Span S-60 (sorbitan monostearate) is a classic nonionic surfactant with CAS number 1338-41-6. Its molecular structure endows it with excellent water-in-oil (W/O) emulsifying ability, enabling it to form a strong interfacial film at the oil-water interface to prepare stable W/O emulsion systems. At the same time, it exhibits good tolerance to acids, alkalis, and hard water media, maintaining stable performance over a wide pH range and in complex formulation environments. This makes it a versatile functional additive across industries and multiple process scenarios.
With extremely low acute oral toxicity (rat oral LD₅₀ > 15,000 mg/kg) and good biocompatibility, Span S-60 is not only widely used in industrial fields but also permitted in products directly related to human health such as food, medicine, and cosmetics. In addition, Span S-60 can be compounded with hydrophilic surfactants such as Tween series to flexibly adjust the HLB value, achieving precise design from W/O to O/W emulsion systems, greatly expanding its application boundaries.
| Industry | Core Function | Typical Process & Application Scenarios |
|---|---|---|
| Cosmetics & Personal Care | W/O primary emulsifier or co-emulsifier | Emulsification and stabilization of formulations such as creams, lotions, sunscreens, imparting a fine texture and good spreadability, and forming a protective film on the skin to provide moisturizing effects |
| Food Industry | Emulsifier, Stabilizer | In high-fat foods such as margarine, ice cream, pastries, and chocolate, it prevents oil separation, improves texture, retards starch aging, and extends shelf life; complies with E491 food additive standard |
| Pharmaceuticals & Health Products | Suppository base, drug carrier | Molding base for suppositories such as vaginal and rectal suppositories; promotes uniform drug dispersion and controlled release in oral and topical formulations, improving system stability and bioavailability |
| Textile Industry | Fiber oil component, softening finishing agent | Provides smoothness, cohesion, and antistatic properties in synthetic fiber spinning oils; reduces processing friction in fabric softening finishing processes, improving hand feel |
| Plastics Industry | Anti-fogging agent, antistatic agent | Internal additive component in agricultural polyolefin films, effectively eliminates fog inside greenhouses and improves light transmittance; reduces electrostatic dust adsorption on film surface, prolonging film service life |
| Agrochemicals | Pesticide emulsifier | In pesticide emulsifiable concentrate (EC) formulations, it helps the active ingredient self-emulsify quickly upon dilution to form a stable oil-in-water emulsion, ensuring uniform spraying and efficacy |
| Coatings & Inks | Pigment wetting and dispersing agent | Improves wetting and dispersion stability of pigments and fillers, preventing pigment agglomeration, floating, flooding, and other defects, ensuring uniform film color and enhancing coating gloss |
In actual formulation design, the HLB value of Span S-60 is approximately 4.7, making it suitable for use alone in W/O emulsification systems. If O/W emulsions or systems with broader HLB values are required, it is recommended to be used in combination with Tween series (e.g., Tween-60, Tween-80). By adjusting the ratio of the two, the overall HLB value can be precisely controlled. The generally recommended dosage is 0.5% to 5% of the total formulation, and the specific dosage should be determined experimentally based on the oil phase ratio of the emulsification system and the desired product characteristics.
Before use, please note that the product may solidify at low temperatures, which is a normal physical change. It can be used normally after returning to room temperature and appropriate stirring. In food-grade applications, ensure that the product complies with the food additive regulations and standards of the corresponding country or region (e.g., GB 25552, FDA 21 CFR, etc.).