Span S-85 is a highly lipophilic nonionic surfactant with an extremely low HLB value, specifically designed for water-in-oil (W/O) systems. Its chemical name is sorbitan trioleate (CAS: 26266-58-0). At room temperature, it appears as an amber to brownish-yellow viscous oily liquid with excellent chemical inertness, resistant to acids, bases, and hard water, maintaining activity under a wide range of environmental conditions.
With its ultra-low hydrophilic-lipophilic balance and excellent interfacial tension reduction capability, Span S-85 is used in multiple industrial fields to build stable water-in-oil emulsion systems, efficiently disperse solid particles and pigments, and is well compatible with various oils, waxes, and active ingredients.
| Industry | Process/Product | Functional Role |
|---|---|---|
| Cosmetics & Skincare | Cold creams, massage creams, sunscreens, foundations, mascaras, eyeshadows | W/O emulsifier, improves feel, spreadability, and uniform pigment dispersion |
| Pharmaceutical preparations | Topical ointments, suppository bases, cream bases | W/O emulsifier, promotes uniform drug distribution and skin absorption |
| Food industry | Candy mold release oils, whipped cream, frostings, shortenings, defoamers | Emulsifier, improves aeration and structural stability |
| Textile industry | Synthetic fiber tow finishing oils, antistatic finishing agents | Reduces friction, imparts smoothness and cohesion to fibers, reduces breakage rate |
| Metalworking | Emulsified cutting fluids, rust preventive oils | Builds stable W/O emulsion system, provides lubrication and corrosion protection |
| Petroleum extraction | Oil-based/synthetic-based drilling fluids, fracturing fluids | Emulsion stabilizer, enhances wellbore stability and cuttings carrying capacity, withstands high temperature and high salinity formations |
| Coatings & Inks | Pigment dispersion, leveling promotion | Wets and disperses pigments, prevents floating and flooding, reduces brush marks or orange peel |
| Pesticide formulations | Emulsifiable concentrates (EC), suspension concentrates (SC) | Improves compatibility of active ingredient with solvent, aids wetting and dispersion of solid active ingredient particles |
Span S-85 is usually used in combination with hydrophilic surfactants (such as Tween series) to adjust the HLB value of the system for optimal emulsification. In W/O emulsion formulations, the recommended dosage is 1%–5% of the oil phase (subject to formulation testing). When operating at high temperatures, avoid prolonged exposure above 120°C.