Process for continuous chemical vapor deposition of carbonaceous films

Claim 1

A process for continuous chemical vapor deposition of a carbonaceous film onto a longitudinally extending web comprised of a plurality of matted or woven fibers, a plurality of parallel individual fiber, or a bundle of fibers, of a refractory ceramic or refractory vitreous material, said web having a leading end and a trailing end, to produce a coated web having a controllable sheet resistance along its length and a substantially uniform sheet resistance across its breadth, comprising: directly applying an organic precursor to the web in liquid and/or solid form, the applying being at a temperature below the sublimation, boiling or decomposition temperature of the organic precursor; and continuously moving the web, leading end followed by trailing end, through a hot chemical vapor deposition zone maintained at a temperature which falls within a range from about 800° C. to about 1200° C. while maintaining said deposition zone substantially oxygen-free, the residence time for each portion of the web within the deposition zone being restricted to be less than that which would deleteriously effect the properties of the web having the vapor deposited carbonaceous film, the organic precursor, under the residence time and temperature conditions in the deposition zone, being selected to be substantially completely converted by sublimation, boiling and/or decomposition, to one or more vaporous species in said decomposition zone and being selected to either (1) sublime or boil at a temperature in excess of about 400° C. or (2) to not decompose at a temperature of below about 300° C. if said organic precursor decomposes at a temperature below its sublimation or boiling temperature, to form said one or more vaporous species.