Marine diesel cylinder lubricating oil compositions

Abstract

A marine diesel engine lubricating oil composition includes (a) a major amount of an oil of lubricating viscosity; and (b) one or more olefin copolymers having a number average molecular weight of 30,000 to 120,000. The marine diesel lubricating oil composition has a TBN of less than 70 mg KOH/g. The marine diesel lubricating oil composition is a monograde lubricating oil composition meeting the specifications for SAE J300 revised January 2015 requirements for a SAE 40, SAE 50 or SAE 60 monograde lubricating oil.

1 . A marine diesel cylinder lubricating oil composition comprising:
 (a) a major amount of an oil of lubricating viscosity; and   (b) one or more olefin copolymers having a number average molecular weight of 30,000 to 120,000; and   wherein the marine diesel engine lubricating oil composition has a TBN of less than 70 mg KOH/g, and further wherein the marine diesel engine lubricating oil composition is a monograde lubricating oil composition meeting the specifications for SAE J300 revised January 2015 requirements for a SAE 40, SAE 50 or SAE 60 monograde lubricating oil.   
     
     
         2 . The composition of  claim 1 , wherein the one or more olefin copolymers are bimodal and have a content of ethylene units ranging from 30% to 80% by weight relative to the weight of olefin copolymer. 
     
     
         3 . The composition of  claim 1 , wherein the one or more olefin copolymers are present, on an actives basis, at 0.5 to 5 wt. % of the lubricating oil composition. 
     
     
         4 . The composition of  claim 1 , wherein the one or more olefin copolymers are present, on an actives basis, at 1 to 2 wt. % of the lubricating oil composition. 
     
     
         5 . The composition of  claim 1 , wherein the one or more olefin copolymers are the only viscosity modifier present in the lubricating oil composition. 
     
     
         6 . The composition of  claim 1 , wherein the lubricating oil composition does not contain bright stock. 
     
     
         7 . The composition of  claim 1 , wherein the lubricating oil composition has a sulfated ash content of 1.5 wt. % or greater. 
     
     
         8 . The composition of  claim 1 , wherein the lubricating oil composition has a TBN of 15 to 40 mg KOH/g. 
     
     
         9 . The composition of  claim 1 , wherein the one or more olefin copolymers consist of one or more ethylene propylene copolymers. 
     
     
         10 . The composition of  claims 1-9 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 4.0 mm 2 /s to less than 8.5 mm 2 /s. 
     
     
         11 . The composition of  claims 1-9 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 8.5 mm 2 /s to 15.0 mm 2 /s. 
     
     
         12 . A method of thickening a cylinder lubricating oil composition in a marine diesel internal combustion engine, the method comprising adding to said engine a cylinder lubricating oil composition comprising:
 (a) a major amount of an oil of lubricating viscosity; and   (b) one or more olefin copolymers having a number average molecular weight of 30,000 to 120,000; and   wherein the marine diesel lubricating oil composition has a TBN of less than 70 mg KOH/g, and further wherein the marine diesel lubricating oil composition is a monograde lubricating oil composition meeting the specifications for SAE J300 revised January 2015 requirements for a SAE 40, SAE 50 or SAE 60 monograde lubricating oil.   
     
     
         13 . The method of  claim 12 , wherein the one or more olefin copolymers are present, on an actives basis, at 1 to 2 wt. % of the lubricating oil composition. 
     
     
         14 . The method of  claim 12 , wherein the one or more olefin copolymers are the only viscosity modifier present in the lubricating oil composition. 
     
     
         15 . The method of  claim 12 , wherein the lubricating oil composition does not contain bright stock. 
     
     
         16 . The method of  claim 12 , wherein the lubricating oil composition has a sulfated ash content of 1.5 wt. % or greater. 
     
     
         17 . The method of  claim 12 , wherein the lubricating oil composition has a TBN of 15 to 40 mg KOH/g. 
     
     
         18 . The method of  claim 12 , wherein the one or more olefin copolymers consist of one or more ethylene propylene copolymers. 
     
     
         19 . The method of  claims 13-18 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 4.0 mm 2 /s to less than 8.5 mm 2 /s. 
     
     
         20 . The method of  claims 13-18 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 8.5 mm 2 /s to 15.0 mm 2 /s. 
     
     
         21 . A method of controlling deposit formation in an internal combustion engine, the method comprising operating the internal combustion engine with a cylinder lubricating oil composition comprising:
 (a) a major amount of an oil of lubricating viscosity; and   (b) one or more olefin copolymers having a number average molecular weight of 30,000 to 120,000; and   wherein the marine diesel lubricating oil composition has a TBN of less than 70 mg KOH/g, and further wherein the marine diesel lubricating oil composition is a monograde lubricating oil composition meeting the specifications for SAE J300 revised January 2015 requirements for a SAE 40, SAE 50 or SAE 60 monograde lubricating oil.   
     
     
         22 . The method of  claim 21 , wherein the one or more olefin copolymers are present, on an actives basis, at 1 to 2 wt. % of the lubricating oil composition. 
     
     
         23 . The method of  claim 21 , wherein the one or more olefin copolymers are the only viscosity modifier present in the lubricating oil composition. 
     
     
         24 . The method of  claim 21 , wherein the lubricating oil composition does not contain bright stock. 
     
     
         25 . The method of  claim 21 , wherein the lubricating oil composition has a sulfated ash content of 1.5 wt. % or greater. 
     
     
         26 . The method of  claim 21 , wherein the lubricating oil composition has a TBN of 15 to less than 40 mg KOH/g. 
     
     
         27 . The method of  claim 21 , wherein the one or more olefin copolymers consist of one or more ethylene propylene copolymers. 
     
     
         28 . The method of  claims 21-27 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 4.0 mm 2 /s to less than 8.5 mm 2 /s. 
     
     
         29 . The method of  claims 21-27 , wherein the oil of lubricating viscosity has a kinematic viscosity at 100° C. from 8.5 mm 2 /s to 15.0 mm 2 /s.