Engine oils that are non-aggressive towards lead

Abstract

Formulated engine oils that comprise certain 1,2,4-triazole metal deactivators are especially non-aggressive towards lead engine parts such as bearings. The inclusion of certain 1,2,4-triazole compounds allows the co-use of corrosive additives such as sulfur-containing additives and vegetable oil-derived friction modifiers while at the same time meeting ASTM D 4485 specifications.

What is claimed is:  
     
         1 . An engine oil composition that is non-aggressive towards lead, which composition comprises 
 a) a base fluid,    (b) at least one compound of the formula (I)                          and    (c) at least one oil additive that is aggressive towards lead and which is selected from the group consisting of antioxidants, antiwear additives, dispersants, detergents, antifoam additives, viscosity index improvers, copper passivators, rust inhibitors, pourpoint depressants, demulsifiers and friction modifiers,    where    R 1  and R 2  are the same or different and are C 1 -C 20  alkyl, C 3 -C 20  alkenyl, C 5 -C 12  cycloalkyl, C 7 -C 13  aralkyl or C 6 -C 10  aryl, or R 1  and R 2 , together with the nitrogen atom to which they are each attached may form a 5-, 6- or 7-membered heterocylic residue, or R 1  and R 2  are a group of formula    R 3 X[(—R 4 —)O] n (—R 4 )—   where    X is O, S or N,    R 3  is hydrogen or C 1 -C 20  alkyl,    R 4  is C 1 -C 12  alkylene,    n is 0 or an integer from 1 to 6,    or one of R 1  and R 2  is a group of formula                          or R 2  is a group of formula (II) and R 1  is a group of formula    —[R 4 ] n —N(R 5 )-A-[N(R 5 ) 2 ] m      where    m is 0 or 1 and, when m is zero, A is a group of formula (II) and, when m is 1, A is alkylene or C 6 -C 10  arylene and R 5  is a group of formula (II), and    where in the absence of component (b), the engine oil composition exceeds about 100 ppm lead as measured according to test ASTM D 6594.    
     
     
         2 . A composition according to  claim 1  in which the compounds of formula (I) are selected from the group consisting of 
 1-(or 4)-(dimethylaminomethyl) triazole  
 1-(or 4)-(diethylaminomethyl) triazole  
 1-(or 4)-(di-isopropylaminomethyl) triazole  
 1-(or 4)-(di-n-butylaminomethyl) triazole  
 1-(or 4)-(di-n-hexylaminomethyl) triazole  
 1-(or 4)-(di-isooctylaminomethyl) triazole  
 1-(or 4)-(di-(2-ethylhexyl)aminomethyl) triazole  
 1-(or 4)-(di-n-octylaminomethyl) triazole  
 1-(or 4)-(di-n-decylaminomethyl) triazole  
 1-(or 4)-(di-n-dodecylaminomethyl) triazole  
 1-(or 4)-(di-n-octadecylaminomethyl) triazole  
 1-(or 4)-(di-n-eicosylaminomethyl) triazole  
 1-(or 4)-[di-(prop-2′-enyl)aminomethyl] triazole  
 1-(or 4)-[di-(but-2′-enyl)aminomethyl] triazole  
 1-(or 4)-[di-(eicos-2′-enyl)aminomethyl] triazole  
 1-(or 4)-(di-cyclohexylaminomethyl) triazole  
 1-(or 4)-(di-benzylaminomethyl) triazole  
 1-(or 4)-(di-phenylaminomethyl) triazole  
 1-(or 4)-(4′-morpholinomethyl) triazole  
 1-(or 4)-(1′-pyrrolidinomethyl) triazole  
 1-(or 4)-(1′-piperidinomethyl) triazole  
 1-(or 4)-(1′-perhydoroazepinomethyl) triazole  
 1-(or 4)-(2′,2″-dihydroxyethyl)aminomethyl] triazole  
 1-(or 4)-(dibutoxypropyl-aminomethyl) triazole  
 1-(or 4)-(dibutylthiopropyl-aminomethyl) triazole  
 1-(or 4)-(di-butylaminopropyl-aminomethyl) triazole  
 N,N-bis-(1- or 4-triazolylmethyl) laurylamine  
 N,N-bis-(1- or 4-triazolylmethyl) oleylamine  
 N,N-bis-(1- or 4-triazolylmethyl) ethanolamine and  
 N,N,N′,N′-tetra(1- or 4-triazolylmethyl) ethylene diamine.  
 
     
     
         3 . A composition according to  claim 1  in which the compound of formula (I) is 1-(di-isooctylaminomethyl)-1,2,4-triazole or 1-(di-(2-ethylhexyl)aminomethyl)-1,2,4-triazole.  
     
     
         4 . A composition according to  claim 1  where in the absence of component (b), the engine oil composition exceeds about 150 ppm lead as measured according to test ASTM D 6594.  
     
     
         5 . A composition according to  claim 4  where in the absence of component (b), the engine oil composition exceeds about 210 ppm lead as measured according to test ASTM D 6594.  
     
     
         6 . A composition according to  claim 1  in which component (b) is present from about 0.01 to about 1.0% by weight, based on the weight of the engine oil.  
     
     
         7 . A composition according to  claim 1  in which component (b) is present from about 0.02 to about 0.5 weight percent, based on the weight of the engine oil.  
     
     
         8 . A composition according to  claim 1  in which component (b) is present from about 0.03 to about 0.3 weight percent, based on the weight of the engine oil.  
     
     
         9 . A composition according to  claim 1  in which the additives of component (c) are selected from the group consisting of antioxidants, antiwear additives, detergents, copper passivators and friction modifiers.  
     
     
         10 . A composition according to  claim 1  in which the additives of component (c) are selected from the group consisting of 
 the sulfur-containing antioxidants, sulfur-containing antiwear additives and sulfur-containing copper passivators; and  
 the vegetable oil-derived friction modifiers.  
 
     
     
         11 . A composition according to  claim 1  in which the additives of component (c) are selected from the group consisting of phenothiazine antioxidants and vegetable oil-derived friction modifiers.  
     
     
         12 . A method of preventing corrosion of lead parts that are in the presence of an engine oil composition comprising 
 (a) a base fluid and    (c) at least one oil additive that is aggressive towards lead and which is selected from the group consisting of antioxidants, antiwear additives, dispersants, detergents, antifoam additives, viscosity index improvers, copper passivators, rust inhibitors, pourpoint depressants, demulsifiers and friction modifiers,    which method comprises incorporating into said engine oil composition    (b) at least one compound of the formula (I) according to  claim 1 ,    where in the absence of component (b), the engine oil composition exceeds about 100 ppm lead as measured according to test ASTM D 6594.