EP3145887A1

EP3145887A1 - Substrate equipped with a multilayer comprising partial metal films, glazing unit, use and process

Info

Publication number: EP3145887A1
Application number: EP15731643.1A
Authority: EP
Inventors: Xavier CAILLET; Jean-Carlos LORENZZI; Benoit Georges
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS
Priority date: 2014-05-23
Filing date: 2015-05-22
Publication date: 2017-03-29
Also published as: EA201692363A1; KR20170010393A; JP2017520507A; CN106573832A; US20170144928A1; FR3021312A1; JP6585165B2; MY178644A; EA034706B1; US10221093B2; WO2015177481A1; CA2949809A1; MX2016015317A

Abstract

The invention relates to a substrate (30) coated on one face (31) with a thin-film multilayer (34, 35, 36) containing at least one metal functional film (140, 180, 220) based on silver or made of silver having a thickness e comprised between 7 nm and 20 nm inclusive of these values, and two antireflection coatings (120, 160, 200, 240), said antireflection coatings each comprising at least one antireflection film (124, 164, 204, 244), said functional film (140) being placed between the two antireflection coatings (120, 160), characterised in that said multilayer comprises two discontinuous metal films (123, 167) each having a thickness e' comprised between 0.5 nm and 5 nm inclusive of these values, a lower discontinuous metal film (123) being located between, on the one hand, said face (31), and on the other hand, the only or the first metal functional film (140) as counted starting from said face (31), and an upper discontinuous metal film (167) being located above the only or the last metal functional film (140, 180, 220) as counted starting from said face (31).

Description

SUBSTRATE PROVIDED WITH A PARTIAL METAL LAYER STACK,

The invention relates to a transparent substrate, in particular a mineral rigid material such as glass, said substrate being coated with a stack of thin layers comprising one or more functional layers that can act on the solar radiation and / or the radiation. long wave infrared.

The invention more particularly relates to a substrate, in particular a transparent glass substrate, provided with a stack of thin layers comprising an alternation of "n" metal functional layers, in particular of functional layers based on silver or metal alloy containing silver, and "(n + 1)" antireflection coatings, with n integer> 1, so that the or each functional layer is disposed between two antireflection coatings. Each antireflection coating comprises at least one antireflection layer and each coating is preferably composed of a plurality of layers, of which at least one or even each layer is an antireflection layer. The concept of antireflection layer is here synonymous with that of dielectric layer; the notion of dielectric layer being used especially in opposition to the concept of metal functional layer, which by its metallic nature can not be dielectric.

The invention relates more particularly to the use of such substrates for manufacturing thermal insulation and / or sun protection glazings. These glazings can be intended both to equip buildings and vehicles, especially in order to reduce the air conditioning effort and / or to prevent excessive overheating (so-called "solar control" glazing) and / or to reduce the amount of energy dissipated to the outside (so-called "low emissive" glazing) driven by the ever increasing importance of glazed surfaces in buildings and vehicle interiors.

These substrates can in particular be integrated in electronic devices and the stack can then serve as an electrode for the conduction of a current (illuminating device, display device, panel photovoltaic, electrochromic glazing, ...) or can be integrated into glazing having particular functionalities, such as, for example, heated windows.

A type of layer stack known to give substrates such properties consists of a functional metallic layer with infrared reflection properties and / or solar radiation, especially a metallic functional layer based on silver or of metal alloy containing silver or completely silver.

In this type of stack, the functional metal layer is thus disposed between two antireflection dielectric coatings each in general comprising several layers which are each made of an antireflection material of the nitride type and in particular silicon nitride or aluminum or oxide type.

A blocking coating is however sometimes interposed between one or each antireflection coating and the functional metal layer, the blocking coating disposed under the functional layer towards the substrate protects it during a possible heat treatment at high temperature, the bending type and and / or quenching and the blocking coating disposed on the functional layer opposite the substrate protects this layer from possible degradation during the deposition of the upper antireflection coating and during a possible high temperature heat treatment, such as bending and / or quenching.

Currently, it is generally desired that each functional metal layer is a complete layer, that is to say is formed on the entire surface and over its entire thickness of the metal material considered.

The person skilled in the art considers that for a given material (for example silver), under the usual conditions for depositing this material, a complete layer is obtained only from a certain thickness only.

The adhesion energy between a complete silver layer and the antireflection layers is very low, of the order of approximately 1 J / m ² , and the adhesion energy between two antireflection layers is five to nine times higher. high that the one between silver and another anti-reflective layer. The adhesion energy of a stack comprising at least one silver-based or silver-based functional layer is therefore limited by this low adhesion energy of a complete metallic functional layer with the other materials.

The inventors have been interested in the possibility of depositing stacks of thin layers with one or more metal layers and with for several, and preferably at most two, metal layers a thickness less than the minimum thickness required to obtain a complete layer in the conditions considered.

The inventors have found that high mechanical strengths, and even, even more surprisingly, high chemical resistance, could be obtained for stacks comprising two discontinuous metal layers arranged, for one between the substrate and a single or a first functional layer. continuous metal of one stack and for the other above the single or the last continuous metallic functional layer of the stack.

In addition, the inventors have found that the stacks thus produced were transparent, without haze or without iridescence, and with colors, both in transmission and in reflection, which could be similar to those obtained with the stacks. functional metallic layer (s) complete.

It is then possible to use the specific non-uniform absorption range in the visible of such discontinuous metal layers to obtain specific absorption effects in certain wavelength ranges and neutralization of certain color characteristics (especially the color in reflection side stack or substrate side).

It is also possible, in the context of the invention, to obtain a higher solar factor than in the case of a similar stack comprising no discontinuous metal layer or comprising one or more continuous absorbent layers.

The prior art is aware of the international patent application No. WO 2011/123402 stacks with three functional metal layers, the metal functional layer which is located between the other two is a discontinuous layer. This discontinuous layer presents a visible light absorption and it is written that the deposition of this discontinuous metal layer on zinc stannate rather than zinc oxide increases the light absorption in the visible of the stack, that is, that is, the discontinuous metallic layer. However, the light absorption values for Examples 1 to 5, 9, as well as for counterexample 6 are not indicated.

Moreover, the integrated values of light transmission, of light reflection on the substrate side or stack side, are not indicated; for stacking on a single substrate (Table 1), only the colors after quenching heat treatment in the L * a * b * system, in reflection on the stacking side, in reflection on the substrate side and in transmission, are indicated.

The light transmission (VLT) is indicated for examples 1 -4, but only after double glazing; it is on average 40%.

The object of the invention is therefore, in its broadest sense, a substrate according to claim 1. This substrate is coated on one side of a stack of thin layers comprising at least one metal or silver-based functional layer having a thickness e of between 7 nm and 20 nm by integrating these values and two antireflection coatings, said antireflection coatings each comprising at least one antireflection layer, said functional layer being disposed between the two antireflection coatings. Said stack comprises two discontinuous metal layers each having a thickness e 'between 0.5 nm and 5 nm by integrating these values, a lower discontinuous metal layer being situated between on the one hand said face and on the other hand a single or the first metallic functional layer starting from said face and an upper discontinuous metal layer being located above a single or the last metallic functional layer from said face.

In a preferred variant, said stack comprises only these two discontinuous metal layers, the one that is lower and the one that is higher, without other discontinuous metal layer. According to the invention, each discontinuous metallic layer thus deposited is a self-structured layer having a structuring in the form of islands connected together, with uncovered areas between the islands.

Said lower discontinuous metal layer is preferably located inside a lower antireflection coating, with an antireflection layer on each side and the upper discontinuous metal layer is preferably located inside an upper antireflection coating, the last anti-reflective coating of the stack starting from the substrate, with an antireflection coating on each side.

In the case where said stack of thin layers comprises several metal functional layers, in particular several silver or silver-based metal functional layers, preferably none of the antireflection coatings which are located between two metallic functional layers comprise discontinuous metallic layer. having a thickness between 0.5 nm and 5 nm by integrating these values.

Within the meaning of the invention, each discontinuous metal layer may have a thickness e 'between 0.5 nm and 2 nm by integrating these values.

Preferably, each discontinuous metal layer is located firstly directly on an antireflection layer having a refractive index at 550 nm of at least 1.9 and secondly directly under an antireflection layer having a refractive index at 550 nm. at least 1, 9; For each discontinuous metal layer, the refractive index of said directly lower antireflection layer is preferably identical to the refractive index of said directly higher antireflection layer.

Preferably, moreover, each discontinuous metal layer is located firstly directly on an antireflection layer having an optical thickness at 550 nm of between 1 nm and 8 nm by integrating these values, or even between 2 nm and 6 nm by integrating these values and secondly directly under an antireflection layer having an optical thickness at 550 nm between 1 nm and 8 nm by integrating these values, or even between 2 nm and 6 nm by integrating these values. Since these discontinuous metal layers are not continuous, this makes it possible to have a direct contact between the antireflection layers which surround each discontinuous metallic layer. These areas have a strong membership. A possible crack developed at the weakest interface, that is between the discontinuous metallic layer and the adjacent antireflection layer, will also have to propagate between the two antireflection layers to advance, which requires a higher energy. It is thus in this way that the adhesion energy of the stack at this point is considerably improved, particularly with respect to a continuous absorbent layer.

By "discontinuous layer" in the sense of the present invention, it should be understood that when considering a square of any size on the surface of the stack according to the invention, then, in this square, the discontinuous functional layer is preferably, only over 50% to 98% of the area of the square, or even 53% to 83% of the area of the square, or even 63% to 83% respectively.

The square considered is located in a main part of the coating; it is not within the scope of the invention to achieve a particular edge or a particular contour which would then be hidden for the end use.

According to the invention, this type of self-structured discontinuous metallic layer has an adhesion energy greater than a continuous metallic functional layer and its optical properties (light transmission, light reflection and emissivity) are reduced while remaining within acceptable ranges for some specific applications.

Preferably, each discontinuous metal layer is silver-based or is silver.

Preferably, each discontinuous metal layer is not in direct contact, either below or above, with a continuous metal layer.

It is also possible that:

said antireflection coating placed under each metallic functional layer comprises an antireflection layer of average index of a material having a refractive index of between 1.8 and 2.2 at 550 nm, this antireflection layer having a mean index preferably being oxide base and / or this antireflection layer of average index preferably having a physical thickness of between 5 and 35 nm.

said antireflection coating disposed between the face and a first or only metallic functional layer comprises a high index antireflection layer made of a material having a refractive index of between 2.3 and 2.7 at 550 nm, this antireflection layer; with a high index preferably being based on oxide and / or said high index antireflection layer preferably having a physical thickness of between 5 and 25 nm.

the antireflection coating disposed above a first or only metallic functional layer, opposite the face, comprises an antireflection layer of average index of a material having a refractive index of between 1.8 and 2.2 to 550 nm, this antireflection layer of average index preferably being based on oxide and / or said antireflection layer of average index preferably having a physical thickness of between 5 and 35 nm.

the antireflection coating disposed above a first or only metallic functional layer, opposite the face, comprises a high index antireflection layer made of a material having a refractive index of between 2.3 and 2.7 to 550 nm, said high index antireflection layer preferably being based on oxide and / or said high index antireflection layer preferably having a physical thickness of between 5 and 25 nm.

said stack comprises two or three silver or silver-based metal functional layers each having a thickness e of between 7 nm and 20 nm by integrating these values and said stack further comprises two discontinuous metal layers each having a thickness e '; between 0.5 nm and 5 nm by integrating these values, a lower discontinuous metal layer being situated between on the one hand said face and on the other hand a single or the first metallic functional layer starting from said face and a metal layer discontinuous upper being located above a single or the last metallic functional layer from said face;

said stack comprises two or three silver or silver-based metal functional layers each having a thickness e between 7 nm and 20 nm by integrating these values and said stacking further comprises only two discontinuous metal layers each having a thickness e 'between 0.5 nm and 5 nm by integrating these values, a lower discontinuous metal layer being located between on the one hand said face and on the other hand a single or the first metallic functional layer starting from said face and an upper discontinuous metal layer being located above a single or the last metallic functional layer from said face.

By "coating" in the sense of the present invention, it should be understood that there may be a single layer or several layers of different materials inside the coating.

By "stacking", it is necessary to understand a set of thin layers deposited on one another, without interposing between these layers of a mineral substrate (such as glass) or organic substrate (such as a plastic sheet).

As usual, by "layer based on a material" it is to be understood that the layer consists mainly of this material, that is to say that the chemical element of the material, or possibly the product of the material considered in its stable stoichiometric formula, constitutes at least 50%, as an atomic percentage of the layer under consideration.

As usual, "metallic functional layer" refers to the deposition of an IR reflective layer and is continuous.

As usually also, by "antireflection layer" in the sense of the present invention, it should be understood that from the point of view of its nature, the material is "non-metallic", that is to say is not a metal. In the context of the invention, this term designates a material having an n / k ratio over the entire visible wavelength range (from 380 nm to 780 nm) equal to or greater than 5.

It is recalled that n denotes the actual refractive index of the material at a given wavelength and k represents the imaginary part of the refractive index at a given wavelength; the ratio n / k being calculated at a given wavelength. The refractive index values given in this document are the values measured as usually at the wavelength of 550 nm.

According to the invention, said, or each discontinuous metal layer may have a thickness e ':

1.0 <e <4.5 nm, or even 1.0 <e <4.0 nm; or 2.0 <e <4.5 nm, or even 2.0 <e '<4.0 nm, deposited on a titanium dioxide-based layer Τ1Ό2, or

1.0 <e <4.5 nm, or even 1.0 <e <4.0 nm; or 2.0 <e '<4.5 nm, or even 2.0 <e'<4.0 nm, deposited on a layer based on zinc oxide and tin SnZnO _x , or

1.0 <e <5.0 nm, or even 1.0 <e <4.5 nm; or 2.0 <e <5.0 nm, or even 2.0 <e <4.5 nm, deposited on a ZnO zinc oxide layer, or

- 1.0 <e <5.0 nm, or even 1.0 <e '<4.0 nm; or 2.0 <e '<5.0 nm, or even 2.0 <e' <4.0 nm, deposited on a silicon nitride layer

Preferably, the stack according to the invention is deposited directly on the face of the substrate.

For a stack according to the invention comprising a single continuous metal functional layer, this functional layer may have a thickness of between 8 and 17 nm, or even between 10 and 15 nm, or even between 12 and 14 nm to achieve an effective low-emissive stack. In another particular version of the invention, at least one metallic functional layer is deposited directly on a sub-blocking coating disposed between the functional layer and the antireflection coating underlying the functional layer and / or at least one functional layer. is deposited directly under an overblocking coating disposed between the functional layer and the antireflection coating overlying the functional layer and the underblocking coating and / or the overblocking coating comprises a thin nickel layer or titanium having a physical thickness of between 0.2 nm and 2.5 nm incorporating these values. The last layer of the overlying antireflection coating, the furthest away from the substrate, may be oxide-based, and is preferably then deposited under stoichiometric conditions; it may in particular be based on titanium dioxide (made of TiO _x ) or on the basis of mixed oxide of zinc and tin (in Sn _z Zn _y O _x ).

The stack can thus comprise a last layer ("overcoat" in English), that is to say a protective layer, deposited preferably stoichiometric. This layer is found oxidized essentially stoichiometrically in the stack after deposition.

The invention furthermore relates to a multiple glazing unit comprising at least two substrates which are held together by a frame structure, said glazing effecting a separation between an outer space and an interior space, in which at least one spacer gas strip is disposed between the two substrates, a substrate being according to the invention.

In a particular variant, the stack according to the invention is positioned in front of a double glazing unit, that is to say on one side of the glazing which is not protected by the intermediate gas blade because stacking is particularly resistant.

The glazing according to the invention incorporates at least the carrier substrate of the stack according to the invention, optionally associated with at least one other substrate. Each substrate can be clear or colored. At least one of the substrates may be colored glass in the mass. The choice of the type of coloration will depend on the desired level of light transmission and / or the colorimetric appearance sought for the glazing once its manufacture is complete.

The glazing according to the invention may have a laminated structure, in particular associating at least two rigid substrates of the glass type with at least one thermoplastic polymer sheet, in order to present a glass-like structure / thin-film stack / sheet (s) / glass / glass sheet. The polymer may especially be based on polyvinyl butyral PVB, ethylene vinyl acetate EVA, PET polyethylene terephthalate, PVC polyvinyl chloride.

The invention furthermore relates to the use of two discontinuous metal layers according to the invention in a stack comprising at least one metallic functional layer based on silver or in silver having a thickness e between 7 nm and 20 nm by integrating these values and two antireflection coatings, said antireflection coatings each comprising at least one antireflection layer, said functional layer being disposed between the two antireflection coatings, said stack comprising two discontinuous metal layers each having a thickness e 'between 0.5 nm and 5 nm by integrating these values, a lower discontinuous metal layer being situated between on the one hand said face and on the other hand a single or the first metallic functional layer starting from said face and an upper discontinuous metal layer being located above a single or the last metallic functional layer from said face. In a preferred variant, said stack comprises only these two discontinuous metal layers, the one that is lower and the one that is higher, without other discontinuous metal layer.

The invention furthermore relates to a method for depositing two discontinuous metal layers according to the invention in a stack comprising at least one metallic or silver-based functional layer having a thickness e of between 7 nm and 20 nm by integrating these values and two antireflection coatings, said antireflection coatings each comprising at least one antireflection layer, said functional layer being disposed between the two antireflection coatings, said stack comprising two discontinuous metal layers each having a thickness e 'of between 0.5 nm and 5 nm; integrating these values, a lower discontinuous metal layer being located between firstly said face and secondly a single or first metallic functional layer starting from said face and an upper discontinuous metal layer being located above a single or last metallic functional layer starting from said face. In a preferred variant, said stack comprises only these two discontinuous metal layers, the one that is lower and the one that is higher, without other discontinuous metal layer.

Advantageously, the present invention thus makes it possible to produce a stack of thin layers having, deposited on a transparent substrate, a visible light transmission T _L > 50% and a light reflection in the visible R _c (stack side) less than 20% and even less than 10% with relatively neutral colors in transmission and reflection, while having a lower emissivity than the substrate alone.

Advantageously, the present invention thus makes it possible to carry out a stack of thin films with 1, 2, 3, 4, or even more, functional layer (s) based on silver or silver and comprising two and preferably only two discontinuous metal layers, one lower and the other upper, so that the stack has high mechanical strength and / or high chemical resistance.

The details and advantageous features of the invention emerge from the following nonlimiting examples, illustrated with the aid of the attached figures illustrating:

- In Figure 1, a monolayer stack functional to a discontinuous metal layer, the discontinuous metal layer being deposited above the metal functional layer;

in FIG. 2, a functional monolayer stack with a discontinuous metal layer, the discontinuous metal layer being deposited below the metallic functional layer;

in FIG. 3, a functional monolayer stack with two discontinuous metal layers, a discontinuous metal layer being deposited above the metallic functional layer and a discontinuous metal layer being deposited below the metallic functional layer;

in Figure 4, a double glazing solution incorporating a stack according to the invention;

in FIG. 5, binary TEM images, from left to right, for a discontinuous silver metal layer having a surface occupation ratio of 53% to 98%;

in FIG. 6, the light transmission T _L , (expressed as a factor of 0 to 1 for values usually considered 0 to 100%) of Examples 1 to 3 as a function of the wavelength λ; in FIG. 7, the absorption spectrum Ab (expressed as a factor of 0 to 1 for values usually considered 0 to 100%) of Examples 1 to 3 as a function of the wavelength λ;

in FIG. 8, the light reflection R _L , (expressed as a factor of 0 to 1 for values usually considered 0 to 100%) of Examples 1 to 3 as a function of the wavelength λ;

in FIG. 9, the light transmission T _L , in%, of the substrate alone and examples 5, 5.0, 5.1 and 5.2 as a function of the wavelength λ;

in FIG. 10, the Ab absorption spectrum, in%, of the substrate alone and of Examples 5, 5.0, 5.1 and 5.2 as a function of the wavelength λ;

in FIG. 1 1, the light reflection R _G , in%, on the opposite side to the stack, of the substrate alone and examples 5, 5.0, 5.1 and 5.2 as a function of the wavelength λ;

in FIG. 12, the light reflection R _c , in%, next to the stack, the substrate alone and examples 5, 5.0, 5.1 and 5.2 as a function of the wavelength λ;

in FIG. 13, a functional bilayer stack with two discontinuous metal layers, a discontinuous metal layer being deposited beneath the first metallic functional layer and a discontinuous metal layer being deposited above the second metallic functional layer;

FIG. 14 shows a functional tri-layer stack with two discontinuous metal layers, a discontinuous metal layer being deposited below the first metallic functional layer and a discontinuous metal layer being deposited on top of the third metallic functional layer.

FIGS. 1 to 3 illustrate a structure of a functional monolayer stack 34 deposited on a transparent glass substrate, and more specifically on a face 31 of this substrate 30, in which the single functional layer 140, based on silver or of metal alloy containing silver and preferably only silver, is disposed between two antireflection coatings, the underlying antireflection coating 120 located below the functional layer 140 towards the substrate 30 and the overlying antireflection coating 160 disposed above the functional layer 140 opposite the substrate 30.

These two antireflection coatings 120, 160 each comprise at least one antireflection layer 128, 168.

Optionally, on the one hand, the functional layer 140 may be deposited directly on a sub-blocking coating 130 placed between the underlying antireflection coating 120 and the functional layer 140 and, on the other hand, the functional layer 140 may be deposited directly under an overblocking coating 150 disposed between the functional layer 140 and the overlying antireflection coating 160.

The layers of under and / or overlocking, although deposited in metallic form and presented as being metal layers, are in practice oxidized layers because their primary function is to oxidize during the deposition of the stack so to protect the functional layer.

This antireflection coating 160 may be terminated by an optional protective layer (not shown), in particular based on oxide, in particular under stoichiometric oxygen.

When a functional monolayer stack is used in a multiple glazing unit 100 of double glazing structure, as illustrated in FIG. 4, this glazing comprises two substrates 10, 30 which are held together by a frame structure 90 and which are separated one from the other by an interposed gas blade 15.

The glazing thus makes a separation between an outer space ES and an interior space IS.

The stack according to the invention, because of its high mechanical strength, can be positioned in face 4 (on the innermost sheet of the building by considering the incident sense of sunlight entering the building and on its face turned inwards).

FIG. 4 illustrates this positioning (the incident direction of the solar light entering the building being illustrated by the double arrow) in face 4 of a stack 34 of thin layers positioned on an outer face 31 of the substrate 30 in contact with the outer space ES, the other face 29 of the substrate 30 being in contact with the spacer gas strip 15. However, it can also be envisaged that in this double glazing structure, one of the substrates has a laminated structure; however, there is no possible confusion because in such a structure, there is no intervening gas blade.

A series of seven examples has been realized:

Example 1 is a reference example: it is a functional monolayer stack without any discontinuous metal layer;

- Example 2 is a comparative example based on Example 1 and which further comprises, in the upper part of the functional monolayer stack (that is to say above this functional layer, starting with of the substrate), an absorbent metal layer 167 ';

Example 3 is an example according to the invention which is based on Example 1 and which further comprises, in the upper part of the functional monolayer stack, a discontinuous metallic layer 167, upper;

Example 4 is a comparative example which is based on Example 1 and which further comprises, in the lower part of the functional monolayer stack (that is to say between this functional layer and the substrate), a layer absorbent 123 ';

Example 5 is an example which is based on Example 1 and which further comprises, in the lower part of the functional monolayer stack, a discontinuous metallic layer 123, lower;

- Example 6 is a comparative example based on Example 1 and which further comprises, in the lower part of the functional monolayer stack (that is to say between this functional layer and the substrate), a absorbent layer 123 'and which further comprises, in the upper part of the functional monolayer stack (that is to say above this functional layer, starting from the substrate), an absorbent layer 167';

Example 7 is an example which is based on Example 1 and which further comprises, in the lower part of the functional monolayer stack, a discontinuous metallic layer 123, which is smaller and which further comprises, in the upper part of the functional monolayer stack, a discontinuous metallic layer 167, upper;

For all the stacks below, the layer deposition conditions are:

The layers deposited for these examples can thus be classified in five categories:

i-layers of dielectric / antireflection material, having an n / k ratio over the entire visible wavelength range greater than 5: Si ₃ N layers 121, 121 ', 128, 162, 168, 169, 169' ₄ : Al, or Ti0 ₂ , or ZnO

i-continuous metal functional layers in A, material with infrared reflection properties and / or in solar radiation ii-overlock layers 150 for protecting the functional layer against a change in its nature during the deposition of the stacking: Ni, NiCr; their influence on the optical and energetic properties is generally ignored when they have a low thickness (equal to or less than 2 nm)

iv- for examples 3, 5 and 7: discontinuous metallic layers 123 and / or 167, or "DML" layers for "Discontinuous Metallic Layer" in English.

v- for examples 2, 4 and 6 comparative: absorbent layers 123 ', 167', titanium metal; this type of layer is a continuous layer.

In all the examples, the stack of thin layers was deposited on a substrate, G, made of clear soda-lime glass with a thickness of 4 mm of the Planilux brand, distributed by the company SAINT-GOBAIN.

For these stacks, - T _L indicates: the light transmission in the visible in%, measured according to the illuminant D65 at 2 °;

- a ^* _T and b ^* _T indicates the transmission color a ^* and b ^* in the LAB system measured according to the illuminant D65 at 2 °;

- RG indicates: the light reflection on the glass side (surface of the substrate opposite that on which the stack is deposited) in the visible in%, measured according to the illuminant D65 at 2 °;

- a ^* _G and b ^* _G indicates the reflection color a ^* and b ^* in the LAB system measured according to the illuminant D65 at 2 °, the opposite side of the substrate to the coated side (face 29);

- R _C indicates: the light reflection side stack of thin layers (surface 31 of the substrate) in the visible in%, measured according to the illuminant D65 to

2 °;

a ^* _c and b ^* _c indicate the reflection color a ^* and b ^* in the LAB system measured according to the illuminant D65 at 2 °, side of the coated substrate (face 31)

- g indicates the factor g, or solar factor of a configuration:

for Examples 1 to 3: of the stack disposed in face 3 of a double glazing comprising two 4 mm glass substrates separated from a 16 mm argon gas plate, the substrate carrying the stack being thus the second substrate traversed by incident solar light, and

for examples 4 to 7: of the stack disposed on side 2 of a double glazing comprising two 4 mm glass substrates separated from a 16 mm argon gas plate, the substrate carrying the stack being thus the first substrate traversed by the incident solar light.

This factor is determined by EN 410 and corresponds to the sum of the direct energy transmission through the glazing and the secondary heat transfer inwards.

According to the invention, a discontinuous metal layer, DML is a discontinuous layer which preferably has a surface occupation ratio (in proportion to the area of the layer which lies just below the discontinuous metal layer and which is covered by the discontinuous metal layer) of between 50% and 98%. According to the invention, a discontinuous metal layer, DML is a layer which preferably comprises (at least 50% by atomic ratio) at least one of the metals chosen from the list: Ag, Au, Cu, Pt.

According to the invention, a discontinuous metal layer, DML is a layer which is preferably framed on each side, above and below, by a layer of dielectric / antireflection material, whose refractive index n is, preferably at least 1, 9.

Figure 5 shows, from left to right:

a surface occupation rate of 53% obtained with a silver thickness of 2 nm; this stack having an emissivity ε = 88.7%;

a surface occupation rate of 63% obtained with a silver thickness of 3 nm; this stack having an emissivity ε = 49.3%;

a surface occupation rate of 84% obtained with a silver thickness of 4 nm; this stack having an emissivity ε = 23.9%;

a surface occupation rate of 98% obtained with a silver thickness of 5 nm; this stack having an emissivity ε = 15.7%,

obtained for a stack Z of thin layers having the structure: Substrate / ZnO / Ag / ZnO DML layer, each layer of ZnO (with a refractive index of n = 1, 9) having a thickness of 10 nm.

The theoretical calculations show that it is possible to obtain, with the Z-type stack, an emissivity ε _ζ , which is less than that of the substrate alone, for a silver thickness of the DML equal to or less than 5 nm. that is to say for a surface occupation rate of between 50% and 98%, while being greater than that found.

In this document, when referring to the thickness e of a DML, it is not the thickness measured in the areas covered by the LMD or of an average thickness, but of the thickness that would be obtained if the layer was continuous.

This value is accessible by considering the deposition rate of the layer (or more precisely the rate of travel of the substrate in the deposition chamber of the metallic functional layer), the quantity of material sprayed per unit time, and the surface area. on which is operated the deposit. This thickness is very practical because it allows a direct comparison with the continuous functional layers.

The thickness e 'is thus the thickness that would be measured if the layer deposited was continuous.

In practice, if usually, under the same magnetron sputtering deposition conditions (very low pressure, composition of the target, rate of travel of the substrate, electrical power at the cathode) the thickness of the functional layer is 10 nm, it It is necessary and sufficient to reduce the rate of travel of the substrate by half to obtain a functional layer thickness which is half, that is to say 5 nm.

In this FIG. 5, this is what has been observed by transmission electron microscopy, TEM, shown in binary (black-white) mode. On the four pieces of this figure, the silver is in white and the ZnO in black.

It has been found that for a Z-stack of this type, the adhesion energy is approximately constant for a silver thickness greater than 5 nm: this energy is between 1.0 and 1.5 J / m ² , which is pretty weak.

Table 1 below illustrates the geometric or physical thicknesses (and not the optical thicknesses) in nanometers of each of the layers of Examples 1 to 3, with reference to FIG.

Layer Ex. 1 Ex. 2 Ex. 3

169 - TiC-2 2 nm 2 nm 2 nm

167 '- Ti 1 nm 167 - Ag 1 nm

169 '- TiC-2 2 nm 2 nm

168 - If ₃ N ₄ : Al 30 nm 28 nm 28 nm

164 - TiC-2 1 1 nm 1 1 nm 1 1 nm

162 - ZnO 6 nm 6 nm 6 nm

140 - Ag 13 nm 13 nm 13 nm

128 - ZnO 5 nm 5 nm 5 nm

124 - TiC-2 23 nm 23 nm 23 nm

Table 1

For these examples 1 to 3, the antireflection coating 120 disposed between the face 31 and the single metallic functional layer 140 comprises a high index antireflection layer 124 made of a material having a refractive index of between 2.3 and 2.7 at 550 nm, this antireflection layer 124 of high index preferably having a physical thickness of between 5 and 25 nm.

For these examples 1 to 3, the antireflection coating 160 disposed above the single metallic functional layer 140, comprises an antireflection layer 162 of average index of a material having a refractive index of between 1.8 and 2.2 at 550 nm, this antireflection layer 162 of average index preferably having a physical thickness of between 5 and 35 nm.

Table 2 below illustrates the physical thicknesses in nanometers of each of the layers of Examples 4 and 5, with reference to FIG. Layer Ex. 4 Ex. 5

168 - If ₃ N ₄ : Al 40 nm 40 nm

162 - ZnO 5 nm 5 nm

150 - 0.5 nm NiCr 0.5 nm

140 - Ag 13 nm 13 nm

128 - ZnO 5 nm 5 nm

121 '- TiC-2 20 nm 20 nm

123 '- NiCr 1 nm 123 - Ag 1 nm

121 - TiC-2 3 nm 3 nm

Table 2

Table 3 below illustrates the physical thicknesses in nanometers of each of the layers of Examples 6 and 7, with reference to FIG.

Table 3 Examples 2, 4 and 6 are comparable respectively to Examples 3, 5 and 7 since they all comprise a single metallic functional layer made of the same material (Ag) and of the same thickness; these examples are also comparable to Example 1 since it also comprises a single metallic functional layer made of the same material (Ag) and of the same thickness; the antireflection coatings are not identical in a series (series of Examples 2-3, series of Examples 4-5, series of Examples 6-7) to the other because their compositions have been optimized to try to obtain the best possible performance.

The following table presents the main optical characteristics of Examples 3, 5 and 7 comprising one (eg 3 and 5) or two (eg 7) DML layer (s) and compares these characteristics with those of Examples 2, 4 and 6 respectively. comprising one (eg 2 and 4) or two (eg 6) absorbent layer (s), made of Ti of a thickness equivalent to that of each DML layer, as well as the characteristics of Example 1 which has no DML layer or absorbent layer.

Table 4 It has been found that it is possible to achieve:

a metal functional monolayer stack having a discontinuous metal layer in the upper antireflection coating (eg 3) which has a solar factor g higher than that of a functional metal monolayer stack having an absorbent metal layer in the upper antireflection coating (e.g. 2) for an almost identical visible light transmission;

a metal functional monolayer stack having a discontinuous metal layer in the lower antireflection coating (eg 5) which has a solar factor g higher than that of a functional metal monolayer stack having an absorbent metal layer in the lower antireflection coating (e.g. 4) for an almost identical visible light transmission;

a metal functional monolayer stack having a discontinuous metal layer in the lower antireflection coating and a discontinuous metal layer in the upper antireflection coating (eg 7) having a solar factor g higher than that of a functional metal monolayer stack having a layer absorbent metal in the lower antireflection coating and an absorbent metal layer in the lower antireflection coating (eg 6) for near identical light transmission.

In addition, it has been found an improvement of the color neutralization, with in particular a less yellow transmission color, with a lower b * _T , or even negative.

FIGS. 6 to 8 show, respectively, the light transmission T _L , the absorption Ab and the light reflection on the stack side R _c as a function of the wavelength λ (in nm) of Examples 1 to 3.

Figure 6 shows that the DML layer stack (eg 3) provides a light transmission in the visible which is very close to that obtained with the absorbent metal layer stack (eg 2); however, absorption is higher in the high and near infrared (from 550 nm to 1000 nm) with Example 3 than with Example 2, and the stack side reflection is lower in the high visible and in the near infrared (from 550 nm to 1000 nm) with Example 3 than with Example 2, which ultimately allows to obtain a higher solar factor for the same level of light transmission in the visible.

FIGS. 9 to 12 show, respectively, the light transmission TL, the absorption Ab, the substrate-side light reflection R _G , and the stack-side light reflection R _C as a function of the wavelength λ (in nm) of the substrate G , alone, that is to say without any layer on one of these faces, of Example 5, and Examples 5.0, 5.1, 5.2 made on the basis of Example 5; these examples 5.0, 5.1, 5.2 have the only difference with example 5:

the thickness of the DML layer which is 0 nm (absence of DML layer) for example 5.0,

the thickness of the DML layer which is 0.9 nm for Example 5.1, and

the thickness of the DML layer which is 1.2 nm for Example 5.2. These figures show that the presence of the DML layer certainly decreases the light transmission because the absorption increases but the light reflection on the substrate side and stack side is low.

Increasing the nominal thickness of DML increases the overall level of absorption and color selectivity.

These tests have shown in particular that the thickness range e 'from 0.9 to 1.2 nm for a discontinuous metal layer is particularly favorable for obtaining a relatively high light transmission in the visible (65-68% ) while having a light reflection on the glass side rather low (6-7%) and a light reflection side stacking quite low (8-9%).

In addition, low values of b * _c (of the order of -15), low values of b * _G (of the order of -10) and low values of a * _T (of the order of -1, 0 to +0.3) were obtained.

For all the preceding examples, the and / or each discontinuous metal layer 123, 167 is located firstly directly on a layer antireflection 121 ', 169' having a refractive index at 550 nm of at least 1, 9 and even in this case 2.3 because of the use of Τ1Ό2 and secondly directly under an antireflection layer 121 , 169 having a refractive index at 550 nm of at least 1.9, and even in this case 2.3 because of the use of Τ1Ό2, the refractive index of said antireflection layer 121 ', 169' directly below being here identical to the refractive index of said antireflection layer 121, 169 directly higher.

Tests have shown that it is possible to use silicon nitride, Si ₃ N ₄ : Al, with a refractive index at 550 nm of 2.0 in place of the Τ1Ό2 for the layers 121, 121 ', 169 , 169 '.

It has been found that the and / or each DML layer 123, 167 has an absorption spectrum such that the absorption is relatively low in the wavelength range of 380 nm to 480 nm, relative to the absorption. in the wavelength range of 480 nm to 780 nm.

It has furthermore been found that it is not necessary for the and / or each DML layer 123, 167 to be in direct contact, either below or above, with a continuous metallic layer, since in this case the spectrum of The specific absorption of the DML layer coincides with the relatively constant absorption spectrum in the visible (from 380 nm to 780 nm) of the continuous metal layer which is in contact with it.

FIGS. 13 and 14 respectively illustrate a structure of a stack of functional bilayers and a structure of a stack of three functional tri-layers, deposited on a transparent glass substrate, and more precisely on a face 31 of this substrate.

Each functional layer 140 180, 220, which is preferably predominantly based on silver or metal alloy containing silver and more preferably solely silver, is disposed between two antireflection coatings, an underlying antireflection coating 120 , 160, 200 located below each functional layer 140, 180, 220 towards the substrate 30 and an overlying antireflection coating 160, 200, 240 disposed above each functional layer 140, 180, 220 on the opposite side substrate 30. Each antireflection coating 120, 160, 200, 240 comprises at least one antireflection layer 128, 168, 208, 248.

FIG. 3 shows a stack 34 which comprises a metallic functional layer 140, preferably mainly based on silver or silver, which is the single metallic functional layer of the stack and two discontinuous metal layers 123, 167, one being located between on the one hand said face 31 and on the other hand the metallic functional layer 140 starting from said face 31 and the other being situated above the metallic functional layer 140 starting from said face 31.

Figure 13 illustrates a similar solution for a functional bilayer stack. This stack 35 comprises two metal functional layers 140, 180, preferably mainly based on silver or silver, and two discontinuous metal layers 123, 167, one being located between said face 31 and the other side. part of the first metal functional layer 140 starting from said face 31 and the other being located above the second metal functional layer 180 starting from said face 31.

Figure 14 illustrates a similar solution for a functional tri-layer stack 36. This stack 36 comprises three metal functional layers 140, 180, 220, preferably mainly based on silver or silver and two discontinuous metal layers 123, 167, one being situated between on the one hand said face 31 and on the other hand, the first metallic functional layer 140 starting from said face 31 and the other being situated above the third metallic functional layer 220 starting from said face 31.

These three dual DML configurations allow for low light reflection stacks with more neutral transmission and reflection colors than if the discontinuous metal layers were both replaced in each configuration by an absorbent metal layer.

Using predominantly one (or more) noble metal of the Ag, Au, PT or Cu type makes it possible to deposit a DML in a simple and reliable manner by magnetron sputtering because this process makes it possible to manage growth well in islands; indeed, the selective absorption rests in particular on the plasmonic character of the metal which is made possible by an island structuring.

The present invention is described in the foregoing by way of example. It is understood that the skilled person is able to realize different variants of the invention without departing from the scope of the patent as defined by the claims.

Claims

1. Substrate (30) coated on one face (31) of a stack of thin layers (34, 35, 36) having at least one metallic functional layer (140, 180, 220) based on silver or silver having a thickness e between 7 nm and 20 nm by integrating these values and two anti-reflective coatings (120, 160, 200, 240), said antireflection coatings each comprising at least one anti-reflection layer (128, 168, 208, 248), said functional layer ( 140) being disposed between the two antireflection coatings (120, 160), characterized in that said stack comprises two discontinuous metal layers (123, 167) each having a thickness e 'of between 0.5 nm and 5 nm by integrating these values a lower discontinuous metal layer (123) being located between said face (31) and a single or first metallic functional layer (140) from said face (31) and a discontinuous metal layer; higher (167 ) being located above a single or the last metallic functional layer (140, 180, 220) from said face (31).

2. Substrate (30) according to claim 1, characterized in that said stack comprises only these two discontinuous metal layers, without other discontinuous metal layer.

3. Substrate (30) according to claim 1 or 2, characterized in that each discontinuous metal layer (123, 167) is located firstly directly on an antireflection layer (121 ', 169') having a refractive index at 550 nm of at least 1, 9 and secondly directly under an antireflection layer (121, 169) having a refractive index at 550 nm of at least 1.9, the refractive index of said antireflection layer ( 121 ', 169') directly lower preferably being identical to the refractive index of said antireflection layer (121, 169) directly higher.

4. Substrate (30) according to any one of claims 1 to 3, characterized in that each discontinuous metal layer (123, 167) is located firstly directly on an antireflection layer (121 ', 169') having a optical thickness at 550 nm between 1 nm and 8 nm in integrating these values, even between 2 nm and 6 nm by integrating these values and secondly directly under an antireflection layer (121, 169) having an optical thickness at 550 nm between 1 nm and 8 nm by integrating these values, even between 2 nm and 6 nm by integrating these values.

5. Substrate (30) according to any one of claims 1 to 4, characterized in that each discontinuous metal layer (123, 167) is based on silver or is silver.

6. Substrate (30) according to any one of claims 1 to 5, characterized in that said antireflection coating (120, 160, 200) disposed under each metal functional layer (140, 180, 220) comprises an antireflection layer (128 , 168, 208) of average index of a material having a refractive index of between 1.8 and 2.2 at 550 nm, said antireflection layer (128, 168, 208) of average index being preferably based on oxide and / or said antireflection layer (128, 168, 208) of average index preferably having a physical thickness of between 5 and 35 nm.

7. Substrate (30) according to any one of claims 1 to 6, characterized in that said antireflection coating (120) disposed between the face (31) and a first or only metallic functional layer (140) comprises a layer high-index antireflection coating (124) made of a material having a refractive index between 2.3 and 2.7 at 550 nm, said high-index antireflection layer (124) being preferably based on oxide and / or this antireflection layer (124) of high index preferably having a physical thickness of between 5 and 25 nm. 8. Substrate (30) according to any one of claims 1 to 7, characterized in that the antireflection coating (160) disposed above a first or the only metallic functional layer (140), the opposite of the face (31), comprises an antireflection layer (162) of average index of a material having a refractive index of between 1,

8 and 2.2 at 550 nm, this antireflection layer (162) of average index preferably being based on oxide and / or said antireflection layer (162) of average index preferably having a physical thickness of between 5 and 35 nm.

9. Multiple glazing (100) comprising at least two substrates (10, 30) which are held together by a frame structure (90), said glazing providing a separation between an external space (ES) and an interior space (IS), wherein at least one spacer gas strip (15) is disposed between the two substrates, at least one substrate (30) according to any one of claims 1 to 8.

10. Use of two discontinuous metal layer (s) (123, 167) in a stack of thin layers (34, 35, 36) which is deposited on a substrate (30) according to any one of Claims 1 to 8.

11. Method of depositing two discontinuous metal layer (s)

(123, 167) in a stack of thin layers (34, 35, 36) which is deposited on a substrate (30) according to any one of claims 1 to 8.