Lubricant Composition Comprising an Antioxidant Composition

Abstract

A lubricant composition is disclosed comprising an antioxidant composition and a lubricating oil. The antioxidant composition comprises a phenolic antioxidant having the following structure (I) and a phosphite antioxidant having the following structure (II) wherein, A is a direct bond or an alkylene; X is —C(O)O—, —OC(O)—, —C(O)N(R 7 )—, —N(R 7 )C(O)—, —C(O)—, —N(R 7 )—, —O—, or —S—; R 1 and R 2 are each independently a C 1 -C 10 alkyl, a C 2 -C 10 alkenyl, a C 2 -C 10 alkynyl, or a C 3 -C 12 aryl; R 3 includes a C 1 -C 80 alkyl, a C 2 -C 80 alkenyl, a C 2 -C 80 alkynyl, or a C 3 -C 12 aryl; R 4 , R 5 , and R 6 are each independently hydrogen, alkyl, alkenyl, alkynyl, or aryl provided that at least one of R 4 , R 5 , and R 6 is not hydrogen; R 7 is H or an alkyl; and m, n, and o are each independently from 1 to 3.

1 - 37 . (canceled) 
     
     
         38 . A lubricant composition comprising:
 an antioxidant composition comprising   a phenolic antioxidant having the following structure (I)   
       
         
           
           
               
               
           
         
       
       and
 a phosphite antioxidant having the following structure (II) 
 
       
         
           
           
               
               
           
         
         wherein,
 A is a direct bond or an alkylene; 
 X is —C(O)O—, —OC(O)—, —C(O)N(R 7 )—, —N(R 7 )C(O)—, —C(O)—, —N(R 7 )—, —O—, or —S—; 
 R 1  and R 2  are each independently a C 1 -C 10  alkyl, a C 2 -C 10  alkenyl, a C 2 -C 10  alkynyl, or a C 3 -C 12  aryl; 
 R 3  includes a C 1 -C 80  alkyl, a C 2 -C 80  alkenyl, a C 2 -C 80  alkynyl, or a C 3 -C 12  aryl; 
 R 4 , R 5 , and R 6  are each independently hydrogen, alkyl, alkenyl, alkynyl, or aryl provided that at least one of R 4 , R 5 , and R 6  is not hydrogen; 
 R 7  is H or an alkyl; and 
 m, n, and o are each independently from 1 to 3; and 
 
         a lubricating oil. 
       
     
     
         39 . The lubricant composition of  claim 38 , wherein the weight ratio of the phenolic antioxidant to the phosphite antioxidant is from 0.1 to 10. 
     
     
         40 . The lubricant composition of  claim 38 , wherein the phenolic antioxidant is present in the lubricant composition in an amount of from 0.01% by weight to 5% by weight. 
     
     
         41 . The lubricant composition of  claim 38 , wherein the phosphite antioxidant is present in the lubricant composition in an amount of from 0.01% by weight to 5% by weight. 
     
     
         42 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a standard RPVOT oxidation induction time of 150 minutes or more as determined according to ASTM D2272-14a and at a temperature of 150° C. 
     
     
         43 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a standard RPVOT oxidation induction time as determined according to ASTM D2272-14a at a temperature of 150° C. of at least 20% greater than an expected standard RPVOT oxidation induction time. 
     
     
         44 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a dry RPVOT oxidation induction time of 200 minutes or more as determined according to a modified ASTM D2272-14a and at a temperature of 150° C. 
     
     
         45 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a dry RPVOT oxidation induction time as determined according to a modified ASTM D2272-14a at a temperature of 150° C. of at least 20% greater than an expected dry RPVOT oxidation induction time. 
     
     
         46 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a PDSC oxidation induction time of 20 minutes or more as determined at a temperature of 160° C. 
     
     
         47 . The lubricant composition of  claim 38 , wherein the lubricant composition exhibits a TEOST 33C deposit of 50 mg or less as determined according to ASTM D6335-16 and a temperature change on a depositor rod from 200° C. to 480° C. 
     
     
         48 . The lubricant composition of  claim 38 , wherein R 1  and R 2  are each a C 1 -C 5  alkyl. 
     
     
         49 . The lubricant composition of  claim 38 , wherein A is a C 1 -C 8  alkylene. 
     
     
         50 . The lubricant composition of  claim 38 , wherein X is —C(O)O—. 
     
     
         51 . The lubricant composition of  claim 38 , wherein R 3  includes a C 10 -C 80  alkyl. 
     
     
         52 . The lubricant composition of  claim 38 , wherein R 3  includes a C 10 -C 20  alkyl. 
     
     
         53 . The lubricant composition of  claim 38 , wherein R 4 , R 5 , and R 6  are each alkyl. 
     
     
         54 . The lubricant composition of  claim 38 , wherein R 4 , R 5 , and R 6  are each independently a C 1 -C 10  alkyl. 
     
     
         55 . The lubricant composition of  claim 38 , wherein m, n, and o are 1 or m, n, and o are 2. 
     
     
         56 . The lubricant composition of  claim 38 , wherein two of m, n, and o are 1 and one of m, n, and o is 2 or one of m, n, and o is 1 and two of m, n, and o are 2 
     
     
         57 . The lubricant composition of  claim 38 , wherein the lubricant composition further comprises an alkanolamine. 
     
     
         58 . The lubricant composition of  claim 38 , wherein the lubricant composition further comprises a triisopropanolamine n an amount of about 5 wt. % or less.