Hochdruckzusatzstoff fuer Schmieroele

A lubricating oil additive (see Group III) is an oil-soluble aliphatic compound having as substituents at least one oxygen-containing group Y and 1-4 groups-S.(CH2)n.X, wherein Y is an alcohol (-OH), ether (-o-), carboxylic acid (-COOH) or ester (-COOC-) group, n is an integer from 1 to 4, X is -OR or -COOR and R is hydrogen or a C1-C4 alkyl group, at least one of the -S.(CH2)n X groups being separated from a Y group by a chain of at least 7 carbon atoms. The compound may be prepared by reacting a mercapto compound of formula HS(CH2)nX (e.g. a mercapto aliphatic carboxylic acid or ester thereof, or a mercapto-alkanol or ether thereof) with an ethylenically unsaturated aliphatic compound containing at least one oxygen-containing group Y and having an ethylenically unsaturated bond separated from an oxygencontaining group Y by a chain of at least 7 carbon atoms (e.g. an unsaturated fatty acid, an unsaturated fatty alcohol, or an unsaturated ester derived from an unsaturated fatty acid or unsaturated alcohol or both). Examples of suitable compounds are (1) a mixture of 9-and 10-carboxymethyl-mercaptostearic acid prepared by reacting oleic acid and mercapto acetic acid, (2) a mixture of ethyl 9- and 10-carboxymethyl-mercapto-stearate prepared by reacting ethyl oleate and mercapto-acetic acid, (3) a mixture of 9- and 10-carboxymethylmercapto-12-hydroxystearic acid prepared by reacting ricinoleic acid and mercapto-acetic acid, (4) a mixture of glyceryl tris (9- and 10-carboxymethyl-mercaptostearate (prepared by reacting glyceryltrioleate and mercapto-acetic acid, (5) a mixture of 9- and 10-carboxymethylmercaptostearyl alcohol prepared by reacting oleyl alcohol and mercapto-acetic acid, (6) a mixture of 9- and 10-carboxymethylmercaptostearyl 91- and 101- carboxymethylmercaptostearate prepared by reacting oleyl oleate and mercapto-acetic acid, (7) a mixture of O-(9- and 10-[21-hydroxyethylmercapto]-stearoyl) -611-oxa-11-thia-caproic acid prepared by reacting vinyl oleate and mercapto-acetic acid and then reacting the product with mercapto-ethanol, (8) a mixture of 12- and 13-(21 hydroxyethylmercapto) - 3 - thialheneicosanoic acid prepared by reacting 1,9-octadecadiene and 2-mercapto-acetic acid and then reacting the product with 2-mercaptoethanol, (9) a mixture of 5-hydroxy-3-thia-amyl 91- and 101-carboxymethylmercaptostearate prepared by reacting equimolecular proportions of oleic acid, 2, 21-thiodiethanol and mercapto-acetic acid and (10) a mixture of 9- and 10-