Verfahren zur Herstellung eines elektrisch leitenden Körpers mit einem spezifischen Widerstand zwischen 10 2 und 10 10 . cm

• Main Authors: WARING,ROBERT WALLINGFORD, EDWARD,JR. KENNEY,JAMES
• Format: Patent
• Language: German
• Published: 31.12.1963
• Subjects: BASIC ELECTRIC ELEMENTS; CABLES; CONDUCTORS; ELECTRICITY; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES

913,155. Electric holding devices. WARING, R. W., and KENNY, J. E. April 1, 1959 [April 9, 1958], No. 11127/59. Class 35. [Also in Group XXXVI] A method of making a semi-conducting body comprises impregnating a porous insulating body with a carbon-rich material dissolved in a solvent, the boiling point of which is substantially above the decomposition temperature of the carbon-rich material, heating said impregnated body to a temperature sufficient to decompose said material but substantially below the boiling point of the solvent and subsequently heating the body to a temperature sufbcient to evaporate the solvent and to form from the carbon-rich material a conductive material within the pores of the body. The porous body is preferably of aluminium silicate having a resistivity greater than 1010 ohm centimetres. The carbon-rich material is preferably a specified solution of sucrose in glycerol. The impregnation is preferably done at an elevated pressure and temperature, the pressure being reduced during part of the process to release entrapped air. The impregnated body is heated in an atmosphere of nitrogen, or helium. The high-conductivity outer surface is then ground off. The resistivity may be controlled by further heating. The finished semi-conductive body may be vacuum impregnated with synthetic resin, polymerized in situ. Two such bodies may be cemented together with epoxy resin. The finished body is suitable for use in electrostatic apparatus for producing mechanical force between the body and a conducting or another semi-conducting body.