Lubricating oil composition

Abstract

The present invention relates to a lubricating oil composition comprising lubricating oil base oil in combination with: (a) one or more substituted phenyl-naphthylamines; (b) one or more anti-wear additives, preferably ashless thiophosphates; and (c) an additional base oil component selected from bright stock oil, polyalkylene glycols (PAGs), alkyl naphtalenes, alkyl benzenes and natural and synthetic esters such as diesters and polyolesters, preferably bright stock oil. In another aspect the present invention provides the use of the lubricating oil composition to lubricate a combination of a gas turbine and a steam turbine.

1 - 11 . (canceled) 
   
   
       12 . A lubricating oil composition comprising:
 (a) one or more substituted phenyl-naphthylamines;   (b) one or more anti-wear additives, at least one said anti-wear additives comprising an ashless thiophosphate;   (c) an additional base oil component selected from bright stock oil, polyalkylene glycols (PAGs), alkyl naphtalenes, alkyl benzenes and natural and synthetic esters such as diesters and polyolesters; and   (d) a lubricating oil base oil.   
   
   
       13 . The lubricating oil composition according to claim  1  wherein the additional base oil component comprises an amount of bright stock oil present as from 0.01 to 10.0 wt. % of the total composition. 
   
   
       14 . The lubricating oil composition according to claim  1  wherein the additional base oil component comprises an amount of bright stock oil present as from 1.0 to 10.0 wt. % of the total composition. 
   
   
       15 . The lubricating oil composition according to claim  1  wherein the additional base oil component comprises an amount of bright stock oil present as from 2.0 to 10.0 wt. % of the total composition. 
   
   
       16 . Lubricating oil composition according to claim  1 , wherein said one or more substituted phenyl-naphthylamines (a) are selected from alkylated phenyl-alpha-naphthylamines and/or alkylated phenyl-beta-naphthylamines. 
   
   
       17 . The lubricating oil composition according to claim  1 , wherein said one or more substituted phenyl-naphthylamines (a) are present in a total amount in the range of from 0.01 to 3.0 wt. %, based on the total weight of the lubricating oil composition. 
   
   
       18 . The lubricating oil composition according to claim  1 , wherein said one or more ashless thiophosphates (b) are present in a total amount in the range of from 0.01 to 1.0 wt. %, based on the total weight of the lubricating oil composition. 
   
   
       19 . The lubricating composition according to  claim 15 , wherein said one or more ashless thiophosphates (b) are compounds according to formula (I) 
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  are each, independently, selected from hydrogen, branched or straight chain C 1  to C 18  alkyl groups which may be interrupted by 1 or 2 oxygen atoms, C 5  to C 12  cycloalkyl groups, C 5  to C 9  cycloalkylmethyl groups, C 9  to C 10  bicycloalkylmethyl groups, C 9  to C 10  tricycloalkylmethyl groups, phenyl or C 7  to C 24  alkylphenyl groups or R 1  and R 2  together may be a C 2  to C 12  alkylene group which may be interrupted by 1 or 2 oxygen atoms, R 3  and R 4  are each, independently, selected from hydrogen and branched or straight chain C 1  to C 8  alkyl groups which may be interrupted by 1 or 2 oxygen atoms, n is an integer from 1 to 5 and X is selected from —OH, —OR 5  wherein R 5  is selected from branched or straight chain alkyl groups having from 1 to 8 carbon atoms, —NR 6 R 7  wherein R 6  and R 7  are independently selected from hydrogen or C 1  to C 18  alkyl groups. 
   
   
       20 . The lubricating oil composition of claim  1  wherein the lubricating oil base oil is a base oil selected from the group consisting of Group II, III and Fischer-Tropsch derived base oils. 
   
   
       21 . The lubricating oil composition according to claim  1 , wherein said lubricating oil composition further comprises one or more additives selected from anti-oxidants, extreme pressure additives, metal passivators, corrosion inhibitors, foam inhibitors and/or demulsifiers. 
   
   
       22 . The use of a lubricating oil composition according to claim  1  to lubricate a combination of a gas turbine and a steam turbine. 
   
   
       23 . The use of a lubricating oil composition according to claim  1  in order to reduce lacquer formation in a turbine. 
   
   
       24 . The use of a lubricating oil composition according to claim  1  in order to reduce lacquer formation in a combination of a gas turbine and a steam turbine.