Dew sensor having a conductive power-containing moisture sensing material disposed between opposing electrodes

摘要

A dew sensor used in a video tape recorder, and the like, can be mounted on a printed circuit board remote from the cylinder. A pair of electrodes are formed on an insulated substrate, a moisture sensing material is disposed on the insulated substrate containing the pair of electrodes, and conductive powder is dispersed therein. The moisture sensing material is produced by reaction of a moisture absorbing resin having a hydrophilic group and an epoxy group, and a hardener containing a hydrazine derivative having a hydantoin skeleton, and, optionally, a long chain diamine compound.