ARC-EXTINGUISHING INSULATING MATERIAL MOLDING, AND CIRCUIT BREAKER USING THE SAME

PROBLEM TO BE SOLVED: To provide an arc-extinguishing insulating material molding that is capable of generating sufficient pyrolysis gas for extinguishing an arc generated upon circuit interruption, suppresses an amount of generated gas to prevent a housing from being damaged and has heat resistance capable of enduring a temperature rise occurring at that time and pressure resistance capable of enduring an internal pressure rise, and further to provide a circuit breaker using the same.SOLUTION: An arc-extinguishing insulating material molding used for a circuit breaker according to the present invention contains an inorganic filler A that is not resolved at 1500°C or lower, and a matrix resin. At least a portion of the inorganic filler A is covered with an inorganic surface treatment agent that is resolved at 1500°C or lower. The arc-extinguishing insulating material molding contains the inorganic filler A that has an acicular shape or a fibrous shape, or an acicular inorganic filler B different from the inorganic filler A.