Heat treatable coated article with niobium nitride IR reflecting layer and method of making same

Abstract

A coated article is provided so as to include a solar control coating having an infrared (IR) reflecting layer sandwiched between at least a pair of dielectric layers. The IR reflecting layer includes niobium nitride (NbxNy). The use of niobium nitride enables the coated article to have good corrosion resistance to acid(s), good mechanical performance such as scratch resistance, and / or good color stability (i.e., a low ΔE* value(s)) upon heat treatment (HT). The coated article may be heat treated (e.g., thermally tempered) in certain example embodiments of the invention.

Description

[0001] This invention relates to coated articles that include at least one niobium nitride infrared (IR) reflecting layer sandwiched between at least a pair of dielectric layers, and / or a method of making the same. Such coated articles may be used in the context of monolithic windows, insulating glass (IG) window units, laminated windows, and / or other suitable applications. BACKGROUND OF THE INVENTION [0002] Solar control coatings having a layer stack of glass / Si3N4 / NiCr / Si3N4 are known in the art, where the metallic NiCr layer is the sole infrared (IR) reflecting layer in the coating. In certain instances, the NiCr IR reflecting layer may be nitrided. [0003] Unfortunately, while such layer stacks provide efficient solar control and are overall good coatings, they sometimes are lacking in terms of: (a) corrosion resistance to acid (e.g., HCl boil); (b) mechanical performance such as scratch resistance; and / or (c) thermal stability upon heat treatment for tempering, heat bending, or ...

AI Technical Summary

Benefits of technology

[0005] In certain example embodiments of this invention, a coating or layer system is provided which includes an infrared (IR) reflecting layer comprising niobium nitride sandwiched between at least a pair of dielectric layers. In certain example embodiments, the coating or layer system has good corrosion resistance to acid(s) such as HCl, good mechanical performance such as scratch resistance, and / or good color stability (i.e., a low ΔE* value(s)) upon heat treatment (HT).

[0006] Due to its spectral selectivity, niobium nitride provides thermal performance (e.g., IR blocking) similar to NiCr, but is surprisingly more chemically and / or mechanically durable than NiCr. The use of niobium nitride as an IR reflecting layer results in a solar control coating having excellent scratch resistance, and its resistance to acids such as HCl is exceptional. Its resistance to alkaline solutions is also good. Moreover, it has surprisingly been found that the use of niobium nitride as an IR reflecting layer enables a solar control coating to have significantly improved thermal stability upon HT (e.g., a lower ΔE* value with a given HT time) than the aforesaid conventional coating where metallic NiCr is used as the IR reflecting layer.

Problems solved by technology

Unfortunately, while such layer stacks provide efficient solar control and are overall good coatings, they sometimes are lacking in terms of: (a) corrosion resistance to acid (e.g., HCl boil); (b) mechanical performance such as scratch resistance; and / or (c) thermal stability upon heat treatment for tempering, heat bending, or the like (i.e., ΔE* value(s)).

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