Silicones-A New Class of High Polymers of Interest to the Radio Industry

New dielectrics obtained from silica by modification with organic groups are described. These new organo-silicon-oxide polymers, commonly called silicones, have a higher order of heat stability than conventional organic insulating materials in the same physical forms. An outgrowth of research in glass by the Corning Glass Works and their Technical Glass Fellowship at the Mellon Institute, silicones went through a period of industrial development at the Dow Chemical Company and are now in large-scale production by Dow Corning Corporation at Midland, Michigan. Silicone products include liquid dielectrics, electrical sealing compounds, insulating varnishes, and many other forms in which organic dielectrics have been known. The liquids are low-loss dielectrics over a wide frequency spectrum, and are used to waterproof ceramic surfaces to prevent surface leakage at high humidities. The sealing compounds are used to exclude moisture from disconnect junctions in aircraft-engine ignition systems and are similarly useful in radio components. The resins are natural complements to inorganic insulations like mica, fibrous glass, and asbestos to produce a new class of electrical insulation capable of withstanding long overloads at severe humidity conditions or high operating temperatures.