Patent ID: 7563393
Filing Date: 2009-07-21
Classification: H01B

Abstract:
1. A crosslinked elastomer body for a sensor, which is composed of an electrically conductive composition comprising an electrically conductive filler and an insulative elastomer as essential components, the elastomer being at least one selected from the group consisting of silicone rubbers, ethylene-propylene copolymer rubbers, natural rubbers, styrene-butadiene copolymer rubbers, acrylonitrile-butadiene copolymer rubbers and acryl rubbers, wherein the electrically conductive filler is a spherical carbon black in a spherical particulate form and has an average particle diameter of 0.05 to 100 μm, wherein the electrically conductive filler has a critical volume fraction (φc) of not less than 30 vol % as determined at a first inflection point of a percolation curve at which an insulator-conductor transition occurs with an electrical resistance steeply reduced when the electrically conductive filler is gradually added to the elastomer, wherein the electrically conductive filler is present in a volume fraction not less than the critical volume fraction (φc) in the composition, whereby a resistance of the elastomer body observed under compressive strain or bending strain increases according to the strain as compared to a resistance of the elastomer body observed under no strain whereby the resistance changing range of the elastomer body can be controlled from one to five or more orders of magnitude.