Non-iridescent glass structures

In a process for avoiding the loss of heat from a building through transparent glassed areas of the building, while achieving an iridescence-free appearance for said areas, said process comprising the step of reflecting infra-red radiation back into said building from a thin coating of an infra-red-reflective semiconductor film which normally exhibits irridescence on the surface of said glass, the improvement comprising the step of utilizing a transparent precoating of a metal nitride, metal oxide, or mixture thereof, between said glass and said thin coating to provide at least two interfaces associated with said precoating layer, and wherein said precoating is selected to have a composite refractive index defined as about the square root of the multiple of the refractive indices of said glass and said thin coating of infra-red reflective semiconductor film, and depositing said precoating in two layers each having an optical thickness of about 1/4 wavelength of light having a vacuum wavelength of about 500 nanometers, and substantially diminishing iridescent colors of said structure by providing at least two additional interfaces which form means, together with the mass of said precoating, to reflect and refract light such that the observability, in daylight illumination, of said iridescent colors in substantially reduced.

In a process for making a substantially non-iridescent structure formed of at least one transparent glass sheet and comprising thereon an inorganic coating of an infra-red reflective material which material is of the type that is a transparent semiconductor and of a thickness that normally exhibits iridescent colors in daylight illumination, the improvement comprising the steps of precoating said glass, subsequently coating with said inorganic material, and wherein said precoating is selected to have a refractive index defined as about the square root of the multiple of the refractive indices of said glass and the inorganic infra-red reflective coating, and depositing said precoating to an optical thickness of about 1/4 wavelength of light having a vacuum wavelength of about 500 nanometers, and substantially diminishing said iridescent colors by providing at least two interfaces which form means, together with the mass of said precoat, to reflect and refract light such that the observability, in daylight illumination, of said iridescent colors is substantially reduced.

In a process for making a substantially non-iridescent structure formed of at least one transparent glass sheet and comprising thereon an inorganic coating of an infra-red reflective material which material is of the type that is a transparent semiconductor and normally exhibits iridescent colors in daylight illumination, the improvement comprising the steps of forming a precoating on said glass and subsequently coating with said inorganic material coating, wherein said precoating is selected to have a composite refractive index defined as about the square root of the multiple of the refractive indices of said glass and the inorganic infra-red reflective coating, and depositing said precoating in two layers each having an optical thickness of about 1/2 wavelength of light having a vacuum wavelength of about 500 nanometers, and substantially diminishing iridescent colors of said structure by providing two additional interfaces which form means, together with the mass of said precoating, to reflect and refract light such that the observability, in daylight illumination, of said iridescent colors is substantially reduced.

In a process for making a substantially non-iridescent structure formed of at least one transparent glass sheet and comprising thereon an inorganic coating of an infra-red reflective material which material is of the type that is a transparent semiconductor and of a thickness that normally exhibits iridescent colors in daylight illumination, the improvement comprising the steps of placing a precoating on said glass under a subsequent coating of said inorganic material wherein said precoating is deposited in the form of a composition which is graded with respect to refractive index by gradually increasing said refractive index as said precoating builds up between said glass and said infra-red reflecting material, from a refractive index closer to that of said glass to a refractive index closer to that of said infra-red reflective material, and diminishing iridescent colors of said structure, together with the mass of said precoat, by reflecting and refracting light such that the observability, in daylight illumination, of said iridescent colors is substantially reduced.