Champion Spark Plug Company

Charles I Kowalski

Joseph Nemeth

Electrically semi-conducting and conducting open celled ceramic networks and methods for producing them are disclosed. The ceramic network is formed by impregnating an organic foam material with a semi-conducting or conducting ceramic composition, and firing the impregnated material to burn out the foam and to vitrify the ceramic. The semi-conducting or conducting ceramic composition may comprise, on a solids basis, from 45 to 80 percent of a lead-free ceramic frit, from 5 to 15 percent of mono aluminum phosphate, from 6 to 45 percent of a silicone resin, from 0.2 to 13.2 percent of a conducting carbon compound, and an organic solvent or water in an amount sufficient to form a dispersion having a viscosity ranging from 300 to 3000 centipoises, and, in the latter case, from 0.5 to 7 percent of a detergent. The electrically semi-conducting or conducting ceramic composition may also comprise, on a solids basis, a modified copper and alumina composition, from 6 to 45 percent of a silicone resin, and an organic solvent or water and detergent to produce a dispersion having a viscosity ranging from 300 to 3000 centipoises. The organic solvent systems and the aqueous systems both constitute dispersions.

Open-celled, electrically conductive ceramic network

A carbon resistor and a method for producing the resistor are disclosed. The method preferably comprises the steps of preparing a uniform, finely-divided mixture by blending a glass frit with at least one temporary binder and substantially 1/4 to 4 percent of conductive carbon, pressing a longitudinally extending shape having opposed ends from the mixture, heating the shape to 450-550 degrees F. for about 30 minutes and cooling to ambient temperature, applying a silver paint containing a lead borosilicate frit composition to the cooled shape to provide electrical contacts, and firing the shape and contacts to vitrify the frit of the resistor. A preferred lead borosilicate frit composition, by weight, consists essentially of from 5 to 15 percent of AlPO.sub.4, from 1/4 to 3 percent of conductive carbon, from 15 to 30 percent of a phenyl lower alkyl silicone resin and from 65 to 80 percent of a lead borosilicate glass frit which consists essentially of substantially 20 percent SiO.sub.2, 15 percent B.sub.2 O.sub.3, 59 percent PbO and 6 percent Na.sub.2 O.

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Mt. Clemens, MI, United States of America

Charles I Kowalski