Lubricant including water dispersible base

Abstract

A lubricant in the form of an oil-insoluble solvent e.g. water in oil emulsion is described where a water soluble or water dispersible base is present in the dispersed phase. These lubricants are beneficial in various applications such as internal combustion engines where the oil desirable has enough basicity to neutralize any inorganic acids generated by sulfur present in the fuel.

1 . A lubricant for an internal combustion engine comprising 
 a) a major amount of oil of lubricating viscosity,    b) at least one emulsifier capable of forming a water in oil emulsion,    c) optionally an oil insoluble solvent or solvent blend and    d) a base in the form of potassium, sodium, calcium, magnesium, lithium or aluminum hydroxide; potassium, sodium, calcium, magnesium or lithium carbonate or bicarbonate; potassium, sodium, calcium, magnesium, or lithium salts of C1-C5 organic acids; magnesium oxide; ammonia; amine, partially neutralized amine, guanidine carbonate; urea; or other organic nitrogen compound which generates ammonia on ignition, or combinations thereof,    wherein said base contributes at least 1 TBN to said lubricant, said base is added as a preformed chemical compound rather than being formed by an in situ chemical reaction within the oil phase of an aluminum, alkali or alkaline earth base with an acid in the presence of an emulsifier (overbasing) and wherein said base is not a borate compound.    
     
     
         2 . A lubricant according to  claim 1 , wherein the lubricant less the base and optional water has a viscosity from about SAE 5 to SAE 70 and said base is in a dispersed phase having a number average particle size by light scattering of 5 nanometers to 100 microns.  
     
     
         3 . A lubricant according to  claim 1 , wherein said oil insoluble solvent is from about 2 to about 50 weight percent of the combined weight of said solvent and said base.  
     
     
         4 . A lubricant according to  claim 1  having a TBN of at least 40 reported in units of mgKOH/g and said base is in a dispersed phase having a number average particle size by light scattering of from 5 nanometers to 100 microns.  
     
     
         5 . A lubricant according to  claim 1 , wherein at least 50% of said TBN value is attributed to said base dissolved or dispersed in said solvent.  
     
     
         6 . A lubricant according to  claim 1  where said emulsifier comprises a hydrocarbyl substituted carboxylic acid acylating agent reacted with at least an amine or ammonia.  
     
     
         7 . A lubricant according to  claim 1 , further comprising at least one conventional lubricating oil dispersant and at least one conventional lubricating oil detergent and/or antioxidant.  
     
     
         8 . A lubricant in an internal combustion engine comprising; 
 a) from about 50 to about 99. wt. % of one or more oils of lubricating viscosity,    b) up to 50 wt. % of an oil insoluble solvent    c) from about 0.5 to about 15 wt. % of a emulsifier(s) capable of forming a water in oil emulsion, and    d) from about 0.5 to about 30 wt. % of a base in the form of potassium, sodium, calcium, magnesium, lithium or aluminum hydroxide; potassium, sodium, calcium, magnesium, or lithium carbonate or bicarbonate; potassium, sodium, calcium, magnesium, or lithium salt of C 1 -C 5  organic acids; magnesium oxide; ammonia; amine, partially neutralized amine, urea; guanidine carbonate or other organic nitrogen compound which generates ammonia on ignition, or combinations thereof,    wherein said base contributes at least 1 TBN to said lubricant, said base is added as a preformed chemical compound rather than being formed by an in situ chemical reaction within the oil phase of an aluminum, alkali, or alkaline earth base with an acid in the presence of an emulsifier (overbasing), and wherein said base is not a borate compound, and optionally wherein said base is dissolved or dispersed in said oil insoluble solvent forming a blended solvent base.    
     
     
         9 . A method of lubricating at least some of the surfaces of the combustion chamber of an internal combustion engine including the steps of adding a lubricating oil with a TBN of at least 10 into the combustion chamber, adding fuel to the combustion chamber, and combusting the fuel in said combustion chamber, the improvement comprising incorporating a water soluble or water dispersible base, dissolved or dispersed in an oil insoluble solvent into said lubricating oil as an emulsified phase, such that the TBN of said lubrication oil is at least 10 units on the TBN scale expressed as mg KOH/g of oil higher than before incorporating said water soluble or water dispersible base and wherein said base is added as a preformed chemical compound rather than being formed by in situ chemical reaction within the oil phase of aluminum, alkali or alkaline earth base with an acid in the presence of an emulsifier (overbasing).  
     
     
         10 . The method of  claim 9 , wherein said base is selected from potassium, sodium, calcium, magnesium, lithium or aluminum hydroxide; potassium, sodium, calcium, magnesium or lithium carbonate or bicarbonate; potassium, sodium, calcium, magnesium, or lithium salt of a C1-C5 organic acid; magnesium oxide; guanidine carbonate; ammonia; urea; or combinations thereof and wherein said base is in a dispersed phase having a number average particle size by light scattering of from 5 nanometers to 100 microns.  
     
     
         11 . The method of  claim 9 , wherein the TBN of said lubricating oil is increased by at least 30 units by incorporating said water soluble or water dispersible base.  
     
     
         12 . (original) The method of  claim 9 , wherein said water soluble or water dispersible base comprises MgO, Mg(OH) 2 , NaOH, Ca(OH) 2 , KOH, guanidine carbonate, LiOH or CaCO 3 , or blends thereof.  
     
     
         13 . The method of  claim 9 , wherein said lubricating oil added to said combustion chamber includes from about 5 to about 30 wt. % water and from about 5 to about 30 wt. % of said base(s).  
     
     
         14 . The method of  claim 10 , wherein said inter combustion engine is a marine diesel engine and said fuel has a sulfur content from about 0.1 to about 4.5 weight percent which generates acidic reaction products in said combustion chamber.  
     
     
         15 . A process for forming a lubricant with a total base number of at least 1 comprising; a) dissolving or dispersing a base in an oil insoluble solvent e.g. water, b) adding said base and oil insoluble solvent to a lubricating oil, c) emulsifying said oil insoluble solvent and base in said lubricating oil, wherein said base comprises potassium, sodium, calcium, magnesium, lithium or aluminum hydroxide; potassium, sodium, calcium, magnesium, or lithium carbonate or bicarbonate; potassium, sodium, calcium, magnesium, or lithium salt of C1-C5 organic acids; magnesium oxide; guanidine carbonate; ammonia; amine, partially neutralized amine, urea; or other organic nitrogen compound which generates ammonia on ignition, or combinations thereof and wherein said base contributes at least 1 mgKOH/g to the TBN of said lubricant and wherein said base is added as a preformed chemical compound rather than being formed in situ in the oil phase by reacting aluminum, alkali, or alkaline earth base with an acid in the presence of an emulsifier (overbasing) and wherein said base is not a borate.  
     
     
         16 . A lubricant according to  claim 5 , wherein the amount of oil insoluble solvent is less than 2 wt. %, and preferably less than 0.5 or 0.1 wt. % based on the combined weight of said solvent and said base.  
     
     
         17 . A lubricant according to  claim 9  further comprising an antioxidant, a dispersant, and an antiwear additive.  
     
     
         18 . A method of lubricating an internal combustion engine including the steps of adding a lubricating oil with a TBN of at least 1 mgKOH/g into the lubricant recirculating system of the engine, adding fuel to the combustion chamber, and combusting the fuel in said combustion chamber, the improvement comprising incorporating a water soluble or water dispersible base, dissolved or dispersed in an oil insoluble solvent comprising a C 1 -C 5  mono or polyhydric alcohol, C 2 -C 5  ether, and/or water, into said lubricating oil as an emulsified phase, such that the TBN of said lubricating oil is at least 1 units on the TBN scale expressed as mgKOH/g of oil higher than before incorporating said water soluble or water dispersible base and wherein said base is added as a preformed chemical compound rather than being formed by in situ chemical reaction in the oil phase between aluminum, alkali, or alkaline earth base and an acid in the presence of an emulsifier (overbasing) and wherein said base is not a borate.