Additive Definition
Substances added together with base oils to enhance or supplement the performance of lubricants

Type and function
Additive | Main function |
---|---|
Viscosity Index Improver | Minimizing viscosity change with temperature of lubricant |
Dispersant | Suppression and acid neutralization of soot, sludge and varnish deposits produced during combustion |
Freshener | Acid neutralization, rust prevention and suppression of piston lacquer, carbon and varnish deposits Prevents piston ring sticking underv high temperature operating conditions |
Antioxidant | Prevents the formation of corrosive acids or sludges produced by oxidation Extend the service life of lubricant |
Rust preventive | Suppresses the occurrence of rust caused by the action of oxygen and water |
Abrasion resistant | Wear protection on metal surfaces |
Antifoam | Control surface tension to change bubbles |
Friction reducing agent | Lower friction coefficient contributes to reduced friction and improved fuel economy |
Pour point depressant | Lower lubricating oil improves low temperature performance (flows well at low temperatures) |
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1. Viscosity Index Improver, Viscosity Modifier
As an additive used to improve viscosity index (stability of viscosity change of oil by temperature change) by reducing viscosity change with temperature, oil-soluble high molecular weight compound of about 10,000 ~ 1,500,000 is usually used. The polymer material aggregates at low temperature and swells at high temperature, and uses it to adjust the viscosity to improve the viscosity index.
Type: Polymethacrylate (PMA), Polyisobutylene, Olefin Copolymer, etc. -
2. Dispersant
It is in the form of colloidal, dispersing sludge produced in relatively low temperature operation conditions in oil, and dispersing soot and other small insoluble particles in oil evenly to prevent formation and acid neutralization of sludge deposits.
That is, it disperses incomplete combustion and blocks the formation of sludge.
Type: Polyisobutenyl Succinimides, Polyisobutenyl Esters, etc. -
3. Detergent
When lubricating oil is used under high temperature, incomplete combustion of fuel and lubricating oil produces deterioration, etc. Cleaner prevents and suppresses deposition of deterioration and neutralizes acidic substances. This prevents corrosion of metal surfaces, seizure and rust of piston rings, and prevents the formation of lacquers, varnishes and deposits.
Type: Metal sulfonates (Neutral & Overbased), Metal Alkyl phenates, etc. -
4. Anti-Oxidant
Lubricants react with oxygen in the air to oxidize. Factors that promote this include operating temperatures, ambient conditions, and catalysts. Antioxidants prolong the service life of lubricants by preventing the formation of corrosive acids or sludges produced by oxidation.
Type: Phenol Type, Amine Type, Zinc dialkyldithiophosphate (ZnDDP) -
5. Corrosion Inhibitor
It suppresses the occurrence of rust caused by oxygen and water.
In order to prevent rust, sufficient adsorption to metal and solubility in oil are required. Therefore, strong polar group and moderate size lipophilic group (hydrocarbon group) should be provided.
Type: Ethoxylated alkyl phenols or neutral detergent substrate salts, Alkenyl succinicacids and amine phosphates, Overbased substrates and amino compounds, etc. -
6. Anti-wear agent
It is an additive used to prevent wear of equipment by creating a solid lubricating film by adsorption of organic polar compound on metal surface and reaction with metal surface.
Type: Organic sulfur and chlorine compound, Organic Phosphate Esters, ZDDP, etc. -
7. Antifoamer Agent
It is used to prevent bubbles generated in lubricating oil, and it uses bubbles of lower surface tension than oil such as silicon to change the surface tension on the surface of the bubble, causing the bubbles to break.
Type: Silicon series, etc. -
8. Friction Modifier
It is a additive that improves lubrication performance by giving low coefficient of friction when sliding between metals. It can improve fuel economy through friction reducing agent.
Type: Long Chain Alkyl Ester, Amine, Acid, etc. -
9. Pour Point Depressant
It is an additive that lowers the pour point (the lowest temperature at which oil can flow) .It is adsorbed by Wax when Wax is produced at low temperature and prevents Wax from agglomeration.
Type: Polymethacrylate (PMA), Polyacrylamide, etc.
Additive application
The additives used vary depending on the lubricating oil product line, and additives are used to suit the characteristics / environment of each product line
Engine oil | ATF | MTF | Gear oil | Hydraulic oil | Turbine oil | |
---|---|---|---|---|---|---|
Detergent | ● | |||||
Dispersant | ● | ● | ||||
Antioxidant | ● | ● | ● | ● | ● | ● |
Antiwear agent | ● | ● | ● | ● | ● | |
Rust inhibitor | ● | ● | ● | |||
Friction modifier | ● | ● | ● | |||
Extreme pressure agent | ● | ● | ||||
Antifoam agent | ● | ● | ● | ● | ● | ● |
Viscosity modifier | ● | ● | ● | |||
Pour point depressant | ● | ● | ● | |||
Seal swell agent | ● |