High transmittance, low emissivity coatings for substrates

A high transmittance, low emissivity coated substrate comprising substrate having a coating on a surface providing the coated substrate with a substantially neutral color, the coating comprising:

• (a) a base coat of an anti-reflective metal oxide having a refractive index of about 2.0 or more applied to a surface of said substrate at a thickness of no more than about 275 Å;
• (b) a reflective metal layer applied over said base coat;
• (c) an anti-reflective layer applied over the reflective metal layer, the ratio of the thickness of the base coat to the thickness of the anti-reflective layer is no more than about 0.33;
• and
• (d) an abrasion-resistant overcoat as the outermost layer of the coating, the overcoat being formed of an oxide of a metal selected from the group consisting of zinc, thin, indium, bismuth, titanium and alloys thereof applied at a thickness which does not substantially affect the optical properties of said coating;
• wherein the total thickness of the coating is about 1700 Å or less.

A high transmittance, low emissivity coated substrate comprising a glass pane having a coating on a surface providing the coated substrate with a substantially neutral color over a wide range of angles of incidence, the coating comprising:

• (a) a base coat of an anti-reflective metal oxide having a refractive index of about 2.0 or more applied to a surface of said substrate at a thickness of no more than about 275 Å;
• (b) a first reflective metal layer applied over said base coat;
• (c) an intermediate anti-reflective layer applied over said first reflective metal layer, the ratio of the thickness of the base coat to the thickness of the intermediate anti-reflective layer is no more than about 0.33;
• (d) a second reflective metal layer applied over said intermediate anti-reflective layer;
• and
• (e) an outer anti-reflective layer carried over said second reflective metal layer;
• wherein the total thickness of the coating is about 1700 Å or less.