초록 ▼

A melt-extrudable conductive polymer composition which contains a polymer, a particulate conductive filler, and a particulate nonconductive filler. When a standard strip heater is made from the composition and tested in a UL VW-1 test, it has comparable performance to a heater made from a second com

A melt-extrudable conductive polymer composition which contains a polymer, a particulate conductive filler, and a particulate nonconductive filler. When a standard strip heater is made from the composition and tested in a UL VW-1 test, it has comparable performance to a heater made from a second composition which is the same as the composition but which does not contain the nonconductive filler. When tested in a standard arcing fault test, the standard heater will trip a fuse in less time than is required by the second heater, i.e. in less than 30 seconds. In some embodiments, the composition also comprises a flame retardant, preferably a halogenated flame retardant. When strip heaters prepared from these compositions are tested in a standard arc propagation test, an arc will not propagate. A preferred nonconductive filler is Sb.sub.2 O.sub.3.

대표청구항 ▼

[ What is claimed is:] [1.] A strip heater circuit which comprises(1) a strip heater which comprises(a) a resistive element which is composed of a conductive polymer composition which comprises(i) a polymer,(ii) a particulate conductive filler,(iii) a particulate nonconductive filler, and(iv) a flam

[ What is claimed is:] [1.] A strip heater circuit which comprises(1) a strip heater which comprises(a) a resistive element which is composed of a conductive polymer composition which comprises(i) a polymer,(ii) a particulate conductive filler,(iii) a particulate nonconductive filler, and(iv) a flame retardant, and(b) two elongate wire electrodes which can be connected to a source of electrical power to cause current to flow through the resistive element,(2) a power supply electrically connected to the strip heater, and(3) a first fuse which(a) is a very fast acting fuse, and(b) is electrically connected to the strip heater and the power supply,wherein the heater is such that when tested in a standard arc propagation test, it will not propagate an arc.