Polyalkylene glycol-based industrial lubricant compositions

Abstract

A lubricant composition comprises as a lubricant base, an oil soluble polyalkylene glycol suitable for use as a lubricant in an industrial oil, grease or metal working fluid; and an additive comprising (1) alkylated phenyl-α-naphthylamine; and (2) 2,2,4-trialkyl-1,2-dihydroquinoline.

1 - 14 . (canceled) 
     
     
         15 . A lubricant composition comprising:
 a lubricant base being present in an amount at least 90% or more by weight of the total lubricant composition, the lubricant base comprising at least 20% polyalkylene glycol;   an additive at about 0.25-2.0% by weight of the total composition, the additive comprising
 (1) C 8  alkylated phenyl-α-naphthylamine; and 
 (2) a mixture of 1,2-dihydro-2,2,4-trimethylquinoline dimers and trimers; with the proviso that, 
 (a) when the additive is present at about 0.25-1.0%, components (1) and (2) are present at a weight ratio from 1:1 to 3:1, and 
 (b) when the additive is present at about 1.0-2.0%, components (1) and (2) are present at a weight ratio from 1:3 to 1:1. 
   
     
     
         16 . The lubricant composition of  claim 15 , wherein components (1) and (2) are present at a weight ratio of about 1:1., and the additive is present at about 0.25-2.0% 
     
     
         17 . The lubricant composition of  claim 15 , wherein the composition is substantially free of ester base oil. 
     
     
         18 . The lubricant composition of  claim 15 , wherein the composition is substantially free of mineral or natural or non-PAG synthetic base oil. 
     
     
         19 . The lubricant composition of  claim 15 , wherein the additive is present at about 1%. 
     
     
         20 . The lubricant composition of  claim 16 , wherein the additive is present at about 1%.