Lube oil dispersant of improved odor and antioxidant properties

A finished lubricating oil composition comprising a major amount of lubricating oil and between about 0.1 and 10 wt. % of a detergent dispersant sulfurized alkoxylated product in a lubricating oil concentrate thereof, said concentrate prepared by the method consisting essentially of:

• a. first contacting a polyalkene of an average molecular weight between about 500 and 50,000 with P.sub.2 S.sub.5 in the presence of between about 0.1 and 1 wt. % sulfur at a temperature between about 100.degree. and 320.degree.C., said P.sub.2 S.sub.5 comprising between about 5 and 40 wt. % of the reaction mixture,
• b. secondly diluting the polyalkene-P.sub.2 S.sub.5 with mineral lubricating oil to form a lube concentrate of between about 10 and 90 wt. % of said lubricating oil,
• c. thirdly contacting the polyalkene-P.sub.2 S.sub.5 lube concentrate with steam at a temperature between about 100.degree. and 260.degree.C. utilizing at least about a mole ratio excess of steam in respect to said polyalkene-P.sub.2 S.sub.5 reaction product,
• d. fourthly removing inorganic phosphorus acid from the steam treated polyalkene-P.sub.2 S.sub.5 concentrate,
• e. fifthly contacting the inorganic acid free, steam hydrolyzed polyalkene-P.sub.2 S.sub.5 concentrate with an alkylene oxide of the formula:
• ##EQU5## where R.sup.1 and R.sup.2 are hydrogen or an alkyl containing 1 to 6 carbon atoms in a mole ratio of said inorganic phosphorus acid free, steam hydrolyzed P.sub.2 S.sub.5 -polyalkene reaction product to said alkylene oxide of at least about 1:1,
• the improvement which comprises the step of contacting the alkoxylated inorganic acid free, steam hydrolyzed polyalkene P.sub.2 S.sub.5 reaction product of step e with added sulfur at a temperature between about 130.degree. and 300 .degree.C. utilizing an initial polyalkene:
• added sulfur mole ratio of between about 1:0.5 and 1:10 to form said sulfurized alkoxylated product.