What is SOD-1 ?
SOD-1 is a lubricant oil additive made from vegetable oil-based ester compounds (VOE), polyolesters (POE), and diesters (DST). It is manufactured in Japan by D1 Chemical Co. Ltd of Fukuoka, advised by Professor Takashi Watanabe of Sojo University and Kurume Institute of Technology. SOD-1 works to improve tribology (lubrication) performance in engines and mechanical devices by:
- washing away and dissolving ultra-fine particle sludge, oxidated substances such as varnish and other contaminants from lubricated surfaces;
- reducing friction, abrasion, and engine noise by switching from boundary to fluid lubrication;
- softening rubber in seals to prevent oil leakages.
SOD-1 contains detergent dispersives, antioxidants, extreme pressure agents, rust-preventative agents, viscosity index improvers, pour point depressants, anti-foaming agents, and friction reducing agents.
In Japan SOD-1 is used as an additive in motor vehicles and cooling fan machinery in a major oil refinery. Unlike other oil additives for motor vehicles, it is a universal additive – it can be used in the engine, transmission, differential, and power steering systems. This eliminates the need for separate additives for each of these parts of a vehicle.
What is an ester ?
‘Oil’ is generally something made from vegetable matter, animal matter, or mineral matter. Oil made from vegetable and animal matter mainly consisting of nutrients and calories is called a fatty oil. Mineral-based oil is used as fuel oil in combustion engines and as a lubricating oil or oil additive in machinery. In recent times biofuel and vegetable oil made from vegetable-based fatty oils has been used both as fuel and lubricant oils.
Because vegetable-based fatty oils have a higher viscosity than mineral oils they cannot be used on their own as biofuels. There is a chemical reaction technology called ‘ester exchange’ which reduces viscosity. The example shown in Diagram A common biodiesel (FAME: fatty acid methyl ester) involves a basic chemical production method in which the vegetable-based fatty oil consists of fatty acids and glycerine (glyceride), and by being made to react with methanol a methyl ester is created, and a fatty acid methyl ester – which is a compound of fatty acids and methanol – and its reproduction creates the glycerine.
Ester-based lubricant oil uses basically the same production process of methyl ester exchange. Common raw material for producing esters includes palm oil and coconut oil.
Esters have been used successfully in lubrication for more than 60 years and are the preferred stock in many severe applications where their benefits solve problems or bring value. For example, esters have been used exclusively in jet engine lubricants worldwide for over 50 years due to their unique combination of low temperature flowability with clean high temperature operation.
In automotive applications, the first qualified synthetic crankcase motor oils were based entirely on ester formulations and these products were quite successful when properly formulated. Esters have given way to PAOs in this application due to polyalphaolefins’ (PAOs) lower cost and their formulating similarities to mineral oil. Nevertheless, esters are often used in combination with PAOs in full synthetic motor oils in order to balance the effect on seals, solubilize additives, reduce volatility, and improve energy efficiency through higher lubricity. The percentage of ester used can vary anywhere from 5 to 25% depending upon the desired properties and the type of ester employed.
The new frontier for esters is the industrial marketplace where the number of products, applications, and operating conditions is enormous. In many cases, the very same equipment which operates satisfactorily on mineral oil in one plant could benefit greatly from the use of an ester lubricant in another plant where the equipment is operated under more severe conditions. The high performance properties and custom design versatility of esters is ideally suited to solve these problems. Ester lubricants have already captured certain niches in the industrial market such as reciprocating air compressors and high temperature industrial oven chain lubricants.