A method for preparing asbestos-free semi-metallic brake pad

Abstract

The invention relates to a method for preparing an asbestos-free semi-metallic brake pad. The method comprises the following steps: mixing an adhesive, nano-nitrile rubber powder, metal fiber, metal powder, filler and graphite, and then performing hot pressing and heat treatment to obtain the asbestos-free semi-metallic brake pad. The adhesive is a cardanol-modified phenolic resin, and cardanol glycidyl ether, tetraaminophenylporphyrin manganese, 1,8-diazacyclo[5,4,0]undecene and xylene are reacted by stirring; then bisphenol A type phenolic epoxy resin and aminophthalic acid zirconium MOF are added, and after the reaction is completed, the xylene is removed by reduced pressure distillation. The asbestos-free semi-metallic brake pad prepared by the method has the advantages of excellent wear resistance, long service life and the like.

Description

Technical Field

[0001] The invention relates to the technical field of brake pad preparation, in particular to a method for preparing an asbestos-free semi-metallic brake pad. Background Art

[0002] As the speed of automobiles increases, the requirements for automobile braking safety performance are also getting higher and higher. When traditional asbestos brake pads are used at high temperatures, the friction coefficient will be greatly reduced, and the wear will increase dramatically. Its performance can no longer meet the requirements of today's high-speed automobiles.

[0003] Chinese patent CN1258050C: describes a non-asbestos high-strength automobile brake friction pad and its production method, which uses a polymer compound double-modified phenolic resin as a binder, metal fibers and organic fibers as reinforcing components, fillers as friction performance regulators, and added barium sulfate, graphite, aluminum oxide and other compounding agents.

[0004] Chinese patent CN100350013C: It relates to a new type of high-performance asbestos-free semi-metallic brake pad material, which can be made into disc or drum brake pads. It consists of the following four composite additives: one is 5-30% Levoth phase reinforced iron-based alloy powder, and 5-20% pure copper powder or bronze powder is added in combination; the second is 5-25% nano-nitrile rubber powder, and 5-25% modified phenolic resin, 0.5-2% dithiuram tetrasulfide and 0.5-2% tetramethylthiuram trisulfide accelerator is added in combination; the third is 5-20% glass fiber or / and 5-20% steel fiber or / and 1-10% natural sisal fiber and 1-10% carbon fiber composite additive; the fourth is 1-10% nano-aluminum trioxide and other fillers, 1-10% flake graphite, 1-12% sulphate, 0.3-3% sulfur and 0.5-3% boron nitride.

[0005] Chinese patent CN204553621U: Provides an improved structure of an asbestos-free semi-metallic brake pad for automobiles, including a back plate device, a heat insulation layer, a friction device, a silencer, an adhesive layer and screw holes, wherein the back plate device is arranged at the lower position of the adhesive layer; the heat insulation layer is arranged at the upper position of the adhesive layer; the friction device is arranged at the upper position of the heat insulation layer; the silencer is arranged on the front surface of the back plate device; and the adhesive layer is arranged at the lower position of the heat insulation layer.

[0006] The brake pads prepared by the above patents and prior art have the disadvantages of low friction coefficient, poor stability, high wear rate and short service life. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for preparing an asbestos-free semi-metallic brake pad, and the operating steps are as follows:

[0008] S1: According to weight, weigh 10-20 parts of adhesive, 5-10 parts of nano-nitrile rubber powder, 20-30 parts of metal fiber, 20-30 parts of metal powder, 30-40 parts of filler, and 5-10 parts of graphite, and stir and mix for 10-20 minutes;

[0009] S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad;

[0010] The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows:

[0011] A1: by weight, 12-24 parts of cardanol glycidyl ether, 0.03-0.3 parts of tetraaminophenylporphyrin manganese, 3-6 parts of 1,8-diazacyclo[5,4,0]undecene, and 500-600 parts of xylene are stirred at 70-80° C. for 100-150 minutes;

[0012] A2: Add 30-60 parts of bisphenol A novolac epoxy resin and 10-20 parts of zirconium aminophthalate MOF, stir at 70-80°C for 60-120 minutes, and remove xylene by vacuum distillation to obtain cardanol-modified phenolic resin.

[0013] The metal fiber is one of copper fiber, nickel fiber, zinc fiber and steel fiber.

[0014] The metal powder is chromite powder or copper powder.

[0015] The filler is one of barite, expanded vermiculite, sepiolite, talc, wollastonite, zeolite, diatomaceous earth and brucite.

[0016] The hot pressing molding process has a pressure of 20-30 MPa, a temperature of 150-160° C., and a time of 10-15 min.

[0017] The heat treatment operation steps are: firstly heating to 140-150°C and keeping the temperature for 150-180min; then heating to 170-180°C and keeping the temperature for 200-240min.

[0018] The zirconium aminophthalate MOF is codenamed UiO-66-BDC-NH2 and has a CAS number of 1260119-00-3.

[0019] Reaction mechanism

[0020] The cardanol glycidyl ether undergoes an epoxy-amine ring-opening reaction with tetraaminophenylporphyrin manganese; then undergoes an epoxy-amine ring-opening reaction with bisphenol A novolac epoxy resin, and the cardanol glycidyl ether undergoes a ring-opening reaction with zirconium aminophthalate to obtain an asbestos-free semi-metallic brake pad adhesive.

[0021] Technical Effects

[0022] The present invention discloses a method for preparing an asbestos-free semi-metallic brake pad. Compared with the prior art, the present invention has the following significant effects:

[0023] 1. Structural characteristics and functions of MOF

[0024] Adsorption performance and stability: Since UiO-66-BDC-NH2 has a large surface area, it provides a good basis for adsorption performance. At the same time, this MOF shows good stability during storage, including thermal stability and chemical stability; in the process of preparing asbestos-free semi-metallic brake pad adhesives, these properties are conducive to improving the environmental adaptability and durability of the final product.

[0025] 2. Epoxy-amine ring-opening reaction

[0026] The epoxy-amine ring-opening reaction is a reaction involving epoxy compounds and amine-containing compounds, which usually results in the ring-opening of the epoxy group and the formation of new chemical bonds; in the preparation of this adhesive, the reaction of cardanol glycidyl ether (containing epoxy groups) with tetraaminophenylporphyrin manganese (containing amine groups) and the subsequent reaction with bisphenol A novolac epoxy resin (also containing epoxy groups) all follow this mechanism.

[0027] 3. Formation of network structure: Through these ring-opening reactions, a cross-linked network structure is formed between different compounds, which helps to improve the mechanical strength and thermal stability of the final adhesive.

[0028] 4. Contribution of porphyrin manganese: As an amine-containing compound, tetraaminophenylporphyrin manganese may play the role of providing amine groups for ring opening. At the same time, the metal center of porphyrin manganese may also have a catalytic effect, promoting the reaction.

[0029] 5. Characteristics and functions of cardanol: As a naturally derived compound, cardanol and its glycidyl ether derivatives act as providers of epoxy groups in the preparation of adhesives. Its use may also bring the advantages of environmental friendliness and renewable resources.

[0030] 6. Effect of zirconium formate: Zirconium aminophthalate can provide reaction sites and participate in the formation of network structure in the ring-opening reaction with cardanol glycidyl ether. Its stable chemical properties may also have a positive effect on improving the performance of the final adhesive. DETAILED DESCRIPTION

[0031] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with embodiments and comparative examples:

[0032] 1. Friction performance test: using a fixed speed friction tester, the test temperature is 350°C, and the test is carried out according to the GB5763-1998 method;

[0033] 2. Brake pad service life test: The brake pad is tested after being installed on the vehicle. The test is based on the fact that the brake pad has no cracks or crazing on the surface, the brake is sensitive and reliable, and the damage to the brake drum is very light. Otherwise, it is unusable.

[0034] Example 1

[0035] A method for preparing an asbestos-free semi-metallic brake pad, the operating steps of which are:

[0036] S1: Weigh 10g of adhesive, 5g of nano-nitrile rubber powder, 20g of metal fiber, 20g of metal powder, 30g of filler, and 5g of graphite, and stir and mix for 10min;

[0037] S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad;

[0038] The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows:

[0039] A1: 12 g of cardanol glycidyl ether, 0.03 g of tetraaminophenylporphyrin manganese, 3 g of 1,8-diazacyclo[5,4,0]undecene, and 500 g of xylene were stirred at 70°C for 100 minutes;

[0040] A2: Add 30 g of bisphenol A novolac epoxy resin E-20 and 10 g of zirconium aminophthalate MOF, stir at 70° C. for 60 minutes, and remove xylene by reduced pressure distillation to obtain cardanol-modified phenolic resin.

[0041] The metal fiber is copper fiber.

[0042] The metal powder is chromite powder.

[0043] The filler is barite.

[0044] The hot pressing molding process is performed at a pressure of 20 MPa, a temperature of 150° C., and a time of 10 min.

[0045] The heat treatment operation steps are: firstly heating to 140°C and keeping the temperature for 150 minutes; then heating to 170°C and keeping the temperature for 200 minutes.

[0046] The zirconium aminophthalate MOF is codenamed UiO-66-BDC-NH2 and has a CAS number of 1260119-00-3.

[0047] Example 2

[0048] A method for preparing an asbestos-free semi-metallic brake pad, the operating steps of which are:

[0049] S1: Weigh 13g of adhesive, 6g of nano-nitrile rubber powder, 23g of metal fiber, 23g of metal powder, 33g of filler, and 6g of graphite, and stir and mix for 13min;

[0050] S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad;

[0051] The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows:

[0052] A1: 16 g of cardanol glycidyl ether, 0.1 g of tetraaminophenylporphyrin manganese, 4 g of 1,8-diazacyclo[5,4,0]undecene, and 540 g of xylene were stirred at 75°C for 110 minutes;

[0053] A2: Add 40 g of bisphenol A novolac epoxy resin E-20 and 13 g of zirconium aminophthalate MOF, stir at 75° C. for 80 minutes, and remove xylene by reduced pressure distillation to obtain cardanol-modified phenolic resin.

[0054] The metal fiber is nickel fiber.

[0055] The metal powder is chromite powder.

[0056] The filler is expanded vermiculite.

[0057] The hot pressing molding process is performed at a pressure of 23 MPa, a temperature of 155° C., and a time of 12 minutes.

[0058] The heat treatment operation steps are: firstly heating to 145°C and keeping the temperature for 160 minutes; then heating to 175°C and keeping the temperature for 210 minutes.

[0059] The zirconium aminophthalate MOF is codenamed UiO-66-BDC-NH2 and has a CAS number of 1260119-00-3.

[0060] Example 3

[0061] A method for preparing an asbestos-free semi-metallic brake pad, the operating steps of which are:

[0062] S1: Weigh 18g of adhesive, 8g of nano-nitrile rubber powder, 28g of metal fiber, 28g of metal powder, 38g of filler, and 8g of graphite, and stir and mix for 18min;

[0063] S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad;

[0064] The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows:

[0065] A1: 20 g of cardanol glycidyl ether, 0.2 g of tetraaminophenylporphyrin manganese, 5 g of 1,8-diazacyclo[5,4,0]undecene, and 580 g of xylene were stirred at 75°C for 140 minutes;

[0066] A2: 50 g of bisphenol A novolac epoxy resin E-12 and 18 g of zirconium aminophthalate MOF were added, stirred at 75° C. for 100 minutes, and xylene was removed by reduced pressure distillation to obtain cardanol-modified phenolic resin.

[0067] The metal fiber is zinc fiber.

[0068] The metal powder is copper powder.

[0069] The filler is sepiolite.

[0070] The hot pressing molding process was performed at a pressure of 28 MPa, a temperature of 155° C., and a time of 14 minutes.

[0071] The heat treatment operation steps are: firstly heating to 145°C and keeping the temperature for 170 minutes; then heating to 175°C and keeping the temperature for 230 minutes.

[0072] The zirconium aminophthalate MOF is codenamed UiO-66-BDC-NH2 and has a CAS number of 1260119-00-3.

[0073] Example 4

[0074] A method for preparing an asbestos-free semi-metallic brake pad, the operating steps of which are:

[0075] S1: Weigh 20g of adhesive, 10g of nano-nitrile rubber powder, 30g of metal fiber, 30g of metal powder, 40g of filler, and 10g of graphite, and stir and mix for 20min;

[0076] S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad;

[0077] The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows:

[0078] A1: 24 g of cardanol glycidyl ether, 0.3 g of tetraaminophenylporphyrin manganese, 6 g of 1,8-diazacyclo[5,4,0]undecene, and 600 g of xylene were stirred at 80°C for 150 minutes;

[0079] A2: Add 60 g of bisphenol A novolac epoxy resin E-12 and 20 g of zirconium aminophthalate MOF, stir at 80° C. for 120 minutes, and remove xylene by reduced pressure distillation to obtain cardanol-modified phenolic resin.

[0080] The metal fiber is steel fiber.

[0081] The metal powder is copper powder.

[0082] The filler is wollastonite.

[0083] The hot pressing molding process is performed at a pressure of 30 MPa, a temperature of 160° C., and a time of 15 minutes.

[0084] The heat treatment operation steps are: firstly heating to 150°C and keeping the temperature for 180 minutes; then heating to 180°C and keeping the temperature for 240 minutes.

[0085] The zirconium aminophthalate MOF is codenamed UiO-66-BDC-NH2 and has a CAS number of 1260119-00-3.

[0086] Comparative Example 1

[0087] The phenolic resin was not modified, and the other steps were the same as in Example 1.

[0088] Comparative Example 2

[0089] The tetraaminophenylporphyrin manganese was not added, and the other steps were the same as in Example 1.

[0090] Comparative Example 3

[0091] No zirconium aminophthalate MOF was added, and the rest was the same as in Example 1.

[0092] Table 1

[0093] Friction coefficient Wear rate / ×10-7cm3·N-1·m-1 Service life / 10,000 km Example 1 0.40 0.18 5.8 Example 2 0.41 0.16 6.0 Example 3 0.43 0.14 6.2 Example 4 0.44 0.13 6.3 Comparative Example 1 0.30 0.31 4.1 Comparative Example 2 0.33 0.27 4.6 Comparative Example 3 0.35 0.25 4.8

[0094] Through the data analysis of the above embodiments and comparative examples, the asbestos-free semi-metallic brake pad prepared by the present invention has excellent friction performance and a long service life.

[0095] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an asbestos-free semi-metallic brake pad, the operating steps of which are: S1: According to weight, weigh 10-20 parts of adhesive, 5-10 parts of nano-nitrile rubber powder, 20-30 parts of metal fiber, 20-30 parts of metal powder, 30-40 parts of filler, and 5-10 parts of graphite, and stir and mix for 10-20 minutes; S2: hot pressing the mixture into a mold, and then heat treating it to obtain an asbestos-free semi-metallic brake pad; The adhesive is cardanol-modified phenolic resin, and its preparation method is as follows: A1: by weight, 12-24 parts of cardanol glycidyl ether, 0.03-0.3 parts of tetraaminophenylporphyrin manganese, 3-6 parts of 1,8-diazacyclo[5,4,0]undecene, and 500-600 parts of xylene are stirred at 70-80° C. for 100-150 minutes; A2: Add 30-60 parts of bisphenol A novolac epoxy resin and 10-20 parts of zirconium aminophthalate MOF, stir at 70-80°C for 60-120 minutes, and remove xylene by vacuum distillation to obtain cardanol-modified phenolic resin.

2. The method for preparing an asbestos-free semi-metallic brake pad according to claim 1, characterized in that: The metal fiber is one of copper fiber, nickel fiber, zinc fiber and steel fiber.

3. The method for preparing an asbestos-free semi-metallic brake pad according to claim 1, characterized in that: The metal powder is chromite powder or copper powder.

4. The method for preparing an asbestos-free semi-metallic brake pad according to claim 1, characterized in that: The filler is one of barite, expanded vermiculite, sepiolite, talc, wollastonite, zeolite, diatomaceous earth and brucite.

5. The method for preparing an asbestos-free semi-metallic brake pad according to claim 1, characterized in that: The hot pressing molding process has a pressure of 20-30 MPa, a temperature of 150-160° C., and a time of 10-15 min.

6. The method for preparing an asbestos-free semi-metallic brake pad according to claim 1, characterized in that: The heat treatment operation steps are: firstly heating to 140-150°C and keeping the temperature for 150-180min; then heating to 170-180°C and keeping the temperature for 200-240min.