Ashless engine lubricants for high temperature applications

Abstract

An ashless lubricating oil having a lubricating oil base stock as a major component, and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components. The lubricating oil base stock is a monoester obtained by a) reacting one Guerbet alcohol of 8 to 20 carbon atoms with a Guerbet acid, a linear or branched acid of 6 to 20 carbon atoms or b) reacting one linear or branched alcohol with at least 6 to 20 carbon atoms with a Guerbet acid of 8 to 20 carbon atoms. The lubricating oil base stock is present in an amount from 30 to 99.8 wt. % of the oil. A method for improving oxidative stability and high temperature stability of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the ashless lubricating oil.

1 . A method for improving oxidative stability of a lubricating oil, in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil an ashless formulated oil, said ashless formulated oil having a composition comprising a lubricating oil base stock as a major component; and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components; wherein the lubricating oil base stock includes at least one monoester derived by:
 a) reacting one Guerbet alcohol of 8 to 20 carbon atoms with a Guerbet acid, a linear acid or a branched acid of 6 to 20 carbon atoms, or   b) reacting one linear alcohol or branched alcohol with at least 6 to 20 carbon atoms with a Guerbet acid of 8 to 20 carbon atoms   wherein the lubricating oil base stock is present in an amount from about 30 to about 99.8 mass percent, based on the total mass of the lubricating oil.   
     
     
         2 . The method of  claim 1  wherein oxidative stability is improved, as compared to oxidative stability achieved using a conventional synthetic engine oil. 
     
     
         3 . The method of  claim 1  wherein the one Guerbet alcohol is selected from the group consisting of 2-ethylhexanol, 2-hexyldecanol, and 2-octyldodecanol. 
     
     
         4 . The method of  claim 1  wherein the one Guerbet acid is selected from the group consisting of 2-ethylhexanoic acid, 2-hexyldecanoic acid, and 2-octyldodecanoic acid. 
     
     
         5 . The method of  claim 1  wherein the one linear acid is selected from the group consisting of n-hexanoic acid, n-heptanoic acid, n-octanoic acid, n-nonanoic (pelargonic) acid, n-decanoic acid, n-undecanoic acid and n-dodecanoic acid. 
     
     
         6 . The method of  claim 1  wherein the one linear alcohol is selected from the group consisting of n-hexanol, n-heptanol, n-octanol, n-nonanol (pelargonol), n-decanol, n-undecanol, and n-dodecanol. 
     
     
         7 . The method of  claim 1  wherein the one branched alcohol is selected from the group consisting of iso-octanol, iso-nonanol, 3,5,5-trimethyl hexanol acid, iso-decanol, neo-decanol, iso-undecanol, iso-dodecanol, iso-tridecanol, iso-tetradecanol, iso-pentadecanol, iso-hexadecanol, iso-heptadecanol, and iso-octadecanol. 
     
     
         8 . The method of  claim 1  wherein the at least one monoester is selected from the group consisting of 2-octyldecylheptanoate, 2-octyldecyloctanoate, 2-octyldecylpelargonate, 2-octyldecyl 2-ethylhexanoate, 2-octyldecyl 3,5,5-trimethylhexanoate, 2-octyldecyl neododecanoate, and iso-tridecyl 2-hexyldecanoate. 
     
     
         9 . The method of  claim 1  wherein the at least one ashless antiwear additive is an amine phosphate or a dithiophosphate. 
     
     
         10 . The method of  claim 1  wherein the at least one ashless detergent is selected from the group consisting of a polyoxyethylene alkyl ether, a polyoxypropylene alkyl ether, and a polyoxybutylene alkyl ether. 
     
     
         11 . The method of  claim 1  wherein the at least one aminic antioxidant is selected from the group consisting of p,p′-dioctyldiphenylamine, octylated phenyl-alpha-naphthylamine, octylated/butylated diphenylamine, and a polymeric aminic antioxidant. 
     
     
         12 . The method of  claim 11 , wherein the polymeric aminic antioxidant is the polymerization reaction product of one or more substituted or hydrocarbyl-substituted diphenyl amines, one or more unsubstituted or hydrocarbyl-substituted phenyl naphthyl amines, or a combination thereof. 
     
     
         13 . The method of  claim 1  wherein the at least one ashless antiwear additive is present in an amount from 0.01 to 1.2 mass percent, based on the total mass of the lubricating oil. 
     
     
         14 . The method of  claim 1  wherein the at least one ashless detergent is present in an amount from 0.01 to 6 mass percent, based on the total mass of the lubricating oil. 
     
     
         15 . The method of  claim 1  wherein the at least one aminic antioxidant is present in an amount from 0.01 to 15 mass percent, based on the total mass of the lubricating oil. 
     
     
         16 . The method of  claim 1  wherein the ashless formulated oil further comprises one or more of a viscosity modifier, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, anti-foam agent, inhibitor, and anti-rust additive. 
     
     
         17 . The method of  claim 1  wherein the engine or other mechanical component comprises a high energy density gasoline engine equipped with turbo chargers or gasoline particular filters (GPFs). 
     
     
         18 . The method of  claim 1  wherein the lubricating oil is a passenger vehicle engine oil (PVEO). 
     
     
         19 . An ashless lubricating oil having a composition comprising a lubricating oil base stock as a major component; and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components; wherein the lubricating oil base stock comprises at least one monoester derived by:
 a) reacting one Guerbet alcohol of 8 to 20 carbon atoms with a Guerbet acid, a linear acid or a branched acid of 6 to 20 carbon atoms, or   b) reacting one linear alcohol or branched alcohol with at least 6 to 20 carbon atoms with a Guerbet acid of 8 to 20 carbon atoms   wherein the lubricating oil base stock is present in an amount from about 30 to about 99.8 mass percent, based on the total mass of the lubricating oil.   
     
     
         20 . The ashless lubricating oil of  claim 19  wherein oxidative stability of the ashless lubricating oil is improved, as compared to oxidative stability achieved using a conventional synthetic engine oil. 
     
     
         21 . The ashless lubricating oil of  claim 19  wherein the one Guerbet alcohol is selected from the group consisting of 2-ethylhexanol, 2-hexyldecanol, and 2-octyldodecanol. 
     
     
         22 . The ashless lubricating oil of  claim 19  wherein the one Guerbet acid is selected from the group consisting of 2-ethylhexanoic acid, 2-hexyldecanoic acid, and 2-octyldodecanoic acid 
     
     
         23 . The ashless lubricating oil of  claim 19  wherein the one linear acid is selected from the group consisting of n-hexanoic acid, n-heptanoic acid, n-octanoic acid, n-nonanoic (pelargonic) acid, n-decanoic acid, and n-dodecanoic acid. 
     
     
         24 . The ashless lubricating oil of  claim 19  wherein the one linear alcohol is selected from the group consisting of n-hexanol, n-heptanol, n-octanol, n-nonanol (pelargonol), n-decanol, and n-dodecanol 
     
     
         25 . The ashless lubricating oil of  claim 19  wherein the one branched alcohol is selected from the group consisting of iso-octanol, iso-nonanol, 3,5,5-trimethyl hexanol acid, iso-decanol, neo-decanol, iso-undecanol, iso-dodecanol, iso-tridecanol, iso-tetradecanol, iso-pentadecanol, iso-hexadecanol, iso-heptadecanol, and iso-octadecanol. 
     
     
         26 . The ashless lubricating oil of  claim 19  wherein the one monoester is selected from the group consisting of 2-octyldecylheptanoate, 2-octyldecyloctanoate, 2-octyldecylpelargonate, 2-octyldecyl 2-ethylhexanoate, 2-octyldecyl 3,5,5-trimethylhexanoate, 2-octyldecyl neododecanoate, and iso-tridecyl 2-hexyldecanoate. 
     
     
         27 . The ashless lubricating oil of  claim 19  wherein the at least one ashless antiwear additive is an amine phosphate, or a dithiophosphate 
     
     
         28 . The ashless lubricating oil of  claim 19  wherein the at least one ashless detergent is selected from the group consisting of a polyoxyethylene alkyl ether, a polyoxypropylene alkyl ether, and a polyoxybutylene alkyl ether. 
     
     
         29 . The ashless lubricating oil of  claim 19  wherein the at least one aminic antioxidant is selected from the group consisting of p,p′-dioctyldiphenylamine, octylated phenyl-alpha-naphthylamine, octylated/butylated diphenylamine, and a polymeric aminic antioxidant. 
     
     
         30 . The ashless lubricating oil of  claim 29  wherein the polymeric aminic antioxidant is the polymerization reaction product of one or more substituted or hydrocarbyl-substituted diphenyl amines, one or more unsubstituted or hydrocarbyl-substituted phenyl naphthyl amines, or a combination thereof. 
     
     
         31 . The ashless lubricating oil of  claim 19  wherein the at least one ashless antiwear additive is present in an amount from 0.01 to 1.2 mass percent, based on the total mass of the lubricating oil. 
     
     
         32 . The ashless lubricating oil of  claim 19  wherein the at least one ashless detergent is present in an amount from 0.01 to 6 mass percent, based on the total mass of the lubricating oil. 
     
     
         33 . The ashless lubricating oil of  claim 19  wherein the at least one aminic antioxidant is present in an amount from 0.01 to 15 mass percent, based on the total mass of the lubricating oil. 
     
     
         34 . The ashless lubricating oil of  claim 19  wherein the ashless formulated oil further comprises one or more of a viscosity modifier, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, anti-foam agent, inhibitor, and anti-rust additive. 
     
     
         35 . The ashless lubricating oil of  claim 19  wherein the lubricating oil is a passenger vehicle engine oil (PVEO).