Patent Description:
Solar control coatings block or filter selected ranges of electromagnetic radiation, typically radiation in the infrared region and/or ultraviolet region of the electromagnetic spectrum. These solar control coatings are placed on transparencies, such as windows, to reduce the amount of selected ranges of solar energy entering a building. This reduces the heat buildup inside the building. Coated articles with a solar-control coating are described for example in <CIT>, <CIT>, <CIT>, and <CIT>.

The solar heat gain coefficient (SHGC) is a measure of how well the coating blocks solar heat. The lower the SHGC, the more solar heat is blocked, i.e., the lower the solar heat buildup inside the building.

The light to solar gain (LSG) ratio is the ratio of the transmittance of visible light divided by the SHGC.

The overall heat transfer coefficient (U factor) is a measure of heat loss, e.g., through the window. The lower the U factor, the lower the heat transfer through the window, i.e., the higher the insulating level of the window.

While solar control coatings provide good solar insulation properties, it would be useful to improve the solar control properties of these coatings. For example, it would be useful to decrease the SHGC and/or to increase the light to solar gain (LSG) ratio.

To decrease the SHGC, the thicknesses of the infrared reflective metal layers could be increased. However, this would also make the solar control coating more reflective of visible light. Consumers prefer transparencies with high visible light transmittance but low visible light reflectance (both interior and exterior visible light reflectance). Further, increasing the thicknesses of the infrared reflective metal layers increases the sensitivity of the solar control coating to random or systematic variations in the thicknesses of the films making up the coating. This can alter or adversely impact upon the performance of the coating or the aesthetics of the coating. Additionally, increasing the thicknesses of the infrared reflective metal layers tends to decrease the durability of the coating to chemical and/or mechanical attack. Moreover, the accessible regions of the aesthetic/color space that are most broadly appealing and that can be reached using conventional solar control coatings employing one or more periods of dielectric/silver/dielectric structures, are constrained by the designs of conventional solar control coatings.

Therefore, it would be desirable to provide a solar control coating that provides enhanced solar control and/or aesthetic performance. For example, it would be desirable to provide a solar control coating having a low solar heat gain coefficient (SHGC) to prevent heat buildup inside of a building. For example, it would be desirable to provide a solar control coating having a high light to solar gain ratio (LSG). A high LSG indicates good solar heat blocking while allowing visible light to pass through the coating. This improves the natural lighting inside the building. For example, it would be desirable to provide a solar control coating having commercially desirable aesthetics and/or a larger available color space. For example, it would be desirable to provide a non-heat-treated solar control coating having one or more of the above advantages.

The present invention provides a coated article and an insulating glass unit (IGU) with a solar control coating as set forth in appended independent claims <NUM> and <NUM>. Specific variants of the coated article are presented in appended dependent claims <NUM> to <NUM>.

The solar control coating provides <NUM> reference insulating glass unit (<NUM> reference IGU) values of luminous transmittance (T) of not greater than <NUM> percent, a solar heat gain coefficient (SHGC) of not greater than <NUM>, and a light to solar gain (LSG) ratio of at least <NUM>.

The solar control coating can be a non-heat-treated solar control coating.

The invention will be described with reference to the following drawing figures wherein like reference numbers identify like parts throughout.

Spatial or directional terms, such as "left", "right", "inner", "outer", "above", "below", and the like, relate to the invention as it is shown in the drawing figures. However, the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting.

All numbers used in the specification and claims are to be understood as being modified in all instances by the term "about". By "about" is meant a range of plus or minus ten percent of the stated value.

All ranges disclosed herein encompass the beginning and ending range values and any and all subranges subsumed therein. The ranges disclosed herein represent the average values over the specified range.

With respect to coating layers or films described herein, the term "over" means farther from the substrate (or base layer) on which the coating layer or film under discussion is located. For example, a second layer located "over" a first layer means that the second layer is located farther from the substrate (or base layer) than is the first layer. The second layer can be in direct contact with the first layer. Alternatively, one or more other layers can be located between the first layer and the second layer.

The term "film" means a region having a chemically distinct and/or homogeneous composition. A "layer" comprises one or more "films". A "coating" comprises one or more "layers".

The terms "polymer" or "polymeric" include oligomers, homopolymers, copolymers, and terpolymers, e.g., polymers formed from two or more types of monomers or polymers.

The term "ultraviolet radiation" means electromagnetic radiation having a wavelength in the range of <NUM> to less than <NUM>. The terms "visible radiation" or "visible light" mean electromagnetic radiation having a wavelength in the range of <NUM> to <NUM>. The term "infrared radiation" means electromagnetic radiation having a wavelength in the range of greater than <NUM> to <NUM>,<NUM>. The term "solar infrared radiation" means electromagnetic radiation having a wavelength in the range of <NUM>,<NUM> to <NUM>,<NUM>. The term "thermal infrared radiation" means electromagnetic radiation having a wavelength in the range of greater than <NUM>,<NUM> to <NUM>,<NUM>.

The term "optical thickness" means the geometric thickness of the material multiplied by the refractive index of the material at a reference wavelength of <NUM>. For example, a material having a geometric thickness of <NUM> and a refractive index of <NUM> at a reference wavelength of <NUM> would have an optical thickness of <NUM>.

The terms "tempered" or "heat-treated" mean that the article or coating under discussion has been heated to a temperature sufficient to achieve thermal tempering, heat bending, and/or heat-strengthening. This definition includes, for example, heating the article in an oven or furnace at a temperature of at least <NUM>, such as at least <NUM>, such as at least <NUM>, for a period of time to achieve thermal tempering, heat bending, and/or heat strengthening. For example, the heating can be for a period of time in the range of <NUM> to <NUM> minutes, such as <NUM> to <NUM> minutes.

The term "non-heat-treated" means not tempered or heat-treated, or not designed to be tempered or heat-treated for final use.

The terms "metal" and "metal oxide" include silicon and silica, respectively, as well as traditionally recognized metals and metal oxides, even though silicon conventionally may not be considered a metal.

By "at least" is meant "greater than or equal to". By "not greater than" is meant "less than or equal to".

Any reference to amounts, unless otherwise specified, is "by weight percent".

Thickness values, unless indicated to the contrary, are geometric thickness values.

A "dopant" is a material present in an amount less than <NUM> wt. %, such as less than <NUM> wt. %, such as less than <NUM> wt. %, such as less than <NUM> wt. For example, less than <NUM> wt. For example, less than <NUM> wt. For example, less than <NUM> wt.

The term "curable" means a material capable of polymerizing or crosslinking. By "cured" is meant that the material is at least partly polymerized or cross-linked, preferably fully polymerized or cross-linked.

The term "critical thickness" means a geometric thickness above which a material forms a continuous, uninterrupted layer, and below which the material forms discontinuous regions or islands of the material rather than a continuous layer.

The term "effective thickness" refers to the theoretical geometric thickness of a material deposited below its critical thickness but at deposition parameters (e.g., deposition rate, line speed, etc.) which would provide a continuous layer of the material at the reported thickness value if it were deposited above its critical thickness. For example, if a material deposited at a deposition line speed of X cm/sec is known to form a continuous layer having a geometric thickness of <NUM>, then increasing the line speed to 2X would be expected to deposit a coating having a geometric thickness of <NUM>. However, if <NUM> is below the critical thickness of the material, then the deposited coating would not have a continuous, uniform thickness of <NUM> but would form discontinuous or islanded structures. This is referred to herein as a "layer" or a "film" having an "effective thickness" of <NUM>.

A "<NUM> reference IGU" is defined as having two spaced apart <NUM> pieces of CLEAR glass separated by a gap of <NUM> inch (<NUM>) filled with air, with the coating on the No. <NUM> surface. By "<NUM> reference IGU value" is meant the reported value (center of glazing) when the coating is incorporated into a <NUM> reference IGU on the No. <NUM> surface.

A "reference laminated unit" is defined as having two plies of <NUM> clear glass connected by a <NUM> interlayer of polyvinyl butyral and with the coating on the No. <NUM> surface. A reference laminated unit value means the reported value when the coating is incorporated into a reference laminated unit on the No. <NUM> surface.

The term "solar control coating" refers to a coating comprised of one or more layers or films that affect the solar properties of the coated article, such as the amount of solar radiation reflected from, absorbed by, or transmitted through the coating.

Optical and solar control performance values (e.g., visible light transmittance and/or haze), unless indicated to the contrary, are those determined using a Perkin Elmer <NUM> Spectrophotometer. Reference IGU values (both <NUM> and <NUM>), unless indicated to the contrary, are determined in accordance with OPTICS (v6. <NUM>) software and WINDOW (v7. <NUM>) software available from Lawrence Berkeley National Laboratory, measured center of glazing (COG), calculated according to NFRC <NUM> (which includes NFRC <NUM>-<NUM>) standard default settings.

U factors, unless indicated to the contrary, are winter/night U factors.

SHGC values, unless indicated to the contrary, are summer/day values.

Sheet resistance values, unless indicated to the contrary, are those determined using a four-point probe (e.g., Nagy Instruments SD-<NUM> measurement device or Alessi four-point probe). Surface roughness values are those determined using an Instrument Dimension <NUM> Atomic Force Microscope.

Color values (e.g., L*, a*, b*, C*, and hue°) are in accordance with the <NUM> CIELAB color system specified by the International Commission on Illumination.

The L*, a*, and b* values in the specification and claims represent color center point values. A reference IGU (<NUM> or <NUM>) or reference laminated unit incorporating the solar control coating of the invention within normal manufacturing variation should have a ΔEcmc color difference, relative to the center point value, of less than <NUM> CMC units (i.e., ΔEcmc < <NUM>), preferably less than <NUM> CMC units (i.e., ΔEcmc < <NUM>).

The discussion of the invention may describe certain features as being "particularly" or "preferably" within certain limitations (e.g., "preferably", "more preferably", or "even more preferably", within certain limitations). It is to be understood that the invention is not limited to these particular or preferred limitations but encompasses the entire scope of the disclosure.

The invention comprises, consists of, or consists essentially of, the following aspects of the invention, in any combination. Various aspects of the invention are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the invention, one or more aspects of the invention shown in one drawing figure can be combined with one or more aspects of the invention shown in one or more of the other drawing figures.

The invention will be discussed with reference to an architectural transparency. By "architectural transparency" is meant any transparency located on a building, such as a window, IGU, or a sky light. However, it is to be understood that the invention is not limited to use with architectural transparencies but could be practiced with transparencies in any desired field, such as laminated or non-laminated residential and/or commercial windows, and/or transparencies for land, air, space, above water and/or underwater vehicles. Therefore, it is to be understood that the specifically disclosed examples are presented simply to explain the general concepts of the invention, and that the invention is not limited to these specific examples. Additionally, while a typical "transparency" can have sufficient visible light transmission such that materials can be viewed through the transparency, in the practice of the invention, the "transparency" need not be transparent to visible light but may be translucent.

A coated article <NUM> incorporating features of the invention is illustrated in <FIG> and <FIG>. The coated article <NUM> includes a substrate or first ply <NUM> having a first major surface <NUM> and an opposed second major surface <NUM>.

A solar control coating <NUM> of the invention is located over at least one of the major surfaces <NUM>, <NUM> of the first ply <NUM>. In the examples shown in <FIG> and <FIG>, the solar control coating <NUM> is located over at least a portion of the second major surface <NUM> of the first ply <NUM>. As shown in <FIG>, the solar control coating <NUM> comprises a first phase adjustment layer <NUM>. A first metal functional layer <NUM> is located over the first phase adjustment layer <NUM>. An optional first primer layer <NUM> can be located over the first metal functional layer <NUM>. A second phase adjustment layer <NUM> is located over the optional first primer layer <NUM>, if present. A second metal functional layer <NUM> is located over the second phase adjustment layer <NUM>. An optional second primer layer <NUM> can be located over the second metal functional layer <NUM>. A third phase adjustment layer <NUM> is located over the optional second primer layer <NUM>, if present. A third metal functional layer <NUM> is located over the third phase adjustment layer <NUM>. An optional third primer layer <NUM> can be located over the third metal functional layer <NUM>. A fourth phase adjustment layer <NUM> is located over the optional third primer layer <NUM>, if present. An optional protective layer <NUM> can be located over the fourth phase adjustment layer <NUM>. At least the metal functional layers <NUM>, <NUM> comprise a metal functional multi-film layer comprising (i) at least one infrared reflective film and (ii) at least one absorptive film.

The first ply <NUM> can be transparent or translucent to visible radiation. By "transparent" is meant having visible radiation transmittance of greater than <NUM>% up to <NUM>%. Alternatively, the ply can be translucent. By "translucent" is meant diffusing visible radiation such that objects on the side opposite a viewer are not clearly visible. Examples of suitable materials include, but are not limited to, plastic substrates (such as acrylic polymers, such as polyacrylates; polyalkylmethacrylates, such as polymethylmethacrylates, polyethylmethacrylates, polypropylmethacrylates, and the like; polyurethanes; polycarbonates; polyalkylterephthalates, such as polyethyleneterephthalate (PET), polypropyleneterephthalates, polybutyleneterephthalates, and the like; polysiloxane-containing polymers; or copolymers of any monomers for preparing these, or any mixtures thereof); ceramic substrates; glass substrates; or mixtures or combinations of any of the above. For example, the ply can comprise conventional soda-lime-silicate glass, borosilicate glass, or leaded glass. The glass can be clear glass. By "clear glass" is meant non-tinted or non-colored glass. Alternatively, the glass can be tinted or otherwise colored glass. The glass can be non-heat-treated or heat-treated glass. The glass can be of any type, such as conventional float glass, and can be of any composition having any optical properties, e.g., any value of visible radiation transmittance, ultraviolet radiation transmittance, infrared radiation transmittance, and/or total solar energy transmittance. By "float glass" is meant glass formed by a conventional float process in which molten glass is deposited onto a molten metal bath and controllably cooled to form a float glass ribbon.

The first ply <NUM> can be clear float glass or can be tinted or colored glass. The first ply <NUM> can be of any desired dimensions, e.g., length, width, shape, or thickness. Examples of glass that can be used for the practice of the invention include clear glass, Starphire®, Solargreen®, Solextra®, GL-<NUM>®, GL-<NUM>™, Solarbronze®, Solargray® glass, Pacifica® glass, SolarBlue® glass, and Optiblue® glass, all commercially available from PPG Industries Inc. of Pittsburgh, Pennsylvania.

The phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> comprise nonmetallic layers. The phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> comprise dielectric or semiconductor materials. For example, the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can comprise oxides, nitrides, oxynitrides, borides, carbides, oxycarbides, borocarbides, boronitrides, carbonitrides, and/or mixtures, combinations, blends, or alloys thereof. Examples of suitable materials for the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> include oxides, nitrides, or oxynitrides of titanium, hafnium, zirconium, niobium, zinc, bismuth, lead, indium, tin, silicon, aluminum, boron, and mixtures, combinations, blends, or alloys thereof. These can have small amounts of other materials. Examples include manganese in bismuth oxide, tin in indium oxide, etc. Additionally, oxides of metal alloys or metal mixtures can be used. Examples include oxides containing zinc and tin (e.g., zinc stannate), oxides of indium-tin alloys, silicon nitrides, silicon aluminum nitrides, or aluminum nitrides. Further, doped metal oxides, suboxides, nitrides, subnitrides, or oxynitrides can be used. Examples include antimony or indium doped tin oxides or nickel or boron doped silicon oxides. Particular examples of materials include zinc oxides, tin oxides, silicon nitrides, silicon-aluminum nitrides, silicon-nickel nitrides, silicon-chromium nitrides, antimony doped tin oxide, tin doped zinc oxide, aluminum doped zinc oxide, indium doped zinc oxide, titanium oxide, and/or mixtures, combinations, blends, or alloys thereof.

One or more of the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can comprise a single material. Alternatively, one or more of the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can comprise multiple materials and/or multiple films. The phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can comprise a stratified sequence of films of chemically distinct materials or phases and/or may comprise one or more composites of one or more chemically distinct materials or phases. The different phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can comprise the same or different materials. The phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can have the same or different thicknesses.

The phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> allow adjustment of the constructive and destructive optical interference of electromagnetic radiation partially reflected from, and/or partially transmitted by, the various interface boundaries of the layers of the solar control coating <NUM>. Varying the thicknesses and/or compositions of the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can change the overall reflectance, transmittance, and/or absorptance of the solar control coating <NUM>, which can alter the solar control performance, thermal infrared insulating performance, color, and/or aesthetics of the solar control coating <NUM>. Additionally, the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can provide chemical and/or mechanical protection for other layers of the solar control coating <NUM>, such as the metal functional layers.

Where high visible light transmittance is desired, the phase adjustment layers <NUM>, <NUM>, <NUM>, <NUM> can act as antireflective layers to antireflect the metal functional layers to reduce the overall visible light reflectance and/or increase the visible light transmittance of the solar control coating <NUM>. Materials having refractive indices around <NUM> are particularly useful for antireflection of metal functional layers.

One or more phase adjustment layers can be located between the ply <NUM> and the lowermost metal functional layer. One or more phase adjustment layers can be located between the uppermost metal functional layer and the ambient environment, e.g., air.

In the illustrated exemplary coating <NUM>, the first phase adjustment layer <NUM> is located over at least a portion of the second major surface <NUM> of the first ply <NUM>. The first phase adjustment layer <NUM> can be a single layer or can comprise one or more films of antireflective materials and/or dielectric materials described above. The first phase adjustment layer <NUM> can be transparent to visible light. The first phase adjustment layer <NUM> may or may not exhibit minimal absorption in one or more regions of the electromagnetic spectrum, for example, visible light.

The first phase adjustment layer <NUM> can comprise any of the phase adjustment materials described above. For example, the first phase adjustment layer <NUM> can comprise a metal oxide, a mixture of metal oxides, or a metal alloy oxide. For example, the first phase adjustment layer <NUM> can comprise doped or non-doped oxides of zinc and tin.

The first phase adjustment layer <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The first phase adjustment layer <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

As shown in <FIG>, the first phase adjustment layer <NUM> can comprise a multi-film structure having a first film <NUM> and a second film <NUM>. The second film <NUM> can be located over the first film <NUM>.

The first film <NUM> can comprise, for example, an oxide of a metal alloy or a mixture of metal oxides. For example, the first film <NUM> can be an oxide of an alloy of zinc and tin. By "an alloy of zinc and tin" is meant both true alloys and also mixtures. The oxide of an alloy of zinc and tin can be that obtained from magnetron sputtering vacuum deposition (MSVD) from a cathode of zinc and tin. The cathode can comprise zinc and tin in proportions of <NUM> wt. % to <NUM> wt. % zinc and <NUM> wt. % to <NUM> wt. % tin, such as <NUM> wt. % to <NUM> wt. % zinc and <NUM> wt. % to <NUM> wt. However, other ratios of zinc to tin could also be used. An exemplary oxide of a metal alloy for the first film <NUM> can be written as ZnXSn<NUM>-XO<NUM>-X (Formula <NUM>) where "x" varies in the range of greater than <NUM> to less than <NUM>. For instance, "x" can be greater than <NUM> and can be any fraction or decimal greater than <NUM> and less than <NUM>. The stoichiometric form of Formula <NUM> is "Zn<NUM>SnO<NUM>", commonly referred to as zinc stannate. A zinc stannate layer can be sputter deposited from a cathode having <NUM> wt. % zinc and <NUM> wt. % tin in the presence of oxygen. For example, the first film <NUM> can comprise zinc stannate.

A doped zinc oxide can be deposited from a zinc cathode that includes another material to improve the sputtering characteristics of the cathode. For example, the zinc cathode can include a small amount of tin (e.g., up to <NUM> wt. %, such as up to <NUM> wt. %) to improve sputtering. In which case, the resultant zinc oxide film would include a small percentage of tin oxide, e.g., up to <NUM> wt. % tin oxide, e.g., up to <NUM> wt. % tin oxide. Examples of the other materials include aluminum, indium, and combinations thereof. Preferably, the other material comprises tin. A tin doped zinc oxide material deposited from a cathode comprising <NUM> wt. % zinc and <NUM> wt. % tin, in the presence of oxygen, is referred to herein as ZnO <NUM>/<NUM>.

The second film <NUM> can comprise a metal oxide, a doped metal oxide, or an oxide mixture. The second film <NUM> can comprise a metal oxide or a doped metal oxide. For example, the second film <NUM> can comprise zinc oxide or doped zinc oxide. For example, the second film <NUM> can comprise tin doped zinc oxide. For example, the second film <NUM> can comprise ZnO <NUM>/<NUM>.

The first film <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The first film <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The second film <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The second film <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The metal functional layer 46can be a single film. For example, the metal functional layer 46can comprise a continuous metal film. By "continuous" metal film is meant an unbroken or non-disconnected film, such as a homogeneous film.

The metal functional layers <NUM>, <NUM> each comprise a metal functional multi-film layer. By "metal functional multi-film layer" is meant a layer comprising (i) at least one infrared reflective film and (ii) at least one absorptive film. The infrared reflective film can have reflectivity in the solar infrared and/or thermal infrared portions of the electromagnetic spectrum. The absorptive film can exhibit enhanced absorptivity in one or more portions of the electromagnetic spectrum. For example, enhanced absorptivity in the visible radiation region and/or the infrared radiation region and/or the ultraviolet radiation region of the electromagnetic spectrum.

A metal functional multi-film layer can comprise an absorptive film over an infrared reflective film. The absorptive film can be in direct contact with an overlying optional primer layer.

A metal functional multi-film layer can comprise an infrared reflective film over an absorptive film. The absorptive film can be in direct contact with the underlying phase adjustment layer.

A metal functional multi-film layer can comprise an infrared reflective film located between two absorptive films. The upper absorptive film can be in direct contact with an overlying optional primer layer. The lower absorptive film can be in direct contact with the underlying phase adjustment layer. Optionally, a primer layer can be located between the lower absorptive film and the underlying phase adjustment layer.

Examples of infrared reflective films include continuous metal films. Examples of infrared reflective metals useful for the infrared reflective films include noble or near noble metals. Examples of such metals include silver, gold, platinum, palladium, osmium, iridium, rhodium, ruthenium, copper, mercury, rhenium, aluminum, and combinations, mixtures, blends, or alloys thereof. For example, one or more of the metal functional films can comprise a continuous metallic silver film.

Examples of absorptive materials for the absorptive film include metals, such as gold, silver, copper, nickel, palladium, platinum, tungsten, rhodium, iridium, tantalum, iron, tin, aluminum, lead, zinc, chromium, molybdenum, niobium, cobalt, manganese, titanium, silicon, chromium, and combinations, mixtures, blends, or alloys thereof. For example, one or more of the absorptive films can comprise copper. One or more of the absorptive films can comprise alloys or super alloys of two or more of the above materials. For example, alloys of nickel, chromium, or nickel and chromium. For example, Inconel® <NUM>, Inconel® <NUM>, Inconel® <NUM>, Inconel® <NUM>, and/or Inconel® <NUM>.

The first metal functional layer <NUM> can comprise a metal functional multi-film layer as described above.

Alternatively, the first metal functional layer <NUM> can comprise a single infrared reflective film comprising any of the above infrared reflective metals. For example, the first metal functional layer <NUM> can comprise a continuous film of metallic silver.

The first metal functional layer <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

Optional primer layers <NUM>, <NUM>, <NUM> can be located in direct contact with the associated underlying metal functional layers. The primer layers <NUM>, <NUM>, <NUM> protect the associated metal functional layers during the coating process and/or subsequent processing, such as thermal tempering. The primer material is deposited as a metal. During subsequent processing, such as the deposition of the overlying phase adjustment layer and/or thermal tempering, some or all of the metal primer oxidizes. When oxide or nitride materials are used in the phase adjustment layers, the primer layers <NUM>, <NUM>, <NUM> can comprise oxophillic or nitrophillic materials, respectively. The primer layers <NUM>, <NUM>, <NUM> need not be all the same material. The primer layers <NUM>, <NUM>, <NUM> need not be of the same thickness.

Examples of materials useful for the primer layers <NUM>, <NUM>, <NUM> include titanium, niobium, tungsten, nickel, chromium, iron, tantalum, zirconium, aluminum, silicon, indium, tin, zinc, molybdenum, hafnium, bismuth, vanadium, manganese, and combinations, mixtures, blends, or alloys thereof.

The optional first primer layer <NUM> can be located over the first metal functional layer <NUM>. The first primer layer <NUM> can be a single film or a multiple film layer. The first primer layer <NUM> can comprise any of the primer materials described above. For example, the first primer layer <NUM> can comprise titanium. For example, the first primer layer <NUM> can be deposited as titanium metal.

The first primer layer <NUM> can have a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, <NUM>.

The second phase adjustment layer <NUM> is located over the first metal functional layer, such as over the optional first primer layer <NUM>, if present. The second phase adjustment layer <NUM> can comprise one or more of the phase adjustment materials and/or films described above for the phase adjustment layers.

The second phase adjustment layer <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The second phase adjustment layer <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The second phase adjustment layer <NUM> can be a single film or a multi-film structure. For example, the second phase adjustment layer <NUM> can include a first film <NUM>, a second film <NUM>, and a third film <NUM>.

The first film <NUM> and/or the third film <NUM> can comprise a metal oxide or a doped metal oxide. For example, the first film <NUM> and/or the third film <NUM> can comprise zinc oxide or doped zinc oxide. For example, the first film <NUM> and/or the third film <NUM> can comprise tin doped zinc oxide. For example, the first film <NUM> and/or the third film <NUM> can comprise ZnO <NUM>/<NUM>.

The second film <NUM> can comprise an oxide of a metal alloy. For example, an oxide comprising zinc and tin. For example, the second film <NUM> can comprise zinc stannate.

The first film <NUM> (and/or the third film <NUM>) can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. The first film <NUM> and the third film <NUM> can comprise the same or different materials and can be of the same or different thickness.

The first film <NUM> (and/or third film <NUM>) can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The second metal functional layer <NUM> is located over the second phase adjustment layer <NUM>. The second metal functional layer <NUM> comprises a multi-film layer. In the example illustrated in <FIG>, the second metal functional layer <NUM> is a metal functional multi-film layer comprising the infrared reflective film <NUM> and an absorptive film <NUM>. The absorptive film <NUM> can be located over or under the infrared reflective film <NUM>. Preferably, the absorptive film <NUM> is located over the infrared reflective film <NUM>.

The infrared reflective film <NUM> comprises any of the infrared reflective materials described above. For example, a continuous metal film. For example, a continuous silver film.

The infrared reflective film <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The absorptive film <NUM> comprises an alloy of nickel and chromium. For example, the absorptive film <NUM> can comprise Inconel® <NUM>, Inconel® <NUM>, Inconel® <NUM>, Inconel® <NUM>, and/or Inconel® <NUM>. For example, the absorptive film <NUM> can comprise Inconel® <NUM>.

The absorptive film <NUM> can have an effective thickness in the range of <NUM> to <NUM>. For example, an effective thickness in the range of <NUM> to <NUM>. For example, an effective thickness in the range of <NUM> to <NUM>. For example, an effective thickness in the range of <NUM> to <NUM>.

The optional second primer layer <NUM> can be located over the second metal functional layer <NUM>. The second primer layer <NUM> can include of any of the primer materials and can be any of the thicknesses described above with respect to the optional first primer layer <NUM>. For example, the second primer <NUM> can comprise titanium.

The second primer layer <NUM> can have a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, a geometric thickness or effective thickness in the range of <NUM> to <NUM>.

The third phase adjustment layer <NUM> is located over the second metal functional layer <NUM>, such as over the optional second primer layer <NUM>, if present. The third phase adjustment layer <NUM> can include any of the phase adjustment materials and/or films as discussed above with respect to the first and second phase adjustment layers <NUM>, <NUM>. For example, the third phase adjustment layer <NUM> can be a multi-film structure. For example, the third phase adjustment layer <NUM> can include a first film <NUM>, a second film <NUM>, and a third film <NUM>.

The third phase adjustment layer <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The third phase adjustment layer <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The first film <NUM> and/or third film <NUM> can comprise a metal oxide or a doped metal oxide. For example, zinc oxide or doped zinc oxide. For example, tin doped zinc oxide. For example, ZnO <NUM>/<NUM>. The second film <NUM> can comprise an oxide of a metal alloy. For example, an oxide comprising zinc and tin. For example, zinc stannate.

The first film <NUM> (and/or third film <NUM>) can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. The first film <NUM> and the third film <NUM> can be of the same or different thickness.

The third metal functional layer <NUM> comprises a multi-film structure. In the example illustrated in <FIG>, the third metal functional layer <NUM> is a metal functional multi-film layer comprising an absorptive film <NUM> and an infrared reflective film <NUM>. The metal functional multi-film layer of the third metal functional layer <NUM> can have any of the film orientations described above for the second metal functional layer <NUM>. The absorptive film <NUM> can be located over or under the infrared reflective film <NUM>. The absorptive film <NUM> can be located under the infrared reflective film <NUM>.

The absorptive film <NUM> can be a metallic film. The absorptive film <NUM> comprises copper. The absorptive film <NUM> can optionally further comprise gold, silver, nickel, iron, tin, aluminum, lead, zinc, chromium and combinations thereof.

The absorptive film <NUM> can have a physical or effective thickness in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The infrared reflective film <NUM> can be a continuous metal film. For example, a continuous metallic film. For example, a metallic silver film.

The optional third primer layer <NUM> can include any of the primer materials described above. For example, the third primer layer <NUM> can comprise titanium.

The third primer layer <NUM> can have a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The fourth phase adjustment layer <NUM> can comprise one or more of the phase adjustment materials and/or films discussed above with respect to the first, second, or third phase adjustment layers <NUM>, <NUM>, <NUM>.

The fourth phase adjustment layer <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The fourth phase adjustment layer <NUM> can have a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>. For example, a geometric thickness in the range of <NUM> to <NUM>.

The fourth phase adjustment layer <NUM> can comprise a first film <NUM> and a second film <NUM>.

The first film <NUM> can comprise a metal oxide or a doped metal oxide. For example, zinc oxide or doped zinc oxide. For example, tin doped zinc oxide. For example, ZnO <NUM>/<NUM>. The second film <NUM> can comprise an oxide of a metal alloy. For example, an oxide comprising zinc and tin. For example, zinc stannate.

The optional protective layer <NUM> can be the terminal layer of the solar control coating <NUM>. The optional protective layer <NUM> can comprise one or more nonmetallic materials, such as those described above with regard to the phase adjustment layers. Alternatively, the protective layer <NUM> can comprise a metal material. The optional protective layer <NUM> can provide chemical and/or mechanical protection to the underlying coating layers. The optional protective layer <NUM> can provide phase adjustment and/or absorption. The protective layer <NUM> can be a single film or have a multi-film structure.

In addition to or instead of the terminal optional protective layer <NUM>, one or more other optional protective layers <NUM> can be located within the solar control coating <NUM>. For example, between two or more of the phase adjustment layers.

The optional protective layer <NUM> can include, for example, a metal oxide or metal nitride material. For example, the protective layer <NUM> can comprise an oxide of titanium, for example titanium dioxide (i.e., titania).

The optional protective layer <NUM> can have an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>. For example, an optical thickness in the range of <NUM> to <NUM>.

The optional protective layer <NUM> can have a geometric thickness or effective thickness in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> can be a non-heat-treated coating.

The layers and/or films of the solar control coating <NUM> can be formed by any conventional method. Examples of such methods include conventional chemical vapor deposition (CVD) and/or physical vapor deposition (PVD) methods. Examples of CVD processes include spray pyrolysis. Examples of PVD processes include electron beam evaporation and vacuum sputtering, such as magnetron sputter vapor deposition (MSVD). Other coating methods could also be used, such as, but not limited to, sol-gel deposition. One or more layers or films can be formed by one method and one or more other layers or films can be formed by a different method. For example, the coating <NUM> can be formed by MSVD.

<FIG> shows the coated article <NUM> of <FIG> and <FIG> incorporated into an insulating glass unit (IGU) <NUM>. The first major surface <NUM> (No. <NUM> surface) faces the building exterior, i.e., is an outer major surface, and the second major surface <NUM> (No. <NUM> surface) faces the interior of the building. The insulating glass unit <NUM> includes a second ply <NUM> having an outwardly facing major surface <NUM> (No. <NUM> surface) and an inwardly facing major surface <NUM> (No. <NUM> surface). This numbering of the ply surfaces is in keeping with conventional practice in the fenestration art.

The second ply <NUM> is spaced from the first ply <NUM>. The first and second plies <NUM>, <NUM> can be connected together in any suitable manner, such as by being adhesively bonded to a conventional spacer frame <NUM>. A gap or chamber <NUM> is formed between the two plies <NUM>, <NUM>. The chamber <NUM> can be filled with a selected atmosphere, such as gas, for example, air or a non-reactive gas such as argon or krypton gas. In the illustrated example, the solar control coating <NUM> located on the No. <NUM> surface <NUM>. However, the solar control coating <NUM> could be located on any of the other surfaces. For example, the solar control coating <NUM> could be located on the No. <NUM> surface <NUM>. For example, the solar control coating <NUM> could be located on the No. <NUM> surface <NUM> or the No. <NUM> surface <NUM>.

The second ply <NUM> can be of any of the materials described above for the first ply <NUM>. The second ply <NUM> can be the same as the first ply <NUM> or the second ply <NUM> can be different than the first ply <NUM>. The first and second plies <NUM>, <NUM> can each be, for example, clear float glass or can be tinted or colored glass or one ply <NUM>, <NUM> can be clear glass and the other ply <NUM>, <NUM> colored glass.

<FIG> shows the coated article <NUM> incorporated into a laminated unit <NUM>. The laminated unit <NUM> includes the first ply <NUM> and the second ply <NUM> connected by a polymeric interlayer <NUM>. The solar control coating <NUM> is shown on the No. <NUM> surface <NUM>. However, as with the IGU <NUM> described above, the solar control coating <NUM> could be on any of the surfaces <NUM>, <NUM>, <NUM>, or <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU SHGC of not greater than <NUM>. For example, not greater than <NUM>. For example, not greater than <NUM>. For example, not greater than <NUM>. For example, not greater than <NUM>. For example, not greater than <NUM>. For example, not greater than <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU SHGC in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU visible light transmittance of not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, in the range of <NUM>% to <NUM>%. For example, in the range of <NUM>% to <NUM>%. For example, in the range of <NUM>% to <NUM>%.

The solar control coating <NUM> provides a <NUM> reference IGU visible light exterior reflectance of not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, in the range of <NUM>% to <NUM>%. For example, in the range of <NUM>% to <NUM>%.

The solar control coating <NUM> provides a <NUM> reference IGU visible light interior reflectance of not greater than <NUM>%. For example, not greater than <NUM>%. For example, not greater than <NUM>%. For example, in the range of <NUM>% to <NUM>%. For example, in the range of <NUM>% to <NUM>%.

The solar control coating <NUM> provides a <NUM> reference IGU LSG ratio of at least <NUM>. For example, at least <NUM>. For example, at least <NUM>. For example, at least <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU transmitted L* in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU transmitted a* in the range of -<NUM> to -<NUM>. For example in the range of -<NUM> to -<NUM>. For example in the range of -<NUM> to -<NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU transmitted b* in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU exterior reflected L* in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU exterior reflected a* in the range of -<NUM> to <NUM>. For example in the range of -<NUM> to -<NUM>. For example in the range of - <NUM> to -<NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU exterior reflected b* in the range of -<NUM> to <NUM>. For example in the range of -<NUM> to -<NUM>. For example in the range of - <NUM> to -<NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU interior reflected L* in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>. For example in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU interior reflected a* in the range of -<NUM> to <NUM>. For example in the range of -<NUM> to -<NUM>. For example in the range of - <NUM> to -<NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU interior reflected b* in the range of -<NUM> to <NUM>. For example in the range of -<NUM> to -<NUM>. For example in the range of - <NUM> to -<NUM>.

The solar control coating <NUM> provides a sheet resistance of less than <NUM> ohms per square (Ω/□). For example, less than <NUM>Ω/□. For example, less than <NUM>Ω/□. For example, less than <NUM>Ω/□. For example, in the range of greater than <NUM> to <NUM>. For example, in the range of greater than <NUM> to <NUM>.

The solar control coating <NUM> can have an emissivity in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a <NUM> reference IGU Winter/night U factor in the range of <NUM> to <NUM> Watt per square meter Kelvin (W/m2-K). For example, in the range of <NUM> to <NUM> W/m2-K. For example, in the range of <NUM> to <NUM> W/m2-K. For example, in the range of <NUM> to <NUM> W/m2-K.

The solar control coating <NUM> provides a <NUM> reference IGU Summer/day U factor in the range of <NUM> to <NUM> W/m2-K. For example, in the range of <NUM> to <NUM> W/m2-K.

The solar control coating <NUM> provides a reference laminated unit transmitted L* in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a reference laminated unit transmitted a* in the range of <NUM> to -<NUM>. For example, in the range of <NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>.

The solar control coating <NUM> provides a reference laminated unit transmitted b* in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (exterior) L* in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (exterior) a* in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (exterior) b* in the range of <NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (interior) L* in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>. For example, in the range of <NUM> to <NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (interior) a* in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>.

The solar control coating <NUM> provides a reference laminated unit reflected (interior) b* in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>. For example, in the range of -<NUM> to -<NUM>.

Table <NUM> shows exemplary coatings of the invention. The reported thicknesses are geometric thicknesses in nanometers (nm). ZS means zinc stannate deposited from a cathode having <NUM> wt. % zinc and <NUM> wt. % tin in the presence of oxygen. TZO means tin doped zinc oxide deposited from a cathode with <NUM> wt. % tin and <NUM> wt. % zinc in the presence of oxygen (i.e., ZnO <NUM>/<NUM>). Ag means silver. TiOx means a titanium primer layer deposited as a metal and oxidized during processing. INC means Inconel® <NUM>. Cu means metallic copper. TiO<NUM> means an oxide of titanium, for example titanium dioxide (titania).

Tables <NUM> and <NUM> show <NUM> reference IGU values for the Samples of Table <NUM>. T(V) means percent visible light transmittance. RE(V) means percent exterior reflectance of visible radiation. RI(V) means percent interior reflectance of visible radiation. T(S) means percent solar radiation transmittance. RE(S) means percent exterior reflectance of solar radiation. RI(S) means percent interior reflectance of solar radiation. UV(T) means percent ultraviolet radiation transmittance. UF(W) means winter/night U factor (W/m2-K). UF(S) means summer/day U factor (W/m2-K). SC means shading coefficient. L*(T), a*(T), and b*(T) mean the transmitted L*, a*, b*. L*(RE), a*(RE), and b*(RE) mean the reflected exterior L*, a*, b*.

Claim 1:
A coated article (<NUM>) comprising:
a substrate (<NUM>); and
a solar control coating comprising:
a first phase adjustment layer (<NUM>),
a first metal functional layer (<NUM>) located over the first phase adjustment layer (<NUM>),
optionally a first primer layer (<NUM>) located over the first metal functional layer (<NUM>),
a second phase adjustment layer (<NUM>) located over the optional first primer layer (<NUM>),
a second metal functional layer (<NUM>) located over the second phase adjustment layer (<NUM>),
optionally a second primer layer (<NUM>) located over the second metal functional layer (<NUM>),
a third phase adjustment layer (<NUM>) located over the optional second primer layer (<NUM>),
a third metal functional layer (<NUM>) located over the third phase adjustment layer (<NUM>),
optionally a third primer layer (<NUM>) located over the third metal functional layer (<NUM>),
a fourth phase adjustment layer (<NUM>) located over the optional third primer layer (<NUM>), and
optionally a protective layer (<NUM>) located over the fourth phase adjustment layer (<NUM>),
wherein the phase adjustment layers (<NUM>, <NUM>, <NUM>, <NUM>) comprise dielectric or semiconductor materials,
wherein the second metal functional layer (<NUM>) comprises a metal functional multi-film layer comprising (i) an infrared reflective film (<NUM>) and (ii) an absorptive film (<NUM>) comprising an alloy of nickel and chromium, and
wherein the third metal functional layer (<NUM>) comprises a metal functional multi-film layer comprising (i) at least one infrared reflective film (<NUM>) and (ii) at least one absorptive film (<NUM>) comprising copper.