Abstract: An improved process for coating the surface of a transparent refractory material such as glass with a semi-reflective film of tin oxide by depositing finely divided particles of a pyrolytically decomposable organotin compound on the surface of a substrate which has been heated to a temperature of between about 400.degree. and 650.degree. C. The finely divided organotin compound has a particle size not greater than about 20 microns. Before deposition, the organotin compound is mixed with a predetermined amount of finely divided particles of a compound containing a halogen constituent. Deposition is accomplished by suspending the mixture of both compounds in an anhydrous carrier gas which is projected onto the surface of the substrate. In an alternative process, a single compound containing both tin and halogen constituents is projected onto the surface of the pre-heated substrate by means of the anhydrous carrier gas.

Abstract: This invention relates to a window with increased resistance to fire, consisting of at least one pane of glass, such as soda glass, mounted in a metal frame in such a way that during a fire the border and edge of the side exposed to the action of heat, or in some cases the borders and edges of both sides, are exposed to the heat.