A porous carbon has an I.sub.D/I.sub.G of 2.0 or more in a Raman spectrum measured by Raman spectroscopy with respect to the porous carbon wherein the I.sub.G is an accumulated intensity of a peak for G band around 1590 cm.sup.−1, and the I.sub.D is an accumulated intensity of a peak for D band around 1350 cm.sup.−1. The porous carbon has pores having a size of less than 1 μm. The porous carbon can be contained in a resin composition for producing a varistor element.

A functional contactor is provided. The functional contactor according to one embodiment of the present invention comprises: a conductive elastic portion having elasticity and electrically contacting one of a circuit board of an electronic device, a bracket coupled to the circuit board, and a conductor which can come into contact with the human body; a substrate made from a dielectric material and having a groove in either the upper surface or the lower surface thereof; and a functional element comprising a high dielectric material inserted into the groove and made from sintered ceramic having a higher dielectric constant than a dielectric material, a first electrode disposed on the upper surface of the substrate and electrically connected in series to the conductive elastic portion, and a second electrode disposed on the lower surface of the substrate and opposite to the first electrode.

A functional contactor is provided. The functional contactor according to one embodiment of the present invention comprises: a conductive elastic portion having elasticity and electrically contacting one of a circuit board of an electronic device, a bracket coupled to the circuit board, and a conductor which can come into contact with the human body; a substrate made from a dielectric material and having a groove in either the upper surface or the lower surface thereof; and a functional element comprising a high dielectric material inserted into the groove and made from sintered ceramic having a higher dielectric constant than a dielectric material, a first electrode disposed on the upper surface of the substrate and electrically connected in series to the conductive elastic portion, and a second electrode disposed on the lower surface of the substrate and opposite to the first electrode.

A functional contactor is provided. The functional contactor according to one embodiment of the present invention comprises: a conductive elastic portion having elasticity and electrically contacting one of a circuit board of an electronic device, a bracket coupled to the circuit board, and a conductor which can come into contact with the human body; a substrate made from a dielectric material and having a groove in either the upper surface or the lower surface thereof; and a functional element comprising a high dielectric material inserted into the groove and made from sintered ceramic having a higher dielectric constant than a dielectric material, a first electrode disposed on the upper surface of the substrate and electrically connected in series to the conductive elastic portion, and a second electrode disposed on the lower surface of the substrate and opposite to the first electrode.

A functional contactor is provided. The functional contactor according to one embodiment of the present invention comprises: a conductive elastic portion having elasticity and electrically contacting one of a circuit board of an electronic device, a bracket coupled to the circuit board, and a conductor which can come into contact with the human body; a substrate made from a dielectric material and having a groove in either the upper surface or the lower surface thereof; and a functional element comprising a high dielectric material inserted into the groove and made from sintered ceramic having a higher dielectric constant than a dielectric material, a first electrode disposed on the upper surface of the substrate and electrically connected in series to the conductive elastic portion, and a second electrode disposed on the lower surface of the substrate and opposite to the first electrode.

A resin composition which includes (A) an epoxy resin, (B) a curing agent, and (C) carbon nanotubes, wherein the carbon nanotubes contain therein semiconducting single-walled carbon nanotubes in an amount of 70% by weight or more. A cured product of a paste made from the resin composition can be used to form a varistor element.

A resin composition which includes (A) an epoxy resin, (B) a curing agent, and (C) carbon nanotubes, wherein the carbon nanotubes contain therein semiconducting single-walled carbon nanotubes in an amount of 70% by weight or more. A cured product of a paste made from the resin composition can be used to form a varistor element.

A nonlinear-resistance resin material includes: a plurality of first particles having nonlinear resistance characteristics that exhibit insulation properties when a voltage lower than a threshold value is applied and exhibit conductivity when a voltage equal to or higher than the threshold value is applied; a first resin phase containing second particles that are semiconducting or conducting, and covering at least partially surfaces of some or all of the plurality of first particles; and a second resin phase having insulation properties, and filling voids where none of the first particles and the first resin phase exists. The first particles adjacent to each other are bound and electrically connected to each other via the first resin phase.

A nonlinear-resistance resin material includes: a plurality of first particles having nonlinear resistance characteristics that exhibit insulation properties when a voltage lower than a threshold value is applied and exhibit conductivity when a voltage equal to or higher than the threshold value is applied; a first resin phase containing second particles that are semiconducting or conducting, and covering at least partially surfaces of some or all of the plurality of first particles; and a second resin phase having insulation properties, and filling voids where none of the first particles and the first resin phase exists. The first particles adjacent to each other are bound and electrically connected to each other via the first resin phase.