Coated article with low-e coating including zirconium oxide and/or zirconium silicon oxynitride and methods of making same

SUMMARY OF EXAMPLES OF EXEMPLARY EMBODIMENTS

Coated articles are known in the art for use in window applications such as insulated glass (IG) window units, vehicle windows, monolithic windows, and / or the like. In some example cases, coated article designers often strive to combine high visible light transmission, low emissivity (or low emittance), and / or low sheet resistance (Rs). High visible light transmission may allow the use of coated products in applications where these features are desirable, such as applications in building or vehicle windows, while the low emissivity (low E) and low sheet resistance properties allow such coated products to block significant amounts of IR radiation to reduce, for example, undesirable heating of vehicle or building interiors. As a result, it is often desirable for coatings used on architectural glass to block significant amounts of IR radiation, high visible transmission. However, low transmittance and / or high reflection in part (s) of the IR spectrum and / or near IR is also desirable to reduce, for example, undesirable heating of vehicle or building interiors.

Unfortunately, low E coatings often do not block significant amounts of ultraviolet (UV) radiation. In other words, low E coatings usually provide only moderate or low UV protection because the materials used in the layer stacks are transparent to short wavelengths (e.g. below 400 nm). In particular, materials used in such layer piles such as tin oxide and titanium oxide cannot provide adequate UV protection considering the small thicknesses of such materials required for low E coatings. Thus, even when such coatings are found on windows such as windows IG or vehicle windows, significant amounts of UV radiation find their way through the window and into the building or vehicle. LAV radiation tends to damage furniture and other items inside buildings or vehicles.

Materials such as vanadium oxide and cerium oxide absorb significant amounts of UV radiation. However, since such materials are characterized by a very steep onset of UV absorption, the onset of radiation absorption occurs in a large part of the visible part of the spectrum, thus leading to significant color distortion when viewed through such a coating (e.g.

yellow shift). Because of this, the visual features tend to degrade when layers of such materials are used.

Document WO 2006/066101 relates to a silver-based layer system and suggests using as a top layer a metal layer based on, for example, Zr. This Zr layer is expected to oxidize in air over a period of time and is to lead to improved scratch resistance of the coated substrate.

The prior art document WO 2005/021456 discloses the use of ZrOx or ZrOxNy as scratch resistant glass substrate layers. In this document, it is suggested to apply an additional layer of diamond-like carbon to the zirconium layer and to burn the DLC during the heat treatment step, thus oxidizing the applied zirconium nitride layer.

EP 1 736 454 discloses similar teachings where a method comprising a zirconium nitride layer and a DLC layer is used to form a zirconium oxide layer on a glass substrate.

Document US 2004/0197574 suggests the use of a double layer coating of nitride / ZrOx, which is provided to improve the mechanical and chemical strength as well as the susceptibility to heat treatment of the silver based reflective layer system.

There is also a need in the art for improved chemical stability (chemical strength) and heat resistance (strength after heat treatment such as thermal quenching).

In view of the above, it will be appreciated that there is a need in the art for a coated article comprising a low E coating that can block some UV radiation in an effective manner. Certain exemplary embodiments of the present invention relate to a coated article that achieves significant UV absorption properties.

In embodiments of the present invention, it has surprisingly been found that providing a layer consisting essentially of, or comprising, silicon zirconium oxynitride (e.g., ZrSiOxNy) unexpectedly improves the blocking (reflection and / or absorption) of UV radiation in a way that does not significantly degrade the other optical properties of the product coated such as visible light transmission and / or color. Surprisingly, when the layer containing silicon zirconium oxazitotide is placed as the top or top of the coated article (e.g., above the silicon nitride-based layer), this results in improved chemical strength and heat resistance in certain example embodiments of this invention.

In certain example embodiments of this invention, the silicon zirconium oxynitride layer may be tuned in a manner to achieve the desired amount of UV blocking and / or absorption, as well as improved strength. It has been found that zirconium oxide or silicon zirconium oxynitride has optical constants (n and k) that allow, for example, to regulate the start of absorption by changing the oxygen content of the layer. Furthermore, it has been found that zirconium oxide, zirconium oxynitride or silicon zirconium oxynitride has a refractive index (n) in a range that is very adaptable to low E coatings, so that such layer (s) can be used ( e) in low E coatings without significantly changing the optical appearance of the coated article or in certain performance data. Thus, in certain example embodiments of this invention, the absorption edge of the curve defined by the layer of silicon zirconium oxynitride can be set by changing its oxygen content, which can for example be done by setting the amount of oxygen introduced into the ion spray chamber (s) during reactive deposition by sputtering. In particular, for example, as the oxygen content increases, the absorption edge of the curve defined by the silicon zirconium oxy nitride layer shifts toward lower wavelengths away from the specified visible wavelengths. Therefore, in certain example embodiments, alignment or tuning may be performed to achieve the desired alignment between visible light transmission and UV absorption.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a cross-sectional view of a coated article according to an exemplary embodiment of the present invention.

FIGURE 2 is a cross-sectional view of a coated article according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLES OF EXEMPLARY EMBODIMENTS

Referring now to drawings in which similar reference numerals indicate similar parts in several views.

Coated articles can be used here for coated article applications such as monolithic windows, IG window units, vehicle windows, and / or other suitable applications that include one or more substrates such as glass substrates.

Certain embodiments of the present invention relate to a coated article that includes at least one glass substrate on which the coating is located. The coating usually has at least one infrared reflecting (IR) layer that reflects and / or blocks at least part of the IR radiation. The IR reflecting layer (s) may be of a material such as silver, gold, NiCr or the like in various embodiments of the present invention. Often, the IR reflecting layer is sandwiched between at least the first and second dielectric layers of the coating. In embodiments of the present invention, it has surprisingly been found that providing a layer 16 consisting essentially of or comprising silicon zirconium oxynitride (e.g. ZrSixNy) as the dielectric layer (s) of such coating unexpectedly improves the blocking (reflection and / or absorption) of UV radiation in a way that does not significantly degrade other optical properties of the coated article such as visible light transmission and / or color. One or more of these silicon zirconium oxynitride layers may be present on a given coating in various embodiments of the present invention. Furthermore, such a silicon zirconium oxynitride layer (s) may be on any type of solar or low E (low emissivity or low emissivity) coating in various embodiments of the present invention (e.g. as a top layer), and specific low E coatings they are described here for the purpose of example only, unless otherwise quoted in claim (s). When the layer comprising silicon zirconium oxynitride is provided as the top layer or top layer of the coated article (e.g., above the silicon nitride based layer), this results in improved chemical strength and heat resistance in certain example embodiments. The use of a silicon zirconium oxynitride layer in this aspect (e.g. as a top layer), surprisingly, it was found to improve chemical strength and heat resistance, and was also found to be stable during ion spray treatment.

In certain example embodiments of this invention, the oxygen content of the silicon zirconium oxy nitride layer (s) 16 (e.g., see Fig. 1) is set such that the layer comprising silicon zirconium oxynitride has a refractive index (n) (at 550 nm) from about 1.6 to 2.8, more preferably from about 1.7 to 2.5, and even more preferably from about 1.8 to

2.4. Furthermore, the oxygen content of the silicon zirconium oxy nitride layer (s) 16 is set such that the silicon zirconium oxy nitride layer has a extinction coefficient (k) (at 550 nm) not more than about 2.3, more preferably not more than about 2.0, even more preferably not greater than about 1.8. It has been found that tuning the oxygen content of silicon zirconium oxynitride 16 in this manner allows for good UV absorption combined with a slight adverse effect on the visibility characteristics of the coated article. Furthermore, tuning oxygen content in this way causes the silicon zirconium oxynitride to have a refractive index close to that of some layers often used in low E coatings such as Ti, Sn, Zn, and / or the like. For example, the absorption edge of the silicon zirconium oxitride layer 16 can be shifted over a large wavelength range and can be positioned above, below, or substantially on the ZnO reference edge only by changing the oxidation level of the layer thus allowing it to fit essentially with ZnO from an optical perspective some examples of cases. Therefore, such silicon zirconium oxynitride can replace some of all such layers in low E coatings in some situations without significantly adversely affecting the visibility characteristics of the coated article. Obtained UV protection largely depends on the position of the absorption edge and the thickness of the layer required by the optical properties of the entire coating.

Furthermore, when forming the silicon zirconium oxynitride layer (s) 16 in accordance with certain example embodiments of this invention (e.g., by reactive sputtering), the nitrogen / oxygen gas ratio (e.g., N3 / O2) used in the sputtering chamber is not greater than about 25, more preferably no greater than about 18, more preferably no greater than about 10. In certain example embodiments of this invention, the nitrogen / oxygen gas ratio (e.g. N2 / O2) used in the sputtering chamber when forming layer 16 with or containing silicon zirconium oxynitride is from about 1 to 25, more preferably from about 2 to 18, and sometimes from about 2 to 10. Additionally, in accordance with certain example embodiments of this invention , the silicon zirconium oxynitride layer 16 here is characterized by a nitrogen to oxygen ratio (atomic percent) of from about 1 to 25, more preferably from about 2 to 18, and sometimes from about 2 to 10. Of course, other gases such as Ar can also be used in the ion spray chamber together with oxygen and nitrogen during the deposition of the silicon zirconium oxitride layer by means of ion sputtering. In certain example embodiments, the amount of Ar gas used in the sputtering is greater than the amount of oxygen but less than the amount of nitrogen used to form the zirconium oxy nitride or silicon zirconium oxy nitride layer 16. For example, in certain example embodiments, the gas ratio used in deposition of the silicon zirconium oxitride layer by sputtering is 40 mL Ar, 55 mL N2, and 10 mL O2.

Furthermore, in certain example embodiments of this invention, the peak of the refractive index curve (e.g., Fig. 4) for the silicon zirconium oxitride layer is at a wavelength shorter than about 400 nm, preferably shorter than about 375 nm, and sometimes shorter than about 350 nm, and sometimes even less than about 300 nm. In addition to the above-mentioned preferred optical properties, the silicon zirconium oxynitride layers in accordance with various embodiments of the present invention provide good mechanical and chemical strength. Thus, such layers may be suitable for use in, for example, basecoats or topcoats in solar and / or low E coatings.

In certain example embodiments of this invention, the ratio (atomic percent) of Zr / Si in the exemplary silicon zirconium oxitride layer may be from about 0.25 to 5.0, more preferably from about 0.5 to 4, even more preferably from about 0.75 to 3.0, and still more preferably from about 1.0 to 2.0, and most preferably from about 1.25 to 1.75. Thus, in certain example embodiments of this invention, there is more Zr than Si in the layer with or containing silicon zirconium oxy nitride by atomic percent. Furthermore, in some exemplary embodiments, an exemplary silicon zirconium oxynitride layer may have a thickness of from about 20 to 400 A, more preferably from about 40 to 300 A, and even more preferably from about 50 to 250 A. In certain example embodiments, the layer 16 with or comprising silicon zirconium oxynitride may be with or contain from about 20-45% (more preferably 25-40%, most preferably from about 30-36%, or 33%) Si, from about 40-65% (more preferably 45-63%, most preferably from about 50-59%, or 54%) Zr, with the remainder consisting of an optional semiconductor dopant such as Al and / or Y2O3. The example has about 60% Zr and about 40% Si, in layer 16 of the embodiment in Fig. 1. In certain exemplary embodiments, layer 16 (in the embodiments of either Figure 1 or Figure 2) contains from about 2-8% more preferably from about 3-7%, or about 5%) Al, and from about

2-12% (more preferably from about 4-10%, or about 6-8%) Y2O3.

As explained above, the layers of silicon zirconium oxynitride in accordance with various embodiments of the present invention can be used at various locations in solar controlled coatings. The coatings described below are provided for example purposes.

Figs 1-2 are cross-sections of a coated article. The coated article includes a glass substrate 1 (e.g., transparent, green, brown, or blue-green glass substrate with a thickness of about 1.0 to 10.0 mm, more preferably about 1.00 mm to 6.0 mm), and a multi-layer coating (or layer system) located on the ground either directly or indirectly. As shown in Fig. 1, the coating 25 comprises a dielectric layer 20, a contact layer 8 with or containing NiCr or chromium nickel oxide (e.g. NiCr or NiCrOx), IR reflecting layer 9 containing or from silver, gold or the like, top contact layer 10 with or containing NiCr or chromium nickel oxide (e.g. NiCr or NiCrOx), dielectric layer 15 (e.g. with or containing silicon nitride ) and dielectric layer 16 with or containing silicon zirconium oxynitride, which may in some example cases be a protective top covering. Some features of layer 16 are discussed above when layer 16 is with or contains silicon zirconium oxynitride. The silicon zirconium oxynitride layer 16 may be doped (e.g., with Al or the like) in certain example embodiments of this invention. In certain example embodiments of this invention, other layers and / or materials may also be provided, and it is also possible that some layers may be removed or separated in certain example cases.

The infrared (IR) reflecting layer 9 is preferably substantially or completely metallic and / or conductive, and may comprise or consist essentially of silver (Ag), gold, or any other suitable IR reflecting material. The IR reflecting layer 9 helps that the coating has low E and / or good solar control features such as low emittance, low sheet resistance, and so on. The IR reflecting layer 9 may, however, be slightly oxidized in certain example embodiments of this invention.

The upper and lower contact layers 8 and 10 may be of or contain Ni and / or Cr oxide. In some exemplary embodiments, the upper and lower contact layers 8, 10 may be with or include nickel (Ni), chromium / dichromate (Cr), a nickel alloy such as chromium nickel (NiCr), Haynes alloy, oxide of any of them, or other relevant material (s). For example, one of these layers may be with or contain zinc oxide instead of NiCr. The use of, for example, NiCr in these layers allows the strength to be improved in certain example cases, and the thicknesses provided allow low ΕΕ * values ​​to be achieved. Contact layers 8 and 10 (e.g., with or containing Ni and / or Cr) may or may not be continuous in various embodiments of the present invention over the entire IR reflecting layer. In certain example embodiments, one or both of the NiCr 8, 10 layers contain from about 70-81% Ni, from about 15-19% Cr, from about 3-6% Al, and possibly from about 0-4% (or 1 -4%) Fe. The example has 76.5% Ni, 17% Cr, 4.3% Al, and optionally about 2.2% FE, for one or both layers 8, 10.

Dielectric layers 15 and 20 may be of or contain silicon nitride (e.g., Si3N4) or any other suitable material in certain example embodiments of this invention such as silicon oxynitride. These layers are intended for strength and protection of the underlying layers as well as for anti-reflective purposes. In certain example embodiments, layers 15 and 20 may each have a refractive index (n) of from about 1.9 to 2.2, more preferably from about 1.95 to 2.05.

It has been found that providing surface layer 16 with or containing zirconia (e.g. see Fig. 2) can reduce and / or eliminate heat resistance problems. In particular, in certain example embodiments not according to the invention, the use of a cover layer 16 comprising zirconia in combination with a silicon nitride layer 15 and a contact layer 10 can result in a coated article that can be significantly thermally treated (e.g. thermally toughened) without suffering significant damage from speckling or other heat treatment damage (e.g., the coated article may achieve acceptable visible light transmission, a * and / or b * values ​​after heat treatment such as thermal quenching). In certain example embodiments, the "n" factor of the zirconia layer 16 is from about 2.1 to 2.25, more preferably about 2.16 (at 550 nm).

It has been found that by using silicon zirconium oxynitride as top or top layer 16 with silicon nitride 15 below it as shown in Fig. 1, the coated article realizes higher light transmission and a significant decrease in sheet resistance, both of which are unexpected improvements / effects. Unexpected UV benefits are also realized as discussed above by using silicon zirconium oxynitride. This embodiment can be thermally treated (thermally hardened with a coating) in certain example embodiments of this invention.

Below or above the coating 25 may be another layer (s). Therefore, when the layer system or coating is "on" or "supported by" substrate 1 (directly or indirectly), another layer (s) may be between them (s). In this way, for example, the coating of Fig. 1 can be considered to be "on" and "supported by" substrate 1 even if the other layer (s) is (s) between layer 3 and substrate 1. Furthermore, some layers of the illustrated coating may be removed in some embodiments, while others may be added between different layers or different layer (s) may be separated by the other layer (s) added (s) between separated sections in other embodiments of the present invention without departing from the overall spirit of certain embodiments of the present invention.

The value (ci) ΔΕ * is (are) important in determining whether or not thermal resistance, compatibility, or substantial color compatibility after HT occurs in the context of some embodiments of the present invention (i.e. the term ΔΕ * is important in determining strength colors after HT). The color is described here by reference to conventional a *, b * values. For example, the term ΔΑ * indicates how much color value a * changes due to HT. The term ΔΕ * (and ΔΕ) is well understood in the art.

The definition of the term ΕΕ * can be found, for example, in WO 02/090281 and / or US Patent No. 6,475,626, the disclosures of which are incorporated herein by reference. In particular, ΔΕ * corresponds to CIE LAB Scale L *, a *, b * and is represented by:

ΔΕ * = {(AL *)² + (Aa *)² + (Ab *)²}¹⁷² (1) where:

<img file="PL2303791T3_D0001.tif" />

<img file="PL2303791T3_D0002.tif" />

<img file="PL2303791T3_D0003.tif" />

Above, the subscript "o" represents the coating (or coated article) prior to heat treatment and the subscript "1" represents the coating (or coated article) after heat treatment; and the numbers used (e.g., A *, b *, L *) are those calculated by the abovementioned L *, a *, b * coordinate technique (CIE LAB 1976). In a similar way, ΔΕ * can be calculated using equation (1) by replacing a *, b *, L * with Hunter Lab values ​​ah, bh, Lh. Also within the scope of the present invention and the quantification of ΕΕ * are the equivalent numbers when converted to those calculated by any other technique using the same concept of ΕΕ * as defined above.

It was found that thinning of NiCr layers 8 and 10 results in good (lower) values ​​of ΕΕ * compared to the situation where layers 8, 10 are not thinned. In certain example embodiments, the top layer based on NiCr 10 is thinner than the bottom layer based on NiCr

8. In certain example embodiments of this invention, layers based on NiCr 8, 10 are thinned and the resulting coated article due to heat treatment has a ΕΕ * value (side reflective glass) of not more than 3.0, preferably not more than 2.5, even more preferably not more than 2.0 and possibly not more than 1.5.

While different thicknesses may be used in different embodiments of the present invention, exemplary thicknesses and materials for respective layers on the glass substrate 1 in the embodiments of Figs. 1-2 a following from the glass substrate outwards:

Table 1 (Sample Materials / Thicknesses)

<td>Layer</td><td>Range (A)</td><td>More favorable (A)</td><td>Example (A)</td>

<td>Si3N4 (layer 20)</td><td>150-700 A.</td><td>200-600 A.</td><td>380 A.</td>

<td>NiCr (layer 8)</td><td>&lt;= 12 A</td><td>&lt;= 10 A</td><td>7-8 A.</td>

<td>Ag (layer 9)</td><td>30-170 A.</td><td>40-110 A.</td><td>67 A.</td>

<td>NiCr (layer 10)</td><td>&lt;= 11 A</td><td>&lt;= 9 A</td><td>6-8 A.</td>

<td>Si3N4 (layer 15)</td><td>150-700 A.</td><td>200-600 A.</td><td>365 A.</td>

<td>ZrO2 or ZrSiOxNy (layer 16)</td><td>40-400 A.</td><td>100-200 A.</td><td>150 A.</td>

In certain example embodiments of this invention, coated articles herein may have the following low E (low emissivity), solar, and / or optical characteristics listed in Table 2 for monolithic measurement.

Feature

Rs (ohmy / kw) Tvis (%):

Table 2: Low E / Solar (Monolithic) Features

General More favorable Most favorable &lt;= 20.0 &lt;= 15.0 &lt;= 10.0&gt; = 50&gt; = 60&gt; = 70 or 75

Furthermore, coated articles comprising coatings according to certain example embodiments of this invention have the following optical characteristics (e.g., when the coating (s) is (a) on a transparent substrate 1 of soda-lime-quartz glass 1 to 10 mm thick, preferably about 4 mm). In Table 3, all parameters are measured monolithically (before and / or after heat treatment).

Table 3: Example Optical Features (Monolithic)

<td>Feature</td><td>General</td><td colspan="2">favorable</td>

<td>Tvis (or TY) (Ill. C, 2 stop):</td><td> &gt;= 60%</td><td>&gt; = 70% or 75%</td><td></td>

<td></td><td>a * t (Ill. C, 2 °):</td><td>-6 to +6</td><td>-3 to 0</td>

<td></td><td>b * t (Ill. C, 2 °):</td><td>-10 to + 10.0</td><td>-4 to 0</td>

<td></td><td>L * t:</td><td> &gt;=89</td><td> &gt;=90</td>

<td>RfY (Ill. C, 2 stop):</td><td></td><td> &lt;=10%</td><td> &lt;= 6%</td>

<td></td><td>a * f (Ill. C, 2 °):</td><td>-5 to +5</td><td>-3 to +2</td>

<td></td><td>b * f (Ill. C, 2 °):</td><td>-14.0 to +10.0</td><td>-10.0 to +5</td>

<td></td><td>L * f:</td><td> 22-30</td><td> 24-27</td>

<td>RgY (Ill. C, 2 stop):</td><td></td><td> &lt;=11%</td><td> &lt;=7%</td>

<td></td><td>a * g (Ill. C, 2 °):</td><td>-7 to +7</td><td>-2 to +2</td>

<td></td><td>b * g (Ill. C, 2 °):</td><td>-10.0 to +10.0</td><td>-2.0 to +7</td>

<td></td><td>L * g:</td><td> 23-38</td><td> 25-37</td>

While the invention has been described with reference to what is currently considered to be the most practical and preferred embodiment, it should be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, it is intended to cover various modifications and equivalent solutions within within the scope of the appended claims.

KANCELA5IA PPAWSO "ATENTOWA" BELLEPAT "

Izabela Szych ulska-Hcwranek ul Słowackiego 44, 37-700 Przi ^ ił-śl tel. (016) 732-37-77 fax: (016) &lt;175-02-87 mobile phone (0608) 503-081 e- Maii <a href="mailto:beliepat@op.pl">beliepat@op.pl</a> NIP: 795-207-16-72 REGON: 180350516

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