EP1699996A1

EP1699996A1 - Insulaing glass unit

Info

Publication number: EP1699996A1
Application number: EP04803403A
Authority: EP
Inventors: Erfindernennung liegt noch nicht vor Die
Original assignee: USD Formteiltechnik GmbH
Current assignee: USD Formteiltechnik GmbH
Priority date: 2003-12-02
Filing date: 2004-12-01
Publication date: 2006-09-13
Also published as: WO2005054617A1; US20070087140A1; DE10356216A1

Abstract

The invention relates to an insulating glass unit comprising at least two window panes, a means for positionally fixing the window panes, and a sealing element for adjusting a distance between two adjacent panes and gas-tightly, laterally insulating the intermediate space enclosed by the panes. The sealing element is provided with at least one gas-tight central part and two lateral gap seals, each of which is disposed in the area between one of the window panes and the central part. At least one diffusion-tight buffer that is made essentially of an elastic material is arranged in the area between the two gap seals of the sealing element. Preferably, a metal layer is vapor-deposited on the inner surfaces of the buffers. In a preferred embodiment, the fastening means is embodied as a metal clamp which embraces the panes on the outside such that the insulating glass unit can be produced substantially without using adhesives.

Description

INSULATING UNIT

The invention relates to an insulating glass unit with at least two glass panes, a fastener for fixing the position of the glass panes and a sealing element for adjusting a distance between two adjacent panes and for gas-tight lateral insulation of the pane space enclosed by the panes. In particular, the invention relates to such an insulating glass unit, in which the sealing element contains at least one gas-tight central part and two lateral gap seals, which are each arranged between a glass pane and the central part.

As also described in the German industrial standard (DIN) 1259, part 2, in such a, also referred to as multi-pane insulating glass, glazing unit, glass panes made of window glass, mirror glass, cast glass, flat glass or similar glasses are usually used. The glass panes are separated from one another by one or more air-filled or gas-filled spaces and are sealed air-tight, gas-tight and moisture-tight at their edges. The edge seal is of great importance for the functionality of the insulating glass unit. If it leaks, e.g. Thermal gas filling can escape, or moisture can accumulate in the insulating glass unit and condense on the inside of the panes. The insulating glass unit then becomes "blind", no longer insulates as desired and is usually irreparably damaged. As a result, the denser and more durable the edge seal of the space between the panes, the higher the value of an insulating glass unit

[0003] The edge seal normally comprises a sealing element and a fastening means. The sealing element runs around the outside, preferably parallel to the edges of the glass pane, and usually consists of a central part and two gap seals located laterally on the central part and oriented towards the two respective glass panes. The middle part, also referred to as a spacer, is usually a hollow profile made of a gas-tight material, such as steel or aluminum. In order to remove water vapor that may have occurred during production or as a result of leakages, a drying agent, for example a molecular sieve, is introduced into the cavity to absorb water vapor However, massive middle section profiles made of a thermoplastic with incorporated desiccants are also known.

In order to seal the areas between the middle part and the two adjacent glass panes gastight, gap seals are arranged here. The gap seals are mainly made of polyisobutylene ("butyl"). This is a thermoplastic synthetic rubber that adheres well to glass and has a very low water vapor diffusion value. The polyisobutylene can either be inserted as a pre-profiled cord between the washers and the central part or can be introduced into the gap area with the aid of an extruder. In addition to sealing the gap, which is also referred to as the diffusion gap, the polyisobutylene seal also serves as a fixing aid in the production of the insulating glass units. However, due to its low material strength, the gap seal cannot make any contribution to the mechanical strength of the edge bond.

For the permanent cohesion of the glasses and the sealing element, a fastening means is therefore additionally arranged. An elastic adhesive has been used as a fastening means since the late 1960s. This adhesive is applied externally to the sealing element and between the glass pane edges which project beyond it, while the glasses are pressed against the sealing element from the outside. After curing, the adhesive acts like a spring that presses the panes against the sealing element, which in the normal state achieves diffusion gap widths of less than 0.5 mm. In addition to one-component (1-component) silicone and hot-melt butyl adhesives, two-component (2-component) adhesives in particular have become established as an adhesive in the prior art. Two-component polysufide and two-component polyurethane adhesives are particularly widespread, as they have high strength and elasticity with a relatively low water vapor diffusion value, as a result of which they also have an additional sealing effect.

In order to be approved by the building authorities, the insulating glass units have to pass system tests in many countries. The system tests depict the load situations of an insulating glass unit in a shortened process. For this purpose, various temperature, pressure, UV radiation, weather (rain) effects and loads are usually simulated. In Germany, an insulating glass unit currently still has to meet the system test requirements of DIN 1286, but in future the European standard prEN 1279. In general, the insulating glass should meet requirements for gas loss rate, sealant liability, fogging safety, ie safety against outgassing of foreign substances that are in the Precipitate the space between the panes as fog, the water vapor absorption of the desiccant, the UV stability, the stability of the sealing unit, in particular the stability of the spacer profiles, the productive workability in the production of insulating glass, the manufacturability of models, the possibility of installing rungs, the manufacturability of Roof glazing and glass facades in which the insulating glass units are attached to a supporting structure behind the glass unit (structural glazing).

With the introduction of prEN 1279, the requirements for the tightness of the insulating glass units in particular are tightened by greatly shortened cycle times of the various load cases. It has been shown that the insulating glass commonly used today, especially when the air pressure changes in quick succession, generally does not meet this standard.

[0008] In general, changes in air pressure lead to deformations of the insulating glass units. Does the outside air pressure quickly change between high and low pressure, e.g. in system tests, so-called "pumping" of the insulating glass units occurs. The glass panes of the insulating glass unit bulge alternately inwards or outwards depending on the changing barometric air pressure. This behavior of the insulating glass units is due to the fact that the space between the panes is hermetically sealed off from the surrounding atmosphere and that no pressure equalization can take place when the barometric pressure changes.

Fig. 7 shows a pane edge of a conventional insulating glass unit 1 of the prior art in the deformed state when the external air pressure is less than the filling pressure in the space between the panes SDR. Due to the low external pressure, the two spaced glass panes 2 and 3 bulge outwards. The glass unit 1 thereby takes on a convex shape, the two spaced glass panes 2, 3 rotating around the outer edges of the rigid central part 6 of the sealing element 5 and their outermost pane edges the fastening means 4 (here, for example, a 2-component adhesive) ) squeeze. Presumably because the fastening adhesive 4 has a relatively high internal compressive strength, the disks 2, 3 can lift off at the outermost edge relative to the spacer 6. As a result of the low tensile strength of the polyisobutylene seals 7, 8, the seals 7, 8 are easily detached, as can be seen in FIG. 6, depending on where the adhesion of the gap seal 7, 8 is first exceeded the seal 7 or 8 either directly from the glass pane 3 or from the side of the spacer 6. In any case, the diffusion gap between the sealing element 5 and the respective glass pane 2, 3 increases, and the leakage rate between the sealing element 5 (spacer 6) and the Glass panes 2, 3 increase.

If the outside air pressure is increased such that a higher pressure prevails outside the insulating glass element 1 than in the space between the panes SDR, the glass element 1 assumes a concave shape. The result of this is that the fastening means 4 is subjected to tensile stress in the edge region while the gap seal 7 or 8 is pressed together. If the gap seal 7, 8 is subjected to particularly high pressure, the adhesive effect of the gap seal 7, 8 on the spacer 6 can be damaged. If the direction of loading then changes, that is to say the air pressure, the gap seal 7 or 8 will subsequently detach from the spacer 6 and the leakage will be further increased. It is also disadvantageous in the prior art that the use of adhesive for fixing the panes delays the manufacture of the insulating glass unit and also pollutes the environment. After the adhesive has been applied in the space between the sealing element and the outer edges of the pane, it must first cure before the Insulating glass unit can be further processed or transported. Outgassing of the adhesive itself and solvent vapors from solvents, which must be used to clean the equipment applying the adhesive and to remove adhesive residues, pollute the environment and production personnel. The components of the insulating glass units of the prior art which are bonded to one another are moreover poorly recyclable.

A u fga be the invention is therefore to provide a simple and inexpensive to manufacture insulating glass unit available, which has a sufficiently tightly sealed space between the panes even with frequent and faster air pressure changes. Furthermore, the insulating glass unit according to the invention should be able to be produced with a minimum of adhesive.

This object is achieved with the insulating glass unit according to claim 1. Preferred embodiments and further developments are described in the subclaims.

The insulating glass unit according to the invention has at least two glass panes, a fastening means for fixing the position of the glass panes and a sealing element for adjusting a distance between the glass panes and for gastight lateral insulation of the space between the panes enclosed by the glass panes. The sealing element contains at least one gas-tight middle part and two lateral gap seals. The gap seals are each arranged in the area between one of the glass panes and the central part, at least one diffusion-tight buffer being arranged in the area between the two gap seals of the sealing element, said buffer consisting essentially of an elastic material. The buffer is arranged in such a way that it directly adjoins the central part and rests directly on one of the two gap seals.

The buffer ensures that changes in distance between the disks and / or rotations of the disks, which can result, for example, from changes in air pressure, are transferred to the buffer and compensated for there. The buffer is expediently installed between the disks under compressive stress, so that movements of the disks are introduced directly into the buffer. Movement of the pane then does not result in any significant change in the diffusion gap between the glass pane and the sealing element, and overstressing of the gap seals or detachment of the gap seals from the panes is effectively avoided.

Preferably, between each of the two gap seals and the central part of the sealing element, a diffusion-tight buffer is arranged directly adjacent to the gap seal and the central part. That's the way it is possible to use a conventional spacer as a central part for the sealing element, on the sides facing the two glass panes, a buffer is arranged. Each gap seal thus has a buffer directly assigned to it, and movements of the disks are initiated directly into the respective buffer via the gap seal. This also has the advantage that movements of a single disk, decoupled from the opposite disk, can be damped in the buffer.

So that the buffer can deform sufficiently under the usual changes in air pressure, it preferably consists of a material with a Shore A hardness according to DIN 53505 of 50 N / mm ² to 70 N / mm ² . To ensure suitability for use, the material should essentially remain permanently elastic over a longer period of more than 20 to 25 years and, if at all, only show slight plastic deformations over this period. The buffer therefore advantageously consists of an elastomeric plastic, in particular of EPDM, polyurethane, an acrylonitrile-butadiene elastomer, a chlorobutadiene elastomer, a fluoroelastomer or a silicone. An embodiment made of EPDM is particularly preferred. This is a synthetic high-performance rubber made from ethylene, propylene and diene monomers. EPDM remains elastic for decades and is already successfully used for sealing lips in aluminum or wooden windows.

It is crucial for the tightness of the sealing element that in addition to the central part, the buffer is also gas-tight. In most cases, the diffusion-tightness of the aforementioned materials is sufficient for sealing the space between the panes. If greater tightness is desired, the buffer can be provided with a gas-tight layer, in particular a metal layer, at least on one surface. Metal-coated plastics are already known for high-vacuum-tight food packaging. For this purpose, the relevant surface of the buffer is expediently metal-vapor-coated or dry-galvanized. If necessary, prefabricated thin films can also be laminated onto the buffer. The gas-tight layer can in turn consist of several individual layers. To effectively prevent water vapor permeation, a total layer thickness of the gas-tight layer that is in the nanometer range is sufficient. Suitable layer thicknesses for a metallic coating lie approximately in the range between 40 and 200 nanometers, with a stainless steel preferably being used as the metal.

It is particularly expedient if the gas-tight layer is applied to the surface of the buffer facing the inner space between the panes. In addition to the advantages already described, this arrangement also has the positive effect that evaporation of the buffer is not released into the space between the panes.

Furthermore, it is advantageous if the buffer is extruded or vulcanized to the central part. This guarantees a gas-tight connection of the buffer to the middle section. In this case, the surface of the buffer is expediently sealed (metallized) gas-tight only after extrusion, which then also seals the transition area between the buffer and the middle part. It is particularly useful for both the outside and the inside of the buffer sealed gastight. Finally, it should be pointed out again that the gas-tight coating can be a suitable measure for increasing the gas-tightness, but this is not absolutely necessary. Rather, there are also materials for the buffer that enable an effective vapor barrier without a metal coating.

In a preferred embodiment of the insulating glass unit according to the invention, the gap seal is made of a synthetic, in particular elastomeric, plastic with a very low diffusion rate. Polyisobutylene with a water vapor diffusion rate of approximately 0.1 g / dm ² / K is preferably used here. It is advantageous if the gap seal is at least partially in a trough of the sealing element. The gap seal is then enclosed on all sides by the glass pane and the sealing element. This effectively prevents the gap seal from shifting, being crushed or flowing away, as is particularly the case with polyisobutylene under high pressure. The depression should preferably be designed in such a way that parts of the sealing element which delimit the depression upwards or downwards lie directly against the glass pane. The troughs are expediently arranged in the side regions of the buffers of the sealing element.

[0022] The trough can be incorporated into the buffer lying against the glass pane. In order to create such a trough in a particularly simple and cost-effective manner, however, a buffer expediently consists of at least two profile strips arranged next to one another. This has the advantage that you can already use commercially available elastomer profile strips - for example with a triangular, semicircular or rectangular cross section. These profile strips can then either be glued to the central part and / or to one another or be assembled directly via a gap seal made of polyisobutylene. If necessary, they can also be used in the sealing element without any adhesive. In any case, only a minimal amount of adhesive is required for their attachment, which is practically insignificant compared to the amount that was previously used for the pane fixation. In addition, the sealing element can already be prefabricated so that there are no delays due to curing times during the manufacture of the insulating glass unit.

The width of the profile strips does not necessarily have to add up to the total height of the central part, which they are arranged adjacent to. It is also possible to arrange the profile strips at a distance from one another on the central part of the sealing element. A variant is also conceivable, for example, in which the gap seal is framed between two profile strips and also adjoins the central part. However, it must then be ensured that the width of the gap seal is chosen wide enough for a secure sealing of the space between the panes. If the profile strips are spaced next to one another, preferably at the outermost edges of the sealing element, one can easily compensate for differences in width of different sealing elements without having to use an individually adapted elastomer buffer for each type and size of sealing element. For the central part of the sealing element, a profile with high transverse strength and gas tightness is preferably used. Metal profiles are particularly advantageous here because they have great structural strength and are easy to machine. Preference is given to hollow profiles which can hold the desiccant in their cavity, which serves to absorb water vapor. So that the desiccant can absorb and bind this water vapor, it is advantageous to open the hollow profile towards the inside of the pane.

In order to reduce the amount of adhesive in the space between the panes, it is preferred according to the invention not to use any adhesive for fixing the panes, but to use at least one clip, which is made in particular of metal. This clamp encompasses the glass panes which are spaced apart from one another and presses them against the sealing element. In other words, there is preferably essentially no adhesive in the space between the panes. “Essentially no adhesive” means here that at most small amounts of adhesive are available for fastening the individual components of the sealing element to one another. In particular, however, there is no adhesive and also no other plastic sealing compound in the area between the outside of the sealing element and the pane edges existing in the space between the panes to fix the panes against each other and also to seal them against each other. The panes can therefore no longer rest on their edges on an adhesive or plastic edge In addition, the entire insulating glass unit can be manufactured practically free of adhesive, as a result of which the insulating glass units according to the invention can be produced faster, with better quality, more cheaply and in a more environmentally friendly manner.

In detail, there is the faster production, because the insulating glass is ready immediately after the attachment of the fastening clips and the otherwise usual setting times of the adhesive no longer have to be observed. The quality of the glass units is improved because there can no longer be fluctuations in dosage when mixing the two-component adhesives and associated fluctuations in the adhesive strength of the fastener. The sealing element can also be arranged further outside on the edge of the glass pane, since the clip obtains its holding force from the spring action and not via the contact surface like the adhesive. This advantageously increases the insulated area of the insulating glass element according to the invention compared to the known elements. In addition, intermediate storage areas (for the curing of the adhesive) as well as gluing and dosing machines can be omitted, which makes production cheaper. Finally, the insulating glass unit is manufactured in a more environmentally friendly manner, whereby not only the adhesive itself, but also the cleaning of production equipment and tools is eliminated.

By dispensing with two-component adhesives, above all, no chlorinated hydrocarbons and no aromatic solvents are required for cleaning machines and mixing sections. During production, when using polyurethane (PU) -based adhesives, no toxic isocyanate and Mercury residues and no more toxic manganese oxides when gluing with polysulfide (PS) -based adhesives. Furthermore, the insulating glass units according to the invention are easier to recycle after the clips have been removed, since all components are immediately available again in almost a single variety.

In an expedient embodiment, the clip surrounds the entire outer edge of the insulating glass unit. This guarantees a continuous and uniform pressing of the pane edge, and the metal clip also acts as a further sealing line and edge protection., Such an edge protection serves on the one hand to protect the insulating glass unit from damage and on the other hand to protect the people handling the insulating glass unit from cuts the very sharp-edged glass panes. The strapping with the metal band also results in multiple fastening options for the glass units, and installation in plastic, wood or aluminum windows is improved. If, apart from polyisobutylene, only metals and possibly gas-tight coated buffers are installed, the insulating glass unit according to the invention can also be used excellently in high-traffic roof areas and in structural glazing constructions.

Preferably, the clip has a U-shaped cross-section with an end face and two leg sides pressing on the glass panes. When assembling the insulating glass units, either prefabricated all-round frames with an L-shaped starting profile are folded into a U-shape around the inserted glass panes, or the U-profile is folded from a steel strip directly around the edges of the glass panes, or U-formi ^rr 6 profiles which together ^{F T} e "rβεsten Glaselementräπder" eεchobeπ. In any case, it is advantageous if the outer ends of the leg sides press against the glass panes, since a relatively large holding force develops in this way. It is particularly advantageous if at least one of the leg sides of the clip has at least one bulge toward the pane. This bulge concentrates the pressure on the disc and the sealing element behind it.

Furthermore, it is advantageous if the clip also has at least one bulge on its end face. This bulge is usually a fold, which ensures that the clip acts like a spring. During the manufacture of the insulating glass unit, the clip is pulled apart in the direction of its leg sides, pushed onto the edge of the insulating glass unit in the stretched state and then relaxed. Due to the fold on the front side, the clamp will contract and exert the desired contact pressure on the outside of the pane. As a result, the glass panes are pressed against the sealing element, the buffer and the gap seals are tensioned, and the space between the panes is effectively sealed.

In a particularly preferred embodiment of the insulating glass unit, the fastening means for fixing the position of the glass panes comprises a plurality of clips and a strap. Instead of a single circumferential clip, a plurality of short clips arranged at a distance are used. Doing so the strap is guided on the outside of the clamps and around the edges of the glass panes and tensioned. The clamps are thus pressed onto the edges of the pane by the tensioning band and thus effectively prevent the panes or clamps from moving relative to one another. The tensioning band expediently runs in bulges on the end faces of the clamps, which correspond as far as possible to the cross-sectional shape of the tensioning band. In this way, the strap is secured against slipping off the clips or the insulating glass unit.

At the corners of the pane edges, special, bevelled corner brackets abutting each other are arranged. In this way, the tensioning strap is guided around the corner areas of the glass panes and is particularly well protected there - for example, against chafing. The tension band itself can consist of tensile material such as stainless steel, webbing or the like and have a round or, which is particularly expedient, an angular and as flat as possible cross-sectional shapes. What is particularly positive about this tensioned embodiment of the insulating glass unit according to the invention is that less material is required for the clips, that is to say the unit can be manufactured more cheaply. In addition, production that uses the tensioned insulating glass units is much easier to adapt to changing pane sizes or geometries. This embodiment is therefore also particularly suitable for insulating glass units which, for example, are only produced in small numbers or deviating from a rectangular outer shape.

Overall, the insulating glass units according to the invention have the advantage that their basic structure is very similar to the insulating glass units of the prior art. This means that, in principle, the same assembly can be carried out on existing production systems and from conventional building materials and components, e.g. Spacers etc., significantly improved insulating glass elements are made.

The invention is explained below with reference to a drawing. It shows schematically:

Figure 1 shows a section through the edge of a first embodiment of an insulating glass unit according to the invention.

2 shows a section through the edge region of the first exemplary embodiment when it is convexly deformed by low outside air pressure;

3 shows a section through the edge region of a second exemplary embodiment of an insulating glass unit according to the invention;

4 shows a detail of a section through the edge region of a third exemplary embodiment of an insulating glass unit according to the invention;

5 shows a section through the edge region of a fourth exemplary embodiment of an insulating glass unit according to the invention; Fig. 6 is a side view of the fourth embodiment of the insulating glass unit shown in Fig. 5; and

7 shows a section through the edge region of an insulating glass unit according to the prior art when it is convexly deformed by low outside air pressure.

Fig. 1 shows schematically a first embodiment of an insulating glass unit 1. According to the invention, a sealing element 5 is arranged between the outer edges of two glass panes 2, 3, which seals the space between the panes SDR between the panes 2, 3 against the environment. Argon is concentrated for insulation in the space between the panes of the SDR. The cohesion of the insulating glass unit is produced at its edge by a continuous, continuous clamp as fastening means 4. In this exemplary embodiment, the sealing element 5 comprises a centrally arranged central part 6 with a cavity 17 which is filled with a desiccant. Two buffers 9 and 10 are extruded onto both sides of the middle part 6 facing the glass panes 2, 3. Both buffers are vapor-coated with metal layers 11 and 12 on their surfaces facing the space between the panes SDR. These metal layers 11 and 12 are gas-tight and prevent argon from leaking out of the space between the panes and diffusing air and water vapor through the elastic buffers 9 and 10. A gap seal 7 and 8 made of polyisobutylene is attached to the sides of the buffers 9 and 10 facing the disks 2 and 3, respectively. These polyisobutylene seals 7 and 8 prevent gas exchange along the contact surfaces of the sealing element 5 and the glass panes 2 and 3, respectively.

[0036] When assembling the insulating glass unit, the two glass panes 2 and 3 are pressed together from the outside and the fastening clip 4 is pushed onto the edge under tension. In the installed state, the clamp 4 presses the two glass panes 2 and 3 against the sealing element 5. As a result, the elastic buffers 9 and 10 are brought into tension, as a result of which the panes 2 or 3 move directly via the polyisobutylene seal 7 or 8 onto the respective buffer 9 or 10 transmitted. Because of the compression, the buffers 9 and 10 therefore exert permanent pressure on the gap seals 7 and 8 and thereby overpressure any tensile stresses that may occur in the gap seals 7 and 8.

It is advantageous if the bulges 21 and 22 of the opposite legs 19 and 20 of the mounting bracket 4 extend linearly, parallel to the edge of the glass unit, and if possible are at the same height. Thus, the opposing disks are pressed against one another in a plane "A" running parallel to the edge. In order to reduce unfavorable tensile forces on the sealing element 5, the sealing element 5 is also arranged in its plane of focus "A". As a result, enlargements of the diffusion gap are already reduced geometrically by avoiding unfavorable leverage effects of the fastening element. In this embodiment, the width of the central part is between 10 mm and 16 mm and the width of the sealing element between 14 mm and 20 mm. The height of the sealing element and thus also of the gap seal 7, 8 has been doubled by approximately 6 mm compared to the conventional dimensions. The clear inside width of the clip is 20 mm to 30 mm with an outer leg length of 5 to 8 mm and a thickness of the clip of around 0.8 mm to 1 mm.

Because the diffusion gap with 6 mm has twice the height of the known insulating glass units, the leakage rate of the sealing unit 5 has been reduced further. In the known systems, gas leak rates of <1% per year are usually present. Since the k-value no longer changes at a gas filling rate of 60% argon in the space between the panes, the space between the panes is usually overfilled by more than 90% argon in order to ensure that the insulating glass unit 1 functions for more than 25 years. In the insulating glass units 1 according to the invention, it is no longer necessary due to the reduced leakage rate to overfill the space between the panes SZR with more than 90% argon, or, with the same overfilling rate, the insulating glass units have a significantly longer functionality.

Fig. 2 shows the pane edge shown in Fig. 1 of the first embodiment of the insulating glass unit 1 according to the invention in the deformed state. The state of deformation shown corresponds to a deformation of the insulating glass unit if the external air pressure is less than the filling pressure in the space between the panes SDR. Compared to the prior art, the insulating glass element 1 according to the invention has the advantage that the glass panes 2, 3 cannot be placed on the fastening element 4 at their outermost edges and can be lifted off relative to the sealing element 5. Rather, the bulges 21 and 22 ensure that the movement of the glass panes 2, 3 essentially takes place in the axis of gravity A of the sealing element 5. Since the disks 2, 3 are pressed together at these points at the same time, it is possible to effectively reduce the tensile stresses on the polyisobutylene seals 7, 8 by providing the necessary deformation paths through the elastic buffers 9, 10. In other words, the buffers 9 and 10 compress on their outer sides 13, 14 while they are being pulled on their inner sides 11, 12 and thereby relieve the pressure on the polyisobutylene seals 7, 8. This results in a significantly increased tightness of the insulating glass unit 1 according to the invention the known insulating glass unit shown in FIG. 7 of the prior art.

In Fig. 3, a second embodiment of the insulating glass unit according to the invention is shown. In order to prevent the gap seals made of polyisobutylene 7, 8 from being displaced or pressed away, the gap seals are arranged in troughs 15, 16 in this exemplary embodiment. The edges of the elastomer buffers 9, 10 delimiting the troughs lie directly on the glass panes 2, 3 and prevent the polyisobutylene from being pressed and exiting from the side. In this embodiment, the elastomer buffers 9, 10 are vapor-coated with metal not only on the sides 11, 12 facing the space between the SDRs but also on the sides 13, 14 facing away from the space between the SDRs. This effectively prevents gases from escaping from the buffers or diffusing through the buffers.

In this exemplary embodiment, the circumferential clamp 4 completely enclosing the edge of the insulating glass unit 1 has a bulge 23 on its end face 18 which gives the clamp 4 a resilient effect. During manufacture, the clip is pulled in the direction of its two outer legs 19 and 20 and pushed laterally onto the edges of the pane. By relaxing the clamp 4, it contracts due to the resilient effect of the bulge 23 on the front side, presses against the glass panes 2, 3 on the inner leg sides 19, 20 and clamps the sealing element 5. The middle part 6 of the sealing element 5 used in this exemplary embodiment is a commercially available hollow spacer made of metal, the interior 17 of which is also filled with a drying agent.

Fig. 4 shows a detail of a particularly preferred third embodiment of an insulating glass unit according to the invention, in which the buffers 9 and 10 of the sealing element 5, each consist of two prismatic elastomer profile strips 25, 26 and 27, 28. The clip 4 located on the edge cannot be seen in this illustration, but this embodiment is also a clamped insulating glass unit 1. The buffering strips 25, 26 and 27, 28 are each arranged in pairs next to one another such that a trough is between them 15 or 16 with a triangular cross section is formed in each well 15, 16, a gap seal 7, 8 made of polyisobutylene. A metal coating of the buffer surfaces facing the pane space SDR is not present in this embodiment.

In the fourth embodiment of the insulating glass unit 1 shown in FIGS. 5 and 6, the sealing element 5 in turn has two permanently elastic buffers 9, 10 which are not provided with a metal coating. Experiments have shown that the buffers 9, 10 can be dispensed with on metallic surfaces in many applications, since the buffers 9, 10 are usually sufficiently vapor-diffusion-tight. For the adsorption of water vapor from the space between the panes of the SDR, the sealing element 5 has a hollow profile 6 which is open inwards through perforations 24 and has a drying agent filled into the cavity 17.

In this embodiment too, the glass panes 2 and 3 and the sealing element 5 are fixed entirely without the aid of an adhesive, namely with several clamps 4 and a tensioned strap 29. The strap 29 is guided in recesses 23 of the clips 4 and thus against lateral slipping secured on the back of the bracket 18. As can be seen in the side view of the insulating glass unit 1 in FIG. 6, the tensioning band 29 runs parallel to and around the pane edges 30 and 31 of the glass panes 2 and 3. In the tensioned installed state, the tensioning band 29 thus presses all the clamps 4 against the pane edges 30, 31 of the glass panes 2, 3 and thus prevents both the panes 2, 3 from slipping as well as the brackets 4. In this embodiment, the brackets 4 have straight leg sides 19, 20 protruding at right angles from the end face 18. The brackets 4 press the glass panes 2, 3 sealingly against the sealing element 5 via the flat legs 19, 20.

At the corners of the insulating glass unit 1, special corner clips 32 and 33 are provided. These are cut at their ends facing the corners so that they can be arranged abutting one another at the corner. In the case of a rectangular corner, the corner brackets 32, 33 are therefore bevelled at 45 ° on their end faces. Due to the brackets 32, 33 enclosing the corners of the glass panes 2, 3, it is also possible to use a tensioning strap 29 which is narrower than the sealing element 5 without being stretched in the space between the panes SDR. In addition, the corner brackets 32, 33 protect wider ones Tension straps 29 before cuts on the window edges of the inside of the corner. The tensioning strap 29 shown here is a flat strap made of stainless steel.

Claims

1. insulating glass unit (1) with at least two glass panes (2, 3), a fastening means (4) for fixing the position of the glass panes (2, 3) and a sealing element (5) for adjusting a distance between the glass panes (2, 3) and gastight lateral insulation of the space between the panes (SDR) enclosed by the glass panes (2, 3), the sealing element (5) including at least one gas-tight central part (6) and two lateral gap seals (7, 8), each in the area between one of the glass panes (2; 3) and the central part (6), characterized in that at least one diffusion-tight buffer (9; 10) is arranged directly adjacent to the central part and bears directly against one of the two gap seals (7, 8).

2. insulating glass unit according to claim 1, characterized in that between each of the two gap seals (7, 8) and the central part (6) of the sealing element (5) each have a diffusion-tight buffer (9; 10) directly to the gap seal (7, 8) and the middle part (6) is arranged adjacent.

3. Insulating glass unit according to one of claims 1 or 2, characterized in that the buffer (9; 10) consists essentially of a material which has a Shore A hardness according to DIN 53505 of 50 N / mm ² to 70 N / mm ² has

4. Insulating glass unit according to one of the preceding claims, characterized in that the buffer (9; 10) consists essentially of an elastomeric plastic, in particular EPDM, polyurethane, an acrylonitrile-butadiene elastomer, a chlorobutadiene elastomer, a fluoroelastomer or a silicone , consists.

5. Insulating glass unit according to one of the preceding claims, characterized in that the buffer (9; 10) at least on one surface (11, 13; 12, 14) is provided with a gas-tight layer, in particular a metal layer.

6. insulating glass unit according to claim 5, characterized in that the gas-tight layer on the inner space between the panes (SDR) facing surface (11; 12) of the buffer (9; 10) is applied.

7. Insulating glass unit according to one of the preceding claims, characterized in that the at least one buffer (9; 10) is extruded onto the central part (6).

8. Insulating glass unit according to one of the preceding claims, characterized in that the gap seal (7; 8) consists of a synthetic, in particular elastomeric, plastic, preferably of polyisobutylene.

9. insulating glass unit according to one of the preceding claims, characterized in that the gap seal (7; 8) is at least partially in a trough (15; 16) in one of the glass pane (2; 3) facing side of the sealing element (5).

10. Insulating glass unit according to claim 9, characterized in that the buffer (9; 10) comprises two profile strips (25, 26; 27, 28) arranged next to one another, which enclose the trough (15; 16) between them.

11. Insulating glass unit according to one of the preceding claims, characterized in that the central part (6) is a gas-tight hollow profile, in particular made of metal, in the cavity (17) of which there is preferably a desiccant.

12. Insulating glass unit according to one of the preceding claims, characterized in that the fastening means (4) is at least one clip, in particular made of metal, which surrounds the glass panes (2, 3) on the outside and presses them against the sealing element (5).

13. Insulating glass unit according to claim 12, characterized in that the clip (4) surrounds the entire outer edge of the insulating glass unit (1)

14. Insulating glass unit according to one of claims 12 or 13, characterized in that the bracket (4) has a U-shaped cross section with an end face (18) and two leg sides (19, 20) pressing on the glass panes (2, 3).

15. Insulating glass unit according to claim 14, characterized in that at least one of the leg sides (19; 20) of the bracket (4) has at least one bulge (21; 22) towards the pane (2; 3).

16. Insulating glass unit according to one of claims 12 to 15, characterized in that the clip (4) has at least one bulge (23) on its end face (18).

17. Insulating glass unit according to one of claims 12 to 15, characterized in that the fastening means has a plurality of clips (4) and a tension band (29), the tension band (29) on the clips (4), preferably in front bulges (23) around the edges (30, 31) of the glass panes (2, 3) and is stretched.