Question

How to use Steareth SG-9?

Answer
2026-05-17 官方文档 硬脂酸聚氧乙烯醚SG-9

The usage method of Steareth SG-9 varies according to the specific application field, generally following the core operation process of "heat melting—metered addition—thorough mixing".

Detailed Description

Steareth SG-9 (PEG-9 Stearate) is a white to light yellow flake solid at room temperature, with a melting point of approximately 28–35°C. Before use, it usually needs to be heated to 40–50°C to melt, allowing accurate metering and uniform dispersion. As an O/W emulsifier, with an HLB value of about 11.6, it is suitable for establishing emulsification systems involving oil and water phases, and can maintain good performance over a wide pH range (5.0–7.0) and in hard water conditions.

According to different industrial fields, the specific usage methods are as follows: In the textile industry, when used in spin finishes, it is recommended to melt and mix it with oily components at 50–60°C, then slowly add deionized water while stirring at high speed to form a uniform emulsion before use, with a recommended dosage of 2%–5% of the total spin finish formulation; when used as a finishing softener, it can be directly dissolved in warm water to prepare a working solution of 0.5%–2%. In cosmetics and personal care products, as an emulsifier for creams and lotions, heat SG-9 together with the oil phase components to 70–75°C, also heat the water phase to the same temperature, then slowly add the oil phase to the water phase, homogenize and emulsify for 3–5 minutes, and after cooling a stable cream is formed, with a recommended dosage of 1%–4% of the total formulation.

In metalworking fluids, mix SG-9 with base oil, rust inhibitors, etc. uniformly at 40–50°C, then add to water while stirring to form a stable semi-transparent to milky white microemulsion, with a recommended dosage of 5%–15% of the concentrate. In pesticide formulations, when preparing emulsifiable concentrates or aqueous emulsions, mix SG-9 uniformly with the active ingredient and solvent; upon dilution it can self-emulsify to form a stable emulsion, with a recommended dosage of 3%–8% of the total formulation. In the plastics and rubber industry, as an internal antistatic agent, it can be directly mixed with resin pellets for injection molding or extrusion, with a recommended addition rate of 0.5%–2%. In coatings and printing inks, for pigment dispersion, it is recommended to first dissolve SG-9 in water or solvent, then add pigment for grinding and dispersion, with a recommended dosage of 1%–5% of the pigment weight.

Technical Parameters

ParameterSpecificationParameterSpecification
AppearanceWhite to light yellow flake solidHLB valueApprox. 11.6
Melting point28–35°CCloud pointApprox. 85–95°C
Active content≥99%pH value (1% aqueous solution)5.0–7.0
Acid value≤2 mgKOH/gSaponification value90–100 mgKOH/g
Hydroxyl value70–80 mgKOH/gCritical micelle concentration (CMC)Approx. 0.07 g/L
Water content≤0.5%Flash point>180°C
Density (40°C)Approx. 0.99 g/cm³SolubilityEasily soluble in water, ethanol, acetone, etc.

The above data are sourced from the Guoli Chemical product database.

Application Recommendations

  • Textile spin finishes: Recommended dosage is 2%–5% of the total spin finish formulation. Melt and mix with oily components at 50–60°C, then emulsify for use.
  • Cosmetic emulsification: Recommended dosage is 1%–4% of the total formulation. Use the hot method (heat both oil and water phases to 70–75°C) and homogenize to emulsify.
  • Metalworking fluids: Recommended dosage is 5%–15% of the concentrate. Mix with base oil at 40–50°C, then add water while stirring to emulsify.
  • Pesticide formulations: Recommended dosage is 3%–8% of the total formulation. Blend with the active ingredient and solvent to obtain a self-emulsifying oil phase system.
  • Plastics antistatic: Recommended addition rate is 0.5%–2% of the resin weight. Mix directly with pellets and then process.

Note: The above recommended dosages are based on general industry experience; the optimal addition amount should be determined through experiments for specific formulations.

Precautions

  • Heating operation: The melting point of this product is 28–35°C. It needs to be appropriately heated to melt before operation, but the heating temperature should not exceed 80°C to avoid local overheating causing color deepening or decomposition.
  • Personal protection: SG-9 is moderately irritating to the eyes and slightly irritating to the skin. Wear chemical safety goggles and chemical-resistant gloves during operation to avoid direct contact.
  • Storage environment: Store in a cool, dry, well-ventilated warehouse, with the temperature recommended not to exceed 35°C. Keep containers tightly closed, avoid moisture and direct sunlight.
  • Incompatibilities: Avoid direct mixing with strong oxidizers, strong acids, or strong alkalis. Under strong alkali conditions the product may hydrolyze. It has good compatibility with anionic, cationic, and other nonionic surfactants.
  • Dissolution characteristics: Easily soluble in water, but the dissolution rate is slow in cold water. It is recommended to dissolve in warm water at 40–50°C, stirring until completely dispersed before subsequent operations.
  • Environmental safety: This product is readily biodegradable (OECD 301B method, >60%), but direct discharge into water bodies should be avoided. Waste liquid after operation should be disposed of according to local regulations.