Patent ID: 8492321

Claim:
A lubricating composition, comprising: a base oil and an additive, the additive comprising a mixture of oligomers that is produced from the reaction of aromatic amines selected from the group consisting of: (i) the reaction of diphenylamine (DPA) compounds with each other, the (DPA) compounds having the formula (I): wherein R 1 and R 2 represent, independently of one another, a hydrogen or a linear or branched alkyl group having from 1 to 30 carbon atoms, (ii) the reaction of phenyl-α-naphthylamine (PAN) compounds with each other, in the presence of potassium permanganate catalyst, the (PAN) compounds having the formula (II): wherein the group R 3 represents a hydrogen or a linear or branched alkyl group having from 1 to 30 carbon atoms, and (iii) the reaction of a (DPA) compound of formula (I) with a (PAN) compound of formula (II), in the presence of potassium permanganate catalyst, said reaction producing an additive comprising: I) (a) from 0% to 3% by weight of diphenylamine of formula (I), (b) from 0% to 3% by weight of phenyl-α-naphthylamine of formula (II), (c) from 1% to 40% by weight of oligomers in the form of dimers, (d) from 25% to 45% by weight of oligomers in the form of trimers, (e)from 20% to 45% by weight of oligomers in the form of tetramers, (f) from 1% to 25% by weight of oligomers in the form of pentamers, (g) from 0% to 10% by weight of oligomers in the form of hexamers, and (h) from 0% to 10% by weight of oligomers in the form of heptamers or oligomers with a higher degree of polymerization, wherein the percentages by weight are expressed relative to the total weight of the (a)-(h) components; or an additive comprising: (II) (a) from 0% to 1% by weight of diphenylamine of formula (I), (b) from 0% to 1% by weight of phenyl-α-naphthylamine of formula (II), (c) from 1% to 5% by weight of oligomers in the form of dimers, (d) from 30% to 45% by weight of oligomers in the form of trimers, (e) from 20% to 35% by weight of oligomers in the form of tetramers, (f) from 10% to 30% by weight of oligomers in the form of pentamers, (g) from 0% to 15% by weight of oligomers in the form of hexamers, and (h) from 0% to 10% by weight of oligomers in the form of heptamers or oligomers with a higher degree of polymerization, wherein the percentages by weight are expressed relative to the total weight of the (a)-(h) components.