DE19526223A1 - Pyrolytically coated glazing - Google Patents

Abstract

A pyrolytically coated glazing panel, in which the reflected colour remains substantially constant as changes in the relative thicknesses of the coating layers are made in order to optimise optical properties, comprises a vitreous material substrate, an undercoat layer comprising a nitride selected from nitrides of titanium, zirconium, niobium and mixtures of two or more thereof and an exposed transparent overcoat layer adjacent said undercoat layer comprising an oxide. The panel is characterised in that the total geometrical thickness of the undercoat and overcoat layers is between 20 nm and 55 nm. The oxide of the overcoat layer is selected from oxides of aluminium, silicon, magnesium, tin, zinc, zirconium, titanium, bismuth, niobium and mixtures thereof. A further coating layer may be positioned between the undercoat layer and the substrate. This may be silicon oxide and have a thickness of 5 - 10 nm.

Description

The invention relates to transparent solar-controlling glazing panes. In particular, the invention relates to pyrolytically coated glazing disc that has a substrate, an underlayer that contains a nitride, and a exposed transparent top layer adjacent to this bottom layer has a metal oxide.

Pyrolysis generally has the advantage of forming what is a hard coating precludes the need for a protective layer. Those formed by pyrolysis Layers have permanent abrasion and corrosion resistant properties. It it is believed that this is due in particular to the fact that the process of depositing the coating material onto a substrate conditionally, that is hot. Pyrolysis is also generally cheaper than alternative Coating processes, such as spraying (sputtering), especially with regard to on the investment for the plant. The deposition of coatings by other processes, for example by spraying (sputtering) leads to product with very different properties, especially a lower stock resistance to abrasion and occasionally a different refractive index.

Reflective transparent solar control glazing are one valuable material for architects to use for the exterior facade of Buildings. Such discs have aesthetic qualities in the Reflecting the immediate environment and as they come in a number of Colors are available to offer design options. Such Windows also have technical advantages by the occupants of a building  provide protection against solar radiation through reflection and / or absorption, and eliminate the dazzling effects of intense sun exposure and provide an effective glare shield, improve visual comfort and reduce eye fatigue. There are a number of documents which glazing panes describe with a coating, the protection against solar radiation. Thus, in EP-A-239 280 (Gordon) trans Parente glass panes described, on which titanium nitride of at least 30 nm thickness as the main solar shielding layer for reducing the Have permeability in the near infrared and a layer of tin oxide over it from about 30 to 80 nm thick. The tin oxide serves to protect the titanium nitride against oxidation and increases abrasion resistance.

It is known that by changing the relative thicknesses of coating layers occur in the optical properties. To the It is therefore desirable to optimize optical properties, a special one to use the relative thickness of the coating layers. However, it is in generally expected for a given selection of coating materials lien changes in the coating thickness to changes in the dominant Wavelength (i.e. color) of reflected light. For example, at a solar control glazing that has a first coating of titanium nitride and has a layer of iron, cobalt and chromium oxides, a change tion found in the color of the reflected light when the thickness of the oxide layer is changed. So were measurements of the properties of samples of such panes, which had coatings that were chemical Vapor deposition was formed on 4 mm glass as in Table I below specified, found.  

TABLE I

It is an object of the present invention to pyrolytically coated glazing deliver slices in which the reflected color remains practically constant, if there are changes in the relative thicknesses of the coating layers be taken to optimize the optical properties.

It has now surprisingly been found that this goal can be achieved can be used for specific coating materials with a specific Ge velvet coating thickness can be applied.  

According to a first aspect of the invention, a pyrolytically coated is Glazing panel provided which is a substrate, an underlayer, which is a Nitride, selected from the nitrides of titanium, zircon, niobium and mixtures of contains two or more of them, and an exposed transparent top layer adjacent to this sub-layer, which contains an oxide and thereby characterized in that the total geometric thickness of the underlayer and Top layers between 20 nm and 55 nm.

The substrate is preferably in the form of a ribbon made of glass-like material like glass or some other transparent rigid material. With regard on the amount of incident solar radiation from the glazing disc is absorbed, especially in environments where the disc is stronger or exposed to long-term solar radiation, there is a heating effect the glass sheet that may require that the glass substrate be attached is then subjected to a hardening process. However, the Durability of the coating that the glazing with the coated side is installed on the outside, which reduces the heating effect.

Preferably the substrate is clear glass, although the invention is also concerned extends the use of colored glasses as a substrate.

The geometric thickness of the underlayer is preferably between 10 nm and 50 nm. This thickness range is particularly suitable for industrial manufacturers tion and allows an effective antisolar effect to be achieved while a sufficient degree of light transmission of the pane is maintained.

The geometric thickness of the top layer is preferably between 9 nm and 35 nm, preferably from 15 to 35 nm. The refractive index of the top layer is preferably 1.8 to 2.7. The material of the transparent top layer comprises materials which have a "refractive index" (nλ) which is greater than, preferably considerably greater than the value of the "spectral absorption index" k (λ) over the entire visible spectrum (380 to 780 nm). The definitions of the refractive index and the spectral absorption index can be found in "International Light ing Vocabulary", published by the "International Commission on Illumination (CIE)", 1987, pages 127, 138 and 139. In particular, an advantage was found in choosing a material for which the refractive index n (λ) is greater than ten times the spectral absorption index k (λ) over the wavelength range from 380 to 780 nm. The top layer is preferably an oxide layer. The transparent material of the top layer can be independently selected from oxides of aluminum, bismuth, magnesium, niobium, silicon (both SiO _x and SiO₂), tin, titanium (both, rutile and anatase), zinc and mixtures of two or more thereof. The following table lists the refractive index n (λ) and the spectral absorption index k (λ) in a number of suitable transparent materials over the range from 380 nm to 780 nm.

TABLE II

It is particularly preferred that the material of the transparent coating is titanium oxide and / or tin IV oxide. The transparent coating layer is an outer layer and for this reason tin IV oxide is favorable if one higher resistance to abrasion is required, such as where the washer is with the coated side is mounted on the outside.

In preferred embodiments of the invention, the nitride comprises the sub layer of titanium nitride, and the oxide of the top layer includes tin oxide. It was on it noted that it was not essential in the oxide or nitride material layers is that the metal and the oxygen or nitrogen in stoichiometric There are quantities.

From a technical point of view, it is desirable that the glazing panel does not allow too much of the total incidence of solar radiation to pass through, so that the interior of the building is not overheated in sunny weather. The The permeability of the total irradiated solar radiation can be reduced by the Expression "solar factor" can be expressed. As used here, it means Expression "solar factor" is the sum of the total energy that passes directly through is left and the energy that is absorbed and on the side away from the Energy source is broadcast again as a proportion of the total beam energy that falls on the coated glass.

The glazing panes according to the invention have a solar factor (FS) of less than 70%, preferably less than 60%.  

It is also desirable that the glazing panel allow a reasonable amount of visible light to pass through to allow natural lighting of the interior of the building and to allow its occupants to see outside. The transmittance of visible light can be expressed by the expression "transmission factor" as a proportion of the incident light that falls on the coated substrate. So it is desirable to increase the selectivity of the coating, ie to increase the ratio of the transmission factor to the solar factor. The light transmission factor (T _L ) of the pane according to the invention is preferably between 30% and 65%.

Preferably, the disc has an average ultraviolet transmittance (T _UV ) across the ultraviolet spectrum (280 nm to 380 nm) of less than or equal to 45%, most preferably less than or equal to 20%, which can be beneficial for damage to light sensitive materials within the building to diminish.

It is preferred that the composition and thickness of the underlayer and Upper layer layers are such that the dominant wavelength, that of the unbe layered side of the disc is reflected in the visible area, in the area from 470 to 490 nm (blue). From an aesthetic point of view, it is preferred Provide glazing panes with a blue color for reflection. Where Buildings have a relatively large glazed area, and if they are high Building is concerned, a blue-reflective coloring provides a less striking Appearance for the observer. In other embodiments, Ver glazing panes with a neutral appearance.

The reflection of visible light (R _L ) from the uncoated side is preferably 10% to 30%. Preferably, the purity of the color reflected from this uncoated side is greater than 5%, preferably at least 8% and most preferably at least 15%, such as between 19% and 22%. The purity of a color is defined on a linear scale, where a defined white light source has a purity of zero and the pure color has a purity of 100%. The term "color purity", as used here, is to be understood as the excitation purity, measured with illumination C, as defined in the International Lighting Vocabulary, published by the "International Commission on Illumination (CIE)", 1987, pages 87 and 89.

The top layer can be selected to improve the The purity of the color is reflected by the uncoated side of the disc is compared with a similar disc that is not with the Oxidober layer is provided. So z. B. a glazing panel with a 40 nm thick coating of titanium nitride, a gray-blue color (purity = 5%), when reflecting from the uncoated side, while after opening bring a blue layer to a top layer of 10 nm thick tin oxide Appearance from the uncoated side and the purity of the color 8% increases. In the case of a 20 nm thick TiN coating, an upper increases layer of 20 nm SnO₂ the purity of the color from 15% to 21%.

In one embodiment of the invention there are no other coatings available. The first layer is thus layered directly on the substrate. However, in an alternative embodiment of the invention, the washer contain a further coating between the underlayer and the substrate ten. In particular, to the reaction between the reagents and the sub Strat can decrease during the formation of the nitride layer, a coating tion layer of silicon oxide can be applied, as in the British sponsors GB 22 34 264 and GB 22 47 691 (Glaverbel) is described. The geome The thickness of this additional layer can be between 50 and 100 nm.

According to a second aspect of the invention, a method for forming a coated glazing panel provided comprising the steps:

• (i) forming an underlayer over a substrate by pyrolysis, wherein this underlayer is a nitride selected from the nitrides of titanium, Zirconium, niobium and mixtures of two or more thereof, and  
• (ii) Formation of an exposed transparent top layer adjacent to it Lower layer by pyrolysis, this upper layer containing an oxide, characterized in that the coating of this underlayer and Top layer is such that the entire geometric thickness thereof is between 20 nm and 55 nm.

The panes according to the invention can be single glazed or multiple glazed arrangements can be installed. The coated surface of the The pane can be the inner surface of the outer glazing pane. On this way the coated surface is not subject to the environmental weather exposed to conditions that would otherwise damage their lifespan due to contamination, physi damage and / or oxidation could decrease more quickly. Coating genes generated by pyrolysis generally have a larger mecha nical resistance than coatings produced by other methods and they can be exposed to the atmosphere. The washers according to of the invention can be usefully used in laminated glass structures be applied, e.g. B. when the coated surface the inside top surface of the outer laminate.

The glazing panes according to the invention can be manufactured as follows will. Each pyrolytic coating step can be carried out at a temperature of 550 ° C to 750 ° C can be carried out.

The coatings can be formed on a glass plate that is in moved in a tunnel oven or on a glass ribbon during formation rend it's still hot. The coatings can be formed in the cooling furnace which follows the forming device for the glass ribbon or within a Float tanks on top of the glass ribbon while the latter on a bath of molten tin floats.

The coating layers are preferably applied to the substrate by chemical Steam separation applied. Chemical vapor deposition becomes special  preferred because it tends to have coatings of regular thickness and composition, keeping the uniformity of the product It is particularly important if the glazing panes ver over large areas should be applied. When using liquids as a reaction materials cannot be affected by the evaporation process. Moreover chemical vapor deposition is more economical with regard to raw materials rialien and leads to less waste.

To form each coating, the substrate was placed in a coating mer brought into contact with a gaseous medium, which one or contains several substances in the gaseous phase. The coating came mer is fed with a reagent gas through one or more nozzles, the Length is at least equal to the width to be coated. Depending on the type of to forming coating and the reactivity of the substances used, if If several substances are to be used, they are either in the form of a Mixture distributed through a single spray nozzle in the coating chamber or separated by several spray nozzles.

Methods and devices for forming such a coating are e.g. B. in French Patent No. 2,348,166 (BFG Glassgroup) or in French described patent application No. 2 648 453 A1 (Glaverbel). These Methods and devices lead to the formation of particularly strong beings layers with advantageous optical properties.

To form coatings of tin oxide SnO₂ or titanium dioxide TiO₂ two consecutive nozzles are used. The reagent that binds the metal (Sn or Ti) which is introduced in the first nozzle is a tetrachloride which is liquid at ambient temperature and in a stream of anhydrous Carrier gas is evaporated at elevated temperature. The evaporation is through the spraying of these reagents in the carrier gas is facilitated. To the oxide too will form the molecules of tetrachloride in the presence of water brought steam, which is fed to the second nozzle. The water vapor is  overheats and is also injected into a carrier gas. SnO₂ can e.g. B. born be detected by using the proportions of SnCl₄ and H₂O, which in the British patent specification GB 20 26 454 (Glaverbel) are specified.

If desired, a dopant such as HF is added to the water vapor sets to form a conductive tin oxide coating.

Coatings of silicon oxide SiO₂ or SiO _x can be deposited from silane, SiH₄, and oxygen as described in British Patent Nos. GB 22 34 264 and GB 22 47 691, which are mentioned above.

The invention will now become more detailed with reference to the following Examples described without restricting them.

example 1

A substrate consisting of a 4 mm thick slice of clear soda lime Glass was coated by pyrolysis in the following manner. An apparatus that containing two consecutive nozzles was used. Contain a reagent tend TiCl₄, evaporates in a stream of anhydrous nitrogen gas at about 600 ° C, is introduced into the first nozzle. Evaporation is controlled by Ver spray these reagents in the carrier gas easier. Ammonia gas becomes the fed to the second nozzle. The ammonia is heated to about 600 ° C and is also injected into a carrier gas which is air heated to approximately 600 ° C. The Flow rate of gas (carrier gas + reagent) in each nozzle is 1 m³ / cm Width of the substrate / hour at operating temperature.

The coating process was continued until the geometric thickness of the coating formed on the substrate was 11 nm. The substrate was then subjected to a second coating. A reagent consisting of tin IV chloride evaporates in a stream of anhydrous nitrogen gas at about  600 ° C, is fed in the first nozzle. Water vapor is in the second Nozzle supplied. The water vapor is overheated to about 600 ° C and also injected into a carrier gas that is air heated to about 600 ° C. The Fließge The speed of gas (carrier gas + reagent) in each nozzle is 1 m³ / cm Width of the substrate / hour at the operating temperature.

The second coating process continued until the geometric Thickness of the tin oxide coating formed on the substrate, based on the nitride coating layer was coated, was 30 nm.

As a modification of Example 1, a silicon oxide coating layer on the Substrate formed before the TiN layer is formed. This allows the Reduce implementation between TiClI₄ and the substrate. The glass is in coated at a coating station that came along the float at one point mer is where the glass is at a temperature of around 700 ° C. The Feed line is fed with nitrogen and silane is fed with a partial pressure of 0.25% is introduced therein and oxygen is at a partial pressure of 0.5% introduced. The coating formed is made of about 70 nm thickness.

The glazing panel described above had an intense blue color with reflection from the uncoated side. Different properties of the Discs were measured and are given in Table III below.

Examples 2 to 7

Using an appropriate procedure as described in Example 1 other samples were prepared. The details of the coatings and the properties of the disks thus formed are subsequently in Table III specified.  

TABLE III

The tolerances given in Table III above are the changes in the coating thickness that is possible without being perceptible Shows effect on the properties of the final product.  

Examples 1 to 6 above show that for a practically constant total coating-thick changes in the optical properties Changes in the relative thicknesses of the nitride and oxide layers were obtained can be, while the reflected color remains practically constant. Example 7 shows the properties available when the tin oxide of Example 1 to 6 is replaced by anatase. Appropriate results can can be obtained when the titanium nitride is replaced by zirconium nitride or niobium nitride becomes.

Example 8

In another example, a solar control glazing was used neutral appearance. The coating layers are the same as in Example 1, however, the glazing pane is held from the coated side viewed from the uncoated side. The measured properties were:

T _L = 52%
F _S = 53%
R _L = 14%
T _L / F _S = 0.98%
T _UV = 39.5%

The dominant wavelength in the reflection from the coated side was 491 nm with a purity of 3.9% (neutral appearance).

Claims (15)

1. pyrolytically coated glazing pane containing a substrate, an underlayer, which contains a nitride selected from the nitrides of titanium, zirconium, niobium and mixtures of two or more thereof, and an exposed transparent top layer adjacent to this underlayer Contains oxide, characterized in that the total geometric thickness of the lower and upper layer layers is between 20 nm and 55 nm. 2. Glazing pane according to claim 1, characterized in that the geometric thickness of the underlayer is between 10 nm and 50 nm. 3. glazing panel according to claim 1 or 2, characterized in that that the geometric thickness of the top layer is between 9 nm and 35 nm, is preferably from 15 to 35 nm. 4. glazing panel according to any one of the preceding claims, characterized in that the refractive index of the upper layer 1.8 to Is 2.7. 5. glazing panel according to any one of the preceding claims, characterized in that the oxide of the top layer is selected from the oxides of aluminum, silicon, magnesium, tin, zinc, zirconium um, titanium, bismuth, niobium and mixtures of two or more thereof. 6. glazing panel according to any one of the preceding claims, characterized in that the top layer is selected to be a Improve the purity of the paint to deliver that of the uncoated th side of the disc is reflected.   7. glazing panel according to claim 6, characterized in that the Nitride of the lower layer titanium nitride and the oxide of the upper layer tin oxide having. 8. glazing panel according to any one of the preceding claims, characterized in that the composition and thickness of the sub layer and top layer layers are such that the dominant wavelength, that of the uncoated side of the pane in the visible area is reflected, is in the range from 470 to 490 nm. 9. glazing panel according to claim 8, characterized in that the Purity of the color reflected from the uncoated side is greater than Is 5%. 10. glazing panel according to any one of the preceding claims, characterized in that they continue to have an additional layer layer contains that lies between the underlayer and the substrate. 11. Glazing pane according to claim 10, characterized in that the geometric thickness of this additional layer between 50 and 100 nm lies. 12. Glazing pane according to claim 10 or 11, characterized in that that this additional layer consists of an oxide. 13. Glazing pane according to claim 12, characterized in that this additional layer consists of silicon oxide. 14. A method of forming a coated glazing panel comprising the steps:

• (i) forming an underlayer over a substrate by pyrolysis, said underlayer comprising a nitride selected from the nitrides of titanium, zirconium, niobium and mixtures of two or more thereof, and
• (ii) formation of an exposed transparent top layer adjacent to the bottom layer by pyrolysis, this top layer containing an oxide,

characterized in that the coating of this underlayer and Top layer is such that the entire geometric thickness thereof is between 20 nm and 55 nm.