Abstract: For the manufacture of an electrically conducting layer in the form of a coating on a base or in the form of a free bearing film, a liquid product is prepared consisting of water, a water-soluble polymer dissolved therein, a pyrrole compound dissolved in the water or present therein in undissolved state in the form of pyrrole, N-methylpyrrole or a mixture of pyrrole and N-methylpyrrole and a substance dissolved therein, such as a ferric compound, with the ability to give an electrically conducting polymerized pyrrole upon polymerization of the pyrrole compound. When the pyrrole compound in the liquid product has been transformed into a polymerized pyrrole, the liquid product is applied on a base and the water is thereafter brought to depart while leaving a layer on the base. The layer can be left as a permanent coating on the base or be removed from there while forming a free bearing film.

Abstract: The electrical conductivity of solid, impregnable materials, such as cellulose-based insulating materials, can be increased by supplying to the solid impregnable material a substance with the ability, during polymerization of a pyrrole compound comprising at least one of the substances pyrrole and N-methylpyrrole, to give a polymer with higher electrical conductivity than the solid impregnable material, as well as a pyrrole compound of the kind stated, whereafter the pyrrole compound is transformed into a polymer in the solid, impregnable material.