A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently CH or N, so long as at least one X is N. A is an electron donating group that (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or (2) is an aryl or alkyl group. Z is chosen from a hydrogen atom and an electron donating group that has an atom having at least one lone pair electrons that is bonded directly to the aromatic ring or is an aryl or alkyl group.

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A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently CH or N, so long as at least one X is N. A is an electron donating group that (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or (2) is an aryl or alkyl group. Z is chosen from a hydrogen atom and an electron donating group that has an atom having at least one lone pair electrons that is bonded directly to the aromatic ring or is an aryl or alkyl group.

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A lubricant base oil composed of an ester. The ester includes a component (A) derived from trimethylolpropane in a molar percentage A.sub.mol % of 25 to 42 mol %; components (B) derived from monovalent straight-chain saturated fatty acids each having a carbon number of 8 to 12 in a molar percentage B.sub.mol % of 33 to 55 mol %: and a component (C) derived from adipic acid in a molar ratio C.sub.mol % of 12 to 34 mol %. The components (B) include lauric acid in a molar percentage of 5 to 50 mol %, and (B.sub.COOH+C.sub.COOH)/A.sub.OH is 0.90 to 1.02. A.sub.OH represents a hydroxyl equivalent of the component (A), B.sub.COOH represents a carboxyl group equivalent of the components (B); and C.sub.COOH represents a carboxyl group equivalent of the component (C).

A lubricant base oil composed of an ester. The ester includes a component (A) derived from trimethylolpropane in a molar percentage A.sub.mol % of 25 to 42 mol %; components (B) derived from monovalent straight-chain saturated fatty acids each having a carbon number of 8 to 12 in a molar percentage B.sub.mol % of 33 to 55 mol %: and a component (C) derived from adipic acid in a molar ratio C.sub.mol % of 12 to 34 mol %. The components (B) include lauric acid in a molar percentage of 5 to 50 mol %, and (B.sub.COOH+C.sub.COOH)/A.sub.OH is 0.90 to 1.02. A.sub.OH represents a hydroxyl equivalent of the component (A), B.sub.COOH represents a carboxyl group equivalent of the components (B); and C.sub.COOH represents a carboxyl group equivalent of the component (C).

A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently C-A or N, so long as at least one X is N but no more than two of X are N. Moreover, A is H, cyano or an electron donating group that: (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring; or (2) is an aryl group or alkyl group. Further, each R is independently H, an alkyl group, or aryl group and each R is independently an alkyl group or an aryl group. ##STR00001##

A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently C-A or N, so long as at least one X is N but no more than two of X are N. Moreover, A is H, cyano or an electron donating group that: (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring; or (2) is an aryl group or alkyl group. Further, each R is independently H, an alkyl group, or aryl group and each R is independently an alkyl group or an aryl group. ##STR00001##

A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently CH or N, so long as at least one X is N. A is an electron donating group that (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or (2) is an aryl or alkyl group. Z is chosen from a hydrogen atom and an electron donating group that has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or is an aryl or alkyl group. ##STR00001##

A lubricant composition includes a base oil present in an amount of greater than 70 parts by weight per 100 parts by weight of the lubricant composition and an antioxidant. The antioxidant has the structure: wherein each X is independently CH or N, so long as at least one X is N. A is an electron donating group that (1) has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or (2) is an aryl or alkyl group. Z is chosen from a hydrogen atom and an electron donating group that has an atom having at least one lone pair of electrons that is bonded directly to the aromatic ring or is an aryl or alkyl group. ##STR00001##

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.