Super Overbased Sulfurized Calcium Alkyl Phenol is a high-performance detergent additive used in engine oils, marine lubricants, industrial oils, and greases. It serves multiple roles, including detergency, acid neutralization, oxidation resistance, and load-carrying protection.
🧪 What Is It?
✅ Chemical Type:
It is a metal detergent additive, specifically:
- Calcium salt of a sulfurized alkyl phenol
- Treated with excess calcium base (e.g., CaO or Ca(OH)₂) and CO₂ to create a super overbased structure
✅ Super Overbased:
Means it contains a very high Total Base Number (TBN)—typically in the range of 300–450 mg KOH/g.
🔍 Structure Overview
- Alkyl phenol group: Surface-active and provides detergency
- Sulfur bridges: Add thermal stability and anti-wear properties
- Calcium carbonate micelles: Fine, dispersed particles that neutralize acids
- Dispersed in oil (usually mineral or synthetic)
🛠️ Key Functions
| Function | Benefit |
|---|---|
| Detergency | Keeps piston ring lands, grooves, and surfaces clean |
| Acid neutralization | Neutralizes combustion acids (e.g., H₂SO₄, NOₓ acids) to prevent corrosion |
| Oxidation inhibition | Sulfurized phenol resists oxidative breakdown of oil |
| Extreme pressure (EP) | Sulfur acts as a mild EP agent in boundary lubrication |
| Rust protection | Calcium and phenol base prevent rust and corrosion |
⚙️ Typical Applications
| Application Area | Role |
|---|---|
| Diesel engine oils (CI-4, CK-4) | Acid control, piston cleanliness |
| Marine cylinder oils (TBN > 70) | Neutralize high sulfur fuel combustion acids |
| Industrial gear oils | Detergency, corrosion resistance, load carrying |
| Greases (e.g., lithium complex) | EP enhancement, corrosion protection |
📈 Performance Metrics
| Property | Typical Value |
|---|---|
| TBN (mg KOH/g) | 300 – 450 |
| Calcium content (%) | 12 – 15 |
| Sulfur content (%) | 1 – 3 |
| Appearance | Dark brown viscous liquid |
| Solubility | Soluble in base oil |
🧬 Additive Synergy
Often blended with:
- ZDDP (anti-wear, antioxidant)
- Dispersants (ashless succinimides)
- Phenolic or amine antioxidants
- Friction modifiers (MoDTC, esters)
⚠️ Considerations
| Factor | Impact |
|---|---|
| Ash content | High, due to calcium carbonate |
| Phosphorus-free | Yes – good for certain catalyst specs |
| Sulfur content | May affect emissions; regulated in some specs |
| Compatibility | Must match with base oil and other additives |
🧴 Typical Treat Rates in Finished Lubricants
| Application | Treat Rate (%) |
|---|---|
| Diesel engine oil (PCMO/HDDO) | 2.0 – 5.0 |
| Marine cylinder oil | 10.0 – 20.0 |
| Industrial gear oil | 1.0 – 4.0 |
| Greases | 1.0 – 3.0 |
✅ Advantages
- Excellent high-TBN neutralization capacity
- Effective detergency at high temperatures
- Robust oxidation and rust protection
- Synergistic with other additive systems
Overbased sulfurized calcium alkyl phenol is an oil soluble surfactant of the alkyl phenol ethoxylates family. It consists of a surfactant end group and a scavenger end group with both being chemically bound together. The scavenger end group consists of one or more sulfur atoms and calcium cations (an ion with a positive charge).
The surfactant end group is usually an alkyl phenol, an ethoxylate group, or both connected together. As the name suggests, these compounds are overbased meaning there are more cations than necessary to “neutralize” the rest of the molecule. This creates products with a higher pH than normal enabling them to be useful for a variety of tasks.
It also gives the product improved stability, solubility, and overall better performance. The most common use for overbased sulfurized calcium alkyl phenol is as defoamers and antifoaming agents in industrial applications. They are also used as dispersants in metalworking fluids, rust preventatives, lubricants, and industrial cleaning products.
This product is a kind of widely used lubricant additive of comprehensive performance, it has extremely good acid neutralization capacity, better antioxidation, abrasion resistance and larger base number than the similar products. It also has excellent detergency and dispersion effects and hydrolysis stability.
- Excellent high-temperature detergency
- Excellent acid neutralization efficiency
- Good antioxidant performance
- Good compatible with other additives.
Super overbased sulfurized calcium alkyl phenol is an additive used in lubricants and fuels. It is made by sulfurizing a calcium alkyl phenol with excess sulfur. The resulting product contains a higher amount of sulfur than the original alkyl phenol, making it more effective as an additive.
Super overbased sulfurized calcium alkyl phenol provides several benefits to lubricants and fuels. It acts as a detergent, dispersant, and anti-wear agent, helping to clean the engine and reduce friction and wear on moving parts. It also helps to reduce oxidation and corrosion, improving the overall performance and longevity of the lubricant or fuel.
This additive is commonly used in engine oils, hydraulic fluids, industrial gear oils, and automotive fuels. It is particularly effective in high-speed and high-temperature applications, where it can help to prevent deposits and maintain engine cleanliness.
In summary, super overbased sulfurized calcium alkyl phenol is a powerful additive that provides cleaning, lubricating, and protective properties to lubricants and fuels. It is widely used in the automotive and industrial sectors to improve the performance and durability of engines and equipment.