阅读说明：本技术 一种低噪音高耐磨阻燃型摩擦材料及制备方法 (Low-noise high-wear-resistance flame-retardant friction material and preparation method thereof ) 是由 颜红侠 丁凡 郭留龙 白天 王莲莲 杨开明 严栋 于 2019-09-12 设计创作，主要内容包括：本发明涉及一种低噪音高耐磨阻燃型摩擦材料及制备方法,以含磷超支化聚硅氧烷强化酚醛树脂为胶粘剂,通过采用干法热压成型工艺制备。以含磷超支化聚硅氧烷强化树脂基摩擦材料的摩擦性能和力学性能,通过硅氧烷的柔性作用和端位官能团的反应性,一方面提高填料和增强材料与树脂之间的界面结合性,另一方面,含磷超支化聚硅氧烷强作为一种柔性的软质颗粒,不仅能实现对树脂进行增韧增强,提高树脂的韧性而抑制其断裂,同时可赋予树脂一定的阻尼性而抑制噪音；以其为强化剂,可制备得到一种低噪音、高耐磨、阻燃型的摩擦材料,可以制作为刹车片用于汽车、摩托车等机动车辆的制动系统,具有非常广阔的应用前景。(The invention relates to a low-noise high-wear-resistance flame-retardant friction material and a preparation method thereof. The friction performance and the mechanical performance of the resin-based friction material are enhanced by the phosphorus-containing hyperbranched polysiloxane, and the interface bonding property between the filler and the resin and the enhanced material is improved on one hand through the flexible action of siloxane and the reactivity of terminal functional groups, and on the other hand, the phosphorus-containing hyperbranched polysiloxane is used as flexible soft particles, so that the resin is toughened and enhanced, the toughness of the resin is improved, the fracture of the resin is inhibited, and meanwhile, the resin can be endowed with certain damping property to inhibit noise; the friction material can be used as a reinforcer to prepare a low-noise, high-wear-resistance and flame-retardant friction material, can be used for manufacturing brake pads for braking systems of motor vehicles such as automobiles and motorcycles, and has a very wide application prospect.)

1. A low-noise high-wear-resistance flame-retardant friction material is characterized by comprising the following components: 25-30% by mass of binder phosphorus-containing hyperbranched polysiloxane reinforced phenolic resin, 25-30% by mass of reinforcing fiber, 20-30% by mass of friction coefficient regulator and 15-25% by mass of filler; the sum of the mass percentages of the components is 100 percent; the reinforcing fiber comprises steel fiber, aramid pulp or composite mineral fiber; the friction coefficient regulator comprises crystalline flake graphite, aluminum oxide and MoS₂Antimony sulfide, Fe powder or quartz sand; the filler comprises barite, vermiculite, diatomite, barium sulfate or wollastonite.

2. The low-noise high-wear-resistant flame-retardant friction material according to claim 1, characterized in that: the phenolic resin reinforced by the phosphorus-containing hyperbranched polysiloxane is prepared by compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100: 1-10.

3. The low-noise high-abrasion-resistant flame-retardant friction material according to claim 2, characterized in that: the structural formula of the phosphorus-containing hyperbranched polysiloxane is as follows:

4. the method for preparing the low-noise high-wear-resistance flame-retardant friction material according to any one of claims 1 to 3 is characterized by adopting a dry hot press molding process, and comprises the following steps:

step 1: uniformly coating a release agent in a die cavity of a hot press template;

step 2: 25-30% by mass of binder phosphorus-containing hyperbranched polysiloxane reinforced phenolic resin, 25-30% by mass of reinforcing fiber, 20-30% by mass of friction coefficient regulator and 15-25% by mass of filler; mixing in a stirrer;

and step 3: pouring the mixed material into a die cavity, adjusting the temperature of a hot press to 140-180 ℃, and pressing under the pressure of 20-30 Mpa;

exhaust gas was exhausted at the start of pressing.

5. The method of claim 4, wherein: and 3, exhausting for 2-3 times between 60s when the pressing is started.

Technical Field

The invention belongs to the technical field of high polymer materials and motor vehicle brake friction materials, and relates to a low-noise high-wear-resistance flame-retardant friction material and a preparation method thereof.

Background

Along with the improvement of society and road conditions, the running speed of automobiles is faster and faster, people put forward higher requirements on the safety and comfort of vehicles, the requirements on friction materials are not only safe and reliable, but also the higher requirements on low noise, good wear resistance, stable braking, no damage to discs, environmental protection and the like are put forward. The friction materials such as brake pads and the like are used as automobile consumables and have a very wide market. However, the friction material used in the current brake pad is mainly made of various raw materials such as asbestos, steel fiber and resin, and has the problems of high hardness, large noise, serious heat fading, damage to a dual disc, easy formation of a carbonized film on a wear surface and the like, so that the brake pad is fast in wear, easy to age and break, short in service life and poor in brake performance, and particularly under the condition of frequent braking or emergency braking, the friction surface of the brake pad is easy to generate metal transfer and occlusion phenomena, so that the clutch sensitivity of the brake pad is reduced, and the requirement of the high-performance friction material cannot be met. The reasons for this were mainly analyzed due to the low flame retardancy of the resin, the large amount of metal added, and the poor interfacial adhesion.

Patent CN 110081107 a relates to a friction material, a brake pad prepared by the friction material and a preparation method thereof, the friction material comprises the following components: 7-15 parts of a binder, 5-20 parts of inorganic fibers, 2-7 parts of an organic regulator, 5.5-15 parts of a friction enhancer, 7-20 parts of a friction reducer, 6-20 parts of a filler, 5-40 parts of steel fibers subjected to rust prevention treatment and 5-15 parts of iron powder subjected to rust prevention treatment. The inventor uses a large amount of metal fibers and powder in the invention, on one hand, the heat conduction and the heat dissipation performance of the material can be effectively improved, and on the other hand, the existence of a large amount of metal materials can cause the metal transfer and the occlusion phenomena on the friction surface, generate huge noise and reduce the reliability of the friction material. Patent CN 105526286a relates to a friction material, a friction plate and a preparation method of the friction plate, wherein the friction material comprises the following components: 100 parts by weight of foamed iron powder, 7-17 parts by weight of binder and 11-35 parts by weight of lubricant. In the invention, the foamed iron powder designed by the inventor has the characteristics of low density, no heat fading, low noise and good wear resistance. However, the foam iron powder is prepared by taking pure iron as a raw material, crushing, magnetic separation, air separation, grading and mixing, and then foaming at a high temperature, and has a complex preparation process and high requirements on equipment.

The common friction material for the brake pad of the motor vehicle has the defects of low heat conductivity coefficient, poor thermal stability, high noise, no high temperature resistance and the like, and has complicated preparation process and higher requirement on equipment.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a low-noise high-wear-resistance flame-retardant friction material and a preparation method thereof. The preparation process is simple, the cost is low, the obtained material has the characteristics of stable braking, low noise, high abrasion resistance, good flame retardance and the like, can be made into a brake pad for a braking system of motor vehicles such as automobiles, motorcycles and the like, and has very wide application prospect. The friction material solves the problems that the common friction material for the brake pad of the motor vehicle has the defects of low heat conductivity coefficient, poor thermal stability, high noise, no high temperature resistance and the like, and the preparation process is complicated and has high requirements on equipment.

Technical scheme

A low-noise high-wear-resistance flame-retardant friction material is characterized by comprising the following components: 25-30% of binder phosphorus-containing hyperbranched polymerThe phenolic resin reinforced by siloxane comprises 25-30% by mass of reinforcing fiber, 20-30% by mass of friction coefficient regulator and 15-25% by mass of filler; the sum of the mass percentages of the components is 100 percent; the reinforcing fiber comprises steel fiber, aramid pulp or composite mineral fiber; the friction coefficient regulator comprises crystalline flake graphite, aluminum oxide and MoS₂Antimony sulfide, Fe powder or quartz sand; the filler comprises barite, vermiculite, diatomite, barium sulfate or wollastonite.

The phenolic resin reinforced by the phosphorus-containing hyperbranched polysiloxane is prepared by compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100: 1-10.

The structural formula of the phosphorus-containing hyperbranched polysiloxane is as follows:

the method for preparing the low-noise high-wear-resistance flame-retardant friction material is characterized by adopting a dry hot press molding process, and comprises the following steps:

step 1: uniformly coating a release agent in a die cavity of a hot press template;

step 2: 25-30% by mass of binder phosphorus-containing hyperbranched polysiloxane reinforced phenolic resin, 25-30% by mass of reinforcing fiber, 20-30% by mass of friction coefficient regulator and 15-25% by mass of filler; mixing in a stirrer;

and step 3: pouring the mixed material into a die cavity, adjusting the temperature of a hot press to 140-180 ℃, and pressing under the pressure of 20-30 Mpa;

exhaust gas was exhausted at the start of pressing.

And 3, exhausting for 2-3 times between 60s when the pressing is started.

Advantageous effects

The invention provides a low-noise high-wear-resistance flame-retardant friction material and a preparation method thereof. The friction performance and the mechanical performance of the resin-based friction material are enhanced by the phosphorus-containing hyperbranched polysiloxane, and the interface bonding property between the filler and the resin and the enhanced material is improved on one hand through the flexible action of siloxane and the reactivity of terminal functional groups, and on the other hand, the phosphorus-containing hyperbranched polysiloxane is used as flexible soft particles, so that the resin is toughened and enhanced, the toughness of the resin is improved, the fracture of the resin is inhibited, and meanwhile, the resin can be endowed with certain damping property to inhibit noise; moreover, good flame retardancy can be imparted to the resin due to the synergistic effect of P, N therein and the silicon element; more importantly, the hyperbranched polysiloxane has good high and low temperature resistance, can improve the heat resistance of resin and the use performance of the resin at low temperature, so that a low-noise, high-wear-resistant and flame-retardant friction material can be prepared by taking the hyperbranched polysiloxane as a reinforcer, can be made into a brake pad for a braking system of motor vehicles such as automobiles, motorcycles and the like, and has very wide application prospect.

Detailed Description

The invention will now be further described with reference to the examples:

the process of the low-noise high-wear-resistance flame-retardant friction material comprises the following steps: batching, hot pressing, heat treatment and cutting.

(I) preparing the ingredients

The binder used by the friction material is prepared by compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100: 1-10, and the mass content of the binder in the friction material is 25-30%; taking steel fibers, aramid pulp and composite mineral fibers as reinforcing fibers, wherein the mass content of the reinforcing fibers is 25-30%; using crystalline flake graphite, alumina and MoS₂Antimony sulfide, Fe powder, quartz sand and the like are used as friction coefficient regulators, and the mass content of the friction coefficient regulators is 20-30%; the filler is barite, vermiculite, diatomite, barium sulfate, wollastonite and the like, and the mass content of the filler is 15-25%. All the raw materials are uniformly mixed and prepared by adopting a dry hot press molding process.

(II) hot pressing

Checking whether the temperature is within the range of 140-180 ℃ and the numerical value of a pressure gauge is within the range of 20-30 MPa before operation; opening the hot press, taking out the template, uniformly coating the release agent in the cavity of the template, putting the mold cavity into a stirrer according to equal proportion for mixing, pouring the mixed material into the cavity of the template, and starting pressing; reasonably exhausting for 2-3 times in the first 60s to see whether the gas is exhausted completely, and if the blank still expands, continuing to exhaust until the gas is exhausted completely; after taking out the product, removing the waste edge of the product gasket, and visually inspecting whether the product has the phenomena of edge deletion, corner deletion, cracks, layering, foaming, sand holes, sound knocking, internal foaming and the like; the products are qualified products without abnormal samples, and the products are orderly placed in a turnover box.

(III) Heat treatment

Placing the products on the grids in order, and putting the grids into an oven; closing the oven door and opening the exhaust valve; and switching on a power supply, starting the fan, starting the heating switch and running the program.

(IV) cutting

Adjusting the cutting machine to the required interval, and fixing and positioning; leaning the blank gasket with the hair removed on the positioning, and switching on a power supply for cutting; the cut liner was tested for size.

Example 1 was carried out:

compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100:5 to prepare an adhesive, and controlling the mass content of the adhesive in the friction material to be 30%; steel fiber is taken as reinforcing fiber, and the mass content of the reinforcing fiber is 25%; flake graphite is used as a friction coefficient regulator, and the mass content of the flake graphite is 20%; barite is used as a filler, and the mass content of the barite is 25%.

The reinforced fiber can also adopt aramid pulp or composite mineral fiber.

The friction coefficient regulator can also adopt alumina, MoS2, antimony sulfide, Fe powder or quartz sand.

The filler can also be vermiculite, diatomite, barium sulfate or wollastonite.

Then carrying out hot pressing operation: the temperature is regulated and controlled within 160 ℃ before operation, and the value of a pressure gauge is within 25MPa or not; opening the hot press, taking out the template, uniformly coating the release agent in the cavity of the template, putting the mold cavity into a stirrer according to equal proportion for mixing, pouring the mixed material into the cavity of the template, and starting pressing; exhausting for 2-3 times in the first 60s after pressing, and if the blank still expands, continuing to exhaust until the gas is exhausted; after taking out the product, removing the waste edge of the product gasket, and visually inspecting whether the product has the phenomena of edge deletion, corner deletion, cracks, layering, foaming, sand holes, sound knocking, internal foaming and the like; the products are qualified products without abnormal samples, and the products are orderly placed in a turnover box.

And (3) performing heat treatment after hot pressing is completed: placing the products on the grids in order, and putting the grids into an oven; closing the oven door and opening the exhaust valve; and switching on a power supply, starting the fan, starting the heating switch and running the program. And finally, cutting: adjusting the cutting machine to the required interval, and fixing and positioning; leaning the blank gasket with the hair removed on the positioning, and switching on a power supply for cutting; the cut liner was tested for size.

Example 2 was carried out:

compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100:10 to prepare an adhesive, and controlling the mass content of the adhesive in the friction material to be 25%; aramid pulp is used as reinforcing fiber, and the mass content of the aramid pulp is 25%; aluminum oxide is used as a friction coefficient regulator, and the mass content of the aluminum oxide is 25%; vermiculite is used as a filler, and the mass content of the vermiculite is 25%.

The reinforcing fiber can also adopt steel fiber or composite mineral fiber.

The friction coefficient regulator can also adopt crystalline flake graphite, MoS2, antimony sulfide, Fe powder or quartz sand.

The filler can also be barite, diatomaceous earth, barium sulfate or wollastonite.

Then, hot pressing operation is carried out: the temperature is regulated and controlled to be 180 ℃ before operation, and the value of a pressure gauge is 25 MPa; opening the hot press, taking out the template, uniformly coating the release agent in the cavity of the template, putting the mold cavity into a stirrer according to equal proportion for mixing, pouring the mixed material into the cavity of the template, and starting pressing; exhausting for 2-3 times in the first 60s to see whether the gas is exhausted, and if the blank still expands, continuing to exhaust until the gas is exhausted; after taking out the product, removing the waste edge of the product gasket, and visually inspecting whether the product has the phenomena of edge deletion, corner deletion, cracks, layering, foaming, sand holes, sound knocking, internal foaming and the like; the products are qualified products without abnormal samples, and the products are orderly placed in a turnover box.

And (3) performing heat treatment after hot pressing is completed: placing the products on the grids in order, and putting the grids into an oven; closing the oven door and opening the exhaust valve; and switching on a power supply, starting the fan, starting the heating switch and running the program. And finally, cutting: adjusting the cutting machine to the required interval, and fixing and positioning; leaning the blank gasket with the hair removed on the positioning, and switching on a power supply for cutting; the cut liner was tested for size.

Example 3 of implementation:

compounding phenolic resin and phosphorus-containing hyperbranched polysiloxane in a mass ratio of 100:10 to prepare an adhesive, and controlling the mass content of the adhesive in the friction material to be 25%; taking composite mineral fiber as reinforcing fiber, wherein the mass content of the composite mineral fiber is 25%; antimony sulfide is used as a friction coefficient regulator, and the mass content of the antimony sulfide is 25%; diatomite is used as a filler, and the mass content of the diatomite is 25%.

The reinforcing fiber can also adopt steel fiber or aramid pulp.

The friction coefficient regulator can also adopt crystalline flake graphite, MoS2, alumina, Fe powder or quartz sand.

The filler can also be barite, vermiculite, barium sulfate or wollastonite.

Then, hot pressing operation is carried out: the temperature is regulated and controlled to be 180 ℃ before operation, and the value of a pressure gauge is 25 MPa; opening the hot press, taking out the template, uniformly coating the release agent in the cavity of the template, putting the mold cavity into a stirrer according to equal proportion for mixing, pouring the mixed material into the cavity of the template, and starting pressing; exhausting for 2-3 times in the first 60s to see whether the gas is exhausted, and if the blank still expands, continuing to exhaust until the gas is exhausted; after taking out the product, removing the waste edge of the product gasket, and visually inspecting whether the product has the phenomena of edge deletion, corner deletion, cracks, layering, foaming, sand holes, sound knocking, internal foaming and the like; the products are qualified products without abnormal samples, and the products are orderly placed in a turnover box.

And (3) performing heat treatment after hot pressing is completed: placing the products on the grids in order, and putting the grids into an oven; closing the oven door and opening the exhaust valve; and switching on a power supply, starting the fan, starting the heating switch and running the program. And finally, cutting: adjusting the cutting machine to the required interval, and fixing and positioning; leaning the blank gasket with the hair removed on the positioning, and switching on a power supply for cutting; the cut liner was tested for size.