Functional fluid composition
View Patent ↗A functional fluid composition comprising a naphthenic bright stock base oil and a Fischer-Tropsch derived base oil, wherein the functional fluid composition has a Viscosity Index (according to ASTM D 2270) of above 95.
1. A functional fluid composition comprising:
a naphthenic bright stock base oil; and
a Fischer-Tropsch derived base oil, wherein the functional fluid composition has a Viscosity Index (according to ASTM D 2270) of above 95.
2. The functional fluid composition according to claim 1 , wherein the naphthenic bright stock base oil has a pour point of below −9° C. (according to ASTM D 5950).
3. The functional fluid composition according to claim 1 wherein the naphthenic bright stock base oil has a Viscosity Index (according to ASTM D 2270) of below 97.
4. The functional fluid composition according to claim 1 wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. of above 7.0 cSt.
5. The functional fluid composition according to claim 1 having a Viscosity Index of above 100.
6. The functional fluid composition according to claim 1 having a Total Base Number (TBN) value (according to ASTM D 4739) of above 35 and below 75 mg KOH/g.
7. The functional fluid composition according to claim 1 comprising less than 1.0 wt. % of polyisobutylene (PIB).
8. The functional fluid composition according to claim 1 comprising at least 20 wt. % of the naphthenic bright stock base oil, based on the total weight of the composition.
9. The functional fluid composition according to claim 1 being a marine cylinder oil.
10. The functional fluid composition according to claim 1 , wherein the naphthenic bright stock base oil has a pour point of below 12° C.
11. The functional fluid composition according to claim 1 wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. of above 3.0 cSt.
12. A method comprising:
applying a lubricating composition to a surface in relative movement to another surface in a marine diesel engine, wherein the lubricating composition comprises:
a naphthenic bright stock base oil; and
a Fischer-Tropsch derived base oil,
wherein the lubricating composition has a Viscosity Index (according to ASTM D 2270) of above 95.
13. The method of claim 12 wherein the naphthenic bright stock base oil has a pour point of below −9° C. (according to ASTM D 5950).
14. The method of claim 12 wherein the naphthenic bright stock base oil has a Viscosity Index (according to ASTM D 2270) of below 97.
15. The method of claim 12 wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. of above 3.0 cSt.
16. The method of claim 12 wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. of above 7.0 cSt.
17. The method of claim 12 wherein the lubricating composition comprises at least 20 wt. % of the naphthenic bright stock base oil, based on the total weight of the composition.
18. The method of claim 12 wherein the lubricating composition has a Viscosity Index of above 100.
19. The method of claim 12 wherein the lubricating composition has a Total Base Number (TBN) value (according to ASTM D 4739) of above 35 and below 75 mg KOH/g.
20. The method of claim 12 wherein the lubricating composition comprises less than 1.0 wt. % of polyisobutylene (PIB).