method for preparing a brake pad / brake shoe, applied to the brake pad / brake shoe according to claim 7, characterized in that: The following steps are involved: Pressing the organic synthetic friction material and the steel back together to obtain a cold blank; The cold blank is heat treated to obtain a brake pad / brake shoe.

9. The method for preparing a brake pad / brake shoe according to claim 8, characterized in that: The pressing method used for pressing the organic synthetic friction material and the steel back together is cold pressing.

10. The method for preparing a brake pad / brake shoe according to claim 8, characterized in that: Heat treatment of cold embryos includes: Performing a first heat treatment on the cold embryo, wherein the temperature of the first heat treatment is room temperature to 110° C., the heating time is 1 to 2 hours, and the heat preservation time is 2 to 4 hours; Performing a second heat treatment on the cold embryo, wherein the temperature of the second heat treatment is 110° C. to 160° C., the heating time is 2 to 3 hours, and the heat preservation time is 1 to 3 hours; The cold embryo is subjected to a third heat treatment, wherein the temperature of the third heat treatment is 160° C. to 190° C., the heating time is 1 to 2 hours, and the heat preservation time is 2 to 5 hours; The cold embryo is subjected to a fourth heat treatment, wherein the temperature of the fourth heat treatment is 190° C. to 220° C., the temperature is raised for 1 to 2 hours, and the temperature is kept for 1 to 3 hours.

Images