Coated substrate having improved mechanical and chemical stability

摘要

A coated substrate comprising a substrate and at least one primary coating layer formed thereon is characterised by an exposed protective additional layer formed thereon by cathode vacuum sputtering of a material selected from oxides and oxynitrides of silicon, and mixtures of one or more of oxides, nitrides and oxynitrides of silicon and has a refractive index of less than 1.7 and a thickness of from 1 to 10 nm. The product has improved chemical and mechanical durability, while any consequential changes in the optical properties are minimised. The primary coating layer may be titanium nitride, tin oxide, titanium oxide or chromium. The protective layer may be SiO2 and the substrate is preferably glass. The primary coating layer may include a reflective coating player.