Abstract: Provided is a polyimide insulation coating, which is prepared by reacting a diacid anhydride compound represented by Formula (I) with a diamine compound represented by Formula (II). By adopting the specific diacid anhydride compound and the specific diamine compound, the synthesized polyimide insulation coating can have a dielectric constant less than 3. Accordingly, the enameled wire having an insulation layer formed from the polyimide insulation coating would not readily produce partial discharge, thereby avoiding the penetrating short-circuit and the damage to the motor.

Abstract: A magnet wire has a conductor and a coating layer. The coated layer is coated around the conductor and has at least one magnetic coating layer; and at least one insulating coating layer. The magnetic coating layer has non-conductive magnetic material. The insulating coating layer and the magnetic coating layer are formed alternately. The alternative structure of the magnetic coating layer and the insulating coating layer prevent precipitation of magnetic material and efficiently offsets the interference between conductors after electricity is supplied, which inhibits occurrence of eddy current and lowers alternative current (AC) resistance.

Abstract: An enameled wire containing a nano-filler includes a metallic wire and at least one layer of insulating coating. At least one layer of the at least one layer of insulating coating includes a nano-filler. The nano-filler is a modified silicon dioxide slurry comprising silicon dioxide, organic solvent and organic silane coupling agent. The nano-filler comprises silicon dioxide modified with an organic silane coupling agent to improve dispersion of the nano-filler and maintain properties of the insulating coating. In addition, material and manufacturing costs of the enameled wire can be lowered.