Lubricating Oil Composition for Marine Applications

Abstract

A lubricating oil and a lubricant additive composition suitable for use in marine gear applications, including the gears of two-cycle or four-cycle outboard marine engines or the gears of an outdrive of an inboard/outboard marine drivetrain. The lubricating oil and additive composition may exhibit improved water emulsification and wear properties.

1 . A marine lubricant, comprising:
 a) a major amount of a base oil;   b) at least one metal-containing detergent;   c) at least one phosphorus-based wear preventative; and   d) at least one surfactant agent.   
     
     
         2 . The marine lubricant of  claim 1  further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5 (ppm/ppm). 
     
     
         3 . The marine lubricant of  claim 1  wherein the lubricant achieves a score of about 5 mL or less water separation in a water emulsion test. 
     
     
         4 . The marine lubricant according to  claim 1 , wherein said at least one metal detergent is an overbased calcium phenate. 
     
     
         5 . The marine lubricant according to  claim 1 , wherein said at least one phosphorus-based wear preventative comprises at least one zinc dihydrocarbyl dithiophosphate compound. 
     
     
         6 . The marine lubricant according to  claim 1 , wherein said at least one surfactant agent comprises a block or graft co-polymer of the general formula (A-COO) m B, where m in an integer of at least 2 and, A is a polymeric component having a molecular weight of at least 500 and is the residue of an oil-soluble complex mono-carboxylic acid of the general structural formula: 
       
         
           
           
               
               
           
         
       
       in which R is hydrogen or a monovalent hydrocarbon or substituted hydrocarbon group, R 1  is hydrogen or a monovalent C 1  to C 24  hydrocarbon group, R 2  is a divalent C 1  to C 24  hydrocarbon group, n is zero or 1 and p is zero or an integer of up to 200; and B is a polymeric component having a molecular weight of at least 500 and, in the case where m is 2, is the divalent residue of a water-soluble polyalkylene glycol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  is hydrogen or a C 1  to C 3  alkyl group, q is an integer from 10 to 500, or, in the case where m is greater than 2, is the residue of valency m of a water-soluble polyether polyol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  and m have their previous significance, r is zero or an integer from 1 to 500, provided that the total number of 
       
         
           
           
               
               
           
         
       
       units in the molecule is at least 10, and R 4  is the residue of an organic compound containing in the molecule m hydrogen atoms reactive with an alkylene oxide. 
     
     
         7 . The marine lubricant according to  claim 5 , wherein said composition contains from about 200 to about 2000 ppm phosphorus from the zinc dihydrocarbyl dithiophosphate compound. 
     
     
         8 . The marine lubricant according to  claim 7 , wherein said composition contains from about 200 to 600 ppm phosphorus from the zinc dihydrocarbyl dithiophosphate compound. 
     
     
         9 . The marine lubricant according to  claim 1 , wherein said composition contains from about 10 ppm to about 800 ppm metal from the metal-containing detergent. 
     
     
         10 . The marine lubricant according to  claim 1 , further comprising at least one component selected from the group consisting of: an extreme pressure agent, an antiwear agent, a friction modifier, a dispersant, a defoamant, an antioxidant, a viscosity index improver, and a pour point depressant. 
     
     
         11 . A gear component of a marine engine lubricated with the composition according to  claim 1 . 
     
     
         12 . An additive composition suitable for use in a lubricant used in a marine environment, comprising:
 a) at least one metal-containing detergent;   b) at least one phosphorus-based wear preventative; and   c) at least one surfactant agent.   
     
     
         13 . The additive composition of  claim 12 , further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5 (ppm/ppm). 
     
     
         14 . The additive composition of  claim 12 , wherein the lubricant achieves a score of about 5 mL or less water separation in a water emulsion test. 
     
     
         15 . The additive composition according to  claim 12 , wherein said at least one metal detergent is an overbased calcium phenate. 
     
     
         16 . The additive composition according to  claim 12 , wherein said at least one phosphorus-based wear preventative comprises at least one zinc dihydrocarbyl dithiophosphate compound. 
     
     
         17 . The additive composition according to  claim 12 , wherein said at least one surfactant agent comprises a block or graft co-polymer of the general formula (A-COO) m B, where m in an integer of at least 2 and, A is a polymeric component having a molecular weight of at least 500 and is the residue of an oil-soluble complex mono-carboxylic acid of the general structural formula: 
       
         
           
           
               
               
           
         
       
       in which R is hydrogen or a monovalent hydrocarbon or substituted hydrocarbon group, R 1  is hydrogen or a monovalent C 1  to C 24  hydrocarbon group, R 2  is a divalent C 1  to C 24  hydrocarbon group, n is zero or 1 and p is zero or an integer of up to 200; and B is a polymeric component having a molecular weight of at least 500 and, in the case where m is 2, is the divalent residue of a water-soluble polyalkylene glycol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  is hydrogen or a C 1  to C 3  alkyl group, q is an integer from 10 to 500, or, in the case where m is greater than 2, is the residue of valency m of a water-soluble polyether polyol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  and m have their previous significance, r is zero or an integer from 1 to 500, provided that the total number of 
       
         
           
           
               
               
           
         
       
       units in the molecule is at least 10, and R 4  is the residue of an organic compound containing in the molecule m hydrogen atoms reactive with an alkylene oxide. 
     
     
         18 . The additive composition according to  claim 12 , further comprising at least one component selected from the group consisting of: an extreme pressure agent, an antiwear agent, a friction modifier, a dispersant, a defoamant, an antioxidant, a viscosity index improver, and a pour point depressant. 
     
     
         19 . A method of making a lubricant suitable for use in marine applications, comprising:
 adding to a major amount of a base oil, a minor amount of an additive composition, comprising:   a) at least one metal-containing detergent;   b) at least one phosphorus-based wear preventative; and   c) at least one surfactant agent.   
     
     
         20 . The method of  claim 19 , further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5 (ppm/ppm). 
     
     
         21 . The method of  claim 19 , wherein the lubricant achieves a score of about 5 mL or less water separation in a water emulsion test. 
     
     
         22 . The method according to  claim 19 , wherein said at least one surfactant agent comprises a block or graft co-polymer of the general formula (A-COO) m B, where m in an integer of at least 2 and, A is a polymeric component having a molecular weight of at least 500 and is the residue of an oil-soluble complex mono-carboxylic acid of the general structural formula: 
       
         
           
           
               
               
           
         
       
       in which R is hydrogen or a monovalent hydrocarbon or substituted hydrocarbon group, R 1  is hydrogen or a monovalent C 1  to C 24  hydrocarbon group, R 2  is a divalent C 1  to C 24  hydrocarbon group, n is zero or 1 and p is zero or an integer of up to 200; and B is a polymeric component having a molecular weight of at least 500 and, in the case where m is 2, is the divalent residue of a water-soluble polyalkylene glycol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  is hydrogen or a C 1  to C 3  alkyl group, q is an integer from 10 to 500, or, in the case where m is greater than 2, is the residue of valency m of a water-soluble polyether polyol of the general formula: 
       
         
           
           
               
               
           
         
       
       in which R 3  and m have their previous significance, r is zero or an integer from 1 to 500, provided that the total number of 
       
         
           
           
               
               
           
         
       
       units in the molecule is at least 10, and R 4  is the residue of an organic compound containing in the molecule m hydrogen atoms reactive with an alkylene oxide. 
     
     
         23 . A method of lubricating a marine engine gear component, comprising:
 adding to the marine engine gear component a marine lubricant, comprising:
 a) a major amount of a base oil; 
 b) at least one metal-containing detergent; 
 c) at least one phosphorus-based wear preventative; and 
 d) at least one surfactant agent; and 
   operating the engine.   
     
     
         24 . The method of  claim 23  further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5. 
     
     
         25 . The method of  claim 23  wherein the lubricant achieves a score of about 5 mL or less water separation in a water emulsion test. 
     
     
         26 . A method for improving the water tolerance of a gear oil suitable for use in marine applications, comprising combining a major amount of a base oil with at least one metal-containing detergent, at least one phosphorus-based wear preventative, and at least one surfactant agent. 
     
     
         27 . The method of  claim 26  further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5. 
     
     
         28 . The method of  claim 26 , wherein the lubricant achieves a score of about 5 mL or less water separation in a water emulsion test. 
     
     
         29 . A method for improving the extreme pressure properties of a gear oil suitable for use in marine applications, comprising combining a major amount of a base oil with at least one metal-containing detergent, at least one phosphorus-based wear preventative, and at least one surfactant agent. 
     
     
         30 . The method of  claim 29 , further comprising a ratio of alkali and/or alkaline earth metal content (ppm) to phosphorus content (ppm), based on total mass of the lubricant, ranging from about 0.025 to about 1.5. 
     
     
         31 . The method of  claim 30 , wherein the lubricant achieves a score of greater than about 350 kgf in an extreme pressure weld point test. 
     
     
         32 . The method according to  claim 31 , wherein the lubricant achieves a score of greater than about 375 kgf in an extreme pressure weld point test. 
     
     
         33 . A marine lubricant comprising:
 a) a major amount of a base oil;   b) an extreme pressure weld point improving effective amount of a phosphorus-based wear preventative; and   c) wherein said marine lubricant achieves a four-ball extreme pressure weld point score of about 350 kgf or greater and a score of about 5 mL or less water separation in a water emulsion test.   
     
     
         34 . The marine lubricant of  claim 33 , further comprising a metal-containing detergent. 
     
     
         35 . The marine lubricant of  claim 33 , further comprising at least one surfactant agent. 
     
     
         36 . A marine lubricant comprising:
 a) a major amount of a base oil;   b) a phosphorus-based wear preventative; and   c) wherein said marine lubricant achieves a four-ball extreme pressure weld point score of about 350 kgf or greater, a passing L-42 score, and a score of about 5 mL or less water separation in a water emulsion test.