Abstract: The inventive electroconductive adhesive comprises a resinous matrix, as a dispersing medium of conductive particles, of a polyester-based urethane resin admixed with a masked isocyanate compound as the curing agent. By virtue of the masking of the isocyanate reactivity of the curing agent, the adhesive composition is stable during prolonged storage under a hot temperature or high-humidity condition but can exhibit curing activity when the adhesive is heated at a temperature at which the isocyanate reactivity can be restored.

Abstract: A film adhesive of a thermoplastic or thermosetting polymeric insulative material can be imparted with anisotropic electroconductivity by dispersing electroconductive fibrils of specified dimensions therein in orientation each lying within a plane substantially parallel to the surface of the film adhesive. The film adhesive is useful in adhesively bonding two circuit boards each having a plurality of electric terminals to be electrically connected each on one circuit board to the oppositely positioned terminal on the other circuit board. The orientation of the fibrils in a plane parallel to the surface of the film adhesive may be either unidirectional or at random.

Abstract: A rod-type insulator is provided with the optimum withstand voltage characteristics under a contaminated condition by selecting the ratio of the leakage distance per shed to the shed pitch to be between 3.8 and 5.0 and also selecting 4.5.ltoreq.l/p.ltoreq.6.0, where p is the distance between the adjoining sheds, i.e., the distance between a given point on the lower surface of one shed and another given point on the upper surface of the other opposing shed, and l is the leakage distance between the two points.