Neutral, low emissivity coated glass articles and method for making
AssigneePPG Industries, Inc.
InventorsGeorge A. Neuman, Royann L. Stewart-Davis
Life of this patent
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Abstract
A coated article and method of producing it are disclosed wherein the iridescence caused by the difference between the refractive index of a transparent substrate and the refractive index of a metal oxide coating is reduced by means of two intermediate layers, the first of which, closest to the substrate, has a refractive index higher than the refractive index of the substrate but lower than the refractive index of the second, and the second has a refractive index higher than the refractive index of the first but lower than the refractive index of the metal oxide coating. The thicknesses of the two intermediate layers for optimizing a neutral appearance are determined by the thickness and refractive index of the metal oxide coating.
Claims14
A neutral, low emissivity coated article comprising:
- a. transparent substrate having a refractive index in the range of about 1.5 to 1.6;
- b. a first transparent coating layer having a refractive index in the range of about 1.66 to 1.73 and a thickness in the range of about 400 to 600 Angstroms;
- c. a second transparent coating layer having a refractive index in the range of about 1.76 to 1.83 and a thickness in the range of about 350 to 550 Angstroms;
- and
- d. a metal oxide coating layer having a refractive index of at least 1.86 and a thickness sufficient to lower the emissivity of the coated substrate below the emissivity of the uncoated substrate.
Dependencies are inferred from the claim text.