Dual silver layer Low-E glass coating system and insulating glass units made therefrom
AssigneeGuardian Industries Corp.
InventorsKlaus W. Hartig, Steven L. Larson, Philip J. Lingle
Life of this patent
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Abstract
A sputter-coated glass layer system particularly useful in insulating glass units ("IGs"), which includes dual layers of silver separated by a layer of Si.sub.3 N.sub.4 having a thickness of about 700 .ANG.-1,100 .ANG. and further including an undercoat and an overcoat of Si.sub.3 N.sub.4 having thicknesses of about 300 .ANG.-550 .ANG. and about 350 .ANG.-700 .ANG. respectively, such that a glass so coated achieves normal emissivity values (E.sub.n 's) of less than about 0.02-0.09 with good durability and very low reflectance.
Claims17
A sputter-coated glass article comprised of a glass substrate having thereon from the glass outwardly, a layer system including:
- a) a layer of Si.sub.3 N.sub.4 having a thickness of about 300 .ANG.-500 .ANG.;
- b) a layer of nickel or nichrome having a thickness of about 7 .ANG. or less;
- c) a layer of silver having a thickness of about 70 .ANG.-130 .ANG.;
- d) a layer of nickel or nichrome having a thickness of about 7 .ANG. or less;
- and
- e) a layer of Si.sub.3 N.sub.4 having a thickness of about 700 .ANG.-1,100 .ANG.;
- f) a layer of nickel or nichrome having a thickness of about 7 .ANG. or less;
- g) a layer of silver having a thickness of about 70 .ANG.-190 .ANG., wherein said layer (g) is thicker than said layer (c);
- h) a layer of nickel or nichrome having a thickness of about 7 .ANG. or less;
- and
- i) a layer of Si.sub.3 N.sub.4 having a thickness of about 350 .ANG.-700 .ANG.;
- wherein
- when said glass substrate has a thickness of about 2 mm-6 mm, said coated glass substrate has a visible transmittance of about 70% or greater, a normal emissivity (E.sub.n) of about 0.02 -0.09, a hemispherical emissivity (E.sub.h) of about 0.03-0.12, a sheet resistance (R.sub.s) of about 2-10 ohms/.sub.sq. and having the following reflectance and color coordinates wherein the glass side characteristics are:
- R.sub.G Y, less than about 10
- a.sub.h is about -3 to +5
- b.sub.h is about 0 to -10
- and wherein the film side characteristics are:
- R.sub.F Y, less than about 10
- a.sub.h is about -3 to +5
- b.sub.h is about 0 to -10
- wherein RY is the reflectance and a.sub.h, b.sub.h are the color coordinates as measured in Hunter units, Ill., C, 10.degree. observer.
Dependencies are inferred from the claim text.