A flexible sheet of positive temperature coefficient (PTC) material formed of a polymer resin and a conductive filler, the sheet of PTC material having a thickness in a range of 10 m to 100 m. A method for forming the flexible sheet of positive temperature coefficient material may include preparing a PTC ink from a polymer resin, a conductive filler, and a solvent, applying the PTC ink to a substrate, pulling a blade over the PTC ink to create a uniformly thick layer of the PTC ink on the substrate, and allowing the PTC ink to dry so that the solvent evaporates and leaves a solid layer of PTC material on the substrate.

A connecting-conductor is disclosed. The connecting-conductor may have a first conductor-element and a second conductor-element. Each conductor-element has a first end that is mechanically-connected and electrically-conductively connected to a resistor-element. The resistor-element has an electrical-insulating substrate, and a resistive material annularly disposed on at least part of the electrical-insulating substrate. The first end of each conductor-element is electrically-conductively connected to the resistive material. The first conductor does not touch the second conductor, and an electrical pathway is created via the resistive material from one of the conductor-elements to the other of the conductor-elements.

The invention is directed to a polyimide-based polymer thick film paste composition for forming a polyimide-based polymer thick film resistor, a process for forming the resistor and an electrical device containing a resistor formed using the paste composition The paste composition comprise a functional component, a polyimide, and an organic solvent and can be cured by heating.

A PTC circuit protection device includes a PTC polymer material and two electrodes attached to the PTC polymer material. The PTC polymer material includes a polymer matrix and a particulate conductive filler dispersed in the polymer matrix. The polymer matrix is made from a polymer composition that contains a non-grafted polyolefin. The conductive filler includes tungsten carbide particles having a total carbon content that is less than 6.0 wt % based on the total weight of the tungsten carbide particles.

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 heater device that includes a planar heating element that is electrically conductive and two electrodes electrically connected to the planar heating element. The planar heating element includes a layered material having a plurality of layers, each layer having a crystal lattice which is represented by: M.sub.n+1X.sub.n (wherein M is at least one metal of Group 3, 4, 5, 6, or 7; X is a carbon atom, a nitrogen atom, or a combination thereof; and n is 1, 2, or 3), and in which each X is positioned within an octahedral array of M, and having at least one modifier or terminal T selected from the group consisting of a hydroxy group, a fluorine atom, an oxygen atom, and a hydrogen atom on at least one of two opposing surfaces of said each layer.

The present invention relates to an article suitable to act as a thermal switch device, the article having a surface resistance of more than 10.sup.5 ohms and formed from a polymer composition comprising from 50 to 99.9 wt % relative to the total weight of the polymer composition, of a polymer being selected from an amorphous polymer having a glass transition temperature Tg, a semi-crystalline polymer having a melting temperature Tm or a mixture thereof, and from 0.1 to 50 wt % relative to the total weight of the polymer composition, of a conductive material, wherein the surface resistance of the article is divided by at least 10, preferably by at least 100, when said article is submitted for a determined period of time of less than 5 minutes to a temperature of switch i) ranging from Tg+10 C. to Tg+250 C. if the polymer composition comprises an amorphous polymer, or ii) ranging from Tm80 C. to Tm+250 C. if the polymer composition comprises a semi-crystalline polymer.

In an example 3D printing method, an electrical conductivity value for a resistor is identified. Based upon the identified electrical conductivity value, a predetermined amount of a conductive agent is selectively applied to at least a portion of a build material layer in order to introduce a predetermined volume percentage of a conductive material to the resistor. Based upon the identified electrical conductivity value and the predetermined volume percent of the conductive material, a predetermined amount of a resistive agent is selectively applied to the at least a portion of the build material layer in order to introduce a predetermined volume percentage of a resistive material to the resistor. The build material layer is exposed to electromagnetic radiation, whereby the at least the portion coalesces to form a layer of the resistor.

A method of making a hot surface igniter is described. A silicon carbide composition that includes both fines fraction and a coarse fraction is sintered in a nitrogen and argon reducing atmosphere in a manner that controls the incorporation of nitrogen with in the lattice of recrystallized silicon carbide. The controlled incorporation of nitrogen in the lattice provides enhanced control over heating and electrical properties, while simultaneously achieving a lower surface area fully recrystallized structure for oxidation resistance and long service life.

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.