Abstract:
The invention relates to an insulating glass unit composed of at least two outer panes and of an edge connector which comprises a spacer profile. With the aim of reducing a relative displacement between the two outer panes under loading, it is proposed according to the invention that the spacer profile has two opposed contact faces which are connected in a shear-resistant manner to the outer panes via an adhesive layer, wherein the spacer profile additionally has at least one articulated region which is designed in such a way that the two contact faces can be rotated at least partially in order thereby to reduce stresses in the adhesive layer.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to an insulating glass unit composed of at least two outer panes and of an edge connection which comprises a spacer profile. 
         [0002]    Such an insulating glass unit is generally known in principle from the prior art. It comprises the two outer panes, a first outer pane generally being arranged on the inside of a room, a house, a warehouse or a building in general, and a second outer pane being arranged on the outside of the building. A thermally insulating gap is arranged within the two outer panes. The advantage provided by this gap is particularly that of relatively high thermal and sound protection. The insulating glass unit therefore forms the customary manner of glazing nowadays. The edge connection normally consists of a metal or plastic hollow profile in which there is accommodated a desiccant for the function of drying the air enclosed within the gap of the insulating glass unit. Towards the outside there is also applied an additional silicone or polysulphide seal. In general, the edge connection does not perform a static function. Under loading, the insulating glass unit behaves statically more or less like two outer panes. The spacers used to date, and also the sealing materials used to date, are not capable of connecting the two outer panes to one another in a shear-resistant manner to the extent that the two outer panes can be supported without visible supporting profiles. 
       SUMMARY OF THE INVENTION 
       [0003]    Based on this problem, the object of the present invention is to develop an insulating glass unit of the type mentioned at the outset to the effect that the insulating glass unit has a self-supporting structure, with the result that visible supporting profiles intended for supporting the insulating glass unit can be dispensed with or at least significantly reduced. 
         [0004]    To achieve this object, it is proposed according to the invention that, in the case of an insulating glass unit of the type mentioned at the outset, the spacer profile has two opposed contact faces which are connected in a shear-resistant manner to the outer panes via an adhesive layer, wherein the spacer profile additionally has at least one articulated region which is designed in such a way that the two contact faces can be rotated at least partially in order thereby to reduce stresses in the adhesive layer. 
         [0005]    The advantages which can be obtained with the solution according to the invention are obvious. The spacer profile is made of a high-strength plastic material, in particular a glass-fibre-reinforced plastic. As a result, use is advantageously made of a material which has a relatively low thermal conductivity yet possesses high strength. A further advantage lies in the coefficient of thermal expansion; this is very similar between glass and glass-fibre-reinforced plastic. This is important since only small additional forces, if any, then occur here as a result of different longitudinal elongations. 
         [0006]    The spacer profile can be attached either by means of correspondingly high-strength adhesives or by means of high-strength composite films. The high-strength adhesive or the high-strength composite film can consist, for example, of a polymer, e.g. polyvinylbutyral, ionoplast (polymer), a partially crystalline thermoplastic or some other material which has the required adhesive strength, durability and thermal stability. The ionoplast polymer in particular offers particularly high strength values here. The connection of the spacer profile to the outer panes makes it possible here to achieve a virtually monolithic load-bearing behaviour of the edge region. Although a few high-strength adhesives are already available for the facade region, adhesive bonding in the edge region is only possible if the profiles used there are tailored to these specific requirements. 
         [0007]    In the edge region of the panes there occur large angular changes at the contact faces particularly as a result of climatic loads. Depending on the stiffness of the adhesives and of the spacer profile, this leads to a greater or lesser degree of clamping, and hence to high tensile stresses at the edges of the adhesive bonds that can lead to the adhesive bonding being overloaded. 
         [0008]    In one possible embodiment of the inventive solution, use is made of a tough elastic epoxy resin-based two-component adhesive. Such adhesives have, in relation to the adhesive surfaces, a tensile shear strength of at least 10 N/mm 2  and their modulus of elasticity under short-term loading is greater than 1000 N/mm 2 . It goes without saying, however, that other adhesives or adhesive types are also suitable. 
         [0009]    In order to reduce the tensile stresses to a reasonable level here, it is necessary for the spacer profile to be designed in such a way that it operates as an articulation which is rigid in shear. In this respect, the spacer profile has two opposed contact faces which are designed with a relatively uniform thickness so as to produce there as uniform as possible a stress characteristic in the adhesive layer. Furthermore, the spacer profile has at least one articulated region which is designed in such a way that the two contact faces can be rotated at least partially relative to one another. The axis of rotation of the articulation here preferably corresponds to the longitudinal axis of the profile. The articulated design makes it possible for the outer panes to be able to rotate with respect to one another as a consequence, for example, of climatic loads without high stresses thereby resulting in the spacer profile and in the adhesive layer. Experience has shown that the highest stresses then arise in the region of the articulation. The proposed material of the spacer profile can absorb these stresses without problem. This arrangement ensures that the stresses decrease in the region of the contact faces and the loading on the adhesive is thereby reduced. 
         [0010]    The spacer profile can have a one-piece or multi-part design. In the case of a two-part spacer profile, composed of a first region and a second region, these regions are adhesively bonded to one another with a high-strength adhesive via an adhesive bond. Alternatively or in addition, the first region and the second region can be connected to one another by means of at least one mechanical connecting part. Here, the at least one mechanical connecting part may comprise a screw, a pin and/or a clamping strip. The spacer profile may be designed as an articulation so as to be able to rotate about an axis or a point or as a taper, with the result that the contact faces can be rotated at least partially relative to one another. 
         [0011]    In a preferred embodiment, the first region and the second region are each designed as a profiled spacer element having an L-shaped cross-sectional geometry. Each of the profile spacer elements has a first leg and a second leg. The two first legs of the profile spacer element extend parallel to one of the two outer panes and are connected in a shear-resistant manner to the outer pane. The second leg of the first profile spacer element extends parallel to the second leg of the second profile spacer element, and the two second legs are connected at least in certain regions. An articulated region is in each case formed in the region of connection of the two legs of each profiled spacer element. 
         [0012]    The spacer profile can also be configured in such a way that one or more desiccants are integrated in one or more cavities of the profile. In a further embodiment, each of the desiccants can also be accommodated in an additional desiccant profile. However, standard commercial spacer profiles containing desiccant can also be incorporated. 
         [0013]    Preferably, an additional profile constituting an interlayer between the contact faces of the spacer profile and the outer panes is fastened to at least one of the two outer panes using a transparent adhesive or a transparent film. 
         [0014]    To obtain increased thermal insulation, at least one further pane or a sheet can be arranged in the gap between the two outer panes in order to form a first and second pane gap. 
         [0015]    Furthermore, it is conceivable for a pressure-equalizing means to be provided in the case of an insulating glass unit which comprises two outer panes and a further pane or sheet. Here, the further pane or sheet is designed to be flexible at least in certain regions. In one possible embodiment of the pressure-equalizing means, there is provided at least one capillary tube which, for the purpose of pressure equalization, connects a pane gap to the external atmosphere. Alternatively or in addition to this, it is conceivable for at least one membrane, in particular an air-permeable but water-impermeable membrane, to be provided in a duct which, for the purpose of pressure equalization, connects a pane gap to the external atmosphere. 
         [0016]    The invention will be explained in more detail below by way of exemplary embodiments with reference to the appended drawings, in which: 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0017]      FIG. 1  shows a cross-sectional view of the edge region of an insulating glass unit according to one embodiment of the invention, where the pressure in the gap between the two outer panes is substantially identical to the external pressure; 
           [0018]      FIG. 2  shows the embodiment represented in  FIG. 1  when the pane gap is subjected to climatic loading; 
           [0019]      FIG. 3  shows a cross-sectional view of an edge region of an insulating glass unit according to a further embodiment of the invention; 
           [0020]      FIG. 4  shows a cross-sectional view of the edge region of an insulating glass unit according to a further embodiment of the invention; 
           [0021]      FIG. 5  shows a cross-sectional view of the edge region of an insulating glass unit according to a further embodiment of the invention; and 
           [0022]      FIG. 6  shows a cross-sectional view of the edge region of an insulating glass unit according to a further embodiment of the invention. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    The insulating glass unit  1  according to the invention is composed of at least two outer panes  2 ,  3  and of an edge connection  4  which comprises a spacer profile  5 . The spacer profile  5  is made of a high-strength plastic and has two opposed contact faces  12 . The spacer profile additionally comprises at least one depression  14 . The two contact faces  12  are connected in a shear-resistant manner to the respective inner sides of the two outer panes  2 ,  3 . For this purpose, it is conceivable to provide an adhesive layer  11  which brings about this shear-resistant connection between the spacer profile  5  and the outer panes  2 ,  3 . 
         [0024]    If the pressure in the gap between the outer panes  2 ,  3  increases, for example as a result of heating through solar radiation, then—as can be seen in particular from the representation in FIG.  2 —the two contact faces  12  of the spacer profile  5 , arranged parallel to one another beforehand, rotate with respect to one another. This is possible since, with the solution according to the invention, the spacer profile  5  has at least one articulated region  13  which is designed in such a way that, when subjected to the climatic loads, the two contact faces  12  can be rotated at least partially relative to one another, with the axis of rotation corresponding to the longitudinal axis of the spacer profile  5 . In the embodiment of the insulating glass unit  1  represented in  FIGS. 1 and 2 , two articulated regions  13  are provided. 
         [0025]    In the embodiment represented in  FIGS. 3 and 4 , use is made—by contrast with the embodiment represented in FIGS.  1  and  2 —of a spacer profile  5  which is composed of a first region  5   a  and a second region  5   b.  In the assembled state, the two regions  5   a,    5   b  are connected to one another in a shear-resistant manner. 
         [0026]    This takes place, for example, via an adhesive bond  15  obtained with a high-strength adhesive. In the embodiment represented in  FIGS. 3 and 4 , it is possible for the individual regions  5   a,    5   b  to be adhesively bonded first of all to the outer panes  2 ,  3 , after which the regions  5   a,    5   b  are connected to one another. This has the advantage that when the regions  5   a,    5   b  are being adhesively bonded first of all to the inner faces of the outer panes  2 ,  3 , they are accessible from all sides and consequently any escaping adhesive residues can still be removed. 
         [0027]    As has already been indicated, it is conceivable in the case of the embodiment represented in  FIGS. 3 and 4  for the two regions  5   a,    5   b  to be connected to one another with a high-strength adhesive via an adhesive bond  15 . However, the regions  5   a,    5   b  can also be connected mechanically to one another with the aid of screws, pins and/or clamping strips. The shear strength of the regions  5   a,    5   b  is achieved either through the adhesive bond  15  alone, but can also be obtained through additional mechanical connecting parts  16 . The depressions  14  present in the regions  5   a,    5   b  can also be used for the fastening of retaining elements. 
         [0028]    In the case of a normal insulating glass unit, it is known practice for the pane gap to be hermetically sealed. The air or the gas in the pane gap is kept as dry as possible by means of a specific desiccant  10 . This is necessary to ensure that, when there is a change in temperature, in particular if the outer pane cools towards the outside, no condensation occurs on the inside. The spacer profile  5  can also be configured such that one or more desiccants  10  are integrated in one or more cavities of the spacer profile  5 . In a further embodiment, each of the desiccants  10  can also be accommodated in an additional desiccant profile  9 . 
         [0029]    The desiccant  10  can be held in the desiccant profile  9  via adhesive spots  21 . However, it is also possible for standard commercial spacer profiles containing desiccant  10  to be incorporated. In a further refinement ( FIG. 4 ), yet additional profiles  19  can be inserted for visual reasons between the regions  5   a,    5   b  and the glass panes  2 ,  3 . This is the case if transparent adhesives are employed and the outer panes  2 ,  3  do not have an imprint in the region of the edge connection  4 . Here, the spacer profile  5  or the regions  5   a,    5   b  are then visible through the outer panes  2 ,  3 . 
         [0030]    However, it would be desirable for various applications if the visible region of the edge connection  4  could also be embodied in different colours or structures. This is implemented as follows: 
         [0031]    Between the spacer profile  5 , or the regions  5   a,    5   b,  and the outer panes  2 ,  3 , an additional flat profile  19  is adhesively bonded by means of a transparent adhesive  20 . The profile  19  may be embodied with one or more folded-over portions. This makes it possible to improve the appearance and the handling of the profile  19 . The profile  19  can be produced from various materials, or it can be embodied in all conceivable colours. By virtue of the transparent adhesive  20 , the material or its colour is visible through the outer panes  2 ,  3 . The transparent adhesive  20  of the additional profile  19  on the outer panes  2 ,  3  can be embodied as a transparent UV-curable or two-component adhesive. The thickness of the additional profile  19  is selected as a function of the material used such that the stresses which occur as a result of different thermal expansions are as small as possible and can be absorbed by the adhesive bonding. 
         [0032]    A further embodiment is shown in  FIG. 5 . Here, an insulating glass unit la is embodied with a total of two outer panes  2 ,  3  and one single pane  22  which is arranged between the outer panes  2 ,  3 . The thicker glass structure which now results means that the stiffness of the insulating glass unit is significantly increased again. Furthermore, such a glass structure having two gaps also has heat-related advantages besides. In further refinements, the regions  5   a,    5   b  can additionally be embodied with additional webs which not only increase the stiffness of the insulating glass unit but can also be used as a structural element. A further embodiment is shown in  FIG. 6 . An insulating glass unit  1   b  comprises two outer panes  2 ,  3 , with at least one further pane or a sheet  22 ,  32  being arranged in a gap defined by the two outer panes  2 ,  3  for the purpose of forming a first and second pane gap  30 ,  31 . The further pane or sheet  22 ,  32  is designed to be flexible at least in certain regions. A spacer profile  5 , which is arranged between the two outer panes  2 ,  3 , has a first region  26  and a second region  27  which can be connected or are connected to one another in a shear-resistant manner in certain regions. The first region  26  and the second region  27  of the spacer profile  5  are each designed as profiled spacer elements having an L-shaped cross-sectional geometry. Each of the profiled spacer elements has two legs  26   a,    26   b;    27   a,    27   b.  An articulated region  13  is formed in each case in the region of connection of the two legs  26   a,    26   b;    27   a,    27   b  of each profiled spacer element. A first leg  26   a,    27   a  of each region  26 ,  27  extends parallel to one of the two outer panes  2 ,  3  and is connected in a shear-resistant manner to the outer pane  2 ,  3 . A second leg  26   b  of one region  26  extends parallel to a second leg  27   b  of the other region  27  and is connected thereto at least in a region  28 . A pressure-equalizing means is provided at least for one of the two pane gaps  30 ,  31 , with at least one pressure-equalizing tube  29 , in particular capillary tube, being provided, and/or with at least one membrane, in particular an air-permeable but water-impermeable membrane, being provided in a duct  29 , which means, for the purpose of pressure equalization, connects a pane gap to the external atmosphere. Furthermore, one or more desiccants  10  can be integrated in one or more cavities in the pane gaps  30 ,  31  and be retained via adhesive spots  25 . In addition, the desiccant  10  can also be held in a desiccant profile  9 . 
         [0033]    The invention is not limited to the exemplary embodiments and can be embodied in further configurations. Furthermore, it should be pointed out that the pressure-equalizing means can also be used in the embodiment of  FIG. 5  or in an insulating glass unit which comprises two outer panes  2 ,  3  and at least one pane or sheet.