The application method of Castor Oil Ethoxylate EL-20 varies by industry, and it is usually added to the oil or water phase under stirring. Based on industrial application practices, the recommended dosage is generally between 1% and 15%, and the specific amount needs to be optimized through experiments.
Detailed Description
Castor Oil Ethoxylate EL-20 (CAS No.: 61791-12-6) is a nonionic O/W emulsifier with an HLB value of 10.5, appearing as a light yellow to yellow viscous liquid. This product is liquid or paste at room temperature. When added directly, it is recommended to heat it appropriately to 30~40°C to reduce viscosity, making it easier to measure and disperse. Because it combines hydrophilicity and lipophilicity, it can be used alone as the main emulsifier or compounded with anionic or cationic surfactants for synergistic effects.
The general operation steps for use are: First, mix EL-20 with the oil phase components to be emulsified, stirring at 50~70°C until uniform and transparent; separately heat the water phase components to the same temperature; then, under rapid stirring (recommended speed 500~1500 rpm), slowly add the water phase to the oil phase, or vice versa, continue stirring and cool to room temperature to obtain a stable emulsion. In pesticide emulsions in water (EW) or microemulsions (ME) formulations, EL-20 is often compounded with anionic emulsifiers (such as calcium salt) to achieve better emulsion stability and particle size distribution.
For reactor feeding scenarios, EL-20 can be added before, during, or after the polymerization reaction. When used as an emulsion polymerization emulsifier, it is recommended to pre-disperse it in some water before adding it to the reaction system to ensure sufficient emulsification of monomer droplets and stable polymerization. As a post-added wetting and dispersing agent, it can be directly added to the grinding base during the pigment dispersion stage to improve the fineness of the color paste and prevent secondary flocculation of pigment particles.
Technical Parameters
| Parameter Item | Specification Indicator |
|---|
| Appearance | Light yellow to yellow viscous liquid |
| Ionic Type | Nonionic |
| HLB Value | 10.5 |
| Active Content | ≥99% |
| pH Value (1% aqueous solution) | 5.0~7.0 |
| Cloud Point (1% aqueous solution) | ≥85°C |
| Water Solubility | Soluble in water, easily soluble in ethanol, ether and other organic solvents |
| Foaming Characteristics | Low foaming |
| Density (25°C) | 1.05~1.10 g/cm³ |
| Freezing Point | <0°C (liquid) |
| Storage Temperature | 5~35°C |
Application Recommendations
The following are industry general recommended dosages for various application fields (based on total formulation weight), data sourced from industry practices:
- Cosmetic Creams and Lotions: Recommended dosage 2%~5%, used as O/W primary emulsifier or auxiliary emulsifier. Suitable for face creams, lotions, cleansing oils, body washes, shampoos, and other products. Can be used alone or compounded with fatty alcohol ethoxylates to adjust texture and stability.
- Pesticide Emulsions in Water (EW) and Microemulsions (ME): Recommended dosage 4%~10%, often used in combination with anionic emulsifiers. The HLB value of 10.5 makes it suitable for formulating with aromatic solvents and vegetable oils as the oil phase, effectively reducing oil-water interfacial tension and improving emulsion resistance to Ostwald ripening.
- Metalworking Fluids: Recommended dosage 5%~15%, used as an emulsifier and lubricating component. It functions to emulsify base oils in emulsified cutting fluids and grinding fluid concentrates, while also providing some oily lubrication and anti-rust properties. Can be used synergistically with sodium petroleum sulfonate, triethanolamine, etc.
- Textile Dyeing and Finishing Auxiliaries: Recommended dosage 1%~5%, used as a leveling agent, dispersant, or softener component. In high-temperature and high-pressure dyeing processes, due to its cloud point ≥85°C, it provides stable dispersion and leveling effects.
- Coatings and Inks: Recommended dosage 0.5%~3% (5%~15% based on pigment weight), used as a pigment wetting and dispersing agent. When added during the color paste grinding stage, it can significantly shorten dispersion time, improve color strength, and storage stability.
- Industrial Cleaners: Recommended dosage 3%~8%, used in hard surface degreasing cleaning and fabric washing formulations. Its low foaming characteristics make it suitable for low to medium temperature cleaning processes, easy to rinse, and residue-free.
Precautions
Operation and Safety
- It has mild irritation to skin and eyes. It is recommended to wear nitrile rubber gloves and chemical safety goggles during operation, and ensure good ventilation in the working environment.
- Turbidity or stratification may occur during low-temperature storage, which is a normal physical phenomenon. After heating to 30~40°C and stirring evenly, it can still be used normally without affecting product performance.
- The HLB value is 10.5, suitable for O/W emulsification systems. If emulsifying oil phases with different polarities, it is recommended to compound with lower HLB emulsifiers (such as EL-10, Span series) to match the required HLB value of the oil phase.
- Storage temperature should be controlled at 5~35°C, avoiding freezing or prolonged exposure to high temperatures. Keep away from strong oxidizers and keep the container tightly sealed.
- The dosages for each application field are only reference ranges. The actual optimal dosage should be determined through gradient experiments based on the specific formulation, oil phase type, and process conditions.
