Disclosed is an effective thermal grease comprising a hyperbranched olefinic fluid and a thermally conductive filler. Property-modifying additives and fillers may also be included. The hyperbranched olefinic fluid is selected to have an average of at least 1.5 methine carbons per oligomer molecule and at least 40 methine carbons per one thousand total carbons. The thermal grease exhibits a flash point of 180° C. or higher, a pour point of 0° C. or lower, and a kinematic viscosity at 40° C. of no more than 200 cSt (0.0002 m 2/s). The composition may offer improved thermal conductivity, reduced tendency to migrate, and lower cost when compared with many other thermal greases, including silicone-based thermal greases.

The present invention relates to lubricating grease compositions comprising (a) at least one high-viscosity fluorinated oil having a viscosity of 500 to 1500 mm.sup.2/s, (b) boron nitride and (c) a binder selected from bentonite, alkali metal phosphates, aluminum phosphates, alkali metal silicates, alkaline earth metal silicates, aluminum silicates, alkaline earth metal carbonates, calcium borate, silicon dioxide, titanium dioxide, aluminum oxide and mixtures thereof. The lubricating grease compositions find use especially in the high-temperature sector, for example for the lubrication of oven pullout rails.

Disclosed is an effective thermal grease comprising a hyperbranched olefinic fluid and a thermally conductive filler. Property-modifying additives and fillers may also be included. The hyperbranched olefinic fluid is selected to have an average of at least 1.5 methine carbons per oligomer molecule and at least 40 methine carbons per one thousand total carbons. The thermal grease exhibits a flash point of 180 C. or higher, a pour point of 0 C. or lower, and a kinematic viscosity at 40 C. of no more than 200 cSt (0.0002 m 2/s). The composition may offer improved thermal conductivity, reduced tendency to migrate, and lower cost when compared with many other thermal greases, including silicone-based thermal greases.