Calcium petroleum sulfonate

Calcium petroleum sulfonate (CAS 61789-86-4), also known as oil-soluble petroleum sulfonate calcium salt, is a metal sulfonate derived from petroleum refining used as a corrosion inhibitor.

It serves as an emulsifier and detergent additive across industrial lubricant and fuel systems. Its oil-soluble character makes it a direct candidate for formulations where water-based alternatives are incompatible.

In metalworking fluids and rust preventive oils, it forms protective films on ferrous metal surfaces. This reduces corrosion during storage, transit, and machining operations in industrial settings.

Lubricant formulators incorporate it into engine oils, gear oils, and greases as a detergent-dispersant. It neutralizes acidic by-products and keeps metal surfaces clean under high-temperature conditions.

In the oil and gas sector, it functions as an emulsifier in drilling fluids and pipeline corrosion inhibitor packages. This ensures the integrity of infrastructure during extraction and transport.

Automotive aftermarket products, including rust-proofing compounds and underbody coatings, rely on it for long-term metal protection. It is essential for maintaining vehicles in exposed environments.

The product is supplied as a viscous liquid or semi-solid, typically in overbased and neutral grades. These are distinguished by their Total Base Number (TBN) for specific formulation needs.

Overbased grades are standard for engine oil additive applications, while neutral grades suit rust preventive uses. Technical grade is the predominant commercial specification for this material.