JPH08304601A - Coating substrate with neutral appearance in high visual transmittance,low solar factor and reflection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a covering base body to show luminous transmittance TLC larger than 70%, a solar factor F less than 47% and purity of a color in a reflection normal to an opposed surface not more than 12% in a kind and a thickness of a covering layer. SOLUTION: A covering base body contains a surface to carry a large number of metallic layer formed of silver or silver alloy and layers of a transparent dielectric unabsorbing agent material. Order of the layers is (i) a first layer of a transparent dielectric unabsorbing agent material which has an optical thickness of 60 to 75nm and is adjacent to the base body, (ii) a first layer of silver or silver alloy having a geometric thickness of 9 to 11nm, (iii) a second layer of a transparent dielectric unabsorbing agent material having an optical thickness of 135 to 170nm, (iv) a second layer of silver or silver alloy having a geometric thickness of 12 to 15nm and (v) a third layer of a transparent dielectric unabsorbing agent material having an optical thickness of 45 to 65nm. A product can be used as a glass panel for a building or a vehicle.

Description

Detailed Description of the Invention

The present invention relates to coated substrates, and in particular to coated substrates having a high degree of luminous transmission, a low solar factor and a neutral appearance with reflection.

Coated substrates have found use in various fields for various purposes. For example, coated glass is used in low emissivity or sunscreen panels for use in buildings and vehicles.

To give the coated substrate specially desired properties, the coating may comprise several layers, each layer meeting the specific requirements of the coating. The layer components and their thickness as a whole are usually narrowly defined in order to ensure that the specific requirements of the coated substrate are achieved.

US Pat. No. 4,985,312 relates to a glass sheet having a multi-layer coating to give it heat-reflecting properties. A base layer of indium-tin oxide or AlN is deposited on a glass plate and subsequently alternately laminated to a thickness of 40 to 200 (4 to
20 nm) silver or copper heat reflecting layer, thickness 20-2
A barrier layer of metallic zinc with 00 and a protective layer of the same material as the base layer are deposited.

EP-B1-0277228 relates to a glass assembly which transmits light in the visible spectrum while blocking solar radiation outside the visible spectrum. The assembly comprises, in order from the glass substrate, a first layer of dielectric material, a second layer of reflective material, a third and fourth layer of dielectric material, a fifth layer of reflective material and a fifth layer of dielectric material. It comprises a glass substrate having a stack of coating layers, including six layers, whereby the light source A transmission through the assembly is at least 70% and its total solar transmission is less than 55%.

WO 90/05439 likewise relates to a transparent glass device with a transparent coating stack for reducing the solar transmission and increasing the solar reflection. The coating contains a conductive component that allows any heating of the glass device. In its broadest feature, the claimed laminate comprises at least two layers of silver metal having a thickness of 80-180 placed between layers of dielectric material, and further comprising a transparent protective coating, whereby Glass equipment is at least 70%
Source A transmittance of 12.5% or less, source C reflectance of 12.5% or less, total sunlight reflectance of at least 29%, and total sunlight transmittance of 42% or less. The dielectric layers other than the silver layer have a thickness of 200 to 5
00 and the dielectric layer between the silver layers has a thickness of 400 to 1500.
Is.

The present invention is directed to specific components in coating laminates to achieve the desired combination of high luminous transmittance, low solar factor and neutral appearance in reflection, and a specially selected range of layer thicknesses. Regarding

For coated substrates to be used in windows for buildings or vehicles, the product of which the coated substrate forms a part does not pass too large a proportion of the total incident solar radiation,
In other words, it is desirable that the inside of a building or vehicle is not passed through because it does not become overheated in a sunny climate. The transmittance of all incident solar radiation is the "solar factor"
(Herein denoted by F _s ).
When used here, the display of the solar factor is
It represents the sum of the energy directly transmitted and the energy absorbed and re-emitted on the side remote from the energy source and is the percentage of total radiation energy incident on the coated substrate. The solar factor data quoted here is from C.I.
I. E. FIG. (Commision Internationale de l'Eclaira
ge) 1972 official document No. Measure according to 20.

International patent application WO 93/19936 (CA
RDINAL IG COMPANY) describes coatings for transparent substrates which exhibit a neutral color due to their transmission over a wide range of angles of incidence of light. The coating uses a base layer having a thickness of about 27.5 nm or less adjacent to the transparent substrate, with an intermediate layer of antireflective metal oxide in between and an outer antireflective layer of metal oxide on the second reflective metal layer. Two reflective metal layers can be included. Such multilayer coated substrates give only 60% luminous transmission with an intense blue color by reflection. However, it is desirable to have a high visible light transmission for the coated substrate, so that, for example, a resident of a building can see the whole thing and not do the resident's work without excessive use of artificial light. There can be enough light in the building to enable it. As used herein, the term "luminous transmittance" (denoted herein as TLC) means the luminous flux transmitted through the coated substrate as a percentage of the incident luminous flux represented by the standard illuminant C (CIE). Should be taken in order to do.

Among the sunscreen products available on the market are glass sheets carrying a single coating or multiple coatings.

It is desirable to provide a coated substrate that is substantially neutral in reflection from the side opposite to the coated side (referred to herein as the opposite side), that is, the color of the reflected color is of low purity. Is desired. Low color purity has been found to be particularly difficult to achieve simultaneously with low solar factors and high luminous transmittance. Color purity is defined according to a linear scale where the defined white light has a purity of zero and the pure water color has a purity of 100%. As used herein, the term "color purity" refers to the International Commission on Illumination
Internationa, published in 1987 by (CIE)
Illumination Vocabulary means the stimulation purity measured with light source C as specified on pages 87-89. "Color purity" is measured from the opposite side of the product.

With prior art coated substrates, the color purity and dominant wavelength in reflection (λ _D ) tend to vary with viewing angle, especially for coated substrates at 45 ° to the facing surface. It tends to have a pink appearance when viewed.

It is an object of the present invention to provide a coated substrate having a high degree of luminous transmission, a low solar factor and a neutral appearance in reflection.

The present inventors have found that a multi-layer coated substrate in which the coating layer is made of a special material and is present within certain thickness limits can achieve this purpose and obtain other advantages. It was

According to the invention, in the following order, the following coating layers: (i) a first layer of transparent dielectric non-absorbent material having an optical thickness of 60 to 75 nm and adjacent to the substrate; ) A first layer of silver or silver alloy having a geometrical thickness of 9-11 nm; (iii) A second layer of transparent dielectric non-absorbent material having an optical thickness of 135-170 nm; (iv) 12- A second layer of silver or silver alloy having a geometrical thickness of 15 nm; (v) a coating having a surface carrying a third layer of transparent dielectric non-absorbent material having an optical thickness of 45-65 nm. The substrate has the following characteristics: luminous transmittance TLC of greater than 70%, preferably at least 75%; solar factor F of less than 47%, preferably less than 46%, most preferably less than 45%.
_s ; and 12% or less, preferably 10% or less, most preferably 9% or less, having a high luminous transmittance showing a color purity at a reflection normal to the facing surface, a low solar factor and a neutral appearance in reflection. A coated substrate is provided.

The illuminated property of the coated substrate has a thickness of 6 mm as observed from the surface facing the coated surface, that is, from the glass side.
It is based on a single sheet of regular clear soda lime glass with. At this point, it should be known that the opposing surface is usually uncoated.

The relationship between the thickness of the various layers of non-absorbent material and the optical properties of the coated substrate is not completely known, but it is clear that the thickness of these layers is critical.

In a preferred embodiment of the invention, the layers have the following thicknesses: (i) the first layer of non-absorbent material has an optical thickness of 63-72 nm; (ii) silver or silver alloys. The first layer of is 9.5 to 10.5 nm
(Iii) the second layer of non-absorbent material has an optical thickness of 144-160 nm; (iv) the second layer of silver or silver alloy has a thickness of 13-14 nm. (V) The third layer of non-absorbent material has an optical thickness of 50-58 nm.

Using the coating layer thicknesses and arrangements defined herein, the coated substrate has a high luminous transmission, a low solar factor and a neutral color in reflection from the opposite side. Higher color stability, i.e. even in the case of some limited variation in one thickness of the coating (e.g. resulting from lack of thickness uniformity between one point on the substrate and another). Colors often approach neutrality when there is no significant variation in color and the viewing angle tends toward the normal to the opposite side.

The coated substrate according to the invention, on the other hand, is not yellow or pink, but provides a color of reflection that is aesthetically pleasing when viewed normal to the facing surface (at a right angle). When the purity of the reflection is low, a yellow or pink color is very noticeable. This color remains aesthetically pleasing even when viewed at an angle to the surface, in other words the reflected color is no longer yellow or pink at smaller viewing angles. This is a very important factor when considering glass panels incorporated into large buildings. In fact, for example, the viewing angle in front of the building is different when a stationary observer looks at the first floor of the building, the middle floor and the top floor. The glass panel on the first floor looks blue green,
On the other hand, this change is quite noticeable when it looks pink on the intermediate floor. Similarly, when the observer moves, the viewing angle changes, but the color remains a good aesthetic criterion.

On the other hand, the particular arrangement of this layer has a low luminous transmittance which is low in the luminous reflectance obtained with the uncoated substrate.
reflection) (here denoted by R _L ).

In the coated substrate according to the present invention, the thickness and type of coating layer is defined as the fraction of the solar energy that passes directly through the coated substrate, with no direct change in energy transmission T _ED (change in wavelength). 34% -40%,
The thickness and type are preferably between 36% and 39%.

The thickness and type of coating layer are such that the color purity remains neutral when the viewing angle is changed, especially for light-resistant surfaces of less than 9%, most preferably less than 6% of coated substrate. The thickness and type is such that it indicates the color purity in reflection at an angle of 45 °.

An angle of 60 ° to the facing surface (according to the convention, a right angle to the surface is designated as 0 °), the purity of the reflected color is preferably less than 1%.

When the coated substrate is used in a single glass device constituted by a single coated sheet of transparent glass having a thickness of 6 mm, the luminous transmittance TLC is 70% to 81.
%, Preferably 75% to 79%, the solar factor is preferably 41% to 46%, and the luminous reflectance _RL is preferably 8% or less. The color in reflection from the opposite side is preferably 10%
Hereafter, it is more preferably neutral with a purity of 9% or less. The dominant wavelength of reflection is preferably 485 to 505 nm. Above this range, a yellow color is observed. Below this range, a pink color is observed as the viewing angle changes. Avoid colors that tend to be pink when the color purity at the reflection normal to the facing surface is at least 3%, when the viewing angle moves away from the normal, especially when the dominant wavelength is at the lower end of the preferred range. It is easy to do. In fact, the purity is on the order of 1-2%, and the dominant wavelength is 495n
Below m, the viewing angle tends to be pinker away from the normal, which is especially noticeable by the eye, even in the case of very low purity.

The metal layer comprises silver or a silver alloy, for example an alloy of silver and platinum or palladium.

The coated substrate according to the present invention further comprises a layer of sacrificial material provided over (ie, substantially attached to) each metal layer and in contact. The purpose of the layer of sacrificial material is to protect the silver or silver alloy during deposition of the next non-absorbent layer.

The coating layer is preferably applied by cathode sputtering. The reason for the cathodic sputtering method is that each metal layer is coated with a thin layer of sacrificial metal (barrier layer) which becomes converted to oxide during the coating process. The sacrificial metal is preferably titanium, but zinc, copper, nickel / chromium alloys or aluminum can also be used instead. Similar barrier layers can be placed underneath each metal layer if desired. It is preferred that the sacrificial material be present in a substantially fully-incorporated state, since non-oxidized materials can have the effect of reducing the luminous transmittance. The sacrificial material becomes oxidized during the deposition of the next layer when depositing the next layer in a reactive atmosphere (eg O ₂ ). As used herein, the term "sacrificial material" refers not only to a sacrificial metal as deposited on a silver or silver alloy layer, but also to an oxide or partial oxide that will cause the sacrificial metal to be converted during subsequent processing. Shall also be included. These sacrificial layers provide an improvement against oxidation by protecting the silver layer and improve chemical resistance, but further increase the sacrificial layer thickness to reduce the luminous transmission of the product. Therefore, the thickness of the sacrificial material layer, if present, is critical to the invention.

A first layer (iia) of sacrificial material having a geometric thickness of 2.5-5 nm is provided between the first metal layer (ii) and the second non-absorbent layer (iii), and A second layer (iva) of sacrificial material having a geometrical thickness of 3-6 nm is provided between the second metal layer (iv) and the third non-absorbent layer (v).

When the next layer of non-absorbent material is a nitride (eg Si ₃ N ₄ ) rather than an oxide, the layer is deposited in a nitrogen atmosphere. In this case, it is not necessary to deposit the sacrificial material on the silver or silver alloy layer before depositing the nitride in a nitrogen atmosphere.

The coating layer is a thin (3 nm) layer of SiO ₂ that protects the coating without significantly modifying the optical properties of the product.
Can be completed with a protective layer, such as a Geometrical Thickness layer (see UK Patent Application No. 9417112.1 filed Aug. 24, 1994, by Gravelbel). Otherwise the third non-absorbent layer usually constitutes the exposed layer.

Preferably, the optional thin exposed additional protective layer is selected from oxides, nitrides and oxynitrides of silicon. This layer provides a coated substrate with improved chemical and / or mechanical durability while minimizing the resulting changes in optical properties. Advantageously, said exposure protection additional layer is SiO ₂ , most preferably having a geometrical thickness of 2-5 nm.

Its influence on the optical properties of the product can be minimized, especially when the thickness of the protective layer is small.

The products according to the invention can usually be used in laminated glass structures. As a glass panel, the products can be stacked in single or multiple glass window assemblies. The coated substrates can also be used for a range of purposes, for example as glass equipment in buildings, especially as double glazing equipment, and in windshields for vehicles, for example laminated glass structures.

The multiple glazing device may have at least two of the transparent vitreous materials positioned in face-to-face spacing and having a gas space delimited by a peripherally extending spacer, wherein at least one of the sheets is The coated substrate according to the invention, the coated surface of which faces the gas space.

The laminated glass device may comprise at least two sheets of transparent vitreous material secured to one another with the aid of an intermediate film of polymeric adhesive material, at least one of the sheets being coated according to the invention. The substrate, the coated side of which faces the polymer adhesive.

In a preferred embodiment of the invention in which the coated substrate was incorporated into a double glazing device formed from two sheets of transparent glass, each having a thickness of 6 mm, and a 15 mm intermediate space was filled with algo, the luminous transmittance TLC was obtained. Is 62% to 72
%, Preferably between 66% and 70%, the solar factor F _s between 34% and 40%, preferably 36%
And 39%, the color purity at the reflection normal to the facing surface is 8% or less, most preferably 7% or less, and the luminous reflectance is 12% or less. To measure the properties of such an example, consider that the device is laminated with coating at position "2" (opposing surface is position "1"), ie the coated substrate is
It is placed in an outward facing position and the coated surface faces the inner glass surface of the double glazing device.

The non-absorbent layer may be represented by a single absorbent material such as zinc oxide, tin oxide or silicon nitride, a complex or mixture of non-absorbent materials such as Zn ₂ SnO ₄ , or a number of successive layers. Can be

By the term "non-absorbent material" as used herein, we have found that the visible spectrum (380-78).
“Spectral absorption k (λ)” over the entire 0 nm)
"Refractive index" greater than, preferably substantially greater than,
It means a material having n (λ). The definitions of refractive index and spectral absorptivity are defined in the International Commission on Ill.
Published by umination (CIE) in 1987
International Lighting Vocabulary, 127 pages, 1
It can be found on pages 38 and 139. In particular, the inventors have found an advantage in choosing the material, for which the refractive index n (λ) is greater than 10 times the spectral absorption k (λ) over the wavelength range of 380-780 nm. Select the material that is. Most preferably, the material of the non-absorbent coating layer is selected from aluminum nitride, silicon nitride, stannic oxide, zinc oxide, zirconium oxide and mixtures thereof. It should be known to deposit silicon nitride using a cathode of, for example, silicon doped with aluminium, nickel, boron, phosphorus and / or tin to facilitate the deposition process. As a result, these dopant elements can be present in the non-absorbent material layer. Preferably the non-absorbent material has an index of refraction measured at 550 nm of 1.85 to 2.2, advantageously 1.9 to 2.1. Zinc oxide is a particularly preferred material because of its high deposition rate, its well-matched index of refraction for the purposes of the present invention, and its beneficial effect on passivation of the silver layer, but its relatively high content in thick coatings. Because of the resulting porosity and its poor chemical resistance, it is preferred to divide the zinc oxide layer into two or more layers with another non-absorbent material placed in between, such as stannic oxide. Thus preferably one or more of said layers of non-absorbent material is a composite coating layer, i.e. a single layer containing two or more non-absorbent materials deposited simultaneously and / or sequentially. Advantageously, said one or more layers of non-absorbent material are ZnO / SnO ₂ / ZnO or Zn
O / SnO ₂ / ZnO / SnO ₂ / ZnO and the like are formed alternately with zinc oxide and stannic oxide.

In some instances, such as for applications in the field of vehicle windows, such as laminated windshields, silicon nitride (Si ₃ N ₄ ) is particularly preferred as a non-absorbent material, especially in terms of chemical durability. . In this case, the sacrificial material layer has no advantage, and therefore is not needed between the silver layer and the non-absorbent layer deposited thereon.

The presence of stoichiometric proportions of metal and oxygen or nitrogen in the metal oxide or nitride non-absorbent material coating is not essential.

Further coating layers may be provided, but the present inventors have found that this may have the effect of reducing the luminous transmittance. Therefore only two or three metal layers are preferred.

The substrate is preferably in the form of a sheet of vitreous material such as glass or some other transparent synthetic material.

The substrate is preferably transparent glass, but the invention extends to the use of colored glass as the substrate, in which case the invention offers the advantage that the intrinsic color of the substrate is not significantly modified by the coating.

The process for forming a product according to the present invention comprises a process chamber containing a suitable magnetron sputtering source and equipped with inlet and outlet gas locks, a conveyor for the substrate, a power source, a sputter lilg gas inlet and an exhaust outlet. This can be done by introducing the substrate therein. The base is
Carried through an activated sputtering source and cold sputtered in a suitable atmosphere (oxygen gas in the case of oxide coatings) to provide the desired layer on the substrate. This method is repeated for each coating layer.

The present invention will now be described in further detail with reference to the following non-limiting examples.

Example 1 A glass sheet was introduced into a processing chamber containing a number of planar magnetron sputtering sources and equipped with an inlet gas lock, a conveyor for the substrate, a power source, a sputtering gas inlet and an exhaust outlet. Deposition was accomplished by passing the substrate several times under the same cathode. The online deposition system contains two deposition chambers and an inlet lock. The first chamber was for depositing the oxide (or nitride) in a reactive atmosphere (oxygen or nitrogen) and provided a target made of zinc and tin, which was necessary for the deposition of the coating. Includes multiple cathodes. The second chamber is for depositing metal in an inert atmosphere (Ar) and contains a silver cathode and a titanium cathode. The substrate is for obtaining the desired continuity of the coating layer,
Many round trips were made under the activated cathode. The pressure in each chamber was reduced to 0.3 Pa.

The coated product had the following composition and optical properties:

Substrate: 6 mm transparent glass layer (i) 35 nm zinc oxide layer (ii) 9.5 nm silver layer (iia) 3 nm titanium layer (iii) 75 nm zinc oxide layer (iv) 13.5 nm silver layer (iva) 5 .5 nm titanium layer (v) 26 nm zinc oxide

Single glass sheet: Transmittance (TLC) 76% Solar factor (F _s ) 43.5% Direct energy transmittance (T _ED ) 37% Luminous reflectance 7-8% Purity of reflected color (normal line) ) 6.6%

Outer sheet of double glazing device: Transmittance (TLC) 67% Solar factor (F _s ) 37% Luminous reflectance 10-11% Main wavelength λ _D (normal) 490 nm Color purity (normal) 6.3% Main wavelength λ _D (45 °) 490nm Color purity (45 °) 4.5%

Example 2 In the first modification of Example 1, a layer of zinc oxide was added to 3 /
ZnO / S depending on the ratio of 4ZnO and 1 / 4SnO _2.
It was divided into nO ₂ / ZnO. The total thickness of these layers is
To maintain the same optical thickness as the ZnO-only layer of Example 1, taking into account the difference between the refractive index of ZnO (about 2.0) and SnO ₂ (about 1.9). Reduced proportionally. Although the properties observed were the same, the coating was more resistant to corrosion.

Examples 3 and 4 In a modification of Example _2, a thin (3) SiO ₂ was deposited on the final coating layer without modifying the optical properties of the coated substrate.
nm) protective coating, but in the cases of Examples 3 and 4 provided improved chemical and / or mechanical durability to the coated substrate, and in the case of Example 4 PVB. (Polyvinyl butyral) It was completely compatible with the intermediate film.

Examples 5-9 In another modification of Example 1, a glass substrate was applied with a coating of the composition shown in Table A1. According to the claims, the stated thickness of the ZnO layer is the optical thickness, Ag
And the thicknesses for Ti were geometrical thicknesses. To help compare the optical and geometrical thickness, we show here that the refractive index of ZnO is 2.0 and the refractive index of TiO ₂ is about 2.5 (optical thickness Is equal to geometric thickness x refractive index).

The coated product had the optical properties shown in Table A2. It will be appreciated that the coating laminate of the present invention achieves a highly effective combination of light transmission, solar factor and color purity. Perhaps the most notable is 4
It has a low solar factor of (Example 6) including as low as 2%.

[0056]

[Table 1]

[0057]

[Table 2]

Claims (19)

[Claims] 1. In the following order, the following coating layers: (i) a first layer of transparent dielectric non-absorbent material having an optical thickness of 60-75 nm and adjacent to a substrate; (ii) 9-11 nm. A first layer of silver or a silver alloy having a geometric thickness; (iii) a second layer of a transparent dielectric non-absorbent material having an optical thickness of 135-170 nm; (iv) a geometry of 12-15 nm. A second layer of silver or silver alloy having a thickness; (v) having a surface bearing a third layer of transparent dielectric non-absorbent material having an optical thickness of 45-65 nm, the coated substrate having the following characteristics: A luminous transmittance TLC of greater than 70%; a solar factor F _{s of} less than 47%; and a high luminous transmittance of less than 12% showing a color purity at the reflection normal to the facing surface, Coated substrate with low solar factor and neutral appearance in reflection. 2. The nature and thickness of the coating layer is such that the coating substrate is 3
A coated substrate according to claim 1, characterized in that it is of such a nature and thickness that it exhibits a direct energy transmission T _{ED of} between 4% and 40%. 3. The property and thickness of the coating layer are such that the luminous transmittance T
Coated substrate according to claim 1 or 2, characterized in that it has a property and a thickness such that LC is 75% or more. 4. The properties and thickness of the coating layer are such that the solar factor F _s is 46% or less, preferably 45% or less.
3. The coated substrate according to any one of 3 above. 5. The nature and thickness of the coating layer are such that the color purity at the reflection normal to the facing surface is 10% or less, preferably 9%.
The coated substrate according to any one of claims 1 to 4, wherein the coated substrate has the following properties and thicknesses. 6. The properties and thicknesses of the coating layer are such that the purity of the color at the reflection normal to the facing surface is at least 3%. The coated substrate according to any one of items. 7. The nature and thickness of the coating layer is 9 for the coated substrate.
%. The coated substrate according to any one of claims 1 to 6, characterized in that it has a property and a thickness such that it exhibits a color purity on reflection of 45% or less on the opposite surface at an angle of 45 °. 8. (i) The first layer of non-absorbent material comprises 63-
Has an optical thickness of 72 nm; (ii) the first layer of silver or silver alloy is 9.5 to 10.5 nm
(Iii) the second layer of non-absorbent material has an optical thickness of 144-160 nm; (iv) the second layer of silver or silver alloy has a thickness of 13- 8. A geometrical thickness of 14 nm; (v) A third layer of non-absorbent material has an optical thickness of 50-58 nm. Coated substrate. 9. The method of claim 1, further comprising a sacrificial material provided on and in contact with each metal layer.
8. The coated substrate according to any one of item 8. 10. The coated substrate of claim 9, wherein the sacrificial material is titanium. 11. The coated substrate according to claim 9, wherein the sacrificial material is in a substantially completely oxidized state. 12. (iia) A first layer of sacrificial material having a geometric thickness of 2.5-5 nm located between a first layer of silver or silver alloy and a second layer of non-absorbent material. (Iva) comprising a second layer of silver or silver alloy and a second layer of sacrificial material having a geometrical thickness of 3-6 nm located between the third layer of non-absorbent material. The coated substrate according to any one of claims 9 to 11. 13. Coated substrate according to any one of claims 1 to 12, characterized in that the non-absorbent material is selected from zinc oxide, tin oxide, silicon nitride and mixtures thereof. 14. Coated substrate according to any one of claims 1 to 13, characterized in that the non-absorbent material has a refractive index of 1.85 to 2.2 measured at 550 nm. 15. The coated substrate of claim 14, wherein the non-absorbent material has a refractive index of 1.9 to 2.1 measured at 550 nm. 16. One or more of said layers of non-absorbent material,
The coated substrate according to any one of claims 1 to 15, which is a composite coating layer. 17. The dominant wavelength of the reflection from the facing surface is 485 to 485.
It is between 505 nm, It is characterized by the above-mentioned.
The coated substrate according to any one of 1. 18. A hollow multi-layer glass device having at least two sheets of transparent vitreous material positioned in face-to-face spacing and having a gas space delimited by peripherally extending spacers, at least one of said sheets. The hollow multi-layer glass device according to any one of claims 1 to 17, characterized in that the coated surface faces the gas space. 19. The hollow multi-layer glass device according to claim 18, wherein the color purity of the reflection normal to the facing surface is 8% or less, preferably 7% or less.