Electret and its manufacturing method and electrostatic induction type conversion element

摘要

PROBLEM TO BE SOLVED: To provide an electret using a liquid crystal resin, which has a high surface charge density and excellent charge retention characteristics. SOLUTION: A liquid crystal resin containing 93 to 100 mol% of asymmetric aromatic monomer residues having an asymmetric molecular structure and having an ultimate viscosity of 1.0 dL / g or more and less than 6.0 dL / g is used as a corona current. It is an electret obtained by performing a corona discharge treatment and performing a polarization treatment so that the value becomes -30 μA or less or 30 μA or more. [Selection diagram] None