Abstract: The present invention relates to a polyimide precursor, a polyimide precursor solution, a polyimide film, a manufacturing method thereof, and a use thereof. The polyimide precursor according to the present invention may provide a polyimide film that has excellent heat resistance and satisfies transparency and a low coefficient of linear thermal expansion, and thus the polyimide film will be usefully applicable in the field of flexible displays requiring high dimensional stability.

Abstract: A polyimide precursor monomer having an E value of 2.0 or more calculated by Equation 1 is selected among polyimide raw materials. A polyimide includes a structural unit derived from the polyimide precursor monomer having the E value of 2.0 or more. Optical properties of a polyimide film formed from the polyimide can be improved, and the optical properties of a polyimide film can be predicted from the E value of the polyimide precursor monomer even before production of the polyimide film.

Abstract: Provided are a separator coating composition for a secondary battery including inorganic particles and a silane salt compound having a specific structure, a separator using the same, and an electrochemical device including the same. Specifically, a separator coating composition for a secondary battery which implements adhesion between an inorganic material layer and a porous substrate without including an acid/polymer-based organic binder in a coating composition for forming the inorganic material layer on one or both surfaces of the porous substrate and does not need a separate dispersing agent for dispersing the inorganic particles, a separator manufactured using the same, and an electrochemical device including the separator are provided.

Abstract: An air conditioner including: a housing having a discharge port and a plurality of holes; a door capable of closing the discharge port; a heat exchanger provided in the housing; a compressor connected to the heat exchanger so as to circulate a refrigerant so that same passes through the heat exchanger: a fan for blowing air so that the air passes through the heat exchanger and is discharged through the discharge port and at least one of the plurality of holes. The air conditioner includes a humidity sensor provided inside the housing so as to sense the humidity of the air having passed through the heat exchanger: and a control unit for controlling the door so as to open or close the discharge port and rotating the fan, on the basis of the humidity sensed by the humidity sensor when the compressor has been stopped.