Water soluble lubricating additives

A method for producing a lubricating additive comprising the steps of:

• reacting a sulfur-containing alcohol selected from the group consisting of mercaptoalcohols, bis(hydroxyalkyl)sulfides and bis(hydroxyalkyl)disulfides with an organic carboxylic acid under suitable esterification conditions to produce an alkylmercapto ester;
• and,
• reacting said alkylmercapto ester with an alkylene oxide selected from the group consisting of ethylene oxide and propylene oxide under suitable etherification conditions to produce a lubricating additive having the generic structural formula:
• ##STR9## wherein R.sub.1 is an alkyl, cycloalkyl, aryl, alkaryl or aralkyl group having from 1 to 34 carbon atoms;
• R.sub.2, R.sub.3 and R.sub.4 are independent alkylene groups having from 2 to 30 carbon atoms;
• x is either 1 or 2;
• m is either 0 or 1 and n=2 to 30.

A lubricating additive comprising a composition having the generic structural formula:

• ##STR11## wherein R.sub.1 is an alkyl, cycloalkyl, aryl, alkaryl or aralkyl group having from 1 to 34 carbon atoms;
• R.sub.2, R.sub.3 and R.sub.4 are independent alkylene groups having from 2 to 30 carbon atoms;
• x is either 1 or 2;
• y is either 0 or 1 when x=1 and is 0 when x=2;
• m is either 0 or 1 and n=2 to 30.