Multi-functional ashless additives improving transmission oils quality

In the presence of KU-2 as a catalyst the reactions of carboxymetyl-amethylalkylphenol with isoamyl and octyl alcohols were studied, as a result of which alkoxycarbonyl-methylaminometyl-alkylphenol has been obtained. The effect of obtained compounds on antiwear, antiscuffing and anticorrosion properties of ТС-14.5 transmission oil has been researched. It was revealed that alkoxycarbonyl-methylaminomethylalkylphenols show high antiwear, antiscuffing and anticorrosion performance. These compounds almost eliminate ТС-14.5 oil corrosivity in the 5 % concentration and improve its antiwear and antiscuffing properties as well.

Tribofilm Formation, Friction and Wear-Reducing Properties of Some Phosphorus-Containing Antiwear Additives

The film-forming, friction and wear properties of a range of model and commercial ashless P and P/S antiwear additives have been studied. A method has been developed for removing the tribofilms formed by such additives in order to effectively quantify mild wear. In general the P/S additives studied formed thinner tribofilms but gave lower wear than the S-free P ones. In extended wear tests, three P/S additives gave wear as low, or lower, than a primary zinc dialkyldithiophosphate (ZDDP). For almost all lubricants tested the wear rate measured in short tests was considerably higher than that in long tests due to the greater contribution of running-in wear in the former. This highlights the importance of basing antiwear additive choice on reasonably long tests, where running-in becomes only a small component of the wear measured. It has been found that for both P and P/S ashless additives the addition of oil-soluble metal compounds based on Ti and Ca boosts tribofilm formation and can lead to very thick films, comparable to those formed by ZDDP. However, this thick film formation tends to be accompanied by an increase in mixed friction and also does not appear to reduce wear but may even increase it.