Multifunctional Lubricant Additive Package

Abstract

The present invention provides a multifunctional lubricant additive package or composition for improving load-carrying capacity, scuffing (scoring) resistance, and other performance characteristics of a lubricant. The composition includes a molybdenum compound, a secondary zinc dithiophosphate compound, an aryl or alkyl phosphite compound, and a compound having an alkylthiocarbamoyl group. The present invention further provides a method for improving the performance characteristics of a lubricant. The method includes mixing a lubricant base stock or a fully-formulated lubricant with the above-described multifunctional lubricant additive composition.

1 . A multifunctional lubricant additive composition comprising:
 (a) a molybdenum compound of the general formula:   
     
       
         
         
             
             
         
       
       wherein X 1  is an oxygen or sulfur atom and R 3  and R 4  are each independently a C n H 2n+1  alkyl group, wherein n is an integer of about 2≦n≦10, and m is an integer of about 0≦m≦4; 
       (b) a secondary zinc dithiophosphate compound of the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 3 , R 4 , R 5 , and R 6  are each a C h H 2h+1  secondary alkyl groups of the formula: 
     
     
       
         
         
             
             
         
       
       wherein h is an integer of about 3≦h≦11, wherein R 7  and R 8  are each a C i H 2i+1  alkyl group, and i is an integer of about 1≦i≦5; 
       (c) an aryl or alkyl phosphite compound of the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 9 , R 10 , R 11 , R 12 , R 13 , and R 14  are each a C j H 2j+1  alkyl group, and j is an integer of about 1≦j≦20, wherein the alkyl groups exhibit tertiary structures, and; 
       (d) a compound having at least one alkylthiocarbamoyl group of the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 15 , R 16 , R 17 , and R 18  are each C k H 2k+1  alkyl groups, and k is an integer of about 1≦k≦30, and R 15 , R 16 , R 17 , and R 18  optionally form a ring structure with the nitrogen atom to which they are bonded; wherein (A) is a chain of sulfur atoms, S n , or S—(CH 2 ) m —S, and n is an integer of about 1≦n≦10, and m is an integer of about 1≦m≦6; wherein the total amount of compounds (a) to (d) is about 15% or less by mole, based on the total amount of lubricant. 
     
   
   
       2 . A composition according to  claim 1 , wherein compound (a) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       3 . A composition according to  claim 1 , wherein compound (a) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       4 . A composition according to  claim 1 , wherein compound (b) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       5 . A composition according to  claim 1 , wherein compound (b) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       6 . A composition according to  claim 1 , wherein compound (c) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       7 . A composition according to  claim 1 , wherein compound (c) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       8 . A composition according to  claim 1 , wherein compound (d) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       9 . A composition according to  claim 1 , wherein compound (d) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       10 . A composition according to  claim 1 , wherein the lubricant is selected from a group consisting of: gear oil, bearing oil, sliding surface lubrication oil, chain lubricating oil, and engine oil. 
   
   
       11 . A method of improving the performance characteristics of a lubricant, comprising the step of:
 mixing a lubricant with a multifunctional lubricant additive composition comprising:   a) a compound represented by the general formula:   
     
       
         
         
             
             
         
       
       wherein X 1  is an oxygen or sulfur atom and R 3  and R 4  are each a C n H 2n+1  alkyl group, wherein n is an integer of about 2≦n≦10, and m is an integer of about 0≦m≦4; 
       (b) a compound represented by the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 3 , R 4 , R 5 , and R 6  are each a C h H 2h+1  secondary alkyl group represented by the formula: 
     
     
       
         
         
             
             
         
       
       wherein h is an integer of about 3≦h≦11; wherein R 7  and R 8  are each a C i H 2i+1  alkyl group, and i is an integer of about 1≦i≦5; 
       (c) a compound represented by the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 9 , R 10 , R 11 , R 12 , R 13 , and R 14  are each a C j H 2j+1  alkyl group, and j is an integer of about 1≦j≦20, wherein the alkyl groups exhibit tertiary structures, and; 
       (d) a compound represented by the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 15 , R 16 , R 17 , and R 18  are each a C k H 2k+1  alkyl group, and k is an integer of about 1≦k≦30, and R 15 , R 16 , R 17 , and R 18  optionally form a ring structure with the nitrogen atom to which they are bonded; wherein (A) is a chain of sulfur atoms, S n , or S—(CH 2 ) m —S, and n is an integer of about 1≦n≦10, and m is an integer of about 1≦m≦6; wherein the total amount of compounds (a) to (d) is equal to or less than about 15% by mole, based on the total amount of lubricant. 
     
   
   
       12 . A method according to  claim 11 , wherein compound (a) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       13 . A method according to  claim 11 , wherein compound (a) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       14 . A method according to  claim 11 , wherein compound (b) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       15 . A method according to  claim 11 , wherein compound (b) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       16 . A method according to  claim 11 , wherein compound (c) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       17 . A method according to  claim 11 , wherein compound (c) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       18 . A method according to  claim 11 , wherein compound (d) is present in an amount from about 0.1% to about 6% by mole based on the total amount of lubricant. 
   
   
       19 . A method according to  claim 11 , wherein compound (d) is present in an amount from about 0.1% to about 3% by mole based on the total amount of lubricant. 
   
   
       20 . A method according to  claim 11 , wherein the lubricant is selected from a group consisting of: gear oil, bearing oil, sliding surface lubrication oil, chain lubricating oil, and engine oil. 
   
   
       21 . A multi-functional lubricant comprising:
 a base lubricant; and   at least one additive selected from the group consisting of: a molybdenum compound, a secondary zinc dithiophosphate compound, an aryl or alkyl phosphite compound, and a compound having at least one alkylthiocarbamoyl group, wherein   (a) the molybdenum compound has the general formula:   
     
       
         
         
             
             
         
       
       wherein X 1  is an oxygen or sulfur atom and R 3  and R 4  are each independently a C n H 2n+1  alkyl group, wherein n is an integer of about 2≦n≦10, and m is an integer of about 0≦m≦4; 
       (b) the secondary zinc dithiophosphate compound has the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 3 , R 4 , R 5 ; and R 6  are each a C h H 2h+1  secondary alkyl groups of the formula: 
     
     
       
         
         
             
             
         
       
       wherein h is an integer of about 3≦h≦11, wherein R 7  and R 8  are each a C i H 2i+1  alkyl group, and i is an integer of about 1≦i≦5; 
       (c) the aryl or alkyl phosphite compound has the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 9 , R 10 , R 11 , R 12 , R 13  and R 14  are each a C j H 2j+1  alkyl group, and j is an integer of about 1≦j≦20, wherein the alkyl groups exhibit tertiary structures, and; 
       (d) the compound having at least one alkylthiocarbamoyl group has the general formula: 
     
     
       
         
         
             
             
         
       
       wherein R 15 , R 16 , R 17 , and R 18  are each C k H 2k+1  alkyl groups, and k is an integer of about 1≦k≦30, and R 15 , R 16 , R 17 , and R 18  optionally form a ring structure with the nitrogen atom to which they are bonded; wherein (A) is a chain of sulfur atoms, S n , or S—(CH 2 ) m —S, and n is an integer of about 1≦n≦10, and m is an integer of about 1≦m≦6; wherein the total amount of compounds (a) to (d) is about 15% or less by mole, based on the total amount of lubricant. 
     
   
   
       22 . The multifunctional lubricant additive composition of  claim 1 , wherein the molar ratio of constituent compounds (a), (b), (c) and (d) is about 1:1:1:1. 
   
   
       23 . The multifunctional lubricant additive composition of  claim 1 , wherein the molar ratio of constituent compounds (a) and (b) is about 1:1. 
   
   
       24 . The multifunctional lubricant additive composition of  claim 1 , wherein the molar ratio of constituent compounds (a), (b), (c) and (d) is about 10:10:5:1.