CN108506387A - A kind of brake pad and preparation method thereof, brake block - Google Patents

Abstract

The application provides a friction block in a brake pad, which is made of the following raw materials: phenolic resin or boron modified phenolic resin or melamine modified phenolic resin, nitrile rubber powder, lignin fiber, activated carbon, expandable graphite, bismuth Molybdenum sulfide, barium sulfate, calcium carbonate, calcium sulfate whiskers, iron oxide yellow, aluminum oxide, iron oxide red powder, silicon carbide, wollastonite, vermiculite powder and high wear-resistant furnace black; The preparation method of the friction block of the component formula; the application strengthens the composition and process of the friction block, and the combination of composition strengthening and process strengthening realizes a strong combination, thereby improving the friction coefficient, hardness, The comprehensive performance including wear resistance, impact resistance toughness, thermal conductivity, high temperature resistance and corrosion resistance can meet the requirements of high load, high temperature, high speed and high corrosion environment. The present application also provides a brake pad comprising the above-mentioned friction block.

Description

A kind of friction block and its preparation method, brake pad

technical field

The invention relates to the technical field of friction materials, in particular to a friction block, a preparation method thereof, and a brake pad.

Background technique

With the rapid development of my country's economy and automobile industry, cars have entered more and more families, and the number of cars in my country has exceeded 300 million and is still growing. The performance of brake pads directly affects the safety of cars and passengers. With the development of society and economy and the advancement of science and technology, more stringent requirements are put forward for the performance of brake pads for automobiles.

Now common brake pad materials mainly include semi-metallic friction materials and NAO friction materials, among which semi-metallic friction material brake pads will produce heavy metals and have large braking noise during use, which will have adverse effects on people's health; NAO friction materials Aramid fiber, carbon fiber, ceramic fiber, mineral fiber, etc. are mainly used as reinforcing fibers. However, due to the complicated and difficult processing technology and high cost, most of my country relies on imports to meet domestic demand.

Therefore, how to improve the comprehensive performance of the friction block in the brake pad, including friction coefficient, hardness, wear resistance, impact toughness, thermal conductivity, high temperature resistance and corrosion resistance, so as to meet the requirements of high load, high temperature, high speed and The requirements for use in highly corrosive environments and meeting the requirements of social and economic development and scientific and technological progress are technical problems urgently needed to be solved by those skilled in the art.

Contents of the invention

The object of the present invention is to provide a friction block in a brake pad. Another object of the present invention is to provide a method for preparing a friction block in a brake pad. Another object of the present invention is to provide a brake pad.

In order to solve the above-mentioned technical problems, the technical solution provided by the invention is:

A friction block in a brake pad is made of the following raw materials in mass percentage: 8% to 9% of phenolic resin or boron modified phenolic resin or melamine modified phenolic resin, 4% to 6% of nitrile rubber powder, 8%~12% lignin fiber, 2%~5% activated carbon, 6%~8% expandable graphite, 2%~4% molybdenum disulfide, 18%~23% barium sulfate, 4%~ 7% calcium carbonate, 2%~3% calcium sulfate whisker, 3%~4% iron oxide yellow, 1%~2% aluminum oxide, 3%~5% iron oxide red powder, 2%~3 % of silicon carbide, 5% to 7% of wollastonite, 4% to 6% of vermiculite powder and 1% to 2% of high wear-resistant furnace black.

Preferably, the iron oxide red powder is superfine iron oxide red powder.

A method for preparing a friction block in the above-mentioned brake pad, comprising the following steps:

1) Prepare each raw material properly according to the above component formula, and then pass the powder of other raw materials except lignin fiber and phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin through the mixer Mix and stir, and then disperse the mixed and stirred raw material mixture through an ultrasonic disperser to make the components evenly dispersed;

2) Mix lignin fiber with phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin: Divide lignin fiber into 4 equal parts, add one part at 4 different positions of the mixer one by one every 6 minutes Mix in phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin, and mix for 6 minutes after the fourth part is added;

3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix;

4) Drying the mixture prepared in step 3) in a drying oven at a temperature of 50°C to 60°C for 3 hours;

5) cold pressing the dried mixture in step 4) on a cold pressing die;

Then perform hot-press curing on a hot-press machine: the hot-press temperature is 170°C-180°C, the hot-press pressure is 12MPa-13MPa, the hot-press time is 10min-15min, and three cycles of hot-pressing;

6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour;

Then cool to room temperature with the furnace;

Then demoulding, and the friction block is made after completion.

A brake pad, comprising a back plate, an adhesive heat insulating layer and a friction block, the friction block is the above friction block or the friction block prepared by the above preparation method.

The application provides a friction block in a brake pad, which is made of the following raw materials in mass percentage: 8% to 9% of phenolic resin or boron modified phenolic resin or melamine modified phenolic resin, 4% to 6% of Nitrile rubber powder, 8%~12% lignin fiber, 2%~5% activated carbon, 6%~8% expandable graphite, 2%~4% molybdenum disulfide, 18%~23% barium sulfate , 4% to 7% calcium carbonate, 2% to 3% calcium sulfate whiskers, 3% to 4% iron oxide yellow, 1% to 2% aluminum oxide, 3% to 5% iron oxide red powder, 2% to 3% of silicon carbide, 5% to 7% of wollastonite, 4% to 6% of vermiculite powder and 1% to 2% of high wear-resistant furnace black; the application also provides a The preparation method of the friction block in the brake pad of the distribution party; the application strengthens the composition and process of the friction block, and the combination of composition strengthening and process strengthening realizes a strong combination, thereby improving the friction coefficient of the friction block in the brake pad , hardness, wear resistance, impact toughness, thermal conductivity, high temperature resistance and corrosion resistance, to meet the requirements of high load, high temperature, high speed and high corrosion environment, to meet the needs of social and economic development and requirements of technological progress.

Detailed ways

In order to further understand the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only to further illustrate the features and advantages of the present invention, rather than limiting the claims of the present invention.

The application provides a friction block in a brake pad, which is made of the following raw materials in mass percentage: 8% to 9% of phenolic resin or boron modified phenolic resin or melamine modified phenolic resin, 4% to 6% of Nitrile rubber powder, 8%~12% lignin fiber, 2%~5% activated carbon, 6%~8% expandable graphite, 2%~4% molybdenum disulfide, 18%~23% barium sulfate , 4% to 7% calcium carbonate, 2% to 3% calcium sulfate whiskers, 3% to 4% iron oxide yellow, 1% to 2% aluminum oxide, 3% to 5% iron oxide red powder, 2% to 3% of silicon carbide, 5% to 7% of wollastonite, 4% to 6% of vermiculite powder and 1% to 2% of high wear-resistant furnace black.

In one embodiment of the present application, the iron oxide red powder is superfine iron oxide red powder.

The present invention uses phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin as bonding agent, takes lignin fiber as main reinforcement fiber, and lignin fiber is compared with steel fiber, carbon fiber etc., and its density is relatively small, can Reduce the quality of the brake pads. Both lignin fiber and phenolic resin are organic macromolecular compounds, they have better affinity, strong cohesive force and higher bonding strength, and lignin fiber is not easy to pull out from the matrix.

The lignin fibers used in the present invention have active phenolic hydroxyl (-OH) and aldehyde (-CHO) functional groups that can react with phenolic resins to enhance the bonding performance of phenolic resin binders, make the internal structure of the brake pads dense, and improve the brake performance. The toughness and hardness of the sheet, the test results show that the impact toughness is 4.36J/cm ² , and the hardness (HRL) is 70.

The lignin fiber can increase the porosity of the friction material and reduce the noise during the friction process due to its special structure of ribbon bending, unevenness and porosity.

As a kind of organic fiber, lignin fiber will be carbonized by the high temperature generated during the friction process. The carbonized lignin fiber is equivalent to carbon fiber and forms a dense friction layer on the surface of the brake pad.

In this application, the addition of molybdenum disulfide can effectively improve the stability of the friction coefficient of the friction block under high temperature conditions, reduce the friction coefficient under high temperature, reduce noise, and increase the service life of the brake pad.

The invention adds molybdenum disulfide, which can effectively improve the stability of the friction coefficient of the friction block under high temperature conditions.

In this application, the addition of expandable graphite can effectively improve the impact resistance and toughness of the friction block, as well as its ability to conduct heat and dissipate heat;

Iron oxide red powder can improve the high temperature resistance and oxidation resistance of brake pads, enhance the density and heat dissipation performance of friction blocks, and reduce brake noise and jitter;

The chemical properties of barium sulfate are stable, insoluble in water, acid, alkali and organic solvents, adding a large amount of it can improve the chemical stability and density of the friction block;

The addition of solid lubricant molybdenum disulfide can adjust the friction coefficient of the friction block and maintain the stability of the friction coefficient;

The addition of alumina can stabilize the friction performance of the friction material at high temperature and improve the thermal fading resistance;

The addition of calcium carbonate can improve the high-speed stability of the friction block;

The addition of wollastonite can improve the thermal stability of the friction block, enhance corrosion resistance and improve wear resistance.

The present application also provides a method for preparing the above-mentioned friction block in the brake pad, comprising the following steps:

1) Prepare each raw material properly according to the above component formula, and then pass the powder of other raw materials except lignin fiber and phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin through the mixer Mix and stir, and then disperse the mixed and stirred raw material mixture through an ultrasonic disperser to make the components evenly dispersed;

2) Mix lignin fiber with phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin: Divide lignin fiber into 4 equal parts, add one part at 4 different positions of the mixer one by one every 6 minutes Mix in phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin, and mix for 6 minutes after the fourth part is added;

3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix;

4) Drying the mixture prepared in step 3) in a drying oven at a temperature of 50°C to 60°C for 3 hours;

5) cold pressing the dried mixture in step 4) on a cold pressing die;

Then perform hot-press curing on a hot-press machine: the hot-press temperature is 170°C-180°C, the hot-press pressure is 12MPa-13MPa, the hot-press time is 10min-15min, and three cycles of hot-pressing;

6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour;

Then cool to room temperature with the furnace;

Then demoulding, and the friction block is made after completion.

In the step 1) of the present invention, the raw material powders are mixed separately and dispersed by an ultrasonic disperser, so that the raw material mixing and distribution are more uniform.

In the present invention, when the lignin fibers are mixed, the lignin fibers are evenly distributed through the time-divided and partitioned adding method, without agglomeration phenomenon, and the toughening effect is better.

The present application also provides a brake pad, including a back plate, an adhesive heat insulating layer and a friction block, and the friction block is the above-mentioned friction block or the friction block prepared by the above-mentioned preparation method.

In order to further understand the present invention, a friction block provided by the present invention and its preparation method will be described in detail below in conjunction with examples, and the scope of protection of the present invention is not limited by the following examples.

Example 1

A friction block in a brake pad, made of raw materials of the following qualities:

9 grams of phenolic resin, 6 grams of nitrile rubber powder, 12 grams of lignin fiber, 2 grams of activated carbon, 8 grams of expandable graphite, 3 grams of molybdenum disulfide, 23 grams of barium sulfate, 6 grams of carbonic acid Calcium, 3 grams of silicon carbide, 3 grams of calcium sulfate whiskers, 4 grams of yellow iron oxide, 2 grams of aluminum oxide, 5 grams of superfine iron oxide red powder, 6 grams of wollastonite, 6 grams of vermiculite powder And 2 grams of high wear-resistant furnace black.

The above-mentioned preparation method of the friction block in the brake pad comprises the following steps:

1) Prepare each raw material according to the component formula in Example 1, then mix and stir the powder of other remaining raw materials except lignin fiber and phenolic resin through a mixer, and then mix and stir the mixed and stirred The raw material mixture is dispersed by an ultrasonic disperser to make the components uniformly dispersed;

2) Mix the lignin fiber with the phenolic resin: Divide the lignin fiber into 4 equal parts, add it successively at 4 different positions of the mixer, add 1 part every 6 minutes to the phenolic resin for mixing, wait for the fourth part to be added After 6 minutes of mixing to complete the mixing;

3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix;

4) The mixture prepared in step 3) was placed in a drying oven at a temperature of 55° C. for 3 hours;

5) cold pressing the dried mixture in step 4) on a cold pressing die;

Then perform hot-press curing on a hot-press machine: the hot-press temperature is 170° C., the hot-press pressure is 13 MPa, the hot-press time is 10 minutes, and three cycles of hot-press;

6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour;

Then cool to room temperature with the furnace;

Then demoulding, and the friction block is made after completion.

According to the national standard GB5763-2008, the friction block prepared in Example 1 was subjected to a friction test on a constant-speed friction machine. The specific test results are shown in Table 1a and 1b:

The main performance indicators of the friction block prepared in Table 1a Example 1

The main performance indicators of the friction block prepared in Table 1b Example 1

Example 2

A friction block in a brake pad, made of raw materials of the following qualities:

9 grams of boron-modified phenolic resin, 6 grams of nitrile rubber powder, 12 grams of lignin fiber, 2 grams of activated carbon, 8 grams of expandable graphite, 3 grams of molybdenum disulfide, 23 grams of barium sulfate, 6 gram of calcium carbonate, 3 grams of silicon carbide, 3 grams of calcium sulfate whiskers, 4 grams of iron oxide yellow, 2 grams of aluminum oxide, 5 grams of superfine iron oxide red powder, 6 grams of wollastonite, 6 grams Vermiculite powder and 2 grams of high wear-resistant furnace black.

The above-mentioned preparation method of the friction block in the brake pad comprises the following steps:

1) Prepare each raw material according to the component formula in Example 2, then mix and stir the powder of other remaining raw materials except lignin fiber and boron-modified phenolic resin by a mixer, and then mix the The stirred raw material mixture is dispersed through an ultrasonic disperser to make the components uniformly dispersed;

2) Mix the lignin fiber with boron-modified phenolic resin: Divide the lignin fiber into 4 equal parts, add them successively at 4 different positions of the mixer, add 1 part every 6 minutes to the boron-modified phenolic resin for mixing , after the fourth part is added, the mixture is mixed for 6 minutes to complete the mixture;

3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix;

4) The mixture prepared in step 3) is placed in a drying oven at a temperature of 50° C. for 3 hours;

5) cold pressing the dried mixture in step 4) on a cold pressing die;

Then perform hot-press curing on a hot-press machine: the hot-press temperature is 180°C, the hot-press pressure is 12MPa, the hot-press time is 15min, and three cycles of hot-press;

6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour;

Then cool to room temperature with the furnace;

Then demoulding, and the friction block is made after completion.

According to the national standard GB5763-2008, the friction block prepared in Example 2 was subjected to a friction test on a constant-speed friction machine. The specific test results are shown in Table 2a and 2b:

The main performance indicators of the friction block prepared in Table 2a Example 2

The main performance indicators of the friction block prepared in table 2b embodiment 2

Example 3

A friction block in a brake pad, made of raw materials of the following qualities:

9 grams of melamine modified phenolic resin, 6 grams of nitrile rubber powder, 12 grams of lignin fiber, 2 grams of activated carbon, 8 grams of expandable graphite, 3 grams of molybdenum disulfide, 23 grams of barium sulfate, 6 gram of calcium carbonate, 3 grams of silicon carbide, 3 grams of calcium sulfate whiskers, 4 grams of iron oxide yellow, 2 grams of aluminum oxide, 5 grams of superfine iron oxide red powder, 6 grams of wollastonite, 6 grams Vermiculite powder and 2 grams of high wear-resistant furnace black.

The above-mentioned preparation method of the friction block in the brake pad comprises the following steps:

1) Prepare each raw material according to the component formula in Example 3, then mix and stir the powder of other remaining raw materials except lignin fiber and melamine-modified phenolic resin by a mixer, and then mix the The stirred raw material mixture is dispersed through an ultrasonic disperser to make the components uniformly dispersed;

2) Mix the lignin fiber with the melamine-modified phenolic resin: divide the lignin fiber into 4 equal parts, add one part to the melamine-modified phenolic resin every 6 minutes in 4 different positions of the mixer, and mix , after the fourth part is added, the mixture is mixed for 6 minutes to complete the mixture;

3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix;

4) The mixture prepared in step 3) is placed in a drying oven at a temperature of 60° C. for 3 hours;

5) cold pressing the dried mixture in step 4) on a cold pressing die;

Then perform hot-press curing on a hot-press machine: the hot-press temperature is 170°C, the hot-press pressure is 13MPa, the hot-press time is 12min, and three cycles of hot-press;

6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour;

Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour;

Then cool to room temperature with the furnace;

Then demoulding, and the friction block is made after completion.

According to the national standard GB5763-2008, the friction block prepared in Example 3 was subjected to a friction test on a constant-speed friction machine. The specific test results are shown in Table 3a and 3b:

The main performance indicators of the friction block prepared in table 3a embodiment 3

The main performance indicators of the friction block prepared in table 3b embodiment 3

The descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. A friction block in a brake pad, characterized in that it is made of the following raw materials in mass percentage: 8% to 9% phenolic resin or boron modified phenolic resin or melamine modified phenolic resin, 4% to 6% nitrile rubber powder, 8% to 12% lignin fiber, 2% to 5% activated carbon, 6% to 8% expandable graphite, 2% to 4% molybdenum disulfide, 18% to 23% Barium sulfate, 4%~7% calcium carbonate, 2%~3% calcium sulfate whisker, 3%~4% iron oxide yellow, 1%~2% aluminum oxide, 3%~5% iron oxide Red powder, 2%-3% silicon carbide, 5%-7% wollastonite, 4%-6% vermiculite powder and 1%-2% high wear-resistant furnace black. 2. The friction block according to claim 1, characterized in that, the iron oxide red powder is superfine iron oxide red powder. 3. A preparation method of the friction block in the brake pad according to claim 1 or 2, characterized in that, comprising the following steps: 1) each raw material is prepared properly according to the component formula in claim 1 or 2, then the powder of other remaining raw materials except lignin fiber and phenolic resin or boron modified phenolic resin or melamine modified phenolic resin Mix and stir through a mixer, and then disperse the mixed and stirred raw material mixture through an ultrasonic disperser to make the components evenly dispersed; 2) Mix lignin fiber with phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin: Divide lignin fiber into 4 equal parts, add one part at 4 different positions of the mixer one by one every 6 minutes Mix in phenolic resin or boron-modified phenolic resin or melamine-modified phenolic resin, and mix for 6 minutes after the fourth part is added; 3) Add the raw material mixture prepared in step 1) to the raw material mixture prepared in step 2) for mixing, the feeding speed is 0.5kg/min, and continue mixing after adding the raw material mixture prepared in step 1) to complete mix; 4) Drying the mixture prepared in step 3) in a drying oven at a temperature of 50°C to 60°C for 3 hours; 5) cold pressing the dried mixture in step 4) on a cold pressing die; Then perform hot-press curing on a hot-press machine: the hot-press temperature is 170°C-180°C, the hot-press pressure is 12MPa-13MPa, the hot-press time is 10min-15min, and three cycles of hot-pressing; 6) Put the heat-cured product in step 5) into an oven for heat treatment: first raise the temperature in the oven from room temperature to 90°C within 1 hour, and then keep it warm for 1 hour; Then raise the temperature in the oven from 90°C to 120°C within 1 hour, and then keep it warm for 1 hour; Then raise the temperature in the oven from 120°C to 170°C within 1 hour, and then keep it warm for 1 hour; Then cool to room temperature with the furnace; Then demoulding, and the friction block is made after completion. 4. A brake pad, comprising a back plate, an adhesive heat insulating layer and a friction block, characterized in that the friction block is prepared by the friction block according to claim 1 or 2 or the preparation method according to claim 3 friction block.