Dow Corning DC 705 (also known as Dowsil 705) is a high-performance, phenyl-substituted silicone fluid formulated specifically for high-vacuum diffusion pumps. Based on pentaphenyl trimethyl trisiloxane, it features an ultra-low vapor pressure of 3×10⁻¹⁰ Torr at 25°C, enabling operation down to 10⁻⁸ Torr without liquid nitrogen traps and 10⁻¹¹ Torr with LN₂ traps. With excellent thermal and chemical stability, a high flash point, and low backstreaming rate, it is ideal for space simulation, thin film coating, and plasma physics research applications.

• Vapor Pressure @25°C: 3×10⁻¹⁰ Torr

• Flash Point: 243°C

• Boiling Point @0.5 Torr: 245°C

• Specific Gravity: 1.09 g/cc

• Viscosity @25°C: 175 cSt

• Appearance: Clear liquid

• Shelf Life: ≥5 years (original container, ambient storage)

• Ultra-low vapor pressure for deep vacuum performance

• Low backstreaming rate minimizes contamination

• High thermal stability and high spontaneous ignition temperature

• Compatible with high-vacuum diffusion pump systems

• Enables 10⁻⁸ Torr operation without LN₂ traps

• Supports 10⁻¹¹ Torr ultimate pressure with LN₂ traps

• High-vacuum diffusion pumps

• Thin film coating and deposition systems

• Surface science and analytical vacuum systems

• Plasma physics research equipment

• Space simulation chambers and environmental testing

• Industrial vacuum processing requiring ultra-clean conditions