WO2012175712A2

WO2012175712A2 - Partially transparent layer system having high ir reflection and method for the production thereof

Info

Publication number: WO2012175712A2
Application number: PCT/EP2012/062149
Authority: WO
Inventors: Holger Pröhl; Falk Milde
Original assignee: Von Ardenne Anlagentechnik Gmbh
Priority date: 2011-06-23
Filing date: 2012-06-22
Publication date: 2012-12-27
Also published as: DE102011105718B4; WO2012175712A3; DE102011105718A1; CN103619775A

Abstract

The invention relates to a partially transparent IR-reflecting layer system (1), which is arranged on a transparent substrate (2) and which comprises, from the substrate (2) upward, a base layer assembly at least having a dielectric base layer (6), a functional layer assembly at least having an IR reflection layer (10), and a surface layer assembly at least having a dielectric surface layer (14). In order to achieve an adjustable color and transmittance, a very highly refractive, partially absorbing layer (4) is arranged between the substrate (2) and the base layer assembly or above the surface layer assembly or at both positions. The invention further relates to a method for producing such an IR-reflecting layer system (1) and to an architectural glass element that uses such an IR-reflecting layer system (1).

Description

The invention relates to a partially transparent layer system with high IR reflection, which is arranged on a transparent substrate. It also relates to a method for producing such a layer system and a

Architectural glass element comprising such an IR reflective layer system.

Transparent IR-reflecting layer systems, which include the partially transparent layer systems and which are referred to below as IR-reflecting layer systems, are known as low-layer systems in

Thermal insulation glazings known. They should be the

Prevent heat radiation, i. have a low energy emission. According to Kirchhoff's law of radiation this is synonymous with low absorption and high reflection in the wavelength range of infrared radiation (IR) of> 3 pm. According to various applications, either a high transmission or a specifically adjustable transmission in the range of global solar radiation (solar energy transmission) is desired at the same time, which covers the wavelength ranges of near infrared (NIR) and visible light (VIS) from 300 nm to <3 pm (solar energy). Area). The ratio of transmission,

limited to the visible light range, relative to the energy transmission characterizes the filter effect for visible light and is referred to as selectivity. In building glazing becomes a high solar in climatic regions with predominant energy loss

Energy transmission of the glazing preferred, resulting in a solar energy gain, while in climatic regions in which the energy input through the glazing predominates, a low energy transmission and thus connected a high selectivity of the glazing used is advantageous.

In the first case required in thermal insulation glazings

Designs of the LowE layer system is desired to have a steep edge in the transition from the NIR to the IR of the light, which represents a large drop in transmission and a large increase in reflection, with the regular

Reflection transmission edge becomes steeper with increasing number of functional IR reflection layers. In the second case, which is also referred to as Sonnenschut zverglasung (LowE-Sun), the transmission in the entire solar area is reduced and / or it is targeted a hue of the layer system adjustable. Furthermore, the above

described edge of the transmission drop preferably in the direction of the transition from the visible (VIS) to near-infrared (NIR) spectral range, which is located at about 800 nm, shifted.

In general, an IR-reflective layer system initially comprises a substrate viewed from the substrate

Base layer arrangement, which in particular the adhesion of the system on the glass, the chemical and / or mechanical resistance and / or the adjustment of optical

Properties of the system, e.g. the mirroring serves.

Over the base layer arrangement follows a

Functional layer arrangement, which comprises the IR reflection layer and optionally further layers, which these

Support function and the influence of their optical, chemical, mechanical and electrical properties. The IR reflection layers consist of a noble metal, usually silver, or a noble metal alloy. There are also other materials used, mostly layers, the metallic or

dielectric nickel or chromium or alloys of both. These materials in turn require one

Adaptation of the remaining, belonging to the layer system Layers. To the optional complementary layers of

Functional layer arrangement in particular count

Blocker layers that prevent or at least significantly inhibit diffusion and migration processes in the functional layer

reduce and over and / or under an IR

Reflection layer can be arranged, as well as absorbing layers through which the light transmission of the

Make SchichtSystems adjustable.

At the top is completed an IR-reflective

Layer system by a cover layer arrangement, the at least one mechanically and / or chemically stabilizing

Protective layer comprises. This can be self or through

complementary layers also the visual effect of

Layer system, e.g. a reflection with the use of interference effects, so that optionally in conjunction with an anti-reflective high-refractive base layer, the transmission can be increased. The

Cover layer assembly typically consists of one or more layers of a dielectric oxide or nitride of a metal or a semiconductor, with more than one layer of varying refractive index. The latter is known as a high-low layer arrangement. As high breaking at

Layer systems generally refers to materials whose refractive index is in the range from 1.8 to 2.6, preferably around 2.0. For comparison, the substrate, usually float glass, which has a low refractive index of about 1.52 on the other hand. This high breaking

Dielectric materials are considered absorption-free

Materials, which qualifies them for the described optical function.

The term "layer arrangement" as described generally comprises more than one layer, but also includes that a layer arrangement consists only of a single layer which realizes the respective function Assignment of individual layers to the basic, functional, deck or further layer arrangement is not always unambiguous, since each layer affects both the adjacent layers and the entire system

Has influence. Generally, a layer is assigned based on its function.

Thus, a base layer arrangement generally becomes such

Attributed to layers that primarily represent a mediator between the substrate and the further layer sequence. Further layers of the base layer arrangement can also be used

Properties of the layer system as a whole, such as Antireflection coatings or protective layers.

In addition to the IR reflection layer, the functional layer arrangement also includes those layers which have their layers

Directly affect properties such as blocking layers to suppress diffusion processes of adjacent layers into the IR reflection layer or like mediator layers which serve to adhere or adjust electrical and optical settings of the adjacent layer. Layers of the cover layer arrangement close this

Layer system upwards and can as well as the

Base layer arrangement functional the entire system

affect .

Such a so-called single-low E can be implemented by inserting one (double-low-E) or several others

Functional layer arrangement by coupling or

Middle layer arrangements on the first

Function layer arrangement are constructed to be supplemented. Also for the assignment of a layer to

Middle layer arrangement are based on the above considerations. The respective sequence of individual layers and layer arrangements can either be within one

Layer arrangement or in the sequence of Layer arrangements can be modified so that specific requirements arising from the application or the manufacturing process can be met.

Thus, in the course of the production of the layer system, different temperature loads occur in already applied layer sequences, which are due to an energy input associated with the deposition or different

Treatment steps of deposited layers are conditional.

In addition, IR-reflective layer systems for curing and / or forming the substrate are becoming common

Subjected to tempering processes. In this case, they have such a layer sequence with such layer properties, which make it possible to heat-treat a substrate carrying the layer system and thereby occurring changes in the optical, mechanical and chemical

Properties of the layer system within defined

To keep borders. Depending on the application of a coated substrate, its layer system is exposed to different climatic conditions during the annealing process in different time regimes.

Due to such temperature loads it comes to

various, the reflectivity of the IR reflective layer and the transmission of the layer system changing processes, in particular for the diffusion of

Components of the antireflective coating into the IR

Reflection layer and vice versa and as a result

Oxidation processes in the IR reflection layer.

To avoid such diffusion and oxidation processes on one or both sides of the IR reflection layer, a blocker layer is inserted, which serves as a buffer for the

serves diffusing components. These blocker layers are structured and arranged according to the occurring temperature load and protect the sensitive often very thin IR reflection layer or the IR reflection layers from the influence of adjacent layers. By inserting one or more blocking layers, in particular color shifts of the layer system as well as the increase of the surface resistance of the layer system as a result of the annealing process are reduced. In particular, NiCr or NiCrOx layers which enclose the IR-reflecting silver layers or protect them at least on one side are known as blocking layers of temperature-capable layer systems.

In addition, it has been found that the reflection and transmission properties of the coating system are also influenced by diffusion processes that are different from the glass

out. In order to influence this, a barrier layer was added in US 2004/0086723 A1 below the functional layer arrangement, which is intended to reduce the diffusion of sodium ions of the glass into the layer system. Also, with such a barrier layer, quality problems due to undefined initial conditions in the raw glass, i. H. fluctuating chemical composition of the glass, in particular in terms of its sodium content, are due. In addition, other glass influences, such as corrosion or imprints of the handling of the glass serving nipple, which are often not detectable by visual inspection and can not be eliminated by conventional cleaning, cause undesirable changes in the properties of the layer system. It is particularly disadvantageous in such glass influences that their effects on the properties of the layer system only after the

Annealing process become visible.

IR reflecting layer systems find particular application in architecture where large wall portions are designed by glass and the low emissivity and high IR reflectance is important to either heat entry or To reduce heat loss. Increasingly, LowE-Sun systems in certain colors are in demand as a replacement for the mostly very color-intensive non-selective coating systems of the SolarControl family. Currently, these correspond

Layers, especially for golden reflective paints, do not meet the energy requirements of LowE systems because they have too low a selectivity and too high an emissivity

exhibit .

Try a LowE-Sun layer system with gold-colored

Glass side reflection by modifications of the

Layer parameters of typical IR-reflective

Creating layer systems with the currently customary neutral, but mostly blue to blue-green, glass-side reflection did not lead to aesthetically acceptable results, since the effect associated with the golden glass surface reflection

Reflection color of the coated side of the glass

is unacceptable.

The invention is therefore based on the object

partially transparent IR-reflecting layer system with a specifically adjustable, in particular a gold-colored

To specify color tone and a method for its production.

The object is achieved by an IR-reflecting layer system which, viewed from the substrate, the known structure of the IR-reflecting layer system, a base layer arrangement at least with a dielectric base layer, a functional layer arrangement at least with an IR reflective layer and a cover layer arrangement at least one has dielectric cover layer, supplemented by at least one very high refractive,

partially absorbing layer. At the same time, it leads to the desired success if this layer or layers are deposited above or below an IR-reflecting layer system known from the prior art or at both positions. The deposition of the layer system according to the invention is carried out by means of magnetron sputtering, which enables the production of dense monolayers even with very small layer thicknesses, whose properties are determined by means of the type of

Sputtering and the sputtering parameters are known to be very well and reproducibly adjusted.

Such, the known IR-reflective layer systems expanding layer system meets the requirements

in terms of selectivity and emissivity and is also specifically adjustable in its color. For example, various gold tones are adjustable, ranging from copper / bronze to light bronze to gold and silver. Very colored layer systems with a metallic luster are also achievable, such as pinks or blues, which can be shifted to silvery ones.

In particular, with such an IR-reflecting layer system according to the invention, a transmission in the

visible range of T _vis <50%, preferably of T _vis <20%, as well as an emissivity of ε <10%, preferably of ε <6%, can be achieved.

For the rest of the layer system, the known

Layer sequences for LowE layer systems find application. In this way, the layer system according to the invention can be adapted to the further requirements, in particular a temperability, by configuring the basic, functional and cover layer arrangement for these requirements. For the tempering such

Layer systems as described above have blocking, barrier and / or migration layers. Also supplements by e.g. adhesive or chemical

Mediator layers and the materials used in the layer system can be selected according to the further requirements of the IR-reflecting layer system. In addition, by means of the supplemented layer or

Layers also vary the transmission due to their partially absorbing property. Semi-absorbent materials are usually referred to as those which, in contrast to the dielectric layers, have the layer thicknesses of a few to a few hundred nanometers usual for solar applications with increasing thickness of the layer

Changes in transmission in the range of several

Show percentage points. Only for

In a conceptual distinction, the partially absorbing layer, which has a very high refractive index, will be referred to hereinafter as the partial absorption layer

The setting of a desired transmission, in accordance with an embodiment of the layer system, in conjunction with a further partially absorbing layer of the IR-reflecting layer system in a very wide

Frame. Such transmission variations for LowE-Sun layer systems are, for example, by means of

Chromium nitride known, which usually as

Blocker layer can be used in the functional layer arrangement. However, other known modifications of the IR-reflecting layer system for influencing the transmission can also be combined with an additional, partially absorbing layer according to the invention. According to the invention, one or the two complementary partially absorbing layers are deposited from such a material, which has a very high refractive index. The range of the very high breaking property of a single layer is as usual in relation to the

Layer system used materials and the substrate and not to be considered absolutely absolute, since an optical effect of the result of the optical density of adjacent

Measures layers. If the substrate is glass, in connection with solar applications thereof Refractive index in the range of about 1.5 and a few tenths above and below to be regarded as low refractive index, while the refractive index of silicon nitride or metal oxides is 2.0 and a few tenths above and is therefore considered to be highly refractive. In contrast to a refractive index of 1.5 and lower, however, a refractive index of 1.8 or 1.9 can also be regarded as highly refractive. These limits are, as stated, oriented to the materials mentioned. At higher refractive indices, close to the high refractive index region are the very high refractive index materials. Move the

Refractive indices of the materials used, then

the limits are also shifting.

Thus, refractive indices are preferred herein

described layer systems applied to glass around the

1.5 as low refractive, in the range of 1.8 to 2.6, preferably around 2.0, as high refractive and in the range of

2.6 and greater, preferably greater than 3.0, to be considered very high refractive. Such refractive indices become one

Design of the layer system with

Partial absorption layers of a semiconducting or a semi-metallic material obtained. In this case, pure semiconductors or semimetals as well as compounds thereof come into consideration. Suitable have e.g. The following materials have been found: silicon having a refractive index of 4.1 to 4.8 at the centroid wavelength of 550 nm, germanium having a refractive index of 4.5 to 5.0 or silicon carbide having a refractive index of about 2.7, the may vary within limits depending on the material structure or deposition. These

Materials can also have admixtures that do not change the semiconducting or metallic character and are, for example, purely technological, such as silicon with Aluminum or borane parts. These are usually up to approx. 10% for taring. Refractive indices of greater than 3.0 can be produced with these materials. In particular, the possibility that the IR-reflective layer system according to the invention already with a

Part absorption layer the desired properties

and that this particular with

silicon-containing materials can be achieved, the production of the layer system according to the invention also makes it possible to use existing sputtering systems in which e.g. one of several base and / or outer layers by a

Part absorption layer is replaced. Depending on

Plant configuration may require only a simple retrofit.

Another advantage is that the lower

Part absorption layer, which lies between the substrate and the base layer arrangement, directly on the substrate

can be deposited. Because for most materials of this layer, a good adhesion to the substrate without adhesion-promoting intermediate layer is possible. Alternatively, such an adhesive layer is also under the

Part absorption layer possible, without appreciable influence on the above-described properties of the IR-reflective layer system according to the invention to take.

Surprisingly, it has been found that regardless of the use of only one or two

Part absorption layers can be set the same color appearance of the IR-reflecting layer system for viewing from both sides of the substrate. This is of interest in that in the known color systems of IR-reflective

Layer systems that have interference from the

Cover layer arrangement can be achieved, the glass side resulting color appearance is strongly linked to the layer-side color appearance, which can lead to unacceptable layer-side color appearance with certain and intense glass-side reflection colors. The

Color appearance is the color that the

Viewer uniquely identified under solar radiation. This excludes minor deviations in the respective

Wavelength range.

The two-sided color adjustment is carried out according to a further process-side embodiment of

Invention by means of the deposited thickness of a

Part absorption layer and / or the optical thickness of a layer adjacent thereto. The thickness adjustment of only one or both layers takes place in accordance with the desired color and transmission and the other materials used in the IR-reflecting layer system. This can be done by coating experiments or simulations of the layer system.

Such an IR-reflective layer system can be described as

Architectural glass element can be used, e.g. as a window and door element or as a facade element of

Glass facades. These are usually designed with multiple glazing for energy reasons, so that different positions are possible for the IR-reflecting layer system depending on the purpose. The possible positions of

Layers and layer systems within

Multiple glazings are counted on the basis of the available surfaces from the outside in, so that the outermost surface is position I, the first inward-pointing position II, etc. During position II, the heat input by solar radiation decreases inwardly and often also a reduced transmission (LowE-Sun systems), reduces an IR-reflective

Layer system on position III, ie on the first inner Glass pane, heat losses to the outside (thermal insulation systems). In the latter, however, usually a high transmission of the IR-reflecting layer system is desired.

Because of these properties, the IR-reflecting layer system with adjustable transmission and adjustable color shade according to the invention is particularly suitable for LowE-Sun layer systems and, at the same time, for energy as well as for design reasons.

The invention will be described below with reference to a

Embodiments will be explained in more detail. In the accompanying drawing shows in

1 shows the structure of an IR-reflecting layer system according to the invention,

Fig. 2A to Fig. 2C, the transmission and glass and

Layer-side reflection of an embodiment of the IR-reflecting layer system and

Fig. 3 shows the basic structure of a

Architectural glass element with an IR-reflective

Layer system.

The IR-reflecting layer system 1 according to FIG. 1 is deposited by means of sputtering on a substrate 2 and has the following structure viewed from the substrate 2 upwards:

Directly on the substrate 2 made of float glass is a very high-refractive, partially absorbing layer, the

Part absorption layer 4, arranged. The

Part absorption layer 4 consists of silicon with an aluminum content of less than 10% and has a refractive index of about 4.7. Its thickness is about 20 nm. Alternatively, small amounts or other admixtures or pure silicon can be used. The thickness of the

Part absorption layer 4 for the embodiment according to Fig. 1 is preferably in the range of 20 to 45 nm, depending on the desired hue and the desired transmission.

Above the partial absorption layer 4 is the

Base layer arrangement deposited. It consists of a dielectric base layer 6 and an overlying adhesion-promoting intermediate layer 8. The base layer 6 consists of titanium oxide (T1O ₂ ), which has a refractive index of about 2.5 and is therefore highly refractive. The

Base layer 6 has an optical thickness (product)

Refractive index and layer thickness) of about 50 nm, wherein this can also be varied depending on the desired hue of the IR-reflecting layer system 1 and is in the range of 20 to 125 nm. This is due to the index of refraction of Ti0 _2, a layer thickness in the range from 6 to 65 nm. As alternative materials for the base layer 6, other high-index

usable as dielectric materials, such as tin oxide (SnO ₂ ) or zinc stannate (ZnSnO), whose layer thickness in the

Range of 9 to 80 nm can be. The adhesion-promoting intermediate layer 8 consists in

Embodiment of zinc oxide (ZnO), the alternative

Aluminum admixtures may have. The thickness of the

Interlayer 8 is in the range of 5 to 8 nm, in

Embodiment at the lower limit of this area. It serves in particular the liability of the above

deposited IR reflective layer 10 and could also be attributed to the functional layer arrangement, since these

Assignment is merely an aid, without affecting the properties of the IR-reflecting layer system 1. The IR reflection layer 10 is made in the embodiment of silver (Ag), but can also be one of the known

alternative IR reflective materials. It has a layer thickness in the range of 10 to 12 nm. Over the IR reflection layer 10, a blocking layer 12 of a nickel chromium oxide (NiCrO _x ) having a thickness of about 2 nm is deposited. This layer can also be deposited with other thicknesses and / or materials. Variants of this layer can be deposited from nickel chrome (NiCr), this also as a partially reactive layer (NiCrN _x ) or from chromium nitride (CrN). The latter is for example in

Bonding with a nitridic overcoat 14, e.g.

Silicon nitride (S1 ₃ N ₄ ), suitable as a further partially absorbing layer. For this purpose, the layer thickness of

Blocker layer 12 preferably in the range of 0.8 to 3 nm, depending on the desired transmission. The usage of

nitridic or oxidic nickel, chromium or a

Combining both also depends on the overlying topcoat 14.

This may also be formed nitridic or oxidic and, alternatively to the silicon nitride of tin oxide (SnC> ₂ ) or zinc stannate (ZnSnO) exist. Their layer thicknesses are in the range of 8 to 12 nm. In the exemplary embodiment, the cover layer of silicon nitride with a

Layer thickness of about 12 nm deposited.

This IR-reflecting layer system 1 according to FIG. 1 has a golden hue combined with a metallic luster, both from the glass side and from the glass side

Seen layer side.

The spectral transmission T and glass-side reflection Rg and layer-side reflection Rf this

Exemplary embodiments, each in percent, are shown in Fig. 2B. The energy transmittance of this IR-reflecting layer system is about 10%, the

Energy reflectance is about 51% on the coating side and about 41% on the glass side. The emissivity is approx. 0.06.

The diagrams of Fig. 2A represent the spectral transmission and FIG. 2C shows a copper-colored IR-reflecting layer system 1 and FIG.

Their values of energy transmission,

Energy reflectance and emissivity are in the

comparable frame as in the embodiment of FIG. 2B.

In Fig. 3 is a architectural glass element with

Double glazing shown, with an outer glass pane 30, which faces the solar light and one with a distance a to the outer arranged inner

Glass pane 31. The incidence of light is shown schematically in FIG. 3 by three arrows. On the side facing away from the light, the outer glass pane 30

by way of example, an IR-reflecting layer system 1 as described above for Fig.l on. Consequently, the outer glass pane 31 is the substrate 2 as described above, so that the following layer structure (not shown in detail) of the IR-reflecting layer system 1 is present from outside to inside:

(1) very high refractive, partially absorbing layer 4,

(2) dielectric base layer 6,

(3) adhesion-promoting intermediate layer 8,

(4) IR reflection layer 10,

(5) blocking layer 12 and

(6) Dielectric capping layer.

Such an arrangement of the IR-reflecting layer system 1 within the multiple glazing in position II

reduces the heat absorption from the outside and thus the entire energy transmission. Semitransparent layer system with high IR reflection and method for its production

LIST OF REFERENCE NUMBERS

1 IR-reflective coating system

2 substrate

4 partial absorption layer

6 base layer

8 intermediate layer

10 IR reflection layer

12 blocker layer

14 topcoat

30 outer glass pane

31 inner glass pane a distance

Rf layer-side reflection

Rg glass side reflection

T transmission

Claims

Semitransparent layer system with high IR reflection and method for its production. Claims

1. Partially transparent IR-reflecting layer system (1) which is arranged on a transparent substrate (2) and from the substrate (2) upwards a base layer arrangement with at least one dielectric base layer (6), a functional layer arrangement with at least one IR reflection layer (10) and a cover layer arrangement

at least with a dielectric cover layer (14), characterized in that between the substrate (2) and the base layer arrangement or over the

Cover layer arrangement or at both positions a very high-refractive, partially absorbing layer, hereinafter referred to as partial absorption layer (4) is arranged.

2. Partially transparent IR-reflecting layer system (1) according to claim 1, characterized in that the

Part absorption layer (4) consists of a semiconducting material or a semi-metal.

3. Partially transparent IR-reflecting layer system (1) according to one of the preceding claims, characterized

characterized in that the partial absorption layer (4) has a refractive index of greater than 3.0.

4. Partially transparent IR-reflecting layer system (1) according to claim 3, characterized in that the partial absorption layer (4) has a refractive index in the range of 4.0 to 5.0.

5. Partially transparent IR-reflecting layer system (1) according to one of the preceding claims, characterized

characterized in that a partial absorption layer (4) is arranged directly on the substrate (2).

6. Partially transparent IR-reflective layer system (1) according to any one of the preceding claims, characterized

characterized in that the IR-reflective

Layer system the same color appearance on both sides

having .

7. Partially transparent IR-reflecting layer system (1) according to one of the preceding claims, characterized

characterized in that the IR-reflective

Layer system (1) a further partially absorbing layer for adjusting the transmission of the IR-reflecting

LayerSystems includes.

8. Architectural glass element with a substrate (2) made of glass or more thereof, wherein on a substrate (2) an IR-reflecting layer system (1) is arranged, characterized in that an IR-reflecting

Layer system (1) according to one of claims 1 to 6 on the inside, i. the light on the

Architectural glass element averted side, that substrate (2) is arranged, which is the outermost of the

Architectural glass element is.

9. A method for producing a partially transparent IR-reflecting layer system (1), wherein by means of sputtering layer arrangements and layers according to one of claims 1 to 7 are deposited one above the other.

10. A process for producing a partially transparent IR-reflecting layer system according to claim 9, wherein the color appearance of the IR-reflecting layer system (1) by means of the thickness to be deposited

Part absorption layer (4) and / or the optical thickness of a thereto adjacent layer is adjusted.