Castor Oil Polyoxyethylene Ether EL-20 is a highly efficient nonionic O\/W (oil-in-water) emulsifier, appearing as a light yellow to yellow viscous liquid. Due to its high viscosity (approximately 700 mPa·s at 25°C), it is recommended to pre-dilute and stir it with warm water (40-50°C) or the oil phase component to be used before adding it to the formulation system, allowing it to fully dissolve or disperse into a uniform liquid before slowly adding it to the formula. This prevents “clumping” or uneven emulsification caused by localized high concentrations. According to information from the Guoli Chemical database, its HLB value is 10.5, it is soluble in water, and it is suitable for emulsifying mineral oils, animal and vegetable oils.
The order of addition of this product varies slightly in different systems: in cosmetic cream\/lotion emulsification systems, it can be dissolved in the oil phase with heating or in the water phase, depending on the specific formula; in pesticide emulsion in water (EW) and microemulsion (ME), it is usually mixed evenly with the active ingredients of the oil phase, then slowly added to the water phase under high-shear stirring for phase inversion and emulsification; in metalworking fluids and industrial cleaners, it can be directly added to the water phase with stirring. The key is to optimize the addition timing and stirring speed based on the formulation process.
| Application Field | Functional Role | Recommended Dosage (% of Total Formula Weight) | Usage Method |
|---|---|---|---|
| Cosmetics and Personal Care Products |
Emulsifier, Solubilizer | 1.0% – 5.0% | Can be dissolved in the oil phase with heating (70-80°C) or combined with a co-emulsifier and added to the water phase. In cleansing oils, it is directly mixed with the base oil. |
| Textile Printing and Dyeing Auxiliaries | Leveling Agent, Dispersant | 0.5 – 2.0 g\/L (Dye Bath) | Pre-dilute with 40-50°C warm water and add to the dye bath, stirring evenly. When used as a softener compound, the dosage can be increased. |
| Pesticide Emulsifiers |
Nonionic Emulsifier | 3.0% – 10.0% | Mix evenly with the active ingredients in the oil phase and oil-soluble auxiliaries, then slowly add water under high-shear (3000-5000 rpm) to achieve phase inversion to a uniform emulsion. |
| Metalworking Fluids |
Emulsifier, Lubricant | 5.0% – 15.0% (in Base Oil Phase) | Combine with base oil, rust inhibitors, etc., in a blending tank. When used, dilute with water to form a working fluid (e.g., 5% dilution). |
| Industrial Cleaners | Degreaser, Emulsifier | 2.0% – 8.0% | Directly dissolve in water with surfactants, auxiliaries, etc., and stir. Better results when combined with alkaline auxiliaries such as sodium metasilicate. |
| Coatings and Inks | Pigment Wetting and Dispersing Agent | 1.0% – 5.0% of Pigment Weight | Add during the grinding stage to help disperse pigments and prevent flocculation. Can also be added after the dilution stage to improve leveling. |
EL-20 has excellent compatibility with anionic (e.g., sulfonates, sulfates), cationic, and other nonionic surfactants. It is often compounded with lower HLB emulsifiers (such as Span series, EL-10, etc.) to fine-tune the overall HLB value and achieve more stable emulsification. During formula debugging, first determine the required HLB value of the emulsion system, then calculate the ratio of EL-20 to low-HLB emulsifiers.