DE10346908A1 - Double glazing unit used for buildings close to airports has a partially reflecting layer formed as a strip pattern of an electrically conducting silver paste printed on the surface of the outer pane - Google Patents

Abstract

Double glazing unit comprises: an outer pane supporting a layer of thin parallel electrical conductors which partially reflect radar beams; an inner pane having a radar-reflecting layer; and an intermediate chamber between the outer and inner panes. The partially reflecting layer is a strip pattern of an electrically conducting silver paste printed on the surface of the outer pane. Double glazing unit comprises: an outer pane (1) supporting a layer of thin parallel electrical conductors which partially reflect radar beams; an inner pane (2) having a radar-reflecting layer (7); and an intermediate chamber (3) formed between the outer pane and the inner pane. The partially reflecting layer is a strip pattern (5) of an electrically conducting silver paste printed on the surface of the outer pane and partially fired. The width of the printed strip is larger than the layer thickness. Preferred Features: The silver paste contains 50-95% silver and is applied by screen printing. A thin layer of a glass ceramic is applied over the strip.

Description

The invention relates generally a bug-proof Glazing, especially for building or vehicles.

With the mass distribution of radio networks in which voice, data and images are transmitted are growing the need for tap-proof Glazing. Especially when large areas or even entire facades of buildings should be glazed the demand for security against eavesdropping difficult to meet. Because on the one hand, tap-proof should also Glazings one if possible allow unimpeded vision, secondly, the damping the radio waves must be high enough to provide effective security against eavesdropping to effect. Especially for large ones glazing surfaces plays of course the cost issue also plays an important role.

In themselves, tap-proof glazing has been around for a long time known. They adopt the well-known principle of the Faraday cage Shielding against electromagnetic waves.

The DE 100 37 918 A1 proposes to use metal foils, metal mesh or very thin layers of metals, such as those obtained by spraying or vapor deposition, as the electrically conductive layer for cladding based on the Faraday cage principle.

In the DE 39 35 401 A1 it is described as known prior art to provide sandwich-like packages made of glass panes for shielding windows, between which metal meshes are inserted and which can also be steamed. However, such glass pane packages only have a low level of transparency, which is in the range of approximately 30 percent.

The patent DE 38 06 619 describes an RF shielding window. According to this document it is known from the literature to lay metallic conductive wire mesh grids in front of glass panes or between glass panes; there are also shielding panes made of transparent glass, which are continuously coated with an electrically highly conductive transparent metal layer. It is also known to insert shielding structures made of transparent, highly conductive electrolytes between glass panes. To improve this, it is proposed to insert an HF honeycomb grate between two glass panes.

Even the patent DE 42 27 032 C1 teaches either to provide glass panes completely with a metallically conductive layer or to embed a layer of wire-shaped electrical conductors arranged parallel to one another between an inner pane and an outer pane. In particular, a double glazing absorbing or damping radar beams is described.

The patent DE 43 40 907 C1 describes a window glazing that absorbs radar rays, consisting of double glazing, in which the layer located in the area of the outer pane consists of mutually parallel, alternately arranged, strip-like first and second partial areas. The first partial areas can be applied, for example, by vapor deposition of metal layers such as silver or gold. In the simplest case, the second partial areas are left blank; alternatively, however, an optically effective layer, such as a sunscreen made of metal oxides, can also be vapor-deposited.

The patent DE 199 29 081 C2 describes a radar beam absorbing laminated glass pane which consists of at least three glass panes connected to one another. A first layer of parallel, thread-like electrical conductors is arranged between the outer disk and the middle disk. A second layer of thread-like electrical conductors is provided between the middle pane and the inner pane.

Known and proven in practice also double glazing absorbing radar rays with a Outer pane, which is designed as a laminated glass pane. Become thin tungsten wires inserted between the two glass panes of the laminated glass pane. The two are attached using a transparent plastic adhesive film Individual panes are then pressed together to form a laminated glass pane. Due to the lateral offset of the highly elastic plastic film this leads to uncontrolled lateral distortions of the individual Wires. As a result, the individual wire-shaped conductors are not in the end more complete aligned parallel to each other. This not only affects the electrical, but also the optical properties of the finished laminated glass pane; in particular, distortions are clearly visible.

The application of stripe-shaped layers made of gold or silver on the surface of a glass pane with the required precision and reproducibility is technically difficult. The evaporation of Gold or silver is also a very complex and expensive technique.

A specified pattern of thin wires exactly on the surface Arranging a pane of glass and permanently fixing it there is very much difficult and so far hardly succeeds in practice.

The present invention relates to in particular a tap-proof Glazing with at least one outer pane made of transparent Glass, which strongly dampens electromagnetic waves Layer thinner electrical conductor carries.

In view of the disadvantages described in the prior art, improved tap-proof glazing should be specified, which is one characterized by a high level of damping of the electromagnetic waves and on the other hand by a practically unimpaired transparency, and which is also suitable for the cost-effective production of large-scale, also curved building glazing.

The task is solved in that as a damping Layer a pattern of strips of an electrically conductive silver paste on a surface the outer pane is printed and partially baked, the width of the printed strip is larger as their layer thickness.

The use of a pasty mass allows an exact and easily reproducible pattern to be applied from thin parallel conductors on the glass surface using well manageable Printing techniques, such as the screen printing process in particular. By the subsequent Branding combines the silver paste or those stored in it Silver particles firmly and permanently with the glass. Branding the printed silver paste is preferably carried out at a temperature in the area of the softening point of the glass, i.e. in the temperature range between 620 and 680 ° C.

Suitable silver pastes are commercially available available. Ferro AG, Frankfurt am Main, Germany, delivers under the Trade name SP 509 a silver paste, which in addition to silver in the form of Powder and frits as further components Terpineol as a solvent and also contains small amounts of lead and dibutyl phthalate. Quality Experience has also been gained with the Johnson AG 2100-85 product Matthey B.V., Maastricht, The Netherlands; it refers to a suspension of silver powder / silver flakes and fries in one organic solvents.

The advantage of the constructed according to the invention Glazing lies primarily in the fact that the printed and then partially into the glass surface burned-in strips of silver paste in the view so good how invisible. Due to the high electrical conductivity However, the printed and baked silver paste can be used at the same time sufficiently high attenuation values achieve. Another advantage of the proposed technique is in the fact that there is also large-area glazing relatively easy and therefore inexpensive to manufacture. Self curved Facades as they are often used in modern architecture can be easily produced.

An optimal compromise between effective shielding on the one hand and unclouded transparency on the other hand, it arises when the width of the printed Strip is between 0.1 mm and 0.5 mm, with particularly good results with strips around 0.15 mm wide.

The pattern of the printed is expedient Streak a grid made up of two sets of parallel lines the same distance is formed. The distances between two neighboring ones Grid lines advantageously between 1 mm and 8 mm, with an area being the optimum between 3 mm and 5 mm was found.

In a preferred embodiment the tap-proof Glazing amounts to the transmittance for visible light between 60 and 80 percent, at the same time the degree of damping for electromagnetic Waves in the frequency range from 50 to 1000 MHz between 40 and 60 Is decibels.

Has proven to be optimal for building glazing Compromise between Clarity on the one hand and effective security against eavesdropping on the other hand, which is achieved by making the transmittance visible Light between 60 and 70 percent and the degree of damping for electromagnetic Waves between 40 and 50 decibels, preferably around 45 decibels. This The coating according to the invention can be used to combine the technical parameters reproducible in the form of narrow strips of silver paste and reasonable Achieve costs.

The strips of silver paste can easily be opened the inside of the outer pane be printed. The glazing can - in a manner known per se - also as Double glazing with outer pane and inner pane be formed. The strips are expedient of silver paste then on one of the inner surfaces of one printed on the two parallel glass panes.

The desired high shielding attenuation is particularly important achieved when a low-resistance is achieved by means of a contact element Connection between the printed conductive strips and earth becomes.

Embodiments of glazing according to the invention are explained below with reference to the accompanying drawings. It demonstrate:

1 a glazing for buildings in which an electromagnetic wave damping grid of narrow strips of silver paste is printed on the inside of the outer pane, in a simplified top view;

2 the glazing of 1 , in a horizontal section along the line AA;

3 double glazing, also on average.

In the drawings, the same elements are the same provided with the same reference numerals.

According to 1 the glazing has a flat outer pane 1 made by a metal frame 2 is surrounded. The outer pane 1 consists of transparent glass and has a thickness of approx. 10 mm.

On the inside of the outer pane 1 is an electromagnetic wave strongly damping Layer applied. This damping layer is formed by a pattern of narrow strips 3 an electrically conductive silver paste on the inside of the outer pane 1 is printed on using a screen printing process and then at least partially baked into the glass surface at a temperature between 620 and 680 ° C.

The pattern of stripes 3 is formed from horizontal lines 3a and vertical lines 3b , which form a grid of points. The grid dimension of this grid corresponds to the distances a between two adjacent lines 3a respectively. 3b and here is 3 mm. The width of a strip 3 is 0.15 mm. The layer thickness of the strips 3 is significantly smaller than their width.

The cross-sectional drawing of 2 shows that the frame 2 has a U-shaped profile and the edges of the outer pane 1 includes. The thickness of the printed strips 3 is exaggerated. Between the frame 2 and the inside of the outer pane 1 is a flat contact element 4 inserted over which the electrically conductive strips 3 are connected to earth.

When glazing according to 3 is an insulating glazing with an outer pane 1 and an inner pane arranged parallel and at a distance from it 5 , The outer pane 1 can, as here, consist of single-pane glass or of multi-layer laminated safety glass. Between the outer pane 1 and the inner pane 5 there is an airtight space 6 , The frame 2 ' is more broad here. The electromagnetic wave damping layer made of stripes 3 is made of silver paste, is located on the inner surface of the outer pane 1 , The one from the strips 3 The pattern formed is again a grid of horizontal and vertical lines, as in 1 shown. The Stripes 3 are about a between the frame 2 ' and the printed strip 3 arranged contact element 4 ' grounded with the contact element 4 ' is designed here as an angle profile.

1

outer pane

2, 2 '

frame

3

Strips of silver paste (on 1 )

3a

horizontal lines

3b

vertical lines

4, 4 '

contact elements

5

inner pane

6

Space (between 1 and 5 )

e

electromagnetic waves

a

Distances (between 3a . 3b )

Claims (11)

Tap-proof glazing, in particular for buildings or vehicles, comprising at least one outer pane made of transparent glass, which carries a layer of thin electrical conductors strongly damping electromagnetic waves, characterized in that - as a damping layer, a pattern of strips ( 3 ) an electrically highly conductive silver paste is printed on a surface of the outer pane and partially baked; - the width of the printed strips ( 3 ) is greater than their layer thickness. Tap-proof glazing according to claim 1, characterized in that the width of the printed strips ( 3 ) is between 0.1 mm and 0.5 mm, preferably around 0.15 mm. Tap-proof glazing according to claim 1 or claim 2, characterized in that the pattern of strips ( 3 ) a grid of two sets of parallel lines ( 3a . 3b ) with equal intervals. Tap-proof glazing according to claim 3, characterized in that the distances between two adjacent lines ( 3a . 3b ) between 1 mm and 8 mm, preferably between 3 mm and 5 mm. Encrypted Glazing according to one of the claims 1 to 4, characterized in that the transmittance for visible Light between 60% and 80% and the degree of damping for electromagnetic Waves in the frequency range from 50 MHz to 1000 MHz between 40 dB and is 60 dB. Encrypted Glazing according to claim 5, characterized in that the transmittance for visible Light between 60% and 70% and the degree of damping for electromagnetic Waves between 40 dB and 50 dB, preferably around 45 dB. Encrypted Glazing according to one of the claims 1 to 6, characterized in that the silver paste 50% to 95 % Contains silver. Encrypted Glazing according to one of the claims 1 to 7, characterized in that the silver paste by means of screen printing is applied. Tap-proof glazing according to one of claims 1 to 8, characterized in that the strips ( 3 ) are printed on the inside of the outer pane. Tap-proof glazing according to one of claims 1 to 8, characterized in that - parallel and at a distance from the outer pane ( 1 ) an inner pane ( 5 ) is arranged; - the Stripes ( 3 ) on one of the inner waiters surfaces of the outer pane ( 1 ) or the inner pane ( 5 ) are printed. Tap-proof glazing according to one of Claims 1 to 10, characterized by a contact element ( 4 . 4 ' ) for the electrically conductive connection of the printed strips to earth.