Patent ID: 6852300
Filing Date: 2005-02-08
Classification: C03C,C23C,Y10T

Abstract:
1. A substrate having a vitreous film deposited thereon, said vitreous film having a thickness greater than 1 μm and said substrate being obtained according to the process comprising: a) preparing a solution or a suspension having a pH ranging from 0.3 to 1.5, comprising at least one silicon alkoxide in water, alcohol or hydroalcoholic mixtures, wherein the solution or the suspension comprises at least 10 moles of water per mole of silicon alkoxide b) hydrolyzing the silicon alkoxide to form a sol; c) adding to the sol about 0.7 moles to about 3.0 moles of silicon oxide per mole of silicon alkoxide; d) depositing the sol on said substrate to form a sol film on said substrate; e) gelling the sol film through solvent evaporation, wherein the gelling is initiated by introducing the sol film on the substrate into an oven preheated at a temperature from 300° C. to 400° C.; and f) densifying said gel film through thermal treatment to form a vitreous film on said substrate.