Positive temperature coefficient polymer composition and circuit protection device

Abstract

A positive temperature coefficient polymer composition comprises a first polymer, a second polymer, and a conductive filler dispersed in the first and second polymers. The first polymer has a melting point of 100°C to 200°C, the second polymer has a melting point greater than 200°C, and the weight ratio of the first polymer to the second polymer ranges from 1:5 to 5:1. The present invention also provides a circuit protection device comprising a PPTC element and two electrodes, the two electrodes being disposed on opposite sides of the PPTC element. The PPTC element comprises a polymer substrate and a conductive filler dispersed in the polymer substrate. The polymer substrate comprises the first and second polymers as described above. The circuit protection device comprising this positive temperature coefficient polymer composition can withstand higher voltages and has better stability and durability.

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