Coated product comprising a layered system deposited on glass substrate and method for producing the coated product

The present invention provides a coated article comprising a layer system coated on a glass substrate and a method of making a coated article. The invention relates to heat treated low E coated articles and to a method of their preparation. Such coated articles can be used as vehicle windshields, insulating glass (IG) units, and other suitable applications.

State of Technology

Multiple coatings intended to alter the characteristics of sunlight are known in the art. Such coatings should most often reflect infrared (IR) radiation with good visible light transmittance. In the automotive industry, for example, car windshields often should have a visible transmittance of at least 70% in the United States and at least 75% in Europe, even when laminated with a polyvinyl butyral (PVB) layer sandwiched between adjacent glass layers. The need for good visible light transmittance is often incompatible with the need for good IR reflection, and it is difficult to achieve both at the same time. The production of low E coated articles is hampered by the need for a mechanically strong and / or chemically resistant coating, as well as the possibility of using a coating with a low visible light reflectance (glass side) that would not substantially change the color of the article when viewed from different angles. The ability to heat treat such coatings is also advantageous so that they can be used in the manufacture of vehicle windshields where heat bending is required, toughened IG units, and the like.

Common US Patent Application No. 5,584,902 discloses a low E coating system having a stack of, from the glass substrate outwardly: Si3N4 / NiCr / Ag / NiCr / Si3N4. Although this coating is heat treatable and although it is inherently a low E coating, it unfortunately has a fairly high emission factor and / or layer resistance, resulting in low Rsolar (Total Solar Reflectance) values ​​of about 22% to about 24 %. For example, the coating disclosed in the '902 patent has a layer drag (R._s) 14.4 ohm / square and normal emission factor (En) 0.15 before heat treatment; and has an Rs of 10.5 ohms / square and a normal emission factor (En) of 0.11 after heat treatment.

Common U.S. Patent Application No. 5,557,462 discloses a low E silver double layer coating comprising, from the glass substrate outwardly, a stack of:

Si₃N₄/ NiCr / Ag / NiCr / Si₃N₄/ NiCr / Ag / NiCr / Si₃N₄.

The coating system disclosed in the '462 patent has good emissivity values ​​and good Rsolar values. Unfortunately, the coating systems disclosed in the '462 patent cannot be heat treated (for example, during heat treatment, Rs increases from about 3-5 to well above 10 and the haze begins to increase). Since the coatings described in the '462 patent are not heat treatable, they cannot in practice be used for the manufacture of vehicle windshields (where hot bending is required) or for other heat treatment (HT) applications such as toughening, heat strengthening or bending.

Certain other silver double layered coatings are described in the prior art section of said provisional application. See also U.S. Patent No. 6,060,178. A disadvantage of these coating systems is, unfortunately, the low durability before and / or after heat treatment.

PL 199520 discloses a mixed nitride layer based on aluminum nitride to which additional material X can be added, for example Si, Zr, or the like. This Al / Si mixed nitride layer requires a significant amount of aluminum (Al) and differs substantially from the SixNy silicon nitride layer as claimed in the present invention.

In the publication of E Paule et al. Vacuum, vol. 37, issues 5-6, 1987, pages 395-397 "Optical properties of reactively sputtered silicon nitride films" disclosed silicon nitride layers are intended for applications in semiconductors (eg for gate insulator layers). These solutions do not apply to low E coated glass products.

Summary of the invention

It is an object of certain example embodiments disclosed in the present invention to provide a heat treatable low E coating (or layered system) that is mechanically stable.

And / or chemically both before and after the heat treatment, the visible light transmittance of the coating system being at least about 70%.

Another object of certain example embodiments of this invention is to use silicon nitride in a layered stack to reduce haze experienced during heat treatment. In certain embodiments of this invention, the silicon nitride layer is a Si-rich layer.

Another object of certain example embodiments of this invention is to provide a coating in accordance with one or more of the above-mentioned purposes that may be used in IG units and / or vehicle windshields.

Another object of the present invention is to fulfill one or more of the above objectives.

Certain example embodiments of this invention meet one or more of the above objectives or needs by providing a method of cathodically sputtering a gradually oxidized layer, the method comprising: providing a substrate; providing a sputtering device including at least one target; directing the first portion of gas close to the first side of the target and the second portion of gas close to the second side of the target such that the first portion of gas contains more oxygen than the second portion of gas, whereby as the substrate passes below the target, an infrared (IR) reflecting layer is formed gradually oxidized layer, wherein the gradually oxidized layer is oxidized more strongly in one part than in the other part.

The invention relates to a coated article comprising a layer system applied to a glass substrate, characterized in that the layer system comprises, from the substrate outward: a Si-rich layer of silicon nitride, SixNy, where x / y has a value of 0 in at least part of the layer. , 76 to 1.5; a first contact layer located on and in direct contact with the Si-rich silicon nitride layer; and an infrared (IR) reflecting layer, wherein the haze value of the coating is reduced by at least 0.05 by the Si-rich silicon nitride layer.

Preferably, the coated article is characterized in that x / y has a value from 0.85 to 1.2 over the entire layer.

In the coated article, a preferably Si-rich silicon nitride layer SixNy has a dielectric constant "n" of at least about 2.05 and an extinction coefficient "k" of at least about 0.001.

In the coated article, a preferably Si-rich silicon nitride layer SixNy has a dielectric constant "n" of at least about 2.08 and an extinction coefficient "k" of at least about 0.003.

Preferably, the coated article is characterized in that the layer system additionally comprises at least one layer of titanium dioxide interposed between the substrate and said Si-rich SixNy silicon nitride layer.

In the coated article, preferably the first contact layer comprises NiCrO x and the infrared (IR) reflecting layer comprises Ag.

The coated article preferably further comprises a second contact layer comprising NiCrO x on the infrared (IR) reflecting layer and at least one dielectric layer on the second contact layer.

The coated article preferably further comprises a second Si-rich silicon nitride layer SixNy, where x / y is from 0.76 to 1.5, disposed over said infrared (IR) reflecting layer, at least one layer being interposed between said a second Si-rich sixNy silicon nitride layer and said infrared (IR) reflecting layer.

Preferably, the coated article further comprises a second infrared (IR) reflecting layer disposed on the second Si-rich silicon nitride layer SixNy.

The invention also relates to a method of making a coated article, the method comprising: providing a substrate; sputtering the substrate of the Si-rich silicon nitride layer SixNy, where x / y is from 0.76 to 1.5 on at least a portion of the layer, using a target including Si and a gas containing more inert gas than nitrogen gas in the vicinity of the target; sputtering on and contacting the contact layer with the Si-rich silicon nitride layer, wherein the first contact layer is on and directly in contact with the Si-rich silicon nitride layer; sputtering an infrared (IR) reflecting layer onto the contact layer; and wherein the ratio of inert gas to nitrogen gas near the target ranges from 1.15 to 3.0.

Preferably, the inert gas comprises argon (Ar) in the process and the ratio of Ar gas to nitrogen gas in the vicinity of the target ranges from about 1.20 to about 2.0.

The invention will now be described with reference to several exemplary embodiments thereof shown in the following drawings.

PL 220 027 B1

Description of Drawings

Fig. 1 is a side sectional view of a coated article according to one embodiment of this invention.

Fig. 2 is a schematic view of a portion of a cross section of a laminated vehicle windshield according to an embodiment of the present invention wherein coatings according to any embodiment of this invention may be used.

Fig. 3 (a) is a sectional view of a portion of the coating showing a pair of progressively oxidized contact layers (e.g., NiCrOx layers) surrounding an infrared (IR) reflecting layer (e.g., Ag layer).

Fig. 3 (b) is a sectional view of a portion of the coating showing an infrared (IR) reflecting layer (e.g., Ag layer) surrounded by a pair of contact layers (e.g., NiCrOx layers)) of which only one layer is gradually oxidized.

Fig. 4 is a schematic sectional view showing how a gradually oxidized contact layer (e.g., a NiCrOx layer) is applied by sputtering.

Fig. 5 is a cross-sectional view of the set of layers of the coatings of Examples 1-3.

Fig. 6 is a sectional view of a coated article according to another embodiment of this invention.

Detailed Description of Certain Exemplary Embodiments of the Invention

A detailed description is now provided with reference to the accompanying drawings where, for several views, like reference numerals indicate similar parts or layers.

Certain embodiments of the present invention relate to a low E coating or layering that may be used in applications such as vehicle windshields, other vehicle windows, skylights, glass doors, IG units, and the like. Coatings according to certain embodiments of this invention have preferably low E and good visible transmittance and are heat treatable. Preferably, the coatings of certain embodiments of this invention are mechanically stable before and / or after heat treatment (HT) and HT does not significantly alter sheet resistance (Rs) and / or haze. It is known in the art that in order to achieve the desired results (e.g., quenching, bending, and / or heat strengthening), the conduct of HT often requires heating the coated substrate to a temperature of between 593 ° C (1,100 ° F) and 788 ° C (1,450 ° F). .

Fig. 1 is a side sectional view of a coated article according to one embodiment of this invention. The coated article comprises a substrate 1 (e.g., a clear, green, brown, or cyan glass substrate from about 1.0 to about 10.0 mm thick, preferably from about 1.8 mm to about 4 mm thick), a first dielectric antireflection layer 3, a second dielectric haze reducing layer 5, first lower contact layer 7 (which is in contact with layer 9), first conductive metallic layer 9 reflecting infrared (IR), first upper contact layer 11 (which contacts layer 9), third dielectric layer 13 (which may be applied in one or more steps in various embodiments of the present invention), fourth dielectric layer 15, second lower contact layer 17 (which contacts layer 19), a second conductive metallic infrared (IR) reflecting layer 19, a second upper contact layer 21 (which is in contact with layer 19), a fifth dielectric layer 23 and finally a sixth dielectric protective layer 25. Each "contact" layer contacts at least one infrared (IR) reflecting layer. Said layers 3-25 together constitute a heat treated low E coating 27 (i.e., a low emissivity coating) that has been applied to a glass substrate 1 or a plastic substrate 1.

In certain embodiments of this invention, first dielectric layer 3 may be formed of or include titanium dioxide (TiO_x) in which x has a value from 1.7 to 2.3, preferably has a value of 2.0), silicon nitride [Si_xN_y wherein x / y is about 0.75 (i.e., Si3N4), or, alternatively, x / y is from about 0.76 to about 1.5 in Si-rich embodiments], silicon dioxide (SiOx, in wherein x is from 1.7 to 2.3, most preferably about 2.0) niobium oxide (e.g., Nb2O5), SiZrN, tin oxide, zinc oxide, silicon oxinitride or any other suitable dielectric material. The first dielectric layer 3 serves as an antireflection layer in some embodiments of this invention.

The second dielectric layer 5 may reduce haze in some embodiments of this invention, and is preferably silicon nitride or includes silicon nitride (e.g., Si3N4, or alternatively, silicon-rich SixNy nitride, where x / y is from 0.76 to 1). 5, preferably from

PL 220 027 B1

0.85 to 1.2). When sputtering a layer or layers of silicon nitride, an Si target or, alternatively, a Si containing target may be used with up to 3-20% by weight of aluminum and / or stainless steel (e.g. SS # 316) with about the same amount of aluminum and / or or steel in a layer or in several layers so formed. Other materials, including SiZrN, among others, may also be used to reduce the haze of layer 5.

Although Si₃N4 may be used in certain embodiments to form layer 5 (and / or layer 15), it has been found that in some embodiments of this invention the silicon-rich type of silicon nitride is better at reducing haze as layer 5 and / or improving mechanical durability. In the absence of layer 5 (and / or layer 15), the haze is typically at least 0.45, while as discussed herein, with this layer or layers the haze is reduced to less than 0.4. In embodiments of the invention comprising Si-rich silicon nitride, layer 5 (and / or layer 15) is preferably composed of or includes silicon nitride Si._xN_ywhere x / y is from 0.76 to 1.5, more preferably from 0.85 to 1.2. For Si3N4, the refractive index "n" is about 2.04 and the extinction coefficient "k" is about 0. However, the Si rich silicon nitride, in some embodiments of this invention, may have a refractive index of at least about 2.05, preferably at least about 2.05. about 2.07, and in exemplary embodiments 2.08 (at 632 nm). Also, the Si rich silicon nitride in accordance with some embodiments of the present invention may have an extinction coefficient "k" of at least about 0.001, more preferably at least about 0.003. In the first example, in the monolithic and post-HT layer 5 of the nitride (and / or layer 15) "n" = 2.099 and "k" = 0.0034, while in the second example in the monolithic system after HT "n" = 2.168 a " k ”= 0.014. Not only did Si rich silicon nitride reduce haze better than Si3N4, it was also found that in the exemplary embodiments it adhered better to the titanium oxide in layer 3. Surprisingly, it was found that Si rich silicon nitride also under the NiCrO layers_x and Ag in Figs. 1.5 and 6 reduced the sheet drag (R._s).

The infrared (IR) reflecting layers 9 and 19 are preferably metallic and conductive layers and may be made of or may include silver (Ag), gold, or any other suitable infrared (IR) reflecting material. Metallic Ag, however, is a material selected for producing the infrared (IR) reflecting layers 9 and 19 in certain example embodiments of this invention. These infrared (IR) reflecting layers facilitate the preparation of the low E coating 27.

In preferred embodiments of the present invention, the contact layers 7, 11, 17 and 21 are formed of or may include a nickel oxide or a nickel alloy such as nickel chromium oxide (NiCrO x). NiCrO x layers may be fully oxidized (ie, fully stoichiometric), or may be at least about 75% oxidized in other embodiments of this invention. Although NiCrO_x is a preferred material for the production of layers 7, 11, 17 and / or 21, those skilled in the art also know other materials that can be used interchangeably (e.g. Ni oxides, Ni alloy oxides, Cr oxides, Cr alloy oxides, NiCrO_xN_y or any other suitable material) for producing one or more such layers. It is known that the contact layers 7, 11, 17 and / or 21 may optionally be continuous layers in various embodiments of the present invention.

When layers 7, 11, 17 and / or 21 contain NiCrO_x in some embodiments of the present invention, Ni and Cr may be incorporated in varying amounts, for example, in the form of nichrome containing about 80-90% Ni and about 10-20% Cr. An exemplary sputtering target for applying these layers contains not only SS-316, which essentially contains 10% Ni and 90% other components, mainly Fe and Cr, but also Haynes alloy 214, which contains (as a nominal composition) mainly the following ingredients, by weight:

root% by weight

<td>Ni</td><td> 75,45</td>

<td>Fe</td><td> 4,00</td>

<td>Cr</td><td> 16,00</td>

<td>C.</td><td> 0,04</td>

<td>Al</td><td> 4,50</td>

<td>Y</td><td> 0,01</td>

PL 220 027 B1

One or more contact layers 7, 11, 17 and / or 21 (e.g. with or including NiCrO_x) is (are) preferably gradually oxidized (oxidized) in certain embodiments of this invention, with the degree of oxidation in the layer (s) varying throughout the thickness of the layer (s). For example, one or more contact layers (7, 11, 17, and / or 21) may be gradually oxidized to be less oxidized at the interfacial contact surface in the immediate vicinity of the infrared (IR) reflecting layer (9 or 19) from this one. the portion of the contact layer or layers that is further away from the immediately adjacent infrared (IR) reflection layer. It is believed that the gradual oxidation of one or more contact layers 7, 11, 17 and / or 21 allows the coating 27 with a low E to simultaneously obtain heat treatment and good visible light transmittance (this has not been achieved so far with NiCrOx contact layers) in a low E double silver layer coating system; see, for example, the cited '462 patent). This is explained in more detail below with reference to Figs. 3 (a) and 3 (b).

Returning to Fig. 1, the third dielectric layer 13 functions as the interface between the two halves of the coating 27 and is of or includes tin oxide in certain embodiments of this invention. However, other dielectric materials, such as silicon nitride, titanium dioxide, niobium oxide, silicon oxinitride, zinc oxide, or the like, among others, may be used instead. The fourth dielectric layer 15 functions as a haze reducing layer in some embodiments of this invention and is preferably silicon nitride or includes silicon nitride (e.g., Si3N4, or, alternatively, includes the silicon-rich silicon nitride discussed above). However, in alternative embodiments of the present invention, other materials (e.g., SiZrN) may be used interchangeably to form the dielectric layer 15.

The fifth dielectric layer 23 may be tin oxide or may include tin oxide in certain embodiments of this invention. However, other dielectric materials, such as, but not limited to, silicon nitride, titanium dioxide, niobium oxide, silicon oxinitride, zinc oxide, or the like, may be used instead. A protective dielectric top layer 25 is provided at least to improve durability, and may be silicon nitride or may include silicon nitride (e.g., Si₃N₄) in certain embodiments of the present invention. However, other dielectric materials may be used in the layer 25 instead, such as, but not limited to, titanium dioxide, silicon oxinitride, tin oxide, zinc oxide, niobium oxide, SiZrN, or the like.

Different or different layers can also be introduced underneath or above said coating 27. Thus, while the layer system or coating 27 is "on" or "applied" (directly or indirectly) to substrate 1, another layer or layers may be interposed therebetween. Thus, for example, the coating 27 of Fig. 1 can be considered to be "on" and "applied" to the substrate 1, even when different or different layers are present between the layer 3 and the substrate 1. Moreover, some embodiments of the present invention may not include certain coating layers 27, while in other embodiments other layers may also be included without departing from the gist of certain embodiments of the present invention.

Fig. 2 shows a laminate (e.g., vehicle windshield) according to one embodiment of the present invention having the coating 27 of Fig. 1. As shown in Fig. 2, a laminate (e.g., vehicle windshield) includes a first glass substrate 1 on which it is provided. there is a coating 27 and a second glass substrate 31. Between these substrates is a layer of PVB arranged in a known manner with their bottom side against the coating 27. In the form shown in Fig. 2 the coating 27 is on the second face (i.e. face 2) 37 of the laminate. The first surface 35 is on the outer side of the laminate exposed to the outside of the car, the second surface 37 is on the inner side or inside of the outer substrate 1, the third surface 39 is inside the inner substrate 31 and the fourth surface 41 inside the car. The coatings 27 are preferably on both second 37 or each of the two thirds 39 of the surfaces of such laminates (the same also applies to the IG units).

Returning to Fig. 1, while different thicknesses may be used in accordance with one or more of the discussed purposes, the following exemplary thicknesses and the following exemplary materials for the respective layers for the glass substrate 1 for the embodiment shown in Fig. 1 are preferred:

PL 220 027 B1

Table 1 (exemplary materials and their thicknesses for embodiments of the invention according to Fig. 1).

<td>layer</td><td>preferred range, A.</td><td>a more preferred range, A.</td><td>for example, A.</td>

<td>T1O2 (layer 3)</td><td>0-400 A.</td><td>50-250 A.</td><td>100 A.</td>

<td>SixNy (layer 5)</td><td>0-400 A.</td><td>50-250 A.</td><td>170 A.</td>

<td>NiCrOx (layer 7)</td><td>5-100 A.</td><td>10-50 A.</td><td>18 A.</td>

<td>Ag (layer 9)</td><td>50-250 A.</td><td>80-120 A.</td><td>105 A.</td>

<td>NiCrOx (layer 11)</td><td>5-100 A.</td><td>10-50 A.</td><td>16 A.</td>

<td>SnO2 (layer 13)</td><td>0-800 A.</td><td>500-850 A.</td><td>650 A.</td>

<td>SixNy (layer 15)</td><td>0-800 A.</td><td>50-250 A.</td><td>170 A.</td>

<td>NiCrOx (layer 17)</td><td>5-100 A.</td><td>10-50 A.</td><td>18 A.</td>

<td>Ag (layer 19)</td><td>50-250 A.</td><td>80-120 A.</td><td>105 A.</td>

<td>NiCrOx (layer 21)</td><td>5-100 A.</td><td>10-50 A.</td><td>16 A.</td>

<td>SnO2 (layer 23)</td><td>0-500 A.</td><td>100-300 A.</td><td>150 A.</td>

<td>Si₃N4 (layer 25)</td><td>0-500 A.</td><td>100-300 A.</td><td>250 A.</td>

Fig. 6 illustrates a low E heat treatable coating 27 according to another embodiment of the present invention. The coating 27 of Fig. 6 is the same as the coating of Fig. 1 described above, except that (i) either the dielectric layer 3 is removed or (ii) layers 3 and 5 are replaced with a single layer 40 of silicon nitride. In other embodiments of the present invention, silicon nitride layer 40 may be formed of or include Si₃N₄. In other embodiments, silicon nitride layer 40 may be formed of or include Si_xN_ywherein x / y may be from about 0.65 to about 0.80, or, alternatively, from about 0.76 to about 1.5 in silicon-rich embodiments. In another particular embodiment of Fig. 6, layer 40 may be made of or include SiZrN. Nitride layer 40 is preferred as it reduces haze and is preferably from about 10 to about 500 Å thick, more preferably from about 200 to about 400 Å thick. In this embodiment, the thickness of the upper IR reflecting layer 19 may also be increased from about 0 to about 10 Å, and / or the thickness of the upper dielectric layer 25 may be increased by from about 0 to about 10%. In another aspect of the Fig. 6 embodiment, silicon nitride may be used to form layer 40, but such that the bottom of the layer is Si.₃N₄ or included Si₃N₄while the top portion is the silicon-rich type of silicon nitride discussed above. As with all embodiments of this invention, silicon-rich silicon nitride exhibits improved haze-reducing properties as compared to Si.₃N₄. The Fig. 6 embodiment has reduced visible transmittance (but still at least 70%) compared to the Fig. 1 embodiment, but may be more stable under certain conditions and the Rsolar value may be higher than the Fig. 1 embodiment. 1, which of course is beneficial.

In certain example embodiments of this invention, the coating (layer) 27 systems of all embodiments of this invention before / after monolithic heat treatment (HT) have the low E shown in Table 2.

Table 2. Monolithic system before / after heat treatment (HT)

<td>properties</td><td>generally</td><td>advantageously</td><td>more preferably</td>

<td>Rs (ohm / square, before HT)</td><td> &lt; 10,0</td><td> &lt; 8,0</td><td> &lt; 5,0</td>

<td>Rs (ohm / square, post HT)</td><td> &lt; 8,0</td><td> &lt; 6,0</td><td> &lt; 4,0</td>

<td>En (before HT)</td><td> &lt; 0,08</td><td> &lt; 0,06</td><td>not given</td>

<td>En (after HT)</td><td> &lt; 0,07</td><td> &lt; 0,05</td><td>not given</td>

<td>haze (after HT)</td><td> &lt; 0,40</td><td> &lt; 0,30</td><td> &lt; 0,28</td>

PL 220 027 B1

Coatings 27, according to certain example embodiments of this invention (for example, according to Fig. 1-6) have the following properties of color, transmittance, reflectance, haze (for example below is a preferred grayish color) on a clear soda lime glass substrate (for example 2.1 mm thick glass) laminated to another similar clear substrate soda-lime glass (e.g. in the form of PVB (polyvinyl butyral) automotive windshields or with indicator oil between two substrates) as shown in Fig. 2 (i.e. on surface 2 of the laminate) as given in Table 3. In Table 3 below, RgY is the reflection of visible light from outside the vehicle as shown in Fig. 2 and RfY is the reflection of visible light from the other side of the laminate, i.e. Fig. 2 and the a *, b * values ​​under these respective reflection parameters also correspond to the glass side (g) (e.g. outside the vehicle in Fig. 2) and the film side (f) (e.g. inside the car in Fig. 2), respectively.

Table 3. Color and transmittance after HT: laminated form

<td>property</td><td>generally</td><td>advantageously</td>

<td>Tvis (Ill. A, 2 degrees)</td><td> &gt; 70%</td><td>&gt; 75% (Fig. 1 only)</td>

<td>Tvis (Ill. C, 2 degrees)</td><td> &gt; 70%</td><td>&gt; 75% (Fig. 1 only)</td>

<td>RgY (Ill. A, C; 2 °)</td><td> &lt; 11%</td><td> &lt; 9%</td>

<td>a * g (Ill. A, C; 2 °)</td><td>-2.0 to +2.0</td><td>-1.0 to +1.0</td>

<td>b * g (Ill. A, C; 2 °)</td><td>-10.0 to +1.0</td><td>-8.0 to -2.0</td>

<td>RfY (Ill. A, C; 2 °)</td><td> &lt; 11%</td><td> &lt; 9%</td>

<td>a * f (Ill. A, C; 2 °)</td><td>-3.0 to +1.0</td><td>-2.0 to 0.0</td>

<td>b * f (Ill. A, C; 2 °)</td><td>-5.0 to 0.0</td><td>-4.0 to -1.0</td>

<td>^Rsolar</td><td> &gt; 26%</td><td> &gt; 28%</td>

<td>haze</td><td> &lt; 0,4</td><td> &lt; 0,3</td>

<td>^T.solar</td><td> &lt; 50%</td><td> &lt; 48%</td>

It has been surprisingly found that the stacks of layers according to some embodiments of the present invention exhibit slight color shifts in the visible light caused by a change in the viewing angle (VA) when viewed from the glass side of the article (for example, from the interior of the vehicle in Fig. 2). Table 4 below shows, for example, small Aa * values_g obtained with coated laminated articles of certain embodiments of this invention when viewed from a normal viewing angle (i.e., right angles) from a viewing angle altered by 60 °. In other words, Table 4 below shows that, according to some embodiments of the present invention, low Aa * values ​​can be kept._g even assuming a 60 ° change in viewing angle (VA), so that coated articles do not change color when viewed from different angles when viewed with the naked eye. Ab * values ​​are considered to be less important than Aa * values ​​because changes in a * are usually more noticeable to the naked eye than corresponding changes in b *. In certain example embodiments of this invention, a * g ranges from -2.0 to +2.0 both before and after a 60 ° (VA) viewing angle change such that a * g stays close to the b * axis (i.e. The b * axis is the vertical axis in the blue (-) / yellow (+) range while the a * axis is the horizontal axis in the green (-) / red (+) range even though the viewing angle index changes, thus minimizing exposure. color changes.

Table 4. Color change when the viewing angle (VA) changes by 60 °

<td>property</td><td>generally</td><td>more preferably</td><td>most preferably</td>

<td>RgY (VA normal)</td><td> &lt; 11%</td><td> &lt; 9%</td><td> &lt; 8%</td>

<td>a * g (VA normal)</td><td>-2.0 to +2.0</td><td>-1.0 to +1.0</td><td>-1.0 to 0.0</td>

<td>RgY (VA 60 °)</td><td> &lt; 18%</td><td> &lt; 16%</td><td> &lt; 15%</td>

<td>a * g (VA 60 °)</td><td>-2.0 to +4.0</td><td>0.0 to +4.0</td><td>0.0 to 2.0</td>

<td>Aa * (VA 60 ° change)</td><td> &lt; 3,0</td><td> &lt; 2,0</td><td>not given</td>

PL 220 027 B1

It is mentioned above that the low E silver double layer coating system according to US Pat. No. 5,557,462 (i.e. glass / Si₃N₄/ NiCr / Ag / NiCr / Si₃N₄/ NiCr / Ag / NiCr / Si₃N₄) cannot be heat treated, at least because during the heat treatment the Rs value increases from about 3-5 to well above 10 and the haze starts to increase. It is now believed that if the thickness of the NiCr layers were significantly increased in the '462 patent in an attempt to achieve heat treatment, it would unfortunately reduce the visible light transmittance to a value well below 70%, which would of course make coated articles unsuitable for use on windshields. vehicles.

However, it has surprisingly been found that by gradually oxidizing one or more non-crystalline contact layers 7, 11, 17 and / or 21, the resultant coated article can maintain good visible light transmittance, with low E, including a low R value._s and good durability in heat treatment (for example, in quenching, hot bending and so on). This is explained in more detail with reference to Figs. 3 (a) and 3 (b).

As shown in Fig. 3 (a) both contact layers 7 and 11 (and / or 17 and 21) on both sides of the applied infrared (IR) reflecting layer 9 (and / or 19) are gradually oxidized so that they are less oxidized. (including fully unoxidized layers in certain optional embodiments of this invention) on an interfacial infrared (IR) reflecting layer (e.g., on an interface Ag layer). In other words, the two contact layers on either side of the Ag layer 9 are oxidized less along their respective thicknesses as they approach the Ag layer 9. Accordingly, in some embodiments of this invention, portions (e.g., 5 Å thickness parts) of layers 7 and 11 (or 17 and 21) of the nearest layers 9 (or 19) are oxidized in the range of about 0 to about 40%, preferably about 0 to about 20%, more preferably from about 0 to about 10%. Meanwhile, the portions (e.g., 5 Å thickness parts) of layer 7 and 11 (or 17 and 21) furthest from layer 9 (or 19 are at least about 50% oxidized, preferably at least about 60% oxidized, more preferably are at least about 75% oxidized, and most preferably are at least about 85% oxidized.

Thus, the contact layers are progressively less oxidized along their respective thicknesses as it approaches the infrared (IR) reflecting layer 9, 19. In certain embodiments of the present invention, this causes contact layers 7 and 11 (or 17 and 21) to become conductive layers or at least semiconducting layers on the interfacial surface with an infrared (IR) reflecting layer 9 (or 19) and are substantially layers. non-conductive in other parts of layers 7 and 11 (or 17 and 21), i.e. in the part 5 A thick farthest from layer 9 (or 19). Thus, when contact layers with or containing partially oxidized NiCrO_x, the value of x decreases progressively along the thickness of the layer towards the infrared (IR) reflecting layer 9, 19. This value of x may even in some cases approach zero or be equal to zero close to the immediately adjacent infrared (IR) reflecting layer.

It is believed that the less oxidized portions of the contact layers 7 and 11 (and / or 17 and 21) close to the infrared (IR) reflecting interface of layer 9 (or 19) make coating 27 withstand heat treatment (HT) and provide good adhesion to layer 9, 19. However, the less oxidized (or unoxidized) portions of the contact layers are also less transparent to visible light than the more oxidized portions of the contact layers. So, in the case of gradual oxidation: (a) the highly oxidized portions of the progressively oxidized contact layers 7 and 11 (and / or 17 and 21) are more transparent to visible light and allow the coating 27 to maintain good visible transmittance, while (b) the less oxidized portions of the progressively oxidized contact layers better support the infrared (IR) reflecting layer (infrared (IR) reflecting layers) 9, 19 during heat treatment (HT), they provide good adhesion and ensure the adhesion of the coating.

The embodiment of the present invention in Fig. 3 (b) is similar to the embodiment shown in Fig. 3 (a), except that only one of the contact layers in contact with the infrared (IR) reflecting layer is gradually oxidized. In this particular embodiment, the upper contact layer is gradually oxidized (upper contact layers 11,21 are gradually oxidized) as discussed above, while the lower layer is not gradually oxidized and is substantially oxidized or is oxidized to at least about 50%. In certain embodiments of the present invention, all four non-crystalline contact layers 7, 11, 17 and 21 may thus be gradually oxidized, while in other embodiments only the upper contact layers 11 and 21 may be gradually oxidized. In still other embodiments of the present invention, the three lines r10

The contact layers may be oxidized gradually, or alternatively only one of the contact layers may be oxidized gradually. While NiCrOx is the preferred material for making progressively oxidized contact layers, those skilled in the art are also familiar with other materials that can be used interchangeably (e.g. that the silver double layer coating system can maintain good transmittance and good low E properties, even when using HT.

Fig. 4 shows how a progressively oxidized contact layer 7, 17 can be applied to a substrate as part of a coating according to an exemplary embodiment of the present invention by asymmetrically introducing oxygen gas into the area of ​​the target. The substrate 1 with part of the layer system thereon passes in the D direction through the sputter coater. Sputtering target 51 in sheath 53 may include a NiCr target or any Ni-containing target discussed above when the contact layer (e.g., layer 7) is to be manufactured with or includes NiCrO x. Other metallic or ceramic targets can be used when other materials are to be used as the contact layer (s). As the substrate 1 moves in the direction D below the disc 51, gas is introduced around the disc on both sides 57 and 59 thereof. At one side 57 of target 51 is introduced at least gaseous oxygen (e.g., O₂) (i.e. an oxygen flux of about 30 ml / min to about 60 ml / min at 4.1 kW) and optionally a mixture of oxygen and an inert gas such as argon (Ar) to the coating zone below and / or near the target. However, less oxygen gas is used on the other side 59 of target 51 and more other gas, such as argon, is introduced into the coating zone below and / or near the target. For example, the gas flowing from the side 57 of the target may include any of the following mixtures: (a) 100% oxygen, (b) a 70/30 oxygen / argon mixture, (c) a 50/50 oxygen / argon mixture, (d) a mixture 30 / 70 oxygen / argon, or (e) a 50/25/25 oxygen / argon / nitrogen mixture; while the gas flowing from the other side 59 of the target may contain (a) 100% argon or any other inert gas, (b) a 50/50 argon / nitrogen mixture or (c) a 90/10 a rgon / oxygen mixture. Thus, the flow of oxygen gas is greater on the side 57 of the target than that on the other side 59. Thus, when the substrate 1 passes under the target 51, the first part of the applied layer 7 due to the presence of oxygen gas is more oxidized on the side 57 of the target, while when a further part of the applied layer 7 is significantly less oxidized due to the lack of gaseous oxygen at the exit side of the target. Thus, near target 51, the substrate first passes through the sputter coating area enriched with oxygen gas and then passes through the sputter coating area depleted in oxygen gas. After the layer 7 of Fig. 1 has been applied, the substrate advances and target 60 may be used to sputter the coating layer 9 onto the pre-coated substrate.

The amounts of oxygen and / or other gases can of course be adjusted in any desired manner to the degree of oxidation of the contact layers. When a gradual oxidation of the contact layer (s) 11, 21 on the upper side of the infrared (IR) reflecting layer 9, 19 is desired, the gas stream shown in Fig. 4 and described above, the more oxygen containing stream is on the target side 59, the less oxygen containing or oxygen free stream is on the target side 57.

Examples 1-3

The following three examples of coated articles were made in accordance with certain aspects of the present invention. For each of the three examples, the coating / layer 27 system shown in Fig. 5 was cathodically sputtered onto a large 2.1 mm thick clear soda lime glass substrate 1, and a specimen of at least 76.2 mm x 76.2 mm was cut. mm (3 in x 3 in). A six-chamber sputter coating device from Leybold Tetra-G was used to sputter the coatings 27 on substrates 1. Each chamber contained 5 cathodes, i.e. the sputter coating device had a total of 30 cathode targets. In cathode numbering, the first digit is used to identify the chamber of the cathodic coating apparatus and the second digit is used to identify the position of the cathode in that chamber. For example, cathode number 32 is the second cathode (second digit) in the third sputter chamber. Cathode numbers C13, C14, C23, C62, C31, C32, C62, C64 and C65 were Twin Mag II cathodes; the C42 cathode was a C-Mag type double cathode; and cathodes C44, C51 and cathodes C44, C51 and C53 were planar cathodes. Those skilled in the art know that the first half of the coating 27 can be applied in a cathodic coating machine and then the article

The PL 220 027 B1 can be re-introduced into the apparatus to apply the second half of the coating to the substrate. In the cathodic coater, layers 7-11 and 17-21 were cathodically sputtered onto the substrate using direct current, while other layers were cathodically sputtered onto the substrate using a medium frequency alternating current type system. The following "*" indicates an Al content of about 10%. The transmission speed for each example was 2.6 m / min. The apparatus systems and process conditions for the three examples are given in Table 5. All gas flow rates (e.g., oxygen, argon, nitrogen) are given in ml / min. In the following examples, although not specified in the cards, the oxygen flow was blocked on the sides of the above-mentioned NiCr targets to gradually oxidize the contact layers 11 and 21 as shown in Fig. 3 (b) (that is, in these examples only two contact layers 11 and 21 above the respective silver layers were gradually oxidized). Volts are for cathode voltage and amps (A) are for cathode current. "Tr" means trimmer, console trimmer (Tr) trimmer (Tr) Mid and pump trimmer (Tr) are measured in ml / min. Pressures were measured in mbar x 10^-3. The gas trimmer deals with individually adjustable gas flows along the cathode length to make corrections for layer thickness uniformity. The NiCr targets were approximately 80/20 NiCr targets. The method for each example was split into three separate tabs (ie, parts 1-3) because too much information was provided; only the cathode and target data are given for all three cards in each example for ease of reference. Both silicon nitride layers 5 and 15 were Si-rich throughout the thickness (s); as can be seen, much more inert argon (Ar) gas than nitrogen gas was used for sputtering these silicon nitride layers.

TABLE 5. Coating apparatus and methods for Examples 1-3.

Example 1.

Example 1 (part 1)

<td>cathode</td><td>shield</td><td>tension, V</td><td>power, kW</td><td>flow Ar, ml / min</td><td>O2 flow, ml / min</td><td>N2 flow, ml / min</td>

<td> 13</td><td>Ti</td><td> 743</td><td> 73</td><td> 200</td><td> 25</td><td> 80</td>

<td> 14</td><td>Ti</td><td> 703</td><td> 64</td><td> 200</td><td> 35</td><td> 50</td>

<td> 23</td><td>Ti</td><td> 738</td><td> 63,5</td><td> 200</td><td> 35</td><td> 50</td>

<td> 42</td><td>Si *</td><td> 456</td><td> 29,7</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 370</td><td> 4,3</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 432</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 386</td><td> 4,1</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 431</td><td> 18,3</td><td> 200</td><td> 240</td><td> 100</td>

<td> 31</td><td>Sn</td><td> 477</td><td> 24,2</td><td> 200</td><td> 290</td><td> 100</td>

<td> 32</td><td>Sn</td><td> 428</td><td> 24,5</td><td> 200</td><td> 300</td><td> 100</td>

<td> 42</td><td>Si *</td><td> 453</td><td> 30,2</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 360</td><td> 4,2</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 430</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 380</td><td> 4,1</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 442</td><td> 18,4</td><td> 200</td><td> 240</td><td> 100</td>

<td> 64</td><td>Si *</td><td> 554</td><td> 40,6</td><td> 200</td><td> 0</td><td> 200</td>

<td> 65</td><td>Si *</td><td> 545</td><td> 40,3</td><td> 250</td><td> 0</td><td> 200</td>

PL 220 027 B1

Example 1 (part 2, continued from part 1 above (common cathode and target)

<td>cathode</td><td>shield</td><td>ampere, A.</td><td>Tank voltage V</td><td>frequency, kHz</td><td>trimmer gas</td>

<td> 13</td><td>Ti</td><td> 128</td><td> 364</td><td> 26,7</td><td>O2</td>

<td> 14</td><td>Ti</td><td> 125</td><td> 346</td><td> 26,7</td><td>O2</td>

<td> 23</td><td>Ti</td><td> 110</td><td> 344</td><td> 26,5</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 230</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,7</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 45</td><td> 203</td><td> 25,03</td><td>O2</td>

<td> 31</td><td>Sn</td><td> 61</td><td> 224</td><td> 25,6</td><td>O2</td>

<td> 32</td><td>Sn</td><td> 60</td><td> 225</td><td> 25,64</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 220</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,6</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,5</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 42</td><td> 208</td><td> 25,1</td><td>O2</td>

<td> 64</td><td>Si *</td><td> 93,5</td><td> 264</td><td> 26,4</td><td>N2</td>

<td> 65</td><td>Si *</td><td> 93,5</td><td> 273</td><td> 26,2</td><td>N2</td>

Example 1 (part 3, continued from part 1-2 above [common cathode and target])

<td>cathode</td><td>shield</td><td>console Tr</td><td>median Tr</td><td>Pump Tr</td><td>pressure</td><td>lambda</td><td>Active lambda</td>

<td> 13</td><td>Ti</td><td> 7,5</td><td> 15</td><td> 7,5</td><td>2.79E^-03</td><td> 252</td><td>Yes</td>

<td> 14</td><td>Ti</td><td> 12,5</td><td> 25</td><td> 12,5</td><td>3.03E^-03</td><td> 252</td><td>Yes</td>

<td> 23</td><td>Ti</td><td> 7,5</td><td> 35</td><td> 7,5</td><td>4.83E^-03</td><td> 252</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.18E^-03</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.26E^-03</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.37E^-03</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.16E^-03</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.12E^-03</td><td> 220</td><td>Yes</td>

<td> 31</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.97E '⁰³</td><td> 220</td><td>Yes</td>

<td> 32</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>3.19E '^03a</td><td> 220</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.52E^-03</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.30E^-03</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.44E^-03</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.38E^-03</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.24E^-03</td><td> 220</td><td>Yes</td>

<td> 64</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>2.88E^-03</td><td> 0</td><td>no</td>

<td> 65</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>3.61E^-03</td><td> 0</td><td>no</td>

PL 220 027 B1

Example 2 (part 1)

<td>cathode</td><td>shield</td><td>voltage, V</td><td>power, kW</td><td>flow Ar, ml / min</td><td>stream O2, ml / min</td><td>stream of N2 ml / min</td>

<td> 13</td><td>Ti</td><td> 729</td><td> 74,6</td><td> 200</td><td> 25</td><td> 80</td>

<td> 14</td><td>Ti</td><td> 703</td><td> 66</td><td> 200</td><td> 35</td><td> 50</td>

<td> 23</td><td>Ti</td><td> 738</td><td> 63,5</td><td> 200</td><td> 35</td><td> 50</td>

<td> 42</td><td>Si *</td><td> 451</td><td> 29,7</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 371,5</td><td> 4,3</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 434</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 390</td><td> 4,1</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 427</td><td> 18,4</td><td> 200</td><td> 240</td><td> 100</td>

<td> 31</td><td>Sn</td><td> 476</td><td> 24,6</td><td> 200</td><td> 290</td><td> 100</td>

<td> 32</td><td>Sn</td><td> 427</td><td> 25,3</td><td> 200</td><td> 300</td><td> 100</td>

<td> 42</td><td>Si *</td><td> 458</td><td> 29,3</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 368</td><td> 4,3</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 431</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 386</td><td> 4,1</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 436</td><td> 18,4</td><td> 200</td><td> 240</td><td> 100</td>

<td> 64</td><td>Si *</td><td> 552</td><td> 40,6</td><td> 200</td><td> 0</td><td> 200</td>

<td> 65</td><td>Si *</td><td> 548</td><td> 40,6</td><td> 250</td><td> 0</td><td> 200</td>

Example 2 (part 2, continued from part 1 above (common cathode and target)

<td>cathode</td><td>shield</td><td>ampere, A.</td><td>tank voltage V</td><td>frequency, kHz</td><td>trimmer gas</td>

<td> 13</td><td>Ti</td><td> 146</td><td> 364</td><td> 26,7</td><td>O2</td>

<td> 14</td><td>Ti</td><td> 125</td><td> 346</td><td> 26,7</td><td>O2</td>

<td> 23</td><td>Ti</td><td> 110</td><td> 344</td><td> 26,5</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 230</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,3</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,3</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 45,5</td><td> 203</td><td> 25,03</td><td>O2</td>

<td> 31</td><td>Sn</td><td> 62</td><td> 225</td><td> 25,6</td><td>O2</td>

<td> 32</td><td>Sn</td><td> 61</td><td> 226</td><td> 25,64</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 230</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,6</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,5</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 44</td><td> 206</td><td> 25,1</td><td>O2</td>

<td> 64</td><td>Si *</td><td> 93,5</td><td> 264</td><td> 26,4</td><td>N2</td>

<td> 65</td><td>Si *</td><td> 93,5</td><td> 273</td><td> 26,2</td><td>N2</td>

PL 220 027 B1

Example 2 (part 3, continued from part 1-2 above (common cathode and target)

<td>cathode</td><td>shield</td><td>console Tr</td><td>middle Tr</td><td>pump Tr</td><td>pressure</td><td>lambda</td><td>active lambda</td>

<td> 13</td><td>Ti</td><td> 7,5</td><td> 15</td><td> 7,5</td><td>2.79E^-03</td><td> 252</td><td>Yes</td>

<td> 14</td><td>Ti</td><td> 12,5</td><td> 25</td><td> 12,5</td><td>3.03E^-03</td><td> 252</td><td>Yes</td>

<td> 23</td><td>Ti</td><td> 7,5</td><td> 35</td><td> 7,5</td><td>4.83E^-03</td><td> 252</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.13E^-03</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.26E^-03</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.35E^-03</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.14E^-03</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.13E^-03</td><td> 220</td><td>Yes</td>

<td> 31</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>3.22E^-03</td><td> 220</td><td>Yes</td>

<td> 32</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>3.25E^-03</td><td> 220</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.21E^-03</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.26E^-03</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.39E^-03</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.18E^-03</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.15E^-03</td><td> 220</td><td>Yes</td>

<td> 64</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>2.75E^-03</td><td> 0</td><td>no</td>

<td> 65</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>3.35E^-03</td><td> 0</td><td>no</td>

Example 3 (part 1)

<td>cathode</td><td>shield</td><td>voltage, V</td><td>power, kW</td><td>flow Ar, ml / min</td><td>stream O2, ml / min</td><td>stream N2, ml / min</td>

<td> 13</td><td>Ti</td><td> 743</td><td> 73</td><td> 200</td><td> 25</td><td> 80</td>

<td> 14</td><td>Ti</td><td> 703</td><td> 64</td><td> 200</td><td> 35</td><td> 50</td>

<td> 23</td><td>Ti</td><td> 738</td><td> 63,5</td><td> 200</td><td> 35</td><td> 50</td>

<td> 42</td><td>Si *</td><td> 456</td><td> 29,7</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 370</td><td> 4,2</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 432</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 386</td><td> 4,1</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 431</td><td> 18,3</td><td> 200</td><td> 240</td><td> 100</td>

<td> 31</td><td>Sn</td><td> 481</td><td> 25,2</td><td> 200</td><td> 290</td><td> 100</td>

<td> 32</td><td>Sn</td><td> 439</td><td> 25,9</td><td> 200</td><td> 300</td><td> 100</td>

<td> 42</td><td>Si *</td><td> 449</td><td> 30,4</td><td> 225</td><td> 0</td><td> 165</td>

<td> 44</td><td>NiCr</td><td> 364</td><td> 4,2</td><td> 150</td><td> 38</td><td> 0</td>

<td> 51</td><td>Ag</td><td> 427</td><td> 3,2</td><td> 100</td><td> 0</td><td> 0</td>

<td> 53</td><td>NiCr</td><td> 383</td><td> 4,0</td><td> 150</td><td> 48</td><td> 0</td>

<td> 62</td><td>Sn</td><td> 452</td><td> 19,5</td><td> 200</td><td> 240</td><td> 100</td>

<td> 64</td><td>Si *</td><td> 553</td><td> 40,6</td><td> 200</td><td> 0</td><td> 200</td>

<td> 65</td><td>Si *</td><td> 545</td><td> 40,3</td><td> 250</td><td> 0</td><td> 200</td>

PL 220 027 B1

Example 3 (part 2, continued from part 1 above (common cathode and target)

<td>cathode</td><td>shield</td><td>ampere, A.</td><td>tank voltage V</td><td>frequency, kHz</td><td>trimmer gas</td>

<td> 13</td><td>Ti</td><td> 128</td><td> 364</td><td> 26,7</td><td>O2</td>

<td> 14</td><td>Ti</td><td> 125</td><td> 346</td><td> 26,7</td><td>O2</td>

<td> 23</td><td>Ti</td><td> 110</td><td> 344</td><td> 26,5</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 230</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,7</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 45</td><td> 203</td><td> 25,03</td><td>O2</td>

<td> 31</td><td>Sn</td><td> 62</td><td> 226</td><td> 25,6</td><td>O2</td>

<td> 32</td><td>Sn</td><td> 62</td><td> 229</td><td> 25,64</td><td>O2</td>

<td> 42</td><td>Si *</td><td>not given</td><td> 230</td><td> 26,18</td><td>N2</td>

<td> 44</td><td>NiCr</td><td> 11,4</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 51</td><td>Ag</td><td> 7,5</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 53</td><td>NiCr</td><td> 10,5</td><td> 0</td><td> 0</td><td>Ar</td>

<td> 62</td><td>Sn</td><td> 45,4</td><td> 212</td><td> 25,1</td><td>O2</td>

<td> 64</td><td>Si *</td><td> 94</td><td> 264</td><td> 26,4</td><td>N2</td>

<td> 65</td><td>Si *</td><td> 93,5</td><td> 273</td><td> 26,2</td><td>N2</td>

Example 3 (part 3, continued from part 1-2 above (common cathode and target)

<td>cathode</td><td>shield</td><td>console Tr</td><td>middle Tr</td><td>pump Tr</td><td>pressure</td><td>lambda</td><td>active lambda</td>

<td> 13</td><td>Ti</td><td> 7,5</td><td> 15</td><td> 7,5</td><td>2.79E⁰³</td><td> 252</td><td>Yes</td>

<td> 14</td><td>Ti</td><td> 12,5</td><td> 25</td><td> 12,5</td><td>3.03E⁰³</td><td> 252</td><td>Yes</td>

<td> 23</td><td>Ti</td><td> 7,5</td><td> 35</td><td> 7,5</td><td>4.83E⁰³</td><td> 252</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.18E⁰³</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.26E⁰³</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.37E⁰³</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.16E⁰³</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.12E⁰³</td><td> 220</td><td>Yes</td>

<td> 31</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>3.01E⁰³</td><td> 220</td><td>Yes</td>

<td> 32</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>3.24E⁰³</td><td> 220</td><td>Yes</td>

<td> 42</td><td>Si *</td><td> 50</td><td> 5</td><td> 45</td><td>2.58E⁰³</td><td> 0</td><td>no</td>

<td> 44</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.27E⁰³</td><td> 0</td><td>no</td>

<td> 51</td><td>Ag</td><td> 15</td><td> 70</td><td> 15</td><td>1.41E^-03</td><td> 0</td><td>no</td>

<td> 53</td><td>NiCr</td><td> 15</td><td> 70</td><td> 15</td><td>2.37E⁰³</td><td> 0</td><td>no</td>

<td> 62</td><td>Sn</td><td> 15</td><td> 70</td><td> 15</td><td>2.26E⁰³</td><td> 220</td><td>Yes</td>

<td> 64</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>2.90E⁰³</td><td> 0</td><td>no</td>

<td> 65</td><td>Si *</td><td> 20</td><td> 60</td><td> 20</td><td>3.69E⁰³</td><td> 0</td><td>no</td>

PL 220 027 B1

After sputtering the coatings 27 of Examples 1-3 onto the respective substrates 1 as above, they were tested and measured as shown in Table 6 (i.e. in monolithic form). The heat treatment was performed by placing the coated articles in an oven heated to a temperature of about 625 ° C for about 5 minutes.

Table 6

Examples 1-3. Monolithic system before and after heat treatment (HT)

<td>properties</td><td>Example 1</td><td>Example 2</td><td>Example 3</td>

<td>Tvis, III. A, 2 degrees (before HT)</td><td> &gt; 70%</td><td> &gt; 70%</td><td> &gt; 70%</td>

<td>Tvis, Ill. A, 2 degrees (after HT)</td><td> &gt; 78%</td><td> &gt; 78%</td><td> &gt; 78%</td>

<td>Rs (ohm / square, before HT)</td><td> 4,43</td><td> 4,37</td><td> 4,27</td>

<td>Rs (ohm / square, post HT)</td><td> 3,46</td><td> 3,33</td><td> 3,44</td>

<td>En (before HT)</td><td> &lt; 0,06</td><td> &lt; 0,06</td><td> &lt; 0,06</td>

<td>En (after HT)</td><td> &lt; 0,05</td><td> &lt; 0,05</td><td> &lt; 0,05</td>

<td>haze (after HT)</td><td> 0,15</td><td> 0,28</td><td> 0,22</td>

Thereafter, all the heat treated monolithic coated articles of Examples 1-3 were laminated to another suitable 2.1 mm thick clear soda lime glass substrate 1, with a PVB layer of about 0.8 mm placed between the substrates in a known manner. wherein a coating 27 has been placed on the surface 2 as shown in Fig. 2. Thereafter, coated laminated articles obtained (see Fig. 2) was tested and measured and found to have the following properties given in Table 7. In Table 7, the side of the glass (G) is the same as the exterior of the vehicle in Fig. 2, while the side of the film (F) is the same as inside the vehicle in Fig. 2.

Table 7. Color for Examples 1-3 in post-HT laminated form (i.e., as in Fig. 2)

<td>value and measurement</td><td>example 1</td><td>example 2</td><td>example 3</td>

<td>III. C. 2 degrees</td><td></td><td></td><td></td>

<td>Transmission (TY or Tvis),%</td><td> 75,37</td><td> 75,32</td><td> 74,68</td>

<td>a * T</td><td> -2,92</td><td> -3,17</td><td> -2,25</td>

<td>b * T</td><td> 3,87</td><td> 4,39</td><td> 4,07</td>

<td>glass side reflectance (G) RgY,%</td><td> 7,93</td><td> 8,02</td><td> 8,22</td>

<td>a * G</td><td> 0,53</td><td> 0,93</td><td> 0,29</td>

<td>b * G</td><td> -5,23</td><td> -7,10</td><td> -5,64</td>

<td>layer / coating side reflectance (F), RfY,%</td><td> 7,83</td><td> 7,85</td><td> 8,11</td>

<td>a * F</td><td> -1,59</td><td> -1,23</td><td> -1,68</td>

<td>b * F</td><td> -2,75</td><td> -3,69</td><td> -2,73</td>

<td>III. D65. 2 degrees</td><td></td><td></td><td></td>

<td>Transmission (TY or Tvis),%</td><td> 75,69</td><td> 75,34</td><td> 74,71</td>

<td>a * T</td><td> -2,81</td><td> -3,05</td><td> -2,16</td>

<td>b * T</td><td> 3,85</td><td> 4,35</td><td> 4,07</td>

<td>glass side reflectance (G) RgY,%</td><td> 7,93</td><td> 8,03</td><td> 8,22</td>

<td>a * G</td><td> 0,26</td><td> 0,57</td><td> 0,01</td>

<td>b * G</td><td> -5,17</td><td> -7,03</td><td> -5,58</td>

PL 220 027 B1

<td>layer / coating side reflectance (F), RfY,%</td><td> 7,84</td><td> 7,85</td><td> 8,12</td>

<td>a * F</td><td> -1,79</td><td> -1,48</td><td> -1,88</td>

<td>b * F</td><td> -2,71</td><td> -3,69</td><td> -2,69</td>

<td>III. A. 2 degrees</td><td></td><td></td><td></td>

<td>transmission (TY or Tvis),%</td><td> 75,27</td><td> 75,23</td><td> 74,78</td>

<td>a * T</td><td> -1,95</td><td> -2,05</td><td> -1,37</td>

<td>b * T</td><td> 3,28</td><td> 3,74</td><td> 3,68</td>

<td>III. C. 10 degrees</td><td></td><td></td><td></td>

<td>transmission (TY or Tvis),%</td><td> 75,16</td><td> 75,08</td><td> 74,91</td>

<td>a * T</td><td> -2,39</td><td> -2,59</td><td> -2,78</td>

<td>b * T</td><td> 3,93</td><td> 4,45</td><td> 4,02</td>

<td>glass side reflectance (G) RgY,%</td><td> 8,01</td><td> 8,14</td><td> 8,31</td>

<td>a * G</td><td> 0,11</td><td> 0,28</td><td> -0,15</td>

<td>b * G</td><td> -5,21</td><td> -7,03</td><td> -5,60</td>

<td>layer / coating side reflectance (F), RfY,%</td><td> 7, 87</td><td> 7,90</td><td> 8,16</td>

<td>a * F</td><td> -1,54</td><td> -1,30</td><td> -1,62</td>

<td>b * F</td><td> -2,79</td><td> -3,78</td><td> -2,77</td>

<td>III. D65. 10 degrees</td><td></td><td></td><td></td>

<td>transmission (TY or Tvis),%</td><td> 75,19</td><td> 75,12</td><td> 74,92</td>

<td>a * T</td><td> -2,29</td><td> -2,49</td><td> -2,66</td>

<td>b * T</td><td> 3,92</td><td> 4,45</td><td> 3,99</td>

<td>glass side reflectance (G) RgY,%</td><td> 8,01</td><td> 8,14</td><td> 8,31</td>

<td>a * G</td><td> -0,09</td><td> 0,01</td><td> -0,37</td>

<td>b * G</td><td> -5,20</td><td> -7,02</td><td> -5,58</td>

<td>layer / coating side reflectance (F), RfY,%</td><td> 7,88</td><td> 7,91</td><td> 8,16</td>

<td>a * F</td><td> -1,69</td><td> -1,49</td><td> -1,78</td>

<td>b * F</td><td> -2,77</td><td> -3,76</td><td> -2,75</td>

<td>III. A. 10 degrees</td><td></td><td></td><td></td>

<td>transmission (TY or Tvis),%</td><td> 75,20</td><td> 75,15</td><td> 74,85</td>

<td>a * T</td><td> -1,41</td><td> -1,63</td><td> -1,75</td>

<td>b * T</td><td> 3,34</td><td> 3,98</td><td> 4,02</td>

Moreover, it was found that in each of Examples 1-3, chemically and mechanically stable articles were obtained as defined below, both before HT and after HT.

As can be seen from the above, more Ar gas than N gas was used during the sputtering of each silicon nitride layer. In the examples, the Ar / N ratio was about 225/165 (i.e. 1.36) as stated above. In preferred embodiments of the present invention, the Ar / N ratio is from about 1.15 to about 3.0, more preferably from about 1.20 to about 2.0, and most preferably from about 1.2 to about 1.5. This ratio, in which more inert gas (e.g., Ar) than nitrogen was used for sputtering the silicon nitride layers, made it possible to obtain Si-rich silicon nitride layers as discussed above.

Table 8 below compares the viewing characteristics of the HT laminate of Example 1 at normal angle (VA) with viewing after changing the viewing angle by 60 degrees (that is, when VA is 60 degrees

PL 220 027 B1 differed by 60 degrees from the normal VA). As can be seen, Example 1 gives very good color fastness over a wide range of viewing angles such that an observer looking at the laminate of Example 1 both at the normal angle VA (i.e. in a straight line such that the line or location is perpendicular to the plane of the article) and also at a VA angle of 60 degrees, he would hardly notice any color change at all. This is due to the low Aa * glass side refractive index (G) (ie. Aa * is the difference between a * under normal VA and after changing the viewing angle by 60 degrees). Note: a color at 60 degrees represents a standard observer according to III. D65, 10 degrees.

Table 8. Color change when the viewing angle (VA) is changed by 60 degrees (example 1)

<td>properties</td><td>example 1 (normal VA)</td><td>example 1 (after VA change by 60 °</td>

<td>^T.vis</td><td> 75,27%</td><td>not given</td>

<td>a * T</td><td> -2,2</td><td>not given</td>

<td>b * T</td><td> 4,2</td><td>not given</td>

<td>^T.solar</td><td> 46,75%</td><td></td>

<td>^Rsolar</td><td> 30,15</td><td> 36,11</td>

<td>RgY</td><td> 7,8%</td><td> 14,56%</td>

<td>^and* g</td><td> -0,23</td><td> 1,6</td>

<td>b * g</td><td> -5,59</td><td> -1,33</td>

<td>Aa * g (VA change by 60 degrees)</td><td> 1,83</td><td>same</td>

<td>AL * g (VA change by 60 degrees)</td><td> 11,4</td><td>same</td>

As seen above, in Table 8, the refractive index change Aa * g (for a 60 degree change in VA) in accordance with some embodiments of the present invention is preferably no greater than 3.0, more preferably no greater than 2.0. In Table 8 it was 1.83. Further, in some embodiments of the present invention, the Tsolar value is preferably no greater than 50%, more preferably no greater than 48%, and most preferably no greater than about 47%.

Certain embodiments of the present invention after heat treatment and lamination were rated as follows for the glass side reflection color (G):

Table 9

<td>parameter</td><td>normal VA</td><td>VA change of 60 degrees</td>

<td>and*</td><td>-2.0 to +2.0</td><td>-2.0 to +3.0</td>

<td>b *</td><td>-1.0 to -12.0</td><td>0 to -9.0</td>

Certain terms are mainly used in the glass coating art, especially to describe the properties and changes in the sunlight characteristics of coated glass. Such terms are used according to their known normal meanings. For example, the description uses:

The intensity of reflected visible light, that is, "reflectance", is defined as a percentage and is reported as RxY or Rx (that is, as the Y value given below in ASTM E-308-85), where "X" is either "G" for glass side or "F" for layer side. "Glass side" (i.e. "G") means viewed from the side of the glass substrate opposite to the side where the coating is placed, while "layer side" (i.e. "F") means viewed from the side of the glass substrate where there is a shell.

The color properties were measured and listed below using the CIE LAB 1976 coordinates and rock a * and b * (i.e. CIE 1976 a * b * plot, observer III. CIE-C 2 degrees), with:

L * stands for brightness units (CIE 1976), and * stands for red-green units (CIE 1976), b * stands for yellow-green units (CIE 1976).

Other similar coordinates with the subscript "h" may be equivalently used to denote normal use of the Hunter method (ie units) III. C, observer of 10 degrees or CIE LUV coordinates u * v *. These scales in this specification are in accordance with ASTM D-2244-93 "Standard Test Method for Calculation of Color Differences from Instrumentally Measured Color Coordinates",

PL 220 027 B1

9/15/93, extended by ASTM E-308-95, Annual Book of ASTM Standards, vol. 06.01 "Standard Method for Computing the Colors of Objects by 10 Using the CIE System" and / or as stated in the lES LIGHTING HANDBOOK 1981 Reference Volume.

The terms "emission factor" (or "emittance") and "transmittance" are understood in the art and used herein in accordance with their well-known meanings. Thus, the term "transmittance" means, for example, solar transmittance, which consists of visible transmittance (TY of T_vis), infrared energy transmittance (IR) (Tir) and UV light transmittance (T_UV). Total solar energy transmittance (TS or Tsolar) can be defined as a weighted average of these other values. Regarding these transmittances, visible transmittance for building purposes can be characterized using the Illuminant C, 2 degree technique; while the visible light transmittance for the automotive industry can be characterized using standard III. A 2 degree technique; (for these techniques, see, for example, ASTM E-308-95, which is hereby incorporated by reference). As for the emission factor, a specific infrared (IR) range is used (that is, the range 2500-40,000 nm). Various standards for the calculation and measurement of any and / or all of the above parameters can be found in the above-mentioned provisional application, with priority being claimed in this application.

The term Rsolar refers to the total solar energy reflectance (glass side); it is the weighted average of IR reflectance, visible reflectance and UV reflectance. The value of this term can be calculated in accordance with DIN 410 and ISO 13837 (12/98) Table 1, p. 22 for vehicle applications and in accordance with the ASHRAE 142 standard for construction applications, both of which are incorporated herein as links.

"Haze" is defined as follows. Light scattered in many directions causes a loss of contrast. The term "haze" is defined herein in accordance with ASTM D 1003, which defines haze as the percentage of light that, when transmitted, deviates on average more than 2.5 ° from the incident light beam. Haze can be measured with a Byk Gardner haze meter (all dimensionless haze values ​​in this specification were measured with such a haze meter).

The "emission factor" (or "emittance") (E) is a measure or property of both absorption and reflectance for a given wavelength. It is usually represented by the formula:

E = 1 - (reflectance) of the layer

In construction, the emission factor values ​​are particularly important in the so-called "middle range", sometimes also called the "far range" of the infrared (IR) spectrum, i.e. in the range from about 2,500 to about 40,000 nm as defined for example in WINDOW 4.1 program, LBL-35298 (1994) by Lawrence Berkeley Laboratories as set forth in the reference below. The term emission factor is used herein to refer to the values ​​of the emission factors measured in the infrared range as defined in ASTM Standard E 1585-93 "Standard Test Method for Measuring and Calculating Emittance of Architectural Elat Glass Products Using Radiometric Measurements". The standard and its provisions are incorporated herein by reference. In this standard, the emission factor is expressed as the hemispherical emission factor (Eh) and as the normal emission factor (En).

Actual data collection for measuring such emission factor values ​​is performed in the usual manner and may be done, for example, by using a Beckman Model 4260 spectrophotometer with a "VW" attachment (Beckman Scientific Inst. Corp.). This spectrophotometer measures the reflectance as a function of the wavelength and on this basis calculates the emission factor using the above-mentioned ASTM Standard 1585-93.

Another term used in this specification is "sheet resistance". Sheet resistance (Rs) is a term known in the art and is used herein as used herein. It is given in ohms per square unit. Generally speaking, the term refers to the resistance in ohms for any square of the layer system on the glass substrate to the electric current passing through the layer system. The sheet resistance tells to what extent a layer or layer system reflects infrared (IR) energy and is therefore often used together with the emission factor as a measure of this property. For example, "sheet resistance" may be advantageously measured with a four point test ohmmeter or alternatively a four point test ohmmeter with a Magnetron Instruments Corp. head type Model M-800 manufactured by Signatone Corp., Santa Clara, California.

PL 220 027 B1

The term "chemical stability" or "chemically stable" is used herein synonymously with the term "chemical resistance" or "chemically resistant". Chemical stability is determined by boiling a 2 full x 5 inch (50.1 mm x 12.7 mm) coated glass substrate sample in approximately 500 mL of 5%. HCl within 5 minutes [ie at about 104.4 ° C (220 ° F)]. As used herein, a sample is considered to pass this test (i.e., that the layered system is "chemically resistant, or that it is considered" chemically stable ", or that it is" chemically stable ") if at least half of the layering of the sample remains after 5 minutes.

"Mechanical durability" is defined herein on the basis of the following tests. The test uses a Pacific Scientific Abrasion Tester (or equivalent) in which a nylon brush (e.g., Hand &amp; Nail Brush, Model 1280 manufactured by Wright Bernet of Franklin Park, Illinois) is cycled over a layering at 500 cycles using a 150 g load on a 152.4 mm x 43.18 mm (6 inch x 17 inch) specimen. If, after this test, no obvious scratches are visible to the naked eye in visible light, the product is considered to have passed the test and to be "mechanically durable" or to have "mechanical durability".

The term "heat treatment" as used herein means heating the article to a temperature sufficient to heat temper, bend, or strengthen the glass-containing article. For example, this definition includes heating a coated article to a temperature of at least about 1100 ° F (593 ° C) [e.g., from about 550 ° C to about 900 ° C] for a period of time sufficient for tempering.

Many other properties, changes, and improvements can be determined by one of ordinary skill in the art from the above disclosure. For example, without limitation, the above-mentioned progressively oxidized contact layers and Si-rich silicon nitride layers may be used both in a stack with single silver layers and in a stack with the double silver layers disclosed herein. Such features, changes and improvements are therefore considered part of the present invention, the scope of which will be defined by the appended claims.