Self-regulating electric heating film and preparation method and use thereof

A self-regulating electric heating film, comprising:

• an insulating isolation layer,
• an interdigital electrode arranged on the surface of the insulating isolation layer,
• a positive temperature coefficient coating covering the surface of a secondary electrode of the interdigital electrode, and
• an insulating protective layer covering the surface of a primary electrode of the interdigital electrode, wherein:
• the positive temperature coefficient coating is not in contact with the primary electrode of the interdigital electrode;
• the insulating protective layer overlaps the positive temperature coefficient coating;
• the nano conductive filler is a mixture of conductive carbon black and carbon nanotube, and a mass ratio of the conductive carbon black to the carbon nanotube is 5:1;
• and
• the insulating isolation layer has a thickness of 10-30 μm, the positive temperature coefficient coating has a thickness of 30-90 μm, and the insulating protective layer has a thickness of 10-30 μm.