Abstract: In an electroviscous fluid comprising electrically insulating fluid as the dispersant and porous solid particles as the dispersed phase, at lease one substance selected from acid, salt and base and at least one substance selected from polyhydric alcohol and water, and further containing dispersing agent, antioxidant and/or corrosion inhibitor are added to obtain the better effects such as high responsiveness in wide temperature range up to high temperature, high reproducibility, excellent electroviscous effect and the higher durability.Therefore, the electroviscous fluid by this invention is useful, for example, for the control systems utilizing viscosity change, and it is capable to increase the control accuracy, particularly in the operation at high temperature.

Abstract: A traction fluid comprising:(i) a diesteric compound or its derivative represented by the formula ##STR1## wherein A' is an ester linkage of --COO-- or --OOC--, n is a number having a value of from 1 to 10, R.sub.1 is independently selected from hydrogen and alkyl groups containing from 1 to 8 carbons, and R.sub.2 is independently selected from hydrogen and alkyl group containing from 1 to 3 carbons; and(ii) from 0.1 to 95% by weight of a branched poly-.alpha.-olefin .

Abstract: The lubricating oil for refrigerator according to the present invention is a lubricating oil for refrigerator using 1,1,1,2-tetrafluoroethane refrigerant. Having esters as base oil, its viscosity range is between 2-30 mm/s at 100.degree.C. By adding esters alone or by adding esters having different viscosity to esters base oil, or by adding polymer, the viscosity is adjusted to obtain the lubricating oil suitable for various types of refrigerators. The lubricating oil thus obtained has excellent compatibility with 1,1,1,2-tetrafluoroethane refrigerant, which is an alternative to freon, and has low hygroscopic property and high heat-resistant property.By reducing the total acid number to 0.05 mg KOH/g or less, the corrosion-resistant property and insulating property of lubricating oil are not decreased, and the lubricating oil for refrigerator having having high refrigerant stability, hydrolytic stability and insulating property can be obtained.

Abstract: A synthetic lubricating fluid comprising at least one ester or its derivative represented by the formula ##STR1## wherein: n is an integer of 0 to 5 and m is an integer of 0 to 5, with the proviso that the sum of n+m is 1 to 10 inclusive;R.sub.1 is independently selected from hydrogen and C.sub.1 to C.sub.8 alkyl groups, andR.sub.2 is independently selected from hydrogen and C.sub.1 to C.sub.3 alkyl groups.

Abstract: A synthetic traction fluid comprising, as a base oil, at least one ester or its derivative selected from monoesters or their derivatives, and triesters or their derivatives represented by the formula ##STR1## wherein Y is independently selected from ##STR2## and --OH with A' being an ester linkage and R.sub.1 being independently selected from hydrogen and C.sub.1 to C.sub.8 alkyl groups, with the proviso that at least one Y is ##STR3## and R.sub.2 is independently selected from hydrogen and C.sub.1 to C.sub.3 alkyl groups.

Abstract: A traction fluid comprising at least one compound selected from diesters or monoesters represented by general formulas ##STR1## wherein: A is an ester linkage ##STR2## n.sub.1 and n.sub.2 are independently integers having a value of from 0 to 5 inclusive;R.sub.1 is hydrogen or a C.sub.1 -C.sub.8 alkyl; andR.sub.2 is a C.sub.1 to C.sub.3 alkyl group.

Abstract: A traction fluid comprising:(i) an ester or its derivative represented by the formula: ##STR1## wherein A' is an ester linkage of --COO-- or --OOC--, n is an integer of from 1 to 14, R.sub.1 is selected from hydrogen and C.sub.1 to C.sub.8 alkyl radicals, and R.sub.2 is independently selected from hydrogen and C.sub.1 to C.sub.3 alkyl radicals; and(ii) from 0.1 to 95% by weight of a polymer selected from hydrocarbonic polymers and polyesters.

Abstract: A synthetic traction fluid comprising, as a base oil, at least one ester or its derivative selected from monoesters, diesters, triesters and derivatives thereof represented by the formula: ##STR1## where Y is independently selected from ##STR2## --(CH.sub.2)n--OH A' is an ester linkage, n is an integer of 1 to 3, and R.sub.

Abstract: A traction fluid comprising a diester or its derivative represented by the formula ##STR1## wherein: A40 is an ester linkage of --COO-- or --OOC--;n is an integer of 1 to 6;R.sub.1 is independently selected from hydrogen and alkyl groups containing 1 to 8 carbon atoms; andR.sub.2 is independently selected from alkyl groups containing from 1 to 3 carbon atoms.

Abstract: A traction fluid comprising a diester or its derivative represented by the formula: ##STR1## wherein A' is an ester linkage, n is an integer of 1 to 10, R.sub.1 is independently selected from hydrogen and C.sub.1 to C.sub.8 alkyl groups, and R.sub.2 is the same or different and is selected from hydrogen and C.sub.1 to C.sub.3 alkyl groups.