摘要 |
A process for applying an adherent electrically insulative moisture-resistant composite coating to a substrate (1). A thin, adherent, highly cross-linked, substantially liquid moisture-impervious primer coating (3) is provided on the substrate (1) by glow discharge polymerization of a low molecular weight hydrocarbon monomer in a low pressure chamber containing the substrate (1), the monomer being selected from among methane, ethane, propane, ethylene, and propylene. A second polymeric coating layer (5) is provided over the primer coating (3) by glow discharge polymerization of a second precursor comprising a hydorcarbon or substituted hydrocarbon. The precursor exhibits a hydrogen yield of not greater than about 0.75 hydrogen atoms per molecule under the glow discharge polymerization conditions under which the second layer (5) is deposited, whereby the second polymeric coating layer (5) is substantially resilient and strongly bonded to the primer coating (3) and the second layer (5) comprises high concentration of surface and bulk free radicals. |