Devices comprising conductive polymer compositions

An electrical sheet heater which comprises:

• (1) a laminar resistive element which is composed of a conductive polymer composition which comprises an organic polymer, and dispersed in the polymer, a particulate filler;
• (2) a plurality of electrodes at least two of which can be connected to a source of electrical power to cause current to pass through the laminar element, and which are dimensioned and positioned on a surface of the element so that when current passes between the electrodes, a substantial proportion of the current is parallel to the faces of the laminar element;
• and
• (3) a dielectric layer positioned over at least part of the electrodes, the dielectric layer having been applied directly onto the electrodes in liquid form, and then solidified so that a solidified layer is formed having a first surface which is intimately bonded to at least part of the electrodes, and a second surface, facing away from the electrodes, with the proviso that if another member is bonded to the second surface of the solidified dielectric layer, at least one of the following conditions is satisfied (a) the peel strength of the bond between the said another member and the second surface of the dielectric layer is less than the peel strength of the bond between the first surface of the dielectric layer and the electrode;
• and (b) the peel strength of the bond between the said another member and the second surface of the dielectric layer is less than 3 lbs. per inch at 20.degree. C.