High vacuum diffusion pump oil 705 is a colorless, transparent oil-like liquid with a viscosity of 170-175cst at 25C and a refractive index of 1.5765-1.5785 at the same temperature. It has a flash point (open cup) of 240C. The oil exhibits exceptionally low vapor pressure and reflux rate, making it suitable for ultra-high vacuum and ultra-clean vacuum applications without requiring steam traps or refrigeration. With the highest phenyl content among all silicone diffusion pump oils, it demonstrates outstanding radiation resistance.
It exhibits a very low saturated vapor pressure, excellent thermal stability, and good oxidation resistance. It is primarily used in high-vacuum smelting industries, electron tube industries, light bulbs, high-vacuum coatings (films), atomic energy accelerators, electron microscopes, and displays.