US Patent 9360114 Coated O-ring

The invention relates to a coated O-ring for forming a seal, in which the core of the O-ring comprises a polymer and/or synthetic rubber, and the coating comprises an inorganic coating with a thickness between 10 nm and 1 μm, resulting in an O-ring that shows a lower permeation than an uncoated O-ring and where the coating shows little or no cracking when the local curvature of the O-ring in any direction is changed by 20%.