Muffling grease is different from low-noise grease, although both are designed to reduce mechanical noise, but low-noise grease is the noise that reduces its own composition, while muffling grease directly reduces or eliminates mechanical noise. In addition, the application fields of the two are different. Low-noise grease is mainly used for electrical miniature sealed bearings, while noise-absorbing grease is mainly used for automotive parts with sliding surfaces, gears and the like.
Adhesive muffling grease is used to improve the adhesion of grease or increase the thickness of the oil film to achieve sound elimination. A polymer such as polybutene, polyisobutylene, an olefin copolymer, an isoprene rubber, or a synthetic rosin is usually added to the grease.
The base oil of the adhesive type muffling grease is a polyoxypropylene glycol monoether, and the thickening agent is lithium stearate, a quaternary ammonium-containing clay, and an ethylene/α-olefin copolymer as a tackifier.
Polyoxypropylene glycol monoether base oil has good low-temperature fluidity, no sludge and paint film, good shear stability, low corrosiveness and permeability to metals, rubber and plastics, and good compatibility with additives. However, the compatibility with mineral oil is not good, and the oxidation stability and thermal stability are poor.
The ethylene/α-olefin copolymer is excellent in oxidation stability, thermal stability, shear stability, low-temperature fluidity, and compatibility with additives.
Adhesive sound-absorbing greases, in addition to lithium stearate and quaternary ammonium-containing clays as thickeners, sodium soap, potassium soap, calcium soap, barium soap, barium soap, lithium soap, etc.; As the chemical agent, bentonite, silica gel or the like can be used; for the organic thickener, a urea compound or the like can be used. When a quaternary ammonium salt-containing clay is used in the preparation, it is first added to the base oil and thoroughly mixed, and then methanol is further added, and once again, it is thoroughly mixed, and the temperature of the mixture is raised to 100 ° C by heating. Thus, the quaternary ammonium salt-containing clay is sufficiently swellable in the base oil. In addition to methanol, acetone, ethanol, or the like can also be used.
The ethylene/α-olefin copolymer as a tackifier has good compatibility with the base oil, and can sufficiently exert the effect of the tackifier. The reason why the ethylene/α-olefin copolymer is dissolved in the mineral oil is because the ethylene/α-olefin copolymer can be easily mixed in the grease, and the viscosity of the grease at a low temperature can be appropriately increased to eliminate the sound. The role.
Adhesive noise-reducing grease is mainly used for the gears of automobile door flaps, door locks, sliding surfaces of seat rails, sliding surfaces of seat rails, wiper motors and car antennas, etc., which can effectively prevent the above-mentioned automobile parts from being emitted by vibration. The sound and the phenomenon of component contamination caused by oil separation.