Abstract: Provided is a spherical alumina powder which, when incorporated into resins in a high concentration, enables a resin composition to have low viscosity and which has reduced viscosity increase in the resin composition over time after surface treatment of the spherical alumina powder. The spherical alumina powder has an alkyl group(s) derived from a silane compound(s) on its surface, and is characterized in that an intensity ratio {I (CH3)/I (CH2)} of a peak (2960±5 cm?1) associated with asymmetric vibration of CH3 to a peak (2925±5 cm?1) associated with asymmetric vibration of CH2 in the alkyl group(s) of the silane compound(s) in the same spectral data obtained by infrared spectroscopic analysis measurement is 0.2 or more and less than 2.0.

Abstract: Provided is a spherical alumina powder which, when incorporated into resins in a high concentration, enables a resin composition to have low viscosity and which has reduced viscosity increase in the resin composition over time after surface treatment of the spherical alumina powder. The spherical alumina powder has an alkyl group(s) derived from a silane compound(s) on its surface, and is characterized in that an intensity ratio {I (CH3)/I (CH2)} of a peak (2960±5 cm?1) associated with asymmetric vibration of CH3 to a peak (2925±5 cm?1) associated with asymmetric vibration of CH2 in the alkyl group(s) of the silane compound(s) in the same spectral data obtained by infrared spectroscopic analysis measurement is 0.2 or more and less than 2.0.

Abstract: A stirring device has an actuator like a plate, a cover shaped like a rectangular box and covering the actuator, a blade designed to be vibrated by the actuator, and a connecting device connecting the blade to the actuator, positioning an axis of vibration amplitude of the blade substantially in one side of the cover.

Abstract: A rubber molded product containing an inorganic filler, in which the relation of an inorganic filler content and a thermal resistance is within the range enclosed by lines connecting points A (20,1.5), B (20,0.1) and C (50,0.1) in the X-Y coordinates wherein the X coordinate expresses the inorganic filler content (vol %) and the Y coordinate expresses the thermal resistance per 1 mm thickness (.degree. C./W).

Abstract: A radiating spacer consisting essentially of a silicone solidified product containing a heat conductive filler, said spacer having a thermal conductivity of at least 0.8 W/m.multidot.K and a compressibility of at least 10% under a load of 30 g/cm.sup.2.