Name: 275# silicone oil for super high vacuum diffusion pump Molecular formula: CH3(C6H5)2SiO(CH3)2SiOSi(C6H5)2CH3 Property and usage: 275# silicone oil for super high vacuum diffusion pump is colorless, transparent oily fluid and owns very low saturated vapor pressure, good heat resistivity property and with excellent resistance to high temperature, oxidant and radiate. It can be used in high vac., electrical industry, coating for high vac., particle accelerator, electronic microscope and display, etc. Technical data: Appearance: colorless transparent liquid Content: 99% min Ultimate vacuum: 5X10-9 Viscosity (25 °C): 165-185 Refractive index(25 °C): 1.5765-1.5785 Flash point: 243 °C Freezing point: -14°C max