FRICTION DEPENDING LUBRICANTS,SUCH AS AUTOMATIC TRANSMISSION AND WET BRAKE FLUIDS

摘要

An increase in the dynamic and/or static coefficients of friction of frictional surfaces is obtained by the use of oil-based functional fluid compositions, eg. formulated for use as automatic transmission fluid or fluid for a wet brake system including a minor amount of at least one alcohol or polyol having less than 12 carbon atoms in the molecule. Preferred for this use is a composition formed by heating at least one ashless dispersant containing basic nitrogen and/or at least one hydroxyl group with a combination of at least (i) an inorganic acid of phosphorus, (ii) a boron compound, and (iii) a polyol having less than 12 carbon atoms, so that a liquid composition is formed. The boron compound and the inorganic phosphorus acid are preferably co-present during the heating. However, either such substance can be added and subjected to the heating step after the other provided that the conditions used result in the formation of a clear, liquid composition. The alcohol or polyol is preferably a 1,2- alkanediol, an aminoalcohol or aminoglycol.