Moisture absorbing anti-arcing coating and method for applying same
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsCatharine A. Ritter, Robert W. Kreps
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Abstract
A moisture absorbing, anti-arcing compound comprises a mixture of a moist active isocyanate resin and a generic anti-arcing compound. The isocyanate resin reacts with residual moisture in a high voltage ceramic insulator, thus tying it up chemically. This prevents diffusion of the moisture into the anti-arcing compound and resultant degradation. The compound according to this invention is especially useful for ceramics which may not be baked dry at elevated temperatures.
Claims14
An improved coating composition for ceramic electrical insulators, the coating composition being of the type having an acrylic resin dissolved in a solvent, wherein the improvement comprises:
- isocyanate containing material selected from the group consisting of isocyanate-terminated prepolymers and monomeric isocyanates intermixed with the acrylic resin solution in a proportion sufficient to provide maximum moisture absorbability without degrading the dielectric strength of the electrical insulating coating below a selected limit.
A method for improving the anti-arcing characteristic of a high voltage ceramic insulator containing trace amounts of moisture, comprising the steps of:
- cleaning the ceramic insulator by applying a surfactant thereto;
- drying the cleaned insulator;
- and
- applying a moisture absorbing, anti-arcing coating to the dried insulator.
Apparatus for insulating an energized high voltage conductor comprising in combination:
- a ceramic member disposed between said high voltage conductor and ground;
- and
- a moisture absorbing, anti-arcing composition coated on said ceramic member.
In the combination of a ceramic insulator and an acrylic resin composition present as an anti-arc coating disposed thereon, the improvement which comprises:
- isocyanate containing materials intermixed with the resin composition, the materials being selected from the group consisting of isocyanate-terminated prepolymers and monomeric isocyanates.
Dependencies are inferred from the claim text.