Silicone oil, also known as polysiloxane, its silicon-oxygen bond is very stable, so silicone oil has good thermal stability and oxidation stability. At present, silicone oil used as lubricating oil mainly includes methyl silicone oil, methyl phenyl silicone oil, methyl chlorobenzyl silicone oil and ethyl silicone oil. Methyl silicone oil is commonly used as damping fluid and grease base oil for special purpose. Ethyl silicon oil is mainly used for precision instrument oil; Because of its high temperature resistance, low freezing point and good oxidation resistance, methyl phenyl silicone oil is often used to make synthetic high temperature grease base oil. Chlorosilicone oil has better lubricity than other silicon oils, so it is often used to prepare base oils with medium load grease.
The lubricating oil is usually forced circulation in the lubricating oil system operation mode, often run into some of the air, in the case of roiling will produce bubbles and bubbles, the larger the air bubble can quickly rose to the surface of the oil, and the smaller bubbles rise slowly, whether in the form of a which exists in oil will bring bad influence to equipment, and may make the pump oil pressure couldn't get on the influence of oil circulation, destruction of the oil film, wear, oil pressure instability at the same time, the influence regulation, serious when bubbles spillover from tank top threat unit operation, so the product must have a foam resistance.
When he worked in the equipment system, in order to eliminate the working medium of bubble, through long-term observation and research, to find a wide variety of defoaming methods, such as physical foam method, mechanical defoaming method, chemical foam, etc., the chemical defoaming antifoaming agent effect is best, in the method is simple, therefore, is widely used at home and abroad. In 1943 shell development and gulf research and development discovered that liquid polysiloxane was an effective anti-foam agent. Methyl silicone oil is still widely used as a lubricant antifoaming agent. Methyl silicone oil as anti-foaming agent, and its following properties related (1) surface tension than lubricating oil low, make foaming agent desorption, but its own formation of the surface film strength is poor. (2) it in the lubricating oil solubility is small, but there is a certain degree of lipophilic. (3) chemical properties are not active, not easy to occur chemical reaction with lubricating oil. (4) low dosage, good effect, even at high temperature can also effectively eliminate the oil in the foam. 5. Methyl silicone oil has low volatility, viscosity temperature, high flash point, low freezing point, thermal stability, long service life. The commonly used viscosity of dimethyl silicone oil, which plays the role of defogging in lubricating oil, is (25℃ kinematic viscosity) 100-100000cs, and the usage amount is 5-50mg/kg.
Silicone oil is a liquid polysiloxane with excellent properties of high and low temperature resistance, chemical stability, shear resistance, viscotemperature resistance and high compression rate. The products are widely used in electronic and electrical equipment, high buildings, Bridges and weapon platforms.