Functional fluid compositions containing epoxide acid scavengers
View Patent ↗A phosphate ester-based functional fluid composition that generates reduced levels of carboxylic acid during use by incorporating at least one acid scavenger selected from the epoxides of the invention. The phosphate ester-based functional fluids are particularly useful as hydraulic fluids.
1. A functional fluid composition that generates reduced levels of carboxylic acid during use comprising:
(a) a base stock comprising a phosphate ester, and
(b) at least one acid scavenger selected from
(i) epoxides of the formula
(ii) epoxides of the formula
(iii) mixtures thereof;
wherein R 1 , R 2 and R 3 are independently selected from H, and —C(O)—R 12 , and wherein one or two of R 1 , R 2 and R 3 are —C(O)—R 12 ; R 4 is selected from H or —CH 3 ; and R 5 , R 6 , R 7 and R 8 are independently selected from H, and —C(O)—R 12 , and wherein one or two of R 5 , R 6 , R 7 and R 8 are —C(O)—R 12 ;
wherein; R 12 is an arylalkyl group having 7 to 12 carbon atoms.
2. The composition of claim 1 wherein said acid scavenger is an epoxide of formula (I).
3. The composition of claim 2 wherein one of R 1 , R 2 and R 3 is —C(O)—R 12 .
4. The composition of claim 2 wherein R 1 and R 2 are —C(O)—R 12 .
5. The composition of claim 2 wherein R 1 and R 3 are —C(O)—R 12 .
6. The composition of claim 2 wherein R 4 is H.
7. The composition of claim 1 wherein said acid scavenger is an epoxide of formula (II).
8. The composition of claim 7 wherein one of R 5 , R 6 , R 7 and R 8 is —C(O)—R 12 .
9. The composition of claim 3 wherein said acid scavenger is