Lubricant composition

Abstract

Disclosed herein is a process for lubricating an internal combustion engine with a lubricant composition that may be substantially ash free. The ashless lubricant composition described herein may comprise primary antioxidants, such as aminic diphenyl amines, alkylated phenyl-naphthyl amines, and phenolic antioxidants. The ashless lubricant composition described herein may also comprise sulfur containing products that may work as secondary antioxidants. Other components such as ashless antiwear components, dispersants, pour point depressants, friction modifiers, and metal deactivators may also be used to formulate an ashless lubricant composition according to an embodiment.

What is claimed is: 
     
         1 . A process for lubricating an internal combustion engine, the process comprising adding a lubricant composition to an internal combustion engine,
 wherein the lubricant composition comprises:
 a base oil, 
 one or more antioxidants selected from the group consisting of alkylated phenyl-naphthyl amines antioxidants, diphenylamine antioxidants, phenolic antioxidants, and combinations thereof, and 
 one or more sulfur-containing additives. 
   
     
     
         2 . The process of  claim 1 , wherein the one or more antioxidants, in total, are present from about 0.2 wt % to about 10.0 wt %, based on the total weight of the lubricant composition. 
     
     
         3 . The process of any one of the preceding claims, wherein a sulfur concentration provided by the one or more sulfur-containing additives, in total, ranges from about 75 ppm to about 1000 ppm by weight, based on the total weight of the lubricant composition. 
     
     
         4 . The process of any one of the preceding claims, wherein the one or more antioxidants comprises N-α-naphthyl-N-phenylamine antioxidants of formula 
       
         
           
           
               
               
           
         
         wherein 
         R is H, C 1 -C 18  alkyl, C 2 -C 18  alkenyl, C 2 -C 18  alkynyl, —C(O)C 1 -C 18  alkyl or —C(O)aryl and R 1 , R 2 , R 3  and R 4  are each independently H, C 1 -C 18  alkyl, C 1 -C 18  alkoxy, C 1 -C 18  alkylamino, C 1 -C 18  dialkylamino, C 1 -C 18  alkylthio, C 2 -C 18  alkenyl, C 2 -C 18  alkynyl or C 7 -C 21  aralkyl. 
       
     
     
         5 . The process of any one of the preceding claims, wherein the one or more antioxidants comprises diphenylamine antioxidants of formula 
       
         
           
           
               
               
           
         
         wherein 
         R is H, C 1 -C 18  alkyl, C 2 -C 18  alkenyl, C 2 -C 18  alkynyl, —C(O)C 1 -C 18  alkyl or —C(O)aryl and R 1 , R 2 , R 3  and R 4  are each independently H, C 1 -C 18  alkyl, C 1 -C 18  alkoxy, C 1 -C 18  alkylamino, C 1 -C 18  dialkylamino, C 1 -C 18  alkylthio, C 2 -C 18  alkenyl, C 2 -C 18  alkynyl or C 7 -C 21  aralkyl. 
       
     
     
         6 . The process of  claim 4 , wherein the N-α-naphthyl-N-phenylamine antioxidants are of formula 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently H or C 1 -C 18  alkyl. 
       
     
     
         7 . The process of  claim 6 , wherein R 2  is H and R 1  is t-butyl, t-octyl or branched nonyl. 
     
     
         8 . The process of  claim 5 , wherein the diphenylamine antioxidants are of formula 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently H, C 1 -C 18  alkyl, C 2 -C 18  alkenyl or C 7 -C 21  aralkyl. 
       
     
     
         9 . The process of  claim 8 , wherein R 1  and R 2  are each independently H, tert-butyl, tert-octyl or branched nonyl. 
     
     
         10 . The process of any one of the preceding claims, wherein the lubricant composition comprises sulfur-containing additives selected from a group consisting of sulfur-containing hindered phenolic compounds, sulfur-containing rust inhibitors, sulfur-containing friction modifiers and sulfur-containing antiwear additives. 
     
     
         11 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more sulfur-containing additives selected from a group consisting of 2,4-di-octylthiomethyl-6-tert-butylphenol, 2,4-di-octylthiomethyl-6-methylphenol, 2,4-di-octylthiomethyl-6-ethylphenol or 2,6-di-dodecylthiomethyl-4-nonylphenol, 2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol), 4,4′-thiobis(6-tert-butyl-3-methylphenol), 4,4′-thiobis-(6-tert-butyl-2-methylphenol), 4,4′-thiobis(3,6-di-sec-amylphenol), 4,4′-bis(2,6-dimethyl-4-hydroxyphenyl) disulfide, octadecyl 4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl 4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl 3,5-di-tert-butyl-4-hydroxy-benzylmercaptoacetate and esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid, β-(3,5-dicyclohexyl-4-hydroxyphenyl)-propionic acid, 3,5-di-tert-butyl-4-hydroxyphenylacetic acid or β-(5-tert-butyl-4-hydroxyphenyl)-3-thiabutyric acid with thiodiethylene glycol, 3-thiaundecanol or thiapentadecanol. 
     
     
         12 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more sulfur-containing additives selected from a group consisting of organomolybdenum dithiocarbamates, organomolybdenum dithiophosphates and organomolybdenum compounds based on dispersants and molybdenum disulfide. 
     
     
         13 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more sulfur-containing additives selected from a group consisting of sulfurized olefins, sulfurized vegetable oils, dialkyldithiophosphate esters, zinc dialkyldithiophosphates, alkyl or aryl di- or tri-sulfides, derivatives of 2,5-dimercapto-1,3,4-thiadiazole, ethyl(bisisopropyloxyphosphinothioyl)-thiopropionate, triphenyl thiophosphate, tris(alkylphenyl) phosphorothioates, diphenylmonononylphenyl phosphorothioate, isobutylphenyl diphenyl phosphorothioate, a dodecylamine salt of 3-hydroxy-1,3-thiaphosphetan 3-oxide, trithiophosphoric acid 5,5,5-tris-isooctyl 2-acetate, derivatives of 2-mercaptobenzothiazole, ethoxycarbonyl 5-octyldithiocarbamate and dihydrocarbyl dithiophosphate metal salts. 
     
     
         14 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more sulfur-containing additives selected from a group consisting of sulfurized olefins. 
     
     
         15 . The process of  claim 14 , wherein the sulfurized olefins comprise sulfurized isobutylene. 
     
     
         16 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more sulfur-containing additives selected from a group consisting of di-tert-alkyl polysulfides. 
     
     
         17 . The process of  claim 16 , wherein the di-tert-alkyl polysulfides are selected from a group consisting of di-tert-butyl polysulfide, di-tert-dodecyl polysulfide and di-tert-nonyl polysulfide. 
     
     
         18 . The process of any one of the preceding claims, wherein the lubricant composition comprises a base oil selected from a group consisting of Group II, Group III and Group IV base oils. 
     
     
         19 . The process of any one of the preceding claims, wherein the lubricant composition comprises a base oil selected from a group consisting of polyalphaolefins. 
     
     
         20 . The process of any one of the preceding claims, wherein the lubricant composition comprises a base oil selected from a group consisting of synthetic esters. 
     
     
         21 . The process of any one of the preceding claims, wherein the lubricant composition comprises a base oil that comprises one or more polyalkylene glycols. 
     
     
         22 . The process of any one of the preceding claims, wherein the lubricant composition comprises one or more N-α-naphthyl-N-phenylamine antioxidants and one or more diphenylamine antioxidants and wherein a weight/weight ratio of N-α-naphthyl-N-phenylamine antioxidants to diphenylamine antioxidants is from about 1/9 to about 9/1. 
     
     
         23 . The process of any one of the preceding claims, wherein the lubricant composition comprises a base oil is an amount of from about 80 wt % to about 99.7 wt %, based on the total weight of the lubricant composition. 
     
     
         24 . The process of any one of the preceding claims, wherein the lubricant composition comprises less than 0.1 wt % of zinc dialkyldithiophosphate salts, based on the total weight of the lubricant composition. 
     
     
         25 . The process of  claim 24 , wherein the lubricant composition is substantially free of zinc dialkyldithiophosphate salts. 
     
     
         26 . The process of any one of  claims 24 - 25 , wherein the zinc dialkyldithiophosphate salts delivers less than about 500 ppm phosphorus by weight, based on the total weight of the lubricant composition. 
     
     
         27 . The process of  claim 26 , wherein the zinc dialkyldithiophosphate salts delivers less than about 300 ppm phosphorus by weight, based on the total weight of the lubricant composition. 
     
     
         28 . The process according to any one of the preceding claims, wherein a sulfur concentration provided by the one or more sulfur-containing additives, in total, ranges from about 50 ppm to about 1000 ppm by weight, based on the total weight of the lubricant composition. 
     
     
         29 . The process according to any one of the preceding claims, wherein the lubricant composition comprises less than about 0.1 wt % overbased calcium, magnesium, salts of alkyl aromatic sulfonates, phenates, or salicylates, independently or in total, based on the total weight of the lubricant composition. 
     
     
         30 . The process according to any one of the preceding claims, wherein the lubricant composition further comprises an ashless antiwear components, dispersants, pour point depressants, friction modifiers, and metal deactivators. 
     
     
         31 . The process of  claim 30 , wherein the ashless antiwear components comprise a phosphorus derivative. 
     
     
         32 . The process of any one of  claims 30 - 31 , wherein the ashless antiwear components are present from about 0.5 wt % to about 10.0 wt %, based on the total weight of the lubricant composition. 
     
     
         33 . The process of any one of  claims 30 - 32 , wherein the dispersants are present from about 0.5 wt % to about 5.0 wt %, based on the total weight of the lubricant composition. 
     
     
         34 . The process of any one of  claims 30 - 33 , wherein the pour point depressants are present from about 0.05 wt % to about 0.2 wt %, based on the total weight of the lubricant composition. 
     
     
         35 . The process of any one of  claims 30 - 34 , wherein the friction modifiers are present from about 0.2 wt % to about 0.9 wt %, based on the total weight of the lubricant composition. 
     
     
         36 . The process of any one of  claims 30 - 35 , wherein the metal deactivators are present from about 0.1 wt % to about 0.9 wt %, based on the total weight of the lubricant composition. 
     
     
         37 . A system comprising an internal combustion engine and an ashless lubricant composition, wherein the ashless lubricant composition comprises:
 a base oil,   one or more antioxidants selected from the group consisting of alkylated phenyl-naphthyl amines antioxidants, diphenylamine antioxidants, phenolic antioxidants, and combinations thereof, and   one or more sulfur-containing additives.