Question

What is Span S-85? What are its main uses?

Answer
2026-06-06 官方文档 司盘S-85

Span S-85 is a highly lipophilic nonionic surfactant (sorbitan trioleate), specifically designed for water-in-oil (W/O) systems, and is a key emulsifying component for preparing stable water-in-oil emulsions and microemulsions.

Detailed Description

Span S-85 (Span 85), with the chemical name sorbitan trioleate (sorbitan trioleate) and CAS number 26266-58-0, is a classic nonionic surfactant produced by Haian Guoli Chemical Co., Ltd. This product appears as a viscous oily liquid ranging from amber to brownish-yellow, possessing an extremely low hydrophilic-lipophilic balance (HLB value), which gives it strong lipophilic characteristics, making it an indispensable core component in water-in-oil (W/O) emulsification systems.

Span S-85 exhibits excellent emulsifying and dispersing capabilities, significantly reducing the oil-water interfacial tension, imparting a fine texture and long-term storage stability to products such as creams and lotions. It also has good chemical inertness and compatibility, remaining stable in acidic, alkaline, and hard water environments, maintaining activity over a wide temperature and pH range, and being well compatible with various oils, waxes, and active ingredients.

Main Application Areas

Span S-85 has a wide range of uses, covering six core industries:

1. Cosmetics and Skincare: Used as a W/O emulsifier in oil-based formulations such as cold creams, massage creams, sunscreens, and liquid foundations, enhancing application feel and spreadability, helping to disperse and suspend UV filters, and improving water resistance.

2. Pharmaceutical Preparations: As a W/O emulsifier in topical ointments, suppository bases, and cream bases, ensuring uniform drug distribution and promoting skin absorption of lipophilic drugs.

3. Food Industry: Used as an emulsifier in candies, pastry release oils, whipped creams, and shortenings to improve aeration and structural stability.

4. Textile Industry: Applied in synthetic fiber tow finishing oils and antistatic agents to reduce friction between fibers and metals, imparting smoothness and cohesion to fibers, reducing breakage rates.

5. Metalworking and Oil Extraction: Forms stable W/O emulsification systems in emulsified cutting fluids and rust-proof oils, providing lubrication and corrosion protection; used as an emulsion stabilizer in drilling fluids and fracturing fluids, capable of withstanding high-temperature and high-salinity formation conditions.

6. Coatings, Inks, and Pesticides: Used as a wetting and dispersing aid for pigments and fillers to prevent float and flooding; assists in emulsification and dispersion in pesticide emulsifiable concentrates (EC) and suspension concentrates (SC), improving formulation stability.

Technical Parameters

ParameterValue
Product NameSpan S-85 (Span 85)
Chemical NameSorbitan Trioleate / Sorbitan Trioleate
CAS Number26266-58-0
Product TypeNonionic Surfactant
AppearanceAmber to brownish-yellow viscous oily liquid
Hydrophilic-Lipophilic CharacteristicUltra-low HLB value, strong lipophilicity
Emulsion TypeWater-in-oil (W/O)
GHS ClassificationNon-hazardous chemical
Water Hazard ClassWGK 1 (Slightly hazardous to water)

Application Recommendations

Span S-85 is typically used in combination with Tween series (e.g., Tween T-80, Tween T-85) and other high HLB value surfactants, adjusting the ratio of the two to achieve the required HLB value of the emulsion system. In water-in-oil formulations, the recommended dosage is generally 1% to 5% of the total formulation, but the exact amount should be optimized through experiments based on the type of oil phase, aqueous phase ratio, and target viscosity. In pesticide emulsifiable concentrates, the recommended dosage is 5% to 10%; in metalworking fluids, it is suggested to be used in conjunction with sulfonate or amide additives to enhance emulsification stability.

Precautions

  • During operation, it is recommended to wear chemical protective gloves and safety goggles, and use in a well-ventilated area.
  • Store in a cool, dry, well-ventilated place, keep the container tightly sealed, and avoid contact with strong oxidizing agents.
  • Avoid direct discharge into water bodies or the environment without dilution or treatment.
  • Prolonged or repeated skin contact may cause slight dryness; hands should be thoroughly washed after operation.