Silicone oil CAS no. 63148-62-9 Silicone oil, English name is Silicone oil, CAS number is 63148-62-9, molecular formula is C6H18OSi₂, it is a kind of polyorganosiloxane with different degree of polymerization chain structure. It is obtained by hydrolyzing dimethyldichlorosilane with water to obtain an initial polycondensation ring body. The ring body is cracked and rectified to obtain a low ring body. A mixture of different degrees of polymerization can be obtained by removing low boilers by distillation under reduced pressure.

According to chemical structure, there are methyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogen-containing silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trifluoropropyl silicone oil Silicone oil, methyl vinyl silicone oil, methyl hydroxy silicone oil, ethyl hydrogen silicone oil, hydroxy hydrogen silicone oil, cyano silicone oil, etc.;

According to the use, there are damping silicone oil, diffusion pump silicone oil, hydraulic oil, insulating oil, heat transfer oil, brake oil, etc.
It is often used as advanced lubricating oil, anti-vibration oil, insulating oil, defoaming agent, mold release agent, polishing agent and vacuum diffusion pump oil. Among various silicone oils, methyl silicone oil is the most widely used and the most important variety in silicone oil, followed by methyl phenyl silicone oil. In addition, there are ethyl silicone oil, methyl phenyl silicone oil, nitrile-containing silicone oil, etc. Various functional silicone oils and modified silicone oils are mainly used for special purposes.

advantage
(1) Excellent shear stability, has the function of absorbing vibration and preventing vibration transmission, and can be used as vibration damping fluid.

(2) Excellent thermal oxidation stability, such as thermal decomposition temperature> 300 ℃, small evaporation loss (150 ℃, 30 days, evaporation loss is only 2%), oxidation test (200 ℃, 72h), viscosity and acid value changes Small.

(3) Excellent electrical insulation, volume resistance, etc. do not change in the range of normal temperature to 130 °C (but the oil cannot contain water).

(4) It is a non-toxic oil with low foaming and strong anti-foaming properties, which can be used as a defoaming agent.

(5) The viscosity-temperature performance is the best among liquid lubricants, and the viscosity changes little in a wide temperature range. Its freezing point is generally less than -50°C, and some are as high as -70°C. When stored for a long time at low temperature, the appearance and viscosity of the oil will not change. It is a base oil that takes into account high temperature, low temperature and wide temperature range.

shortcoming
(1) Small surface tension (easy to leak from the machine).

(2) The gas solubility is relatively large (it is difficult to design a gas sealing device).

(3) The thermal expansion coefficient of silicone oil is large (may cause overpressure problems).

(4) The lubricity of silicone oil is poor, especially the lubricity of steel-steel friction pairs.

(5) Certain hygroscopicity (after the water content is higher than 100×10-6, the electrical properties drop sharply)