Lockheed Martin Corporation

Martin Marietta Corporation

James E Foreman

Bobby G Isler

Douglas R Dowell

Rickey D Akins

John Walvoord

Dorinne J Palmieri

An improved durable, low density, high build polyurethane coating is disclosed, as well as its method of manufacture. A slow reacting polyisocyanate is combined with a polyol so as to form a uniform mixture with an extremely long pot life. The low viscosity uniform mixture can then be sprayed onto a substrate using a conventional spray gun. A polyurethane catalyst is introduced after formation of the uniform mixture, preferably via a second spray nozzle so that catalyst is externally mixed into the polyisocyanate/polyol spray stream. This is a 100%, or near 100%, solids system so that there is very low volatile organic compound emissions.

High build polyurethane coating

In a method for fabricating a reusable conformal photomask for a doubly contoured hemispherical substrate such as a radome or a three-dimensional printed circuit board, a light blocking material is deposited on a shell or tool corresponding to the shape of the radome or printed circuit board. A pattern is then formed in the light blocking material, and portions of the light blocking material corresponding to the pattern are removed. The resulting pattern corresponds to the pattern to be formed on the three-dimensional printed circuit board or radome. A light transmissive layer is then deposited over the light blocking layer for support. The light blocking material and the light transmissive material comprise the reusable conformal photomask which is then removed from the shell. The reusable conformal photomask can be used to form an image of the desired pattern on the three-dimensional printed circuit board or radome.

Conformal photomask for three-dimensional printed circuit board

A process for the gelling of a silicone varnish comprises reacting the silicone varnish with an organic coupling agent, preferably an organometallic coupling agent under conditions which are effective and to provide a gel. This gel has a viscosity which is effective for suspending high density particles in the resin without settling of the particles during subsequent processing such as spraying, casting, and/or curing processes. The silicone varnish contains hydroxyl substituents, and is preferably a polyhydroxy substituted silicone varnish, i.e., silanols.

Growing community of inventors

Orlando, FL, United States of America

James E Foreman