The composition of the the brake pads binder, reinforcing fiber, friction modifier, filler.

The friction performance modifier can be divided into 2 categories: (1) Anti-friction material: Mohs hardness is generally less than 2, its addition can improve the friction resistance of the material, reduce noise and reduce the friction coefficient. Such materials mainly include: graphite, molybdenum disulfide, lead, copper, etc. (2) Friction material: Mohs hardness is generally more than 4 and its addition can increase the friction coefficient of the material. Most inorganic fillers and some metals and their oxides belong to this category. The addition of friction performance modifier is mainly to adjust the thermal stability of the material and its working stability.

Molybdenum disulfide has the advantages of good dispersibility, wear resistance and noise reduction. It is added as a friction performance regulator in brake pads. The main functions are:

1. Anti-friction: The particle size of molybdenum disulfide is 1.5-20 microns, the friction coefficient can reach 0.05, the dispersion performance is excellent and the anti-friction effect is good.

2. Friction: When the friction material rises sharply due to frictional temperature, molybdenum disulfide oxidizes and appears molybdenum trioxide, which expands with increasing temperature to play a role in increasing friction.

3. Anti-oxidation and anti-shedding: Molybdenum disulfide is slightly acidic. It covers the surface of the friction material to protect other materials from oxidation making it difficult to fall off and strong adhesion.

4. Expansion: When the friction material is in the high-temperature state of braking, many low-temperature materials such as fillers and resins are easily carbonized and burned, which causing the internal voids of the material to increase, while molybdenum trioxide can better to make a compensate.

5. Reduce the specific gravity: The specific gravity of molybdenum disulfide crystals is 4.5-5.2. As the fineness increases, the specific surface area also increases, the specific gravity decreases, and the brake pad weight is reduced to a certain extent.