Giessfolien mit kristallinen TCNQ‐radikalionensalzen: Ein neuer weg zur erhöhung der elektrischen leitfähigkeit

The electrical conductivity of conventional polymers like, for example, polycarbonate can be increased many magnitudes by adding suitable radical ion salts based on tetracyanoquinodimethane. The formation of suitable crystal structures like dendrites, fibrous crystals and whiskers plays a vital rôle in this: the crystalline precipitation must form a three‐dimensional network throughout the entire polymer matrix, and can only be produced by crystallization from solution. Given an ideal distribution of crystals in the films, additions of approx. 0.5 % by weight will give conductivities of up to 10−3 S/cm. Unlike conventional anti‐static agents (hydrophilizing agents), crystalline radical ion salts give films electrically conductive properties which are practically independent of atmospheric humidity. The films behave like electrical semiconductors and have a positive temperature gradient. In view of the small amount of additive required, these modified polycarbonate films can be used as transparent packaging films whose anti‐static properties are unaffected by atmospheric moisture.