Abstract: Disclosed is a polyamide ester which comprises a plurality of specific amide ester recurring units including, in a specific ratio, recurring units containing a tetravalent benzene group and recurring units containing a tetravalent diphenyl ether group, and which is adapted to be converted to a polyimide in a coating form by heat-curing, wherein the polyimide coating exhibits a residual stress of 33 MPa or less as measured with respect to a 10 &mgr;m-thick polyimide coating formed on a silicon substrate. Also disclosed is a polyamide ester composition comprising a plurality of different polyamide esters, wherein the plurality of different polyamide esters collectively contain, in a specific ratio, the recurring units containing a tetravalent benzene group and the recurring units containing a tetravalent diphenyl ether group.

Abstract: Refuse 21 in a refuse container 2 is heated by a heater 16, and the steam generated from the refuse 21 is condensed by a condenser 8. The ambient temperature near the refuse container 2 is detected by a first temperature detector 6, and the output of the heater 16 is controlled by the output of the first temperature detector 6 so that the temperature near the refuse container 2 may be a specific temperature, and the temperature of the steam flowing out from the refuse container 2 into the condenser 8 is detected by a second temperature detector 7 at the condenser 8. When the temperature change of the second temperature detector 7 exceeds a specific value, the drying process is terminated, so that the drying end time can be detected accurately without allowing to scorch.