Conductive polymer composition, and method of making the conductive polymer composition

• Main Authors: WARTENBERG, MARK F, LAHLOUH, JOHN G, TOTH, JAMES
• Format: Patent
• Language: English
• Published: 21.06.2003
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; RESISTORS

A conductive polymer composition which has a resistivity at 20 DEG C of at most 1.0 ohm-cm and a PTC anomaly of at least 10 contains at most 64% by volume of a crystalline polymeric component and at least 36% by volume of a particulate conductive filler. A preferred conductive filler is carbon black having a DBP number of 60 to 120 cm /100 g. Compositions of the invention, as well as other conductive polymer compositions, are preferably prepared by a method in which the polymeric component and the filler are blended in a first step at a temperature greater than the melting temperature of the polymer, the mixture is then cooled, and the mixture is then mixed in a second step. The resulting composition has a PTC anomaly that is at least 1.2 times the PTC anomaly of the first mixture.