Provided are a novel dielectric material and a novel electrostrictive material. The dielectric material or electrostrictive material comprises a charge-separation type non-coulombic ionic solid in which complex cations each composed of a metal element and a ligand are aggregated to form cation clusters, the cation clusters are arranged in a closest packed structure, and anions are aggregated to form anion clusters in interstices of the closest packed structure.

An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, and a conductive filler. The polymer matrix has a fluoropolymer. The total volume of the PTC material layer is calculated as 100%, and the fluoropolymer accounts for 47-62% by volume of the PTC material layer. The fluoropolymer has a melt viscosity higher than 3000 Pa.Math.s.

An over-current protection device includes a first metal layer, a second metal layer and a heat-sensitive layer laminated therebetween. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a polymer matrix and a first conductive filler. The polymer matrix includes a polyolefin-based polymer and a fluoropolymer. The fluoropolymer has a melt flow index higher than 1.9 g/10 min, and the polyolefin-based polymer and the fluoropolymer together form an interpenetrating polymer network (IPN). The first conductive filler has a metal-ceramic compound dispersed in the polymer matrix.

A composite circuit protection device includes a polymer positive temperature coefficient (PPTC) component, a voltage-dependent resistor, a first conductive lead and a second conductive lead. The PPTC component is formed with a hole and includes a positive temperature coefficient (PTC) polymeric layer, and first and second electrode layers respectively disposed on two opposite surfaces of the PTC polymeric layer. The hole is formed in the PTC polymeric layer. The voltage-dependent resistor is connected to the second electrode layer of the PPTC component. The first and second conductive leads are respectively bonded to the first electrode layer of the PPTC component and the voltage-dependent resistor.

A polymer positive temperature coefficient (PPTC) material is provided. The PPTC material may include a polymer matrix that defines a PPTC body, and further includes a high temperature polymer. The PPTC material may include a conductive filler component, disposed in the polymer matrix, an arc suppressant, and a high temperature antioxidant, disposed in the polymer matrix.

A double-switching heater includes a double-switching PTC ink deposited on a substrate to form one or more resistors. The double-switching PTC ink has a first resin that provides a first PTC effect at a first temperature range and a second resin that provides a second PTC effect at a second temperature range, where the second temperature range is higher than the first temperature range. The substrate may be a flexible substrate or a rigid substrate, and may bedeformable to generate a three-dimensional structure. The substrate may be: polyester, polyimide, polyamide, polypropylene, thermoplastic polyurethane, fiberglass, cement board, carbon composite materials, polyethylene terephthalate, polyethylene, aluminum, steel, glass composite, molded plastic, high-density polyethylene or styrene ethylene butylene styrene.

The invention describes electrically conductive shaped bodies with an inherent positive temperature coefficient (PTC), produced from a composition which contains at lest one organic matrix polymer (compound component A), at least one submicroscale or nanoscale, electrically conductive additive (compound component B) and at least one phase-change material with a phase-transition temperature in the range from 42 C. to +150 C. (compound component D). The phase-change material is incorporated into an organic network (compound component C). The electrically conductive shaped body with an inherent PTC effect is, in particular, a filament, a fibre, a spun-bonded web, a foam, a film, a foil or an injection-moulded article. The switching point for the PTC behavior is dependent on the type and also the phase-conversion temperature of the phase-change material. By way of example, a self-regulating surface heater in the form of a film, foil and/or textile can be realized in this way.

An example method includes: (i) depositing an insulating layer on a substrate; (ii) forming a conductive polymer layer on the insulating layer; and (iii) repeating deposition of a respective insulating layer, and formation of a respective conductive polymer layer to form a multilayer stack of respective conductive polymer layers interposed between respective insulating layers. Each respective conductive polymer layer has a respective electrical resistance, such that when the respective conductive polymer layers are connected in parallel to a power source, a resultant electrical resistance of the respective conductive polymer layers is less than each respective electrical resistance.

A jelly roll-type PTC device including a PTC material layer, a first electrode layer disposed on a first surface of the PTC material layer, a second electrode layer disposed on a second surface of the PTC material layer opposite the first surface between overlapping portions of the first electrode layer and the second electrode layer, and an insulation layer disposed on a surface of the second electrode layer opposite the PTC material layer and covering a region where the first electrode layer overlaps the second electrode layer, wherein the first electrode layer, the PTC material layer, the second electrode layer, and the insulation layer are rolled together to define a jelly roll structure with the PTC material layer providing an electrically conductive pathway between the overlapping first and second electrode layers, and with the insulation layer providing an electrically insulating barrier between the first and second electrode layers.

The present invention provides a conductive polymer composition, a conductive polymer sheet, an electrical device, and their preparation methods. The conductive polymer composition of the present invention includes a polymer and a conductive powder at a volume ratio of 35:65 to 65:35. The polymer includes at least one semicrystalline polymer selected from polyolefin, a copolymer of at least one olefin and at least one non-olefinic monomer copolymerizable therewith, and a thermoformable fluorine-containing polymer. The stated conductive powder includes at least one powder of a transition metal carbide, a transition metal carbon silicide, a transition metal carbon aluminide, and a transition metal carbon stannide. And the stated size distribution of the conductive powder satisfies: 20>D.sub.100/D.sub.50>6, where D.sub.50 denotes a corresponding particle size when a cumulative particle-size distribution percent in the conductive powder reaches 50%, and D.sub.100 denotes a maximum particle size. The stated conductive polymer composition has excellent processability, and can be used for preparing a PPTC device with ultralow resistance and stability in air without an oxygen barrier coating.