Abstract: An over-current protection apparatus with high voltage endurance comprises a first electrode layer, a second electrode layer and a ceramic current-sensitive layer, where both the first and second electrode layers are continuous and uniform to enhance electrical and thermal conductivities thereof. The ceramic current-sensitive layer is sandwiched between the first and second electrode layers, and is essentially composed of basic matrix, dopants, conductors and sintering material. The resistance of the over-current protection apparatus with high voltage endurance is less than 10 ohms before being tripped, and the resistance-jumping ratio is less than 1.3.

Abstract: An over-current protection device and manufacturing method thereof are revealed. The method for manufacturing an over-current protection device comprises the steps of: (1) providing at least two polymer current-sensing elements, the at least two polymer current-sensing elements comprise flame retardant, and the switching temperatures of adjacent polymer current-sensing elements differ from each other by at least 5° C.; (2) irradiating the at least two polymer current-sensing elements; (3) annealing the at least two polymer current-sensing elements; and (4) combining a first electrode foil and a second electrode foil with the at least two polymer current-sensing elements as a laminate. The at least two polymer current-sensing elements can be irradiated of less than 50 Mrads by Cobalt 60, and be annealed 6-20 hours with a temperature between 100-120° C. Moreover, the flame retardant may be composed of magnesium hydroxide or talc.

Abstract: Processes and apparatus for melt extrusion of polymeric compositions, particularly conductive polymers, in which a gear pump delivers molten polymeric composition to an extrusion orifice. Overfeeding of the composition due to pressure variations is avoided by means of a polymer relief means, preferably a second, smaller gear pump, which removes a portion of the molten composition when the pressure exceeds a selected level.

Abstract: An electrical device which includes a resistive element which exhibits PTC behavior, is composed of a conductive polymer composition, has a planar shape with first and second major surfaces, and has a thickness of at most 0.64 mm . The resistive element is sandwiched between first and second metal foil electrodes, at least one of which has a thickness of at least 0.055 mm, so that the ratio of the resistive element thickness to electrode thickness is 1:1 to 16:1. The device can be used as a circuit protection device in an electrical circuit.

Abstract: A circuit protection device for protecting batteries is formed from a resistive element composed of a PTC conductive polymer composition and two electrodes. The device has a resistive element thickness of 0.025 to 0.20 mm; a crosslinking level equivalent to 1 to 20 Mrads; a surface area of at most 120 mm.sup.2 ; a resistance at 20.degree. C., R.sub.20, of at most 0.030 ohm; and a resistivity at 20.degree. C., .rho..sub.20, of at most 2.0 ohm-cm. Devices of the invention are sufficiently small to be easily inserted into an assembly comprising a battery, particularly a rechargeable battery, and the device. Such assemblies are used for powering portable electronic equipment such as cellular telephones.

Abstract: A conductive polymer composition containing a particulate conductive filler dispersed in a polymeric component. The polymeric component comprises a first polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) is polyethylene, and a second polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) comprises units derived from a first monomer which is ethylene and a second monomer which is an alkyl acrylate having the formula --CH.sub.2 .dbd.CHCOOC.sub.m H.sub.2m+1 --, where m is at least 4. The resulting composition is useful in preparing electrical devices, e.g. circuit protection devices, which have lower resistivities, higher PTC anomalies, and better thermal and electrical stability than devices comprising conventional conductive polymer compositions.

Abstract: A conductive polymer composition containing a particulate conductive filler dispersed in a polymeric component. The polymeric component comprises a first polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) is polyethylene, and a second polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) comprises units derived from a first monomer which is ethylene and a second monomer which is an alkyl acrylate having the formula --CH.sub.2 .dbd.CHCOOC.sub.m H.sub.2m+1, where m is at least 4. The resulting composition is useful in preparing electrical devices, e.g. circuit protection devices, which have lower resistivities, higher PTC anomalies, and better thermal and electrical stability than devices comprising conventional conductive polymer compositions.

Abstract: A conductive polymer composition which has a resistivity of less than 10 ohm-cm and which exhibits PTC behavior comprises a polymeric component and a particulate conductive filler. The polymeric component comprises a first crystalline fluorinated polymer having a first melting point T.sub.m1 and a second crystalline fluorinated polymer having a second melting point T.sub.m2 which is from (T.sub.m1 +25).degree. C. to (T.sub.m1 +100).degree. C. The composition exhibits one of a number of characteristics, including a relatively high PTC anomaly. The composition is useful in circuit protection devices to be used at high ambient conditions.

Abstract: A conductive polymer composition in which a particulate conductive filler is dispsered in a polymeric component which is a mixture of an essentially amorphous thermoplastic resin and a thermosetting resin. In preferred compositions, the amorphous thermoplastic resin and the thermosetting resin are substantially mutually soluble. In order to improve the thermal stability of the composition on exposure to successive thermal cycles, it is preferred that the composition be cured by heating the uncured mixture of amorphous thermoplastic resin, thermosetting resin, and particulate conductive filler at a rate of at least 15.degree. C./minute to the cure temperature.

Abstract: A conductive polymer composition which has low resistivity and good electrical stability. In one aspect the composition comprises a nonconductive filler which is a dehydrated metal oxide. In another aspect the composition comprises a conductive filler which is metal particles in which the bulk density is less than 0.15 times the true density. Compositions of the invention are particularly useful for circuit protection devices.

Abstract: A composition which contains 35 to 85% by weight of a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), 10 to 60% by weight of a copolymer of tetrafluoroethylene and perfluoropropylvinyl ether (PFA), and 5 to 60% by weight of melt-processable polytetrafluoroethylene (PTFE). The composition is particularly suitable for use as an insulating material on a substrate such as a resistive element in a conductive polymer heating cable. The composition has good physical properties, low creep, and low secondary crystallization, and exhibits little stress-cracking when exposed to elevated temperatures.

Abstract: A conductive polymer composition in which a particulate conductive filler is dispersed in a polymeric component which is a mixture of an essentially amorphous thermoplastic resin and a thermosetting resin. In preferred compositions, the amorphous thermoplastic resin and the thermosetting resin are substantially mutually soluble. In order to improve the thermal stability of the composition on exposure to successive thermal cycles, it is preferred that the composition be cured by heating the uncured mixture of amorphous thermoplastic resin, thermosetting resin, and particulate conductive filler at a rate of at least 15.degree. C./minute to the cure temperature.

Abstract: Curable compositions contain a low molecular weight polyphenylene ether and a polyepoxide composition containing brominated and non-brominated bisphenol polyglycidyl ethers, in combination with further components including specific catalysts. Said compositions are preferably free from hardeners for epoxy resins. They may be used in the preparation of bonding sheets which are useful in the manufacture of multilayer printed circuit assemblies and which have excellent physical and electrical properties.

Abstract: Curable compositions contain a low molecular weight polyphenylene ether and a polyepoxide composition containing brominated and non-brominated bisphenol polyglycidyl ethers, in combination with further components including specific catalysts. Said compositions are preferably free from hardeners for epoxy resins. They may be used in the preparation of bonding sheets which are useful in the manufacture of multilayer printed circuit assemblies and which have excellent physical and electrical properties.