Abstract: A macromolecule-based conductive composite material and a PTC element. The macromolecule-based conductive composite material comprises: a macromolecule base material, having a volume fraction of the macromolecule base material of 20%-75%; a conductive filler with a core-shell granule structure and dispersed in the macromolecule base material, having a volume fraction of 25%-80%; and a coupling agent, being a titanate coupling agent and accounting for 0%-5% of the volume of the conductive filler. The PTC element prepared by using the macromolecule-based conductive composite material comprises at least two metal electrode plates (12, 12?), a macromolecule-based conductive composite material (11) being closely combined with the metal electrode plates (12, 12?). The PTC element prepared from the macromolecule-based conductive composite material has the advantages of low room-temperature resistivity, outstanding weather durability, good voltage resistance and good resistor repeatability.

Abstract: The present invention relates to a process for preparing polysulfone, comprising reacting bisphenol monomers with a salt forming agent to form bisphenolate, followed by subjecting the bisphenolate and 4,4?-dihalodiphenyl sulfone to polycondensation to give polysulfone, characterized in that the reaction for forming bisphenolate and the polycondensation are performed in the presence of a composite ionic liquid as the solvent, the composite ionic liquid containing zwitterionic liquid of formula (I) and/or (II) as component A and ionic liquid of formula (III) and/or (IV) as component B, wherein variables are respectively defined in the description of the present invention. The process of the present invention enables a shortened preparation period of polysulfone, particularly a shortened reaction time (including the time of water removal) of the salt forming stage; in addition, the polysulfone thus prepared has an improved molecular weight which is much higher.

Abstract: A macromolecule-based conductive composite material and a PTC element. The macromolecule-based conductive composite material comprises: a macromolecule base material, having a volume fraction of the macromolecule base material of 20%-75%; a conductive filler with a core-shell granule structure and dispersed in the macromolecule base material, having a volume fraction of 25%-80%; and a coupling agent, being a titanate coupling agent and accounting for 0%-5% of the volume of the conductive filler. The PTC element prepared by using the macromolecule-based conductive composite material comprises at least two metal electrode plates (12, 12?), a macromolecule-based conductive composite material (11) being closely combined with the metal electrode plates (12, 12?). The PTC element prepared from the macromolecule-based conductive composite material has the advantages of low room-temperature resistivity, outstanding weather durability, good voltage resistance and good resistor repeatability.

Abstract: The present invention relates to a process for preparing polysulfone, comprising reacting bisphenol monomers with a salt forming agent to form bisphenolate, followed by subjecting the bisphenolate and 4,4?-dihalodiphenyl sulfone to polycondensation to give polysulfone, characterized in that the reaction for forming bisphenolate and the polycondensation are performed in the presence of a composite ionic liquid as the solvent, the composite ionic liquid containing zwitterionic liquid of formula (I) and/or (II) as component A and ionic liquid of formula (III) and/or (IV) as component B, wherein variables are respectively defined in the description of the present invention. The process of the present invention enables a shortened preparation period of polysulfone, particularly a shortened reaction time (including the time of water removal) of the salt forming stage; in addition, the polysulfone thus prepared has an improved molecular weight which is much higher.

Abstract: A PTC conductive composite material and the overcurrent protection device made of the material are disclosed. The PTC conductive composite material includes: (a) A matrix of crystalline polymer material at least, occupies 20%-70% of the volume fraction of the PTC conductive composite material, (b) One kind of conductive filler occupies 30%-80% of the volume fraction of the material. The solid solution conductive filler is uniformly dispersed in the polymer material, whose average particle size ranges from 0.1 ?m to 10 ?m, and the volume resistivity is no more than 300 ??·cm. The overcurrent protection device prepared by using the PTC conductive composite material as described above includes two metal foils, which are made into a sandwich, separated by a layer of the PTC conductive composite material. And the advantages of the overcurrent protection device of the invention are low resistance, good reproducibility of resistance and well PTC intensity.

Abstract: A surface-mount type over-current protection element includes two single-layer composite chips, wherein one chip is made of a first core material and a first and a second metallic foil layer attached on the two surfaces of the first core material, the other chip is made of a second core material and a third and a fourth metallic foil layer attached to the two surfaces of the second core material. The protection element also has an insulating layer arranged between the two chips to electrically insulate and bond to the second and third metallic layers to form a bi-layer composite chip. Part of the first metallic foil layer and the corresponding part of the fourth metallic foil layer are etched to expose part of the first core material and correspond part of the second core material. One or more through-holes are made on the bi-layer composite chip for mounting.

Abstract: A PTC conductive composite material and the overcurrent protection device made of the material are disclosed. The PTC conductive composite material includes: (a) A matrix of crystalline polymer material at least, occupies 20%-70% of the volume fraction of the PTC conductive composite material, (b) One kind of conductive filler occupies 30%-80% of the volume fraction of the material. The solid solution conductive filler is uniformly dispersed in the polymer material, whose average particle size ranges from 0.1 ?m to 10 ?m, and the volume resistivity is no more than 300 ??·cm. The overcurrent protection device prepared by using the PTC conductive composite material as described above includes two metal foils, which are made into a sandwich, separated by a layer of the PTC conductive composite material. And the advantages of the overcurrent protection device of the invention are low resistance, good reproducibility of resistance and well PTC intensity.

Abstract: A surface-mount type over-current protection element includes two single-layer composite chips, wherein one chip is made of a first core material and a first and a second metallic foil layer attached on the two surfaces of the first core material, the other chip is made of a second core material and a third and a fourth metallic foil layer attached to the two surfaces of the second core material. The protection element also has an insulating layer arranged between the two chips to electrically insulate and bond to the second and third metallic layers to form a bi-layer composite chip. Part of the first metallic foil layer and the corresponding part of the fourth metallic foil layer are etched to expose part of the first core material and correspond part of the second core material. One or more through-holes are made on the bi-layer composite chip for mounting.