Marine diesel cylinder lubricant oil compositions

Abstract

Disclosed herein are marine diesel cylinder lubricating oil compositions comprising (a) a major amount of one or more Group I basestocks, and (b) a detergent composition comprising (i) one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a total base number (TBN) greater than 250, and (ii) one or more high overbased alkyl aromatic sulfonic acids or salts thereof, wherein the aromatic moiety of the alkyl aromatic sulfonic acids or salts thereof contains no hydroxyl groups; and wherein the marine diesel cylinder lubricating oil composition has a TBN of about 5 to about 120, and further wherein the marine diesel cylinder lubricating oil composition is substantially free of tetrapropenyl phenol (TPP) and its unsulfurized metal salt.

What is claimed is: 
     
         1 . A marine diesel cylinder lubricating oil composition comprising (a) a major amount of one or more Group I basestocks, and (b) a detergent composition comprising (i) one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a total base number (TBN) greater than 250, and (ii) one or more high overbased alkyl aromatic sulfonic acids or salts thereof; wherein the aromatic moiety of the alkyl aromatic sulfonic acids or salts thereof contains no hydroxyl groups; and wherein the marine diesel cylinder lubricating oil composition has a TBN of about 5 to about 120, and further wherein the marine diesel cylinder lubricating oil composition is substantially free of tetrapropenyl phenol (TPP) and its unsulfurized metal salt. 
     
     
         2 . The marine diesel cylinder lubricating oil composition of  claim 1 , having a TBN of from about 20 to about 100. 
     
     
         3 . The marine diesel cylinder lubricating oil composition of  claim 1 , having a TBN of from about 10 to about 40. 
     
     
         4 . The marine diesel cylinder lubricating oil composition of  claim 1 , containing less than about 0.1 wt. % of TPP and its unsulfurized metal salt, based on the total weight of the marine diesel cylinder lubricating oil composition. 
     
     
         5 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid are one or more calcium salts of an alkyl-substituted hydroxyaromatic carboxylic acid. 
     
     
         6 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the alkyl-substituted moiety of the alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid is a C 10  to C 40  alkyl group. 
     
     
         7 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the alkyl-substituted moiety of the alkaline earth metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid is a C 12  to C 28  alkyl group. 
     
     
         8 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid have a TBN greater than 250 and up to about 800. 
     
     
         9 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the one or more high overbased alkyl aromatic sulfonic acids or salts thereof are one or more high overbased alkaline earth metal alkyl aromatic sulfonates. 
     
     
         10 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the one or more high overbased alkyl aromatic sulfonic acids or salts thereof are one or more high overbased calcium alkyl aromatic sulfonates. 
     
     
         11 . The marine diesel cylinder lubricating oil composition of  claim 10 , wherein the one or more high overbased calcium alkyl aromatic sulfonates are one or more high overbased calcium alkyl toluene sulfonates. 
     
     
         12 . The marine diesel cylinder lubricating oil composition of  claim 1 , wherein the one or more high overbased alkyl aromatic sulfonic acids or salts thereof have a TBN of greater than 250. 
     
     
         13 . The marine diesel cylinder lubricating oil composition of  claim 1 , comprising:
 about 0.1 to about 35 wt. % on an actives basis of the one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a TBN of greater than 250, based on the total weight of the marine diesel cylinder lubricating oil composition; and   about 0.1 to about 34 wt. % on an actives basis of the one or more high overbased alkyl aromatic sulfonic acids or salts thereof, based on the total weight of the marine diesel cylinder lubricating oil composition.   
     
     
         14 . The marine diesel cylinder lubricating oil composition of  claim 1 , further comprising one or more marine diesel cylinder lubricating oil composition additives selected from the group consisting of an antioxidant, ashless dispersant, detergent, rust inhibitor, dehazing agent, demulsifying agent, metal deactivating agent, friction modifier, pour point depressant, antifoaming agent, co-solvent, corrosion-inhibitor, dyes, extreme pressure agent and mixtures thereof. 
     
     
         15 . The marine diesel cylinder lubricating oil composition of  claim 1 , which is substantially free of any dispersants and/or zinc compounds. 
     
     
         16 . A method for lubricating a marine two-stroke crosshead diesel engine with a marine diesel cylinder lubricant composition having improved high temperature detergency; wherein the method comprises operating the engine with a marine diesel cylinder lubricating oil composition comprising (a) a major amount of one or more Group I basestocks, and (b) a detergent composition comprising (i) one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a TBN greater than 250, and (ii) one or more high overbased alkyl aromatic sulfonic acids or salts thereof; wherein the aromatic moiety of the alkyl aromatic sulfonic acids or salts thereof contains no hydroxyl groups; and wherein the marine diesel cylinder lubricating oil composition has a TBN of about 10 to about 120, and further wherein the marine diesel cylinder lubricating oil composition is substantially free of TPP and its unsulfurized metal salt. 
     
     
         17 . The method of  claim 16 , wherein the marine diesel cylinder lubricating oil composition has a TBN of from about 10 to about 40. 
     
     
         18 . The method of  claim 16 , wherein the marine diesel cylinder lubricating oil composition contains less than about 0.1 wt. % of TPP and its unsulfurized metal salt, based on the total weight of the marine diesel cylinder lubricating oil composition. 
     
     
         19 . The method of  claim 16 , wherein the marine diesel cylinder lubricating oil composition comprises:
 about 0.1 to about 35 wt. % on an active basis of the one or more salts of an alkyl-substituted hydroxyaromatic carboxylic acid, based on the total weight of the marine diesel cylinder lubricating oil composition; and   about 0.1 to about 34 wt. % on an active basis of the one or more high overbased alkyl aromatic sulfonic acids or salts thereof, based on the total weight of the marine diesel cylinder lubricating oil composition.   
     
     
         20 . The method of  claim 16 , wherein the marine diesel cylinder lubricating oil composition further comprises a marine diesel cylinder lubricating oil composition additive selected from the group consisting of an antioxidant, ashless dispersant, detergent, rust inhibitor, dehazing agent, demulsifying agent, metal deactivating agent, friction modifier, pour point depressant, antifoaming agent, co-solvent, corrosion-inhibitor, dyes, extreme pressure agent and mixtures thereof.