| abstract |
A functional fluid composition comprising: (a) from 70% to 99.99%, by weight of the fluid composition, of a base oil composition comprising: (i) from 50% to 95%, by weight of the base oil composition, of a naphthenic base oil; and (ii) from 5% to 50%, by weight of the base oil composition, of a Fischer-Tropsch derived base oil. The functional fluid compositions according to the present invention are suitable for use in hydraulic fluids and shock absorber fluids and are useful for reducing the volume swell of synthetic rubbers. |