Substrate which is equipped with a stack having thermal properties

The present invention is a thin film multilayer coating made of a transparent substrate, particularly a rigid inorganic material such as glass, comprising at least one metallic functional layer capable of acting on solar radiation and / or long wavelength infrared rays. With respect to the coated substrate.

More specifically, the present invention relates to the use of such substrates for manufacturing insulation and / or sun protection glass units. These glass units reduce the load on the air conditioner and / or reduce excessive heating (glass called "sunlight control" glass) and / or by expanding the glass surface in the cabin of a building or vehicle. It is intended to be installed in both buildings and vehicles in order to reduce the amount of energy dissipated to the outside (glass called "low E" or "low radiation" glass).

One type of multi-layer coating known to give the substrate the above properties is at least one metal placed between two thin films made of a metal oxide or nitride type dielectric material. It consists of a functional layer, for example a silver layer. This multilayer coating is generally obtained by a continuous deposition operation performed using vacuum techniques such as sputtering, preferably magnetically enhanced or magnetron sputtering. Also, two very thin films may be provided, which are placed on each side of the silver layer. Here, the underlying film exists as a protective layer for protection during the possible heat treatments after tethering, nucleation, and / or deposition, and the upper layer is an oxide layer on which oxygen is present. It exists as a "sacrifice" or protective layer to prevent damage to the silver when deposited by sputtering in the presence of and / or when the multilayer coating undergoes heat treatment after deposition.

Therefore, this type of multilayer coating with one or two silver-based functional layers is known from European Patents EP-0611213, EP-0678484, and EP-0638528.

To obtain characteristics unique to the substrate itself, especially aesthetic characteristics (so that the glass can be curved), mechanical properties (to be stronger), or safety properties (so that broken pieces do not cause injury). However, there is currently an increasing demand for this low emissivity or sun protection glass. This requires the glass substrate to undergo bending, annealing, or self-known heat treatment of a toughened type and / or processing associated with the production of laminated glass.

The multilayer coating must then be adapted to preserve the integrity of the silver layer type functional layer, especially to prevent its damage. The first solution is to significantly increase the thickness of the above thin metal layer around the functional layer. Therefore, measures are taken to ensure that oxygen, which is easily diffused from the surrounding atmosphere and / or easily moves from the glass substrate at high temperatures, is "captured" by these metal layers, without the oxygen reaching the functional layer. Oxidizes these metal layers.

These layers are sometimes referred to as "blocking layers" or "blocker layers".

See in particular patent application EP-A-0506507 for a description of "strengthening" multilayer coatings with a silver layer between the tin layer and the nickel-chromium layer. However, it was clear that the substrate coated before the heat treatment was simply a "semi-finished" product, which was often unusable on its own due to its optical properties. Therefore, it is necessary to develop and manufacture two types of multilayer coatings in parallel, one is a non-curved / unreinforced coating and the other is a glass to be strengthened or curved. Is complicated, especially in terms of raw material management and production.

The improvements proposed in patent EP-0718250 have made it possible to overcome this limitation. According to the teachings of this document, a thin film multilayer coating is devised so that its optical and thermal properties do not substantially change whether the substrate once coated with the multilayer coating undergoes heat treatment or not. can do. Such a result is achieved by combining the following two characteristics.

On the one hand, a layer made of a material that can act as a barrier against high temperature oxygen diffusion is provided on the functional layer, but the material itself is chemically or structurally such that its optical properties change even at high temperatures. Not subject to change. Therefore, this material is silicon nitride Si₃N₄Or it may be aluminum nitride AlN; On the other hand, the functional layer is in direct contact with the underlying dielectric, especially the zinc oxide ZnO coating.

Preferably, a single blocker layer (or single layer blocker coating) is also provided on top of one or more functional layers. This blocker layer is a metal selected from niobium Nb, tantalum Ta, titanium Ti, chromium Cr, or nickel Ni, or alloys based on at least two of these metals, especially niobium / tantalum (Nb / Ta) alloys. , Niobium / Chromium (Nb / Cr) alloy, or Tantal / Chromium (Ta / Cr) alloy, or Nickel / Chromium (Ni / Cr) alloy.

This solution is T in the substrate after heat treatment._LIt is possible to maintain the appearance of level and almost constant external reflection, but it can be further improved.

Moreover, research into better resistivity, or lower resistivity, of multilayer coatings is ongoing research.

The state of the functional layer is, of course, a major factor in the resistivity of the functional layer and has been the subject of many studies.

We have chosen another approach to improve resistivity, namely exploring the properties of the interface between the functional layer and the blocker layer directly adjacent to it.

Prior art in international patent application WO2004 / 058660 teaches a solution in which the overblocker membrane is probably a NICrOx monolayer with an oxidation gradient. According to this document, using a particular deposition atmosphere, the portion of the blocker layer in contact with the functional layer is less likely to be oxidized than the portion of the blocker layer farther from the functional layer.

<p> Therefore, an object of the present invention is to correct the shortcomings of the prior art by developing a new type of multilayer coating containing one or more of the above types of functional layers. This multilayer coating can retain its optical properties and mechanical integrity and have improved resistivity even when subjected to bending, strengthening, or annealing type high temperature heat treatment. The present invention, in particular, is a suitable solution to the usual problems in intended applications and consists of developing a compromise between the thermal and optical properties of thin film multilayer coatings.</p><p> In fact, improving resistivity, infrared reflection properties, and emissivity of a multi-layer coating usually causes poor light transmission and light color reflection of this multi-layer coating.</p>

<p> Therefore, the subject matter of the present invention is, in a broad sense, one modification of n functional layers having reflective properties in infrared and / or solar rays, especially with metal functional layers based on silver or metal alloys containing silver. A substrate to which a thin film multilayer coating containing (n + 1) dielectric films (where n 1 and n is of course an integer) is attached, particularly a glass substrate, said dielectric film. Consists of one or more layers, including at least one made of a dielectric material, so each functional layer is on a substrate that sits between at least two dielectric films and has at least one function. The layer comprises a blocker film consisting of at least one boundary layer in direct contact with the functional layer, which boundary layer is characterized by being based on titanium oxide TiOx.</p><p> Accordingly, the present invention provides a blocker membrane for a functional layer having at least one layer, which blocker membrane is below the functional layer ("underblocker" membrane) and / or above the functional layer ("underblocker" membrane). Located on the "overblocker" membrane).</p><p> Therefore, we considered the fact that the oxidation state of the layer in direct contact with the functional layer and even the degree of oxidation can have a significant effect on the resistivity of the layer.</p><p> The present invention does not apply only to multilayer coatings that include a single "functional" layer placed between two films. The present invention also comprises a plurality of functional layers, particularly three membranes and two alternating functional layers, or four membranes and three alternating functional layers, or even five membranes and four alternating functional layers. It is also applied to multi-layer coatings that have.</p><p> In the case of a multilayer coating having a plurality of functional layers, at least one functional layer, preferably each functional layer, comprises an underblocker film and / or an overblocker film of the present invention, that is, a blocker film containing at least two separate layers. ing.</p><p> In one specific embodiment, the boundary layer is partially oxidized. Therefore, this layer is not stoichiometric, but is deposited in a non-stoichiometric, preferably semi-stoichiometric, MOx type, where M represents the material and x is titanium oxide TiO.₂It is a number different from the stoichiometry of, that is, preferably less than 2, rather than 2, especially 0.75 to 0.99 times the normal stoichiometry of oxides. TiOx is particularly such that 1.5 x 1.98, or 1.5 &lt;x &lt;1.7, or even 1.7 x 1.95.</p><p> The boundary layer preferably has a geometric thickness of less than 5 nm, preferably 0.5-2 nm, and thus the blocker film has a geometric thickness of preferably less than 5 nm, preferably 0.5-2 nm. However, this thickness may be thicker than, especially twice that, the thickness of the boundary layer if another layer is provided for the blocker membrane.</p><p> The underlying action of the present invention has been confirmed by local chemical analysis in contact with the functional layer and in contact with the blocker membrane using a transmission electron microscope (TEM) in combination with electron energy loss spectroscopy (EELS). Can be done.</p><p> The boundary layer of the present invention comprises the following substances: Ti, V, Mn, Co, Cu, Zn, Zr, Hf, Al, Nb, Ni, Cr, Mo, Ta, or at least one of these substances. It can contain one or more chemical elements selected from one-based alloys.</p><p> Further, the blocker film of the present invention may further include one or more other layers, such as a metal layer, particularly a titanium metal Ti layer, further away from the functional layer than the TiOx boundary layer.</p><p> The glass of the present invention incorporates a substrate supporting the multilayer coating of the present invention, at least optionally in combination with at least one other substrate. Each substrate may be transparent or colored. At least one of the substrates may be made of particularly bulk colored glass. The choice of type of coloration will depend on the level of light transmission and / or the color of the desired appearance of the glass when its production is complete.</p><p> Therefore, the standard for glass to be attached to the vehicle is the windshield, and in some standards the light transmittance T._LIs regulated to be about 75% and 70% by another standard, but such a level of transmittance is not required for side windows and sunroofs, for example. The colored glass that can be used is, for example, T for a thickness of 4 mm._LIs 65% to 95%, energy transmission T_E40% to 80%, the main wavelength of transmission is 470nm to 525nm, and the light source D₆₅Below it is associated with a permeation purity of 0.4% -6%. This is (L, a^*, b^*) In the color system, a^*Value and b^*You can "give" transparent values with values -9 ~ 0 and -8 ~ + 2, respectively.</p><p> For building-mounted glass, preferably light transmission T for "low E" applications._LIs at least 75% or more and has a light transmittance of T for "sunlight control" applications._LIs at least 40% or more.</p><p> The glass of the present invention may have a laminated structure, in particular at least two rigid substrates of the glass type and at least one thermoplastic polymer so as to have a glass / thin film multilayer coating / sheet / glass type structure. A combination of sheets can be mentioned. In particular, the polymer may be based on polyvinyl butyral (PVB), ethylene / vinyl acetate (EVA), polyethylene terephthalate (PET), or polyvinyl chloride (PVC).</p><p> The glass may also have what is called an asymmetric laminated glass structure, which combines a glass-type rigid substrate with at least one polyurethane-type polymer sheet that has energy absorption to provide "self-healing" properties. Another polymer layer having is optionally combined. See patents EP-0132198, EP-0131523, and EP-0389354 for more details on this type of glass. Therefore, the glass may have a structure: glass / thin film multilayer coating / polymer sheet.</p><p> In the laminated structure, the substrate supporting the multilayer coating is preferably in contact with the polymer sheet.</p><p> The glass of the present invention can be heat treated without damaging the thin film multilayer coating. Therefore, the glass can be curved and / or strengthened.</p><p> The glass may be curved and / or strengthened when it consists of a single substrate with a multi-layer coating. Such glass is called "monolithic" glass. The thin film multilayer coating is preferably, at least partially, on a non-planar surface, especially when the glass is curved to make a vehicle window.</p><p> The glass may also be a multi-glass unit, especially a double glazing unit, at least the substrate supporting a curved and / or reinforced multilayer coating. This is preferred in multi-glass configurations when the multilayer coating is arranged so as to face an intermediate gas filling space.</p><p> When the glass is monolithic or in the form of double glazing or multilayer glass of laminated glass type, the substrate supporting the multilayer coating may be made of at least curved or reinforced glass, and the substrate may be made of curved or reinforced glass. The multilayer coating can be curved or strengthened before or after it is deposited.</p><p> The present invention also relates to a method of manufacturing the substrate of the present invention. The method of the present invention involves depositing a thin film multilayer coating, especially on a substrate made of glass, by a vacuum method of sputtering, optionally a type of magnetron sputtering.</p><p> The coated substrate can then be bent, reinforced, or annealed without compromising its optical and / or mechanical properties.</p><p> However, it is not excluded that one or more first layers can be deposited by another method, for example by a pyrolysis type or CVD type pyrolysis method.</p><p> The boundary layer is deposited using a ceramic target in a non-oxidizing atmosphere (ie, without the intentional introduction of oxygen), preferably consisting of a noble gas (He, Ne, Xe, Ar, or Kr).</p>

The details and advantageous features of the present invention will be apparent from the following non-limiting examples exemplified in the drawings. FIG. 1 shows a multilayer coating containing a single functional layer in which the functional layer is coated with the blocker film of the present invention. FIG. 2 shows a multilayer coating containing a single functional layer in which the functional layer is deposited on the blocker film of the present invention. FIG. 3 shows a multilayer coating containing a single functional layer deposited on and under the underblocker film of the present invention. FIG. 4 shows the resistivity ohms per square () of the multilayer coating of Example 5 as a function of the angstrom thickness of the boundary layer of the present invention. FIG. 5 illustrates a multilayer coating containing two functional layers, each of which is deposited on the underblocker film of the present invention. FIG. 6 illustrates a multilayer coating containing four functional layers, each of which is deposited on the underblocker film of the present invention.

For ease of understanding, the thickness of the various layers of the multi-layer coating in the figure is not drawn in the correct proportions.

FIG. 1 and FIG. 2 show schematic views of a multilayer coating containing a single functional layer when the functional layer is provided with an overblocker film and when the functional layer is provided with an underblocker film, respectively.

In Examples 1-5 and 11-13 below, the multilayer coating is deposited on substrate 10, which is a substrate made of clear soda lime silica glass with a thickness of 2.1 mm. This multilayer coating contains a single silver-based functional layer 40.

Below the functional layer 40 is a dielectric film 20 composed of a plurality of overlapping dielectric-based layers 22, (23), 24, and above the functional layer 40 is a plurality of overlapping dielectric-based layers 62. , There is a dielectric film 60 consisting of 64.

In Examples 1 to 3 and Examples 11 to 13, Layer 22 is Si₃N₄Based on, has a physical thickness of 20 nm, Layer 24 is based on ZnO and has a physical thickness of 8 nm. Layer 62 is based on ZnO and has a physical thickness of 8 nm. Layer 64 is Si₃N₄Based on, has a physical thickness of 20 nm, and Layer 40 is silver-based and has a physical thickness of 10 nm.

In various Examples 1 to 3 and 11 to 13, only the properties and thickness of the blocker film change.

In the case of Example 1 and Example 11, these examples are comparative examples, and each blocker film 50, 30 contains a single metal layer made of titanium metal that has not been oxidized or nitrided, respectively. Is deposited in a pure argon atmosphere.

In the case of Example 2 and Example 12, these examples are examples of the present invention, where each blocker membrane 50, 30 was deposited using a ceramic cathode in a pure argon atmosphere, 1 nm thick stoichiometry. Includes boundary layers, 52 and 32, respectively, made of an oxide that is a typical titanium oxide TiOx.

In the case of Example 3 and Example 13, these examples are examples of the present invention, where each blocker membrane 50, 30 was deposited using a ceramic cathode in a pure argon atmosphere, 2 nm thick stoichiometry. Includes oxide boundary layers 52, 32, which are typical titanium oxide TiOx.

In all these examples, successive layers of multi-layer coating are deposited by magnetron sputtering, but any other if those layers are deposited in a well-controlled manner and with a well-controlled thickness. Deposition method may be used.

The depositor includes at least one sputtering chamber in which a cathode made of a suitable material and under which a cathode with a target through which the substrate 1 passes continuously is provided. The deposition conditions for each layer are as follows:

The silver-based layer 40 is deposited in a pure argon atmosphere under a pressure of 0.8 Pa using a silver target;

ZnO-based layers 24 and 62 are deposited in an argon / oxygen atmosphere under a pressure of 0.3 Pa by reactive sputtering using a zinc target; and

Si₃N₄Base layers 22 and 64 are deposited in an argon / nitrogen atmosphere under a pressure of 0.8 Pa by reactive sputtering using an aluminum-doped silicon target.

The output density and run rate of the substrate 10 are adjusted by known methods to obtain the desired layer thickness.

For each example, the resistance of each multilayer coating was measured before heat treatment (BHT) and after heat treatment (AHT).

The heat treatment applied consists of heating at 620 ° C for 5 minutes in each case followed by rapid cooling in ambient air (about 25 ° C).

The result of the resistance measurement is converted into the resistivity R of ohms per square () and shown in the table below.

<tables num="1"><img file="JP2009514770A_D0001.tif" /></tables>

In the case of the TiOx boundary layer, the comparison of the resistivity value before heat treatment in Example 1 with the resistivity value before heat treatment in Example 2 and Example 3 clearly showed the improvement in resistivity of Example 2 and Example 3, and they were shown. The resistivity value is much lower than that of Example 1.

Therefore, the presence of a TiOx layer deposited on a silver-based functional metal layer instead of the titanium metal layer improves resistivity before or without heat treatment.

The comparison between the resistivity value after the heat treatment of Example 1 and the resistivity value after the heat treatment of Example 2 and Example 3 clearly shows the improvement of the resistivity in the cases of Example 2 and Example 3, and their resistivity values are Lower than that obtained in Example 1.

These results demonstrate the strong effect of the oxidation state at the interface with the silver-based functional metal layer in the overblocker film.

Thus, in the case of overblocker films, the oxidation state of titanium at the interface with the silver-based layer improves resistivity, while the metallic state is detrimental to resistivity.

To confirm this, we performed the deposition in the same manner as in Example 3, but changed the atmosphere for depositing the boundary layer 52 made of TiOx: we The atmosphere changed from a non-oxidizing atmosphere to a slightly oxidizing atmosphere with an oxygen flux of 1 sccm for an argon flux of 150 sccm.

We have observed that the resistivity of the multilayer coating was much higher than in Example 1 even with the slightest oxidation state.

The basic mechanism of this reduction in resistivity at the interface with silver is not fully understood. Probably there is a chemical reaction and / or diffusion of oxygen.

A profile of the blocker membrane was obtained from Comparative Example 3 using electron energy loss spectroscopy (EELS). This experiment showed that an oxygen signal was detected near the functional layer in this comparative example.

<tables num="2"><img file="JP2009514770A_D0002.tif" /></tables>

The underblocker film is more complex in the case of the underblocker film than in the case of the overblocker because it affects the heteroepitaxy of silver on the underlying oxide layer (in this case zinc oxide based).

Unlike overblocker membranes, underblocker membranes are generally not exposed to an oxygen-containing plasma atmosphere. This means that when the underblocker film is made of non-oxidized and / or non-titanium nitride metal, it is neither oxidized nor nitrided at the interface with the silver-based functional layer as well as the underblocker film.

Therefore, the deposition of the oxide boundary layer between the metal blocker layer and the metal functional layer is the only way to control the oxygen content at the interface between the underblocker film and the functional metal layer.

In the case of the TiOx boundary layer, a comparison of the resistivity values before heat treatment in Example 11 with the resistivity values before heat treatment in Examples 12 and 13 clearly showed the improvement in resistivity of Examples 12 and 13. The resistivity value is much lower than that of Example 11.

Therefore, the presence of a TiOx layer deposited in place of the titanium metal layer and under the silver-based metallic functional layer improves resistivity before or without heat treatment.

The comparison between the resistivity value after the heat treatment of Example 11 and the resistivity value after the heat treatment of Example 12 and Example 13 clearly shows the improvement of the resistivity in the cases of Example 12 and Example 13, and these resistivity values are Equivalent to that obtained in Example 11.

These results also demonstrate the strong effect of the oxidation state at the interface with the silver-based functional metal layer in the underblocker film.

Thus, even in the case of underblocker films, the oxidation state of titanium at this interface with the silver-based layer improves resistivity, while the metallic state is detrimental to resistivity.

In addition, the presence of the TiOx boundary layer 32 improves light transmission both before and after heat treatment.

Finally, the colorimetric measurement of the reflection on the multilayer coating side is, in the case of Example 13, a of the Lab system.^*Value and b^*The values are in a suitable "color palette", i.e. a^*Value is almost 0 and b^*The value is approximately -3.5, while in Example 11, a^*The value is almost 1.2 and b^*It was shown that the value was almost -6.8.

The results of mechanical resistance to various tests commonly performed on thin multi-layer coatings (Taber test, Erichsen brush test, etc.) are not very good, but these results are improved by the presence of a protective layer on top of the multi-layer coating. ..

In Examples 4 and 5 of the present invention, configurations similar to those in FIG. 1 were used on the substrate in the following order: SnO₂Base layer 22; TiO₂Base middle layer 23 (not shown in Figure 1); ZnO-based layer 24; Silver-based functional metal layer 40; Boundary layer 52 made of stoichiometric titanium oxide TiOx with a physical thickness of 2 nm; ZnO-based layer 62; Si₃N₄Base layer 64; and A protective layer based on zinc mixed oxide with a physical thickness of 3 nm.

In the case of Example 4 and Example 5 (these examples are examples of the present invention), each blocker film 50 is a 2 nm thick oxide boundary layer 52 deposited using a ceramic cathode in a pure argon atmosphere. (Here, stoichiometric titanium oxide TiOx) is included.

Layers 24, 40, 52, 62, and 64 were deposited as described above.

SnO₂Layer 22 of the base is deposited in an argon / oxygen atmosphere under a pressure of 0.3 Pa by reactive sputtering using a metallic tin target, TiO₂Layer 23 of the base was deposited in an argon / oxygen atmosphere under a pressure of 0.3 Pa by reactive sputtering using a metallic tin target.

Table 3 below summarizes the physical thicknesses (nanometers) of both the layers of Examples 4 and 5 of the invention, and Table 4 shows the basic characteristics of these examples.

<tables num="3"><img file="JP2009514770A_D0003.tif" /></tables>

Further, the same multilayer coating as that of Example 5 was deposited to prepare a comparative example of Example 5, but in this example, the layer 52 was not deposited in the form of titanium oxide having a thickness of 2 nm, and a metal having a thickness of 0.5 nm. In the form of titanium, it was deposited in an inert (argon) atmosphere.

<tables num="4"><img file="JP2009514770A_D0004.tif" /></tables>

The properties of this comparative example clearly show the positive effect of the boundary layer of the present invention on the resistivity of the multilayer coating and on the colorimetric measurement.

To better understand this effect, a series of tests was performed based on Example 5 with varying thickness of the boundary layer between 0.5 and 3 nanometers.

The resistivity obtained is shown in Fig. 4. This figure shows that the resistivity obtained is almost constant (which is about 3.5-3.7 Ω / ) regardless of the thickness of the boundary layer within the tested range.

Using the same type of multilayer coating, but using a metal Ti blocker layer instead of the boundary layer, and varying the thickness of the metal Ti blocker over the same thickness range, as in Comparative Example 5. It was found that a change of several ohms was observed from one end to the other end of the range.

<u style="single">Underblocker film 30 and overblocker film 50</u> FIG. 3 shows one embodiment of the invention corresponding to a multilayer coating comprising a single functional layer 40. An underblocker film 30 and an overblocker film 50 are provided on the functional layer 40.

For the multilayer coatings of Example 2, Example 3 and Example 12 and Example 13 on the one hand, the effect obtained was cumulative, and it was found that the resistivity of the multilayer coating was further improved.

To improve mechanical resistance, the multilayer coating is covered with a protective layer 200 based on a mixed oxide, such as a mixed tin-zinc oxide.

An example containing several functional layers was also made. These examples give the same conclusions as described above.

Therefore, FIG. 5 shows one embodiment having two silver-based functional metal layers 40, 80 and three dielectric films 20, 60, 100. These layers consist of multiple layers 22, 24; 62, 64, 66; 102, 104, respectively, so each functional layer is placed between at least two dielectric films: Silver-based layers 40, 80 are deposited in a pure argon atmosphere under a pressure of 0.8 Pa using a silver target; Layers 24; 62, 66; 102 are ZnO based and are deposited in an argon / oxygen atmosphere under a pressure of 0.3 Pa by reactive sputtering using a zinc target; and Layers 22, 64, and 104 are Si₃N₄It is a base and is deposited in an argon / nitrogen atmosphere under a pressure of 0.8 Pa by reactive sputtering using an aluminum-doped silicon target.

The multilayer coating is covered with a protective layer 200 based on a mixed oxide, for example a mixed tin-zinc oxide.

The functional layers 40 and 80 are deposited on the underblocker films 30 and 70 composed of the boundary layers 32 and 72 made of titanium oxide TiOx in direct contact with these functional layers, respectively.

FIG. 6 also shows one embodiment. In this case, it has four silver-based functional metal layers 40, 80, 120, 160, and five dielectric films 20, 60, 100, 140, 180, each of which has a plurality of layers. It consists of layers 22, 24; 62, 64, 66; 102, 104, 106; 142, 144, 146; 182, 184, so each functional layer is placed between at least two dielectric films: Silver-based layers 40, 80, 120, 160 are deposited in a pure argon atmosphere under a pressure of 0.8 Pa using a silver target; Layers 24; 62, 66; 102, 106; 142, 146; 182 are ZnO based and are deposited in an argon / oxygen atmosphere under a pressure of 0.3 Pa by reactive sputtering using a zinc target; and Layers 22, 64, 104, 144, and 184 are Si₃N₄It is a base and is deposited in an argon / nitrogen atmosphere under a pressure of 0.8 Pa by reactive sputtering using a boron-doped or aluminum-doped silicon target.

The multilayer coating is also covered with a protective layer 200 based on a mixed oxide, such as a mixed tin-zinc oxide.

Each functional layer 40, 80, 120, 160 is on the underblocker membranes 30, 70, 110, 150 composed of boundary layers 32, 72, 112, 152 made of titanium oxide TiOx in direct contact with the functional layer, respectively. Is deposited in.

The present invention has been described above with reference to examples. It will be appreciated by those skilled in the art that various alternative embodiments of the present invention can be made without departing from the scope of the patent as defined by the claims.

<figref num="1">FIG. 5 is a cross-sectional view showing a multilayer coating containing a single functional layer in which the functional layer is coated with the blocker film of the present invention.</figref><figref num="2">FIG. 5 is a cross-sectional view showing a multilayer coating containing a single functional layer in which the functional layer is deposited on the blocker film of the present invention.</figref><figref num="3">FIG. 5 is a cross-sectional view showing a multilayer coating containing a single functional layer deposited on the overblocker film of the present invention and under the underblocker film of the present invention.</figref><figref num="4">It is a graph which shows the resistivity ohm per square () of the multilayer coating of Example 5 as a function of the angstrom thickness of the boundary layer of this invention.</figref><figref num="5">FIG. 5 is a cross-sectional view illustrating a multilayer coating containing two functional layers, each functional layer deposited on the underblocker film of the present invention.</figref><figref num="6">FIG. 5 is a cross-sectional view illustrating a multilayer coating including four functional layers in which each functional layer is deposited on the underblocker film of the present invention.</figref>