GB1460082A - Pressure sensitive resistance elements and process of making same - Google Patents

Abstract

1460082 Pressure-sensitive resistors DYNACON INDUSTRIES Inc 20 Feb 1974 [26 Feb 1973] 7726/74 Heading HIS [Also in Division C3T] A pressure-sensitive resistor comprises conductive particles of a size between 0À1 and 44 microns dispersed in cured elastomeric resin, a semi-conductive layer being formed at the interfaces of the particles with the resin. This layer may be produced by mixing the conductive particles with both a polymerization catalyst and a polymerization inhibitor before adding the particles to the resin which may be incompletely cured at the interfaces. Alternatively an already semi-conductive material may be added to the particles. The resistor may be in strip form. The conductive particles may be of iron, copper, chromium, titanium, tungsten, platinum, boron, steel, silicon, silver, gold, nickel, cobalt, aluminium, zinc, tin or carbon, preferred materials being nickel, mercury-coated nickel and silver-coated nickel, and carbon mixed with other conductive particles. The resin, which may contain a filler, is preferably a silicone elastomer which is curable either by a peroxy catalyst or by a metal soap catalyst. In each case both peroxy and metal soap materials are pre-mixed with the conductive particles, one material acting as the polymerization catalyst and the other as the inhibitor. An aryl compound is also preferably included. One embodiment described demonstrates a pressure polarizable effect when subjected to given conditions of pressure and voltage, an instant return response being obtained upon reversing the applied polarity; this may be employed in memory devices. The resistance of the resistor varies under tension, as will as when compressed, and may be anisotropic.