EP3440299B1 - Insulating glass unit for a refrigerated cabinet - Google Patents

Description

The invention relates to an insulating glass unit for a refrigerated cabinet, a door for a refrigerated cabinet, a method for producing such an insulating glass unit and its use.

Cooling shelves or refrigerators with transparent doors are widely used to display and present refrigerated goods to customers. The goods are kept in the refrigerated shelf at temperatures below 10 ° C and thus protected from spoilage. In order to keep the heat loss as low as possible, insulating glass units are often used as doors. Transparent doors make it possible to look at the goods without having to open the cupboards or shelves. Each time the doors are opened, the temperature in the refrigerated shelf increases and the goods are exposed to the risk of heating up. It is therefore desirable to present the goods in such a way that the number of opening processes is minimized. For this it is important that the view through the closed doors is restricted as little as possible. In conventional insulating glass units, the view is obstructed, at least in the edge area, by elements of the non-transparent surrounding door frame. With conventional insulating glass units, the door frame conceals the likewise non-transparent all-round edge bond. The edge bond of an insulating glass unit usually comprises at least one circumferential spacer, moisture-binding desiccant and a primary sealant for fastening the spacer between the panes and a secondary sealant that stabilizes and additionally seals the edge bond. These components are usually not transparent, which means that the view is restricted in the area of the surrounding edge seal.

Various approaches are known to solve this problem. From the DE 10 2012 106 200 A1 a refrigerator is known which comprises two insulating glass units as doors which contain a transparent spacer element on at least one vertical side and no frame element on this side. The spacer element is designed as a T-shaped cross-sectional profile, which simultaneously fulfills a load-bearing and a sealing function. The spacer element is designed as a one-piece, solid profile that is produced by extrusion.

Another approach is in the WO2014 / 198549 A1 described. Here, too, transparent spacer elements are used, which are arranged between the panes on at least one vertical side. The transparent spacer elements are fixed between the panes in particular with adhesive strips. Spacers made of transparent plastic resins are also disclosed which can be used in combination with metallic spacers along the horizontal sides. The combination of such different materials is problematic in insulating glass units. Different expansion coefficients of the materials used can lead to leaks in the edge seal in the long run. In addition, the sealants must be matched to the materials of the spacers. If several types of sealant are used, material incompatibilities between the sealants can easily arise, which in turn can cause leaks in the edge seal.

From the international patent application WO 2013/104507 A1 a spacer for multiple-pane insulating glazing is known which comprises at least one composite of a glass fiber-reinforced, polymeric base body, two parallel pane contact surfaces, a bonding surface and a glazing interior surface, as well as an insulating film. The pane contact surfaces and the bonding surface are connected to one another directly or via connecting surfaces. By choosing the proportion of glass fiber in the base body, the coefficient of thermal expansion of the base body can be varied and adapted. By adapting the thermal expansion coefficients of the base body and the polymeric insulation film, temperature-related stresses between the different materials and the insulation film can be avoided. The base body preferably has a glass fiber content of 20% to 50%, particularly preferably from 30% to 40%. The glass fiber content in the base body improves the strength and stability at the same time, but the production of transparent spacers or of spacers with colored patterns is disturbed due to the presence of the reinforcing fibers.

From the German patent DE 11 2014 002 800 T5 a glazed element comprising insulating glazing is known. The insulating glazing contains at least a first and a second glass pane, which are connected by means of a spacer. The spacer is made of a transparent resin made of polymethyl methacrylate, polycarbonate, polystyrene, polyvinyl chloride, acrylonitrile butadiene styrene, Nylon or a mixture of these compounds is selected. Such a spacer offers the advantage that it resists the possible exchange of gas, moisture and dust between the surrounding areas and the gas filling of the glazing and at the same time is transparent, which makes it possible to see the products contained in the refrigerated container furniture through it without the consumer's view being obstructed by the presence of a frame or, in particular, side struts. It is also mentioned in passing that in the prior art the spacers are generally a hollow, extruded or shaped profile made of metal or an organic material or also a profile with connecting angles or a profile folded at the corners. A reference to the polymers mentioned is not made. DE 11 2014 002800 T5 discloses all features of the preamble of claim 1.

The object of the present invention is to provide an improved insulating glass unit for a refrigerated cabinet, to provide a door for a refrigerated cabinet, and also to provide a simplified method for producing an insulating glass unit. In particular, it was the object of the present invention to provide an insulating glass unit for a refrigerated cabinet which, on the one hand, has a particularly high stability and compressive strength of the spacers and, on the other hand, multiplies the design possibilities of the spacers.

The object of the present invention is achieved according to the invention by an insulating glass unit according to independent claim 1. Preferred embodiments of the invention emerge from the subclaims.

The insulating glass unit according to the invention for a refrigerated cabinet comprises at least a first pane, a second pane spaced therefrom and a circumferential spacer frame between the first pane and the second pane. An inner space between the panes is delimited by the spacer frame, the first pane and the second pane. The inner space between the panes is enclosed by the spacer frame. The insulating glass unit has four sides. The sides of the insulating glass unit are the sides along which the edge area of the insulating glass unit is located. The two first sides are opposite each other and the two second sides are opposite each other. The spacer frame comprises at least four polymeric hollow profile spacers. Each hollow polymer profile spacer is attached along one of the four sides of the insulating glass unit. The polymeric hollow profile spacers are each along the four sides between the first washer and the second washer are secured by a primary sealant. Two first polymeric hollow profile spacers are arranged along the two opposite first sides and two second polymeric hollow profile spacers are arranged along the two second sides of the insulating glass unit. The first polymer hollow profile spacers contain 5% to 50% reinforcement fibers. The reinforcing fibers lead to an increased stability of the polymer hollow profile spacers and thus to a longer service life of the insulating glass unit. At the same time, the polymer hollow profile spacers have advantageously low thermal conductivities compared to metallic hollow profile spacers. The second polymer hollow profile spacers contain 0% to 0.5% reinforcing fibers, which means that the design options are particularly diverse. The fact that no or almost no reinforcing fibers are contained enables, for example, the production of transparent spacers or spacers with colored patterns, which would otherwise be disturbed by the presence of the reinforcing fibers. Due to the lack of reinforcement, the second polymeric hollow profile spacers have a lower compressive strength. Surprisingly, however, the insulating glass unit according to the invention with first and second polymeric hollow profile spacers has excellent stability. The arrangement according to the invention along opposite sides of the insulating glass unit results in a highly stable insulating glass unit which is comparable to insulating glass units which have reinforced spacers along all four sides. Compared to insulating glass units with both metallic and polymeric spacers, the insulating glass unit according to the invention has the advantage that the edge bond has a lower thermal conductivity. In addition, due to the different coefficients of thermal expansion of the metallic and polymer spacers, there is an increased build-up of stress in the spacer frame, which can lead to premature detachment of the sealant in the edge area. The invention thus provides a stable insulating glass unit which has a polymeric spacer profile along all four sides and thus has excellent heat-insulating properties.

In a preferred embodiment of the insulating glass unit according to the invention, the second polymeric hollow profile spacers are transparent. This has the advantage that there is no visual barrier along two opposite sides, so that the transparent area is maximized. As the second polymer According to the invention, hollow profile spacers contain practically no reinforcing fibers, they can be designed to be transparent. In conventional insulating glass units, reinforcement fibers are generally provided all around for polymeric hollow profile spacers. For this reason, no insulating glass units with transparent hollow profile spacers have been used so far. The insulating glass unit according to the invention is surprisingly stable along all four sides even without the stabilizing effect of the reinforcing fibers, so that the transparent design is possible.

Transparent in the context of the invention means that the material is transparent. A viewer can recognize the objects arranged behind the material layer. The material is accordingly translucent and preferably has a light transmission in the visible spectrum of at least 30%, particularly preferably of at least 50%.

Reinforcing fibers in the context of the invention denote fibers which are added to the polymeric base body of the hollow profile to reinforce the profile. These fibers are preferably glass fibers, natural fibers or ceramic fibers. These fibers increase the rigidity and strength of the profile. The fibers are preferably used in the form of short fibers with lengths between 0.05 mm and 0.5 mm. These lengths can be processed particularly well in an extruder, so that the reinforcing fibers can be incorporated directly during the extrusion. The percentages are percentages by mass of reinforcing fibers based on the proportion of reinforcing fibers in the polymer base body, i.e. any barrier films or coatings are not taken into account.

In a preferred embodiment of the insulating glass unit according to the invention, the polymeric hollow profile spacers comprise at least one polymeric base body at least comprising a first side wall, a second side wall arranged parallel thereto, a glazing interior wall, an exterior wall and a cavity. The cavity is enclosed by the side walls, the interior glazing wall and the exterior wall. The glazing interior wall is arranged perpendicular to the side walls and connects the first side wall to the second side wall. The side walls are the walls of the polymeric hollow profile spacer to which the outer panes of the insulating glass unit are attached. The first side wall and the second side wall run parallel to each other. The interior wall of the glazing is the wall of the polymer hollow profile spacer that faces the inner space between the panes in the finished insulating glass unit. The outer wall is arranged essentially parallel to the glazing interior wall and connects the first side wall to the second side wall. The outer wall faces the outer space between the panes. The cavity of the polymer base body leads to a weight reduction compared to a solidly shaped spacer and can be completely or partially filled with a desiccant.

Preferably, at least one of the two first polymeric hollow profile spacers contains a desiccant and the cavity of the two second polymeric hollow profile spacers is free of desiccant. The desiccant binds moisture that is present in the space between the panes and thus prevents the insulating glass unit from fogging up from the inside. The second polymer hollow profile spacers do not have to be filled with desiccant, since the attachment in at least one of the hollow profile spacers is sufficient to prevent the panes from fogging up. On the one hand, this saves material and, on the other hand, this procedure also has optical advantages.

The desiccant preferably contains silica gels, molecular sieves, CaCl ₂ , Na ₂ SO ₄ , activated carbon, silicates, bentonites, zeolites and / or mixtures thereof.

The outer wall of the polymer base body is the wall opposite the glazing interior wall, which points away from the inner space between the panes in the direction of the outer space between the panes. The outer wall preferably runs perpendicular to the side walls. The sections of the outer wall closest to the side walls can, however, alternatively be inclined at an angle of preferably 30 ° to 60 ° to the outer wall in the direction of the side walls. This angled geometry improves the stability of the polymeric hollow profile spacer and enables better bonding of the base body to a barrier film. A flat outer wall, which is perpendicular to the side walls (parallel to the glazing interior wall) in its entire course, has the advantage that the sealing surface between the polymer hollow profile spacer and the side walls is maximized and a simpler shape facilitates the production process.

The polymeric base body of the polymeric hollow profile spacer is preferably made from polymers, since these have a low thermal conductivity, which leads to improved heat-insulating properties of the edge seal. The polymer base body particularly preferably contains biocomposites, polyethylene (PE), polycarbonates (PC), polypropylene (PP), polystyrene, polybutadiene, polynitriles, polyesters, polyurethanes, polymethyl methacrylates, polyacrylates, polyamides, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinyl chloride (PVC), particularly preferred acrylonitrile-butadiene-styrene (ABS), acrylic ester-styrene-acrylonitrile (ASA), acrylonitrile-butadiene-styrene / polycarbonate (ABS / PC), styrene-acrylonitrile (SAN), PET / PC, PBT / PC and / or copolymers or mixtures thereof.

In a preferred embodiment of the insulating glass unit according to the invention, the first polymeric hollow profile spacers contain 15% to 40% glass fibers as reinforcing fibers, based on the polymeric base body. The first polymeric hollow profile spacers particularly preferably contain 20% to 35% glass fibers. In this area a particularly good stabilization of the polymeric hollow profile spacers is achieved with glass fibers and at the same time a low thermal conductivity of the hollow profile spacer is achieved. By choosing the proportion of glass fiber in the hollow profile, the coefficient of thermal expansion of the hollow profile can be varied and adapted. In this way, stresses between the different materials of the first and second polymer hollow profile spacers can be avoided. Glass fibers can be processed particularly well and, in particular, can be extruded together well together with the material of the polymer base body.

The polymeric hollow profile spacer preferably has a width of 5 mm to 45 mm, preferably 10 mm to 24 mm, along the interior wall of the glazing. For the purposes of the invention, the width is the dimension extending between the side walls. The width is the distance between the surfaces of the two side walls facing away from one another. The distance between the panes of the insulating glass unit is determined by the choice of the width of the glazing interior wall. The exact dimensions of the glazing interior wall depend on the dimensions of the insulating glass unit and the desired size of the space between the panes.

The polymer hollow profile spacer preferably has a height h _G of 5 mm to 15 mm, particularly preferably 6 mm to 10 mm, along the side walls. In In this area for the height, the hollow profile spacer has an advantageous stability, but on the other hand is advantageously inconspicuous in the insulating glass unit. In addition, the cavity of the hollow profile spacer has an advantageous size for the possible accommodation of a suitable amount of desiccant. The total height h _G is the distance between the surfaces of the outer wall facing away from one another and the interior wall of the glazing.

The wall thickness d of the polymeric hollow profile spacer is 0.5 mm to 15 mm, preferably 0.5 mm to 10 mm, particularly preferably 0.7 mm to 1.2 mm.

In a preferred embodiment of the insulating glass unit according to the invention, the compressive strength of the second polymeric hollow profile spacers is 20% to 40% lower than that of the first polymeric hollow profile spacers. With this difference in compressive strength, particularly stable insulating glass units are obtained and at the same time the flexibility in the design of the polymeric hollow profile spacers is increased.

The compressive strength of a polymer hollow profile spacer in the context of the invention denotes the compressive strength in the transverse direction of the hollow profile spacer. The transverse direction is perpendicular to the direction of extension of the hollow profile in the plane of the glazing interior surface of the hollow profile spacer. The distance between the first disk and the second disk is determined by the width b of the hollow profile spacer in the transverse direction. The compressive strength describes the stability of a spacer on which pressure is exerted by the first and second panes in an insulating glass unit. The compressive strength is given in force / length [N / cm]. The length L is measured in the direction of extent of the hollow profile spacer and indicates how long the piece of hollow profile spacer is on which the force acts laterally. An exemplary measurement is described together with the example.

In the case of a polymer hollow profile spacer with a width b of 12 mm - 20 mm, a wall thickness d of 1 mm and a total height h _G of 5 mm - 8 mm, the first polymer hollow profile spacers preferably have a compressive strength of 350 N / cm to 450 N / cm . The compressive strength of the second polymeric hollow profile spacer is preferably 50 N / cm to 150 N / cm less than that of the first polymer Hollow profile spacer, particularly preferably 100 N / cm smaller. A particularly stable insulating glass unit is obtained in these areas.

In a preferred embodiment of the insulating glass unit according to the invention, the first polymeric hollow profile spacers and the second polymeric hollow profile spacers are attached to the first pane and the second pane via a transparent primary sealant. The polymer hollow profile spacers are arranged in such a way that an outer space between the panes is created between the first pane and the second pane, delimited by the outer wall of the hollow profile spacer facing towards the surroundings. The panes therefore protrude slightly beyond the hollow profile spacer, so that the outer space between the panes is created. The outer space between the panes is filled with a transparent secondary sealant. The outer space between the panes of the insulating glass unit is delimited by the two panes and the outer wall of the hollow profile spacer. The secondary sealant serves to stabilize the edge bond of the insulating glass unit and absorbs the mechanical forces acting on the edge bond. The primary sealant is used to fasten the panes and to seal the inner space between the panes against the ingress of moisture and the loss of any gas filling that may be present. The fastening of all polymer hollow profile spacers via a transparent sealant has the advantage that material incompatibilities between different sealants can be avoided. The use of a transparent sealant primarily has optical advantages. Particularly in combination with visually appealing hollow profile spacers, a transparent sealant allows a view of the base body. In combination with second, transparent polymeric hollow profile spacers, a transparent sealing means has the advantage that the see-through area is maximized along the opposite second sides of the insulating glass unit.

In an alternative preferred embodiment, the primary and secondary sealants are not transparent. These sealants are available inexpensively, but have optical disadvantages.

The secondary sealant preferably contains polymers or silane-modified polymers, particularly preferably organic polysulfides, silicones, room temperature crosslinking (RTV) silicone rubber, peroxide crosslinked silicone rubber and / or addition crosslinking Silicone rubber, polyurethane and / or butyl rubber. These sealants have a particularly good stabilizing effect. These sealants are each available in a transparent and opaque version.

The primary sealant preferably contains a polyisobutylene. The polyisobutylene can be a crosslinking or non-crosslinking polyisobutylene. Polyisobutylenes are available in transparent and opaque versions.

The first and second polymeric hollow profile spacers of the insulating glass unit according to the invention have the advantage over metallic hollow profile spacers that they have a lower thermal conductivity. A high thermal conductivity, on the other hand, leads to the formation of a thermal bridge in the area of the edge seal, which, in the case of large temperature differences between the cooled interior and the ambient temperature, can lead to the accumulation of condensation on the glass pane facing the environment. This in turn leads to an obstruction of the view of the goods displayed, for example in a refrigerated shelf. This problem can be avoided by using polymeric hollow profile spacers with low thermal conductivity. However, the polymeric materials often have poorer properties in terms of gas and vapor tightness. In a preferred embodiment of the insulating glass unit according to the invention, the first and second polymeric hollow profile spacers therefore contain a gas-tight and water-vapor-tight barrier at least on their outer wall. In a preferred embodiment, a gas- and vapor-tight barrier is attached to the outer wall and part of the side walls of the polymeric hollow profile spacers. The attachment to a part of the side walls improves the tightness of the polymer hollow profile spacer significantly. The barrier increases the gas and moisture diffusion tightness of the polymeric hollow profile spacer and thus improves the sealing of the insulating glass unit according to the invention against the loss of any gas filling that may be present and against the penetration of moisture into the inner space between the panes. Suitable barriers are known from the prior art. In particular, metallic foils and polymeric foils with metallic coatings are possible, for example in FIG WO2013 / 104507 disclosed.

In a preferred embodiment of the insulating glass unit according to the invention, the two second polymeric hollow profile spacers contain on their outer wall a gas-tight and vapor-tight transparent barrier in the form of a transparent barrier film or a transparent barrier coating. The barriers known from the prior art are usually not transparent. The transparent barrier has optical advantages in particular. The transparent barrier enables a view of the polymeric hollow profile spacer, which is particularly advantageous in the case of a hollow profile spacer with a pattern or, in particular, in the case of a transparent hollow profile spacer. In this case, the view through the transparent hollow profile spacer is not disturbed by a nontransparent barrier.

In a preferred embodiment of the insulating glass unit according to the invention, the transparent barrier is designed as a transparent barrier film. The transparent barrier film is preferably a multilayer film which contains at least one polymer layer and one ceramic layer. Transparent polymer layers are available inexpensively. The ceramic layer can be applied as a transparent layer and contributes to the necessary gas diffusion density and moisture diffusion density of the hollow profile spacer. The structure of the polymer layer and ceramic layer thus enables the production of a transparent barrier film.

In a further preferred embodiment, the transparent barrier film contains at least one polymeric layer and at least two ceramic layers which are arranged alternately with the at least one polymeric layer. The alternating arrangement of several ceramic layers with at least one polymer layer advantageously ensures a particularly long-lasting improvement in tightness, since imperfections in one of the ceramic layers are compensated for by the remaining layer or layers. The adhesion of several thin layers on top of one another is also easier to achieve than the adhesion of a few thick layers.

The transparent barrier film particularly preferably contains at least two polymer layers which are arranged alternately with at least two ceramic layers. In this case, at least one of the ceramic layers is protected from damage by external mechanical influences by two polymer layers.

The transparent barrier film particularly preferably contains as many polymer layers as there are ceramic layers. Such a barrier film can be produced particularly easily by gluing or laminating individual polymer layers that are provided with a ceramic layer.

In a further preferred embodiment, the barrier film is attached to the hollow profile spacer in such a way that a ceramic layer points in the direction of the external environment. In this case, the ceramic layer in the finished insulating glass unit acts as a bonding agent for the secondary sealant.

The ceramic layers preferably contain silicon oxides (SiO _x ) and / or silicon nitrides. The ceramic layers preferably have a thickness of 20 nm to 200 nm. Layers of this thickness improve the gas diffusion density and moisture diffusion density while maintaining the desired transparent optical properties.

The ceramic layers are preferably deposited on a polymeric layer in a vacuum thin-layer process known to the person skilled in the art. This technology enables the targeted deposition of defined ceramic layers without the use of additional adhesive layers.

Further polymer layers are preferably connected to the remaining layers of the transparent barrier film via adhesion-promoting adhesive layers. For example, transparent adhesive layers based on polyurethane are suitable as adhesion-promoting adhesive layers.

In a further preferred embodiment, the transparent barrier film contains at least one polymer layer and at least one transparent metallic layer. Transparent metallic layers improve the gas diffusion density and the moisture diffusion density of the hollow profile spacer.

In a further preferred embodiment, the transparent barrier film contains at least two transparent metallic layers which are arranged alternately with at least one polymer layer. Transparent metallic layers improve the tightness of the transparent barrier film and can be produced cost-effectively in large numbers. At least two transparent ones are preferred metallic layers arranged alternately with at least two polymer layers. This achieves particularly good results.

The transparent metallic layers preferably contain aluminum, silver, magnesium, indium, tin, copper, gold, chromium and / or alloys or oxides thereof. The transparent metallic layers particularly preferably contain indium tin oxide (ITO), aluminum oxide (Al ₂ O ₃ ) and / or magnesium oxide. The metallic layers are preferably applied in a vacuum thin-film process and each have a thickness of 20 nm to 100 nm, particularly preferably 50 nm to 80 nm. In these thickness ranges, the layers can be made transparent and are at the same time thick enough to ensure the tightness of the hollow profile spacer improve.

The polymeric layers of the transparent barrier film preferably comprise polyethylene terephthalate, ethylene vinyl alcohol, polyvinylidene chloride, polyamides, polyethylene, polypropylene, silicones, acrylonitriles, polyacrylates, polymethyl acrylates and / or copolymers or mixtures thereof.

A polymeric layer is preferably designed as a single-layer film. This is advantageously inexpensive. In an alternative preferred embodiment, the polymeric layer is designed as a multilayer film. In this case, several layers of the materials listed above are glued together. This is advantageous because the material properties can be perfectly matched to the sealant, adhesive or adjacent layers used.

The polymeric layers preferably each have a layer thickness of 5 μm to 80 μm.

The transparent barrier film preferably has a gas permeation of less than 0.001 g / (m ² h).

In an alternative preferred embodiment, the gas- and vapor-tight transparent barrier is designed as a barrier coating. This transparent barrier coating contains aluminum, aluminum oxides and / or silicon oxides and is preferably applied via a PVD process (physical vapor deposition). The transparent barrier coating containing aluminum, Aluminum oxides and / or silicon oxides provide particularly good results in terms of tightness and additionally show excellent adhesion properties to the secondary sealants used in the insulating glass unit. The application via a vacuum coating process enables the deposition of particularly thin and transparent layers.

In a preferred embodiment of the insulating glass unit according to the invention, the glazing interior wall of at least one of the polymer hollow profile spacers has at least one opening. A plurality of openings are preferably made in the interior wall of the glazing of a hollow profile spacer. The total number of openings depends on the size of the insulating glass unit. The polymeric hollow profile spacers preferably contain openings in the cavity of which a desiccant is introduced. The openings connect the cavity with the inner space between the panes, which enables gas to be exchanged between them. This enables air humidity to be absorbed by a desiccant located in the cavity and thus prevents the windows from fogging up. The openings are preferably designed as slots, particularly preferably as slots with a width of 0.2 mm and a length of 2 mm. The slots ensure an optimal exchange of air without desiccant penetrating from the cavity into the space between the panes.

The first pane and the second pane of the insulating glass unit preferably contain glass and / or polymers, particularly preferably quartz glass, borosilicate glass, soda-lime glass, polymethyl methacrylate, polycarbonate and / or mixtures thereof.

The first disk and the second disk have a thickness of 2 mm to 50 mm, preferably 3 mm to 16 mm, whereby the two disks can also have different thicknesses.

The insulating glass unit is preferably filled with an inert gas, particularly preferably with a noble gas, preferably argon or krypton, which reduce the heat transfer value in the inner space between the panes.

In a further preferred embodiment, the insulating glass unit comprises more than two panes. The hollow profile spacers can, for example, have grooves included, in which at least one further disk is arranged. Several panes could also be designed as a laminated glass pane.

The invention further relates to a door for a refrigerated cabinet at least comprising an insulating glass unit according to the invention and two horizontal frame elements. The horizontal frame elements are arranged along the first sides of the insulating glass unit. The horizontal frame elements are arranged in such a way that they obscure the view of the first polymer hollow profile spacers. The horizontal frame elements are therefore not made transparent, that is, they block the view of the edge bond with the first polymeric hollow profile spacers and sealing means. This improves the visual appearance of the door. The horizontal frame elements encompass the first pane and the second pane in the edge area. The horizontal frame elements thus stabilize the door and also offer the possibility of attaching additional fastening means, for example for the pane suspension. The second polymer hollow profile spacers are designed to be transparent and are fastened between the first pane and the second pane by means of a transparent primary sealant. A transparent secondary sealant is arranged along the second sides of the insulating glass unit. The second hollow polymer profile spacers are positioned along the vertical sides of the door. This means that the view of the goods presented in the refrigerated cabinet is not blocked along the vertical sides. In particular, the combination of transparent primary and secondary sealing means surprisingly improves the visual appearance of the transparent second hollow profile spacer.

When installing the door in a showcase or a refrigerated shelf, the horizontal sides indicate the top and bottom of the door. The vertical sides in this case are the right and left sides. When installing the door in, for example, a freezer in a horizontal orientation, the vertical sides are also the right and left sides, as seen from the observer, and the horizontal sides are the rear and the front side.

To open the door of the refrigerated cabinet, a door handle is preferably arranged on the first pane. The first pane is the pane that, after the door has been installed in the refrigeration unit, points towards the surroundings, i.e. towards a customer. Despite the use of the second polymer hollow profile spacer without additional reinforcing fibers along the second sides of the insulating glass unit, the stability is surprisingly so high that the insulating glass unit is permanently stable when a door handle is used on the surface of the first pane. The door handle is preferably glued. This is particularly advantageous visually.

In a further preferred embodiment of the door according to the invention for a refrigerated cabinet, an additional vertical frame element is attached which is attached along one of the second sides and engages around the edges of the first pane and the second pane at least in partial areas. In this way, an optimal stabilization of the door is achieved and additional elements such as the door suspension can be attached to the vertical frame element. The vertical frame element is attached in the refrigerated cabinet on the side of the insulating glass unit opposite the door opening.

The frame element preferably comprises a metal sheet, particularly preferably an aluminum or stainless steel sheet. These materials enable the door to be stabilized well and are compatible with the materials typically used in the area of the edge seal.

In an alternative preferred embodiment, the frame element comprises polymers. Polymer frame elements are advantageously light in weight.

• Bereitstellen einer ersten Scheibe und einer zweiten Scheibe,
• Bereitstellen eines Abstandhalterrahmens mindestens umfassend zwei erste polymere Hohlprofilabstandhalter und zwei zweite polymere Hohlprofilabstandhalter,
• Anbringen der ersten Scheibe und der zweiten Scheibe am Abstandhalterrahmen über ein primäres Dichtmittel, wobei ein innerer Scheibenzwischenraum und ein äußerer Scheibenzwischenraum entstehen,
• Füllen des äußeren Scheibenzwischenraums mit einem sekundären Dichtmittel,
• wobei mindestens entlang der beiden ersten Seiten ein transparentes primäres Dichtmittel und ein transparentes sekundäres Dichtmittel angebracht werden.

The invention further comprises a method for producing an insulating glass unit according to the invention for a refrigerated cabinet comprising the steps:

• Providing a first disc and a second disc,
• Providing a spacer frame at least comprising two first polymeric hollow profile spacers and two second polymeric hollow profile spacers,
• Attaching the first pane and the second pane to the spacer frame via a primary sealant, creating an inner space between the panes and an outer space between the panes,
• Filling the outer space between the panes with a secondary sealant,
• wherein a transparent primary sealant and a transparent secondary sealant are applied at least along the two first sides.

The process is preferably carried out in the order given above.

The invention further comprises the use of the insulating glass unit according to the invention as a door in a refrigerated shelf or in a freezer.

Figur 1

einen Querschnitt durch eine erfindungsgemäße Isolierglaseinheit durch die Ebene des Abstandhalterrahmens,

Figur 2

eine Aufsicht auf eine mögliche Ausführungsform einer erfindungsgemäßen Tür für ein Kühlmöbel,

Figur 3

einen Querschnitt durch eine erfindungsgemäße Isolierglaseinheit im Randbereich,

Figur 4

einen perspektivischen Querschnitt durch einen polymeren Hohlprofilabstandhalter für eine erfindungsgemäße Isolierglaseinheit,

Figur 5

einen Querschnitt durch eine geeignete transparente Barrierefolie,

Figur 6

einen Querschnitt durch eine weitere geeignete transparente Barrierefolie,

Figur 7

einen perspektivischen Querschnitt durch einen polymeren Hohlprofilabstandhalter.

The invention is explained in more detail below with reference to drawings. The drawings are purely schematic representations and are not true to scale. They do not limit the invention in any way. Show it:

Figure 1

a cross section through an insulating glass unit according to the invention through the plane of the spacer frame,

Figure 2

a plan view of a possible embodiment of a door according to the invention for a refrigerated cabinet,

Figure 3

a cross section through an insulating glass unit according to the invention in the edge area,

Figure 4

a perspective cross-section through a polymeric hollow profile spacer for an insulating glass unit according to the invention,

Figure 5

a cross section through a suitable transparent barrier film,

Figure 6

a cross section through another suitable transparent barrier film,

Figure 7

a perspective cross-section through a polymer hollow profile spacer.

Figure 1 shows a schematic cross section through an insulating glass unit according to the invention through the plane of the spacer frame. The insulating glass unit I has a first pane 11 and a second pane 12 (shown in FIG Figure 3 ). A circumferential spacer frame 10, which delimits an inner space 8 between the panes, is arranged between the first pane 11 and the second pane 12. The spacer frame 10 comprises four polymeric hollow profile spacers 13.1, 13.2, 13.3 and 13.4, which are each arranged along one of the four sides 14.1, 14.2, 14.3 and 14.4 of the insulating glass unit I. The four polymer hollow profile spacers 13.1, 13.2, 13.3 and 13.4 are plugged together at the corners of the insulating glass unit by means of corner connectors 25. The connection via plug connectors has the advantage that different types of hollow profile spacers can easily be combined with one another in a spacer frame 10. In addition, the corner connectors 25 can be designed in such a way that one of the four hollow profile spacers is prevented from being filled with a desiccant 21 is that the desiccant 21 penetrates into the next hollow profile spacer. The insulating glass unit I is rectangular and has two opposite first sides 14.1, 14.2 and two opposite second sides 14.3 and 14.4. Two first polymeric hollow profile spacers 13.1 and 13.2 are attached along the two first sides 14.1 and 14.2. Two second polymeric hollow profile spacers 13.3 and 13.4 are arranged along the two second sides. The first two polymeric hollow profile spacers 13.1 and 13.2 are polymeric hollow profile spacers according to the prior art with a polymeric base body 1 consisting essentially of styrene acrylonitrile (SAN) with 35% glass fibers as reinforcing fibers. These reinforcing fibers increase the mechanical stability of the polymeric hollow profile spacer and have proven themselves as reinforcing fibers for polymeric spacers. The first polymer hollow profile spacers 13.1 and 13.2 are provided on the outer wall with a gas- and vapor-tight barrier which seals the inner space between the panes. For example, a multilayer film comprising three layers of polyethylene terephthalate (PET) with a thickness of 12 μm each and two aluminum layers with a thickness of 150 nm each is suitable. The aluminum layers are arranged alternately with the PET layers. In the glazing interior surface 3 of the first polymer hollow profile spacers openings 29 are made, via which any moisture in the inner space between the panes 8 can be absorbed by the molecular sieve, which is filled as desiccant 21 in the cavities 5 of the first polymer hollow profile spacers 13.1 and 13.2. The second polymeric hollow profile spacers 13.3 and 13.4 comprise a polymeric base body 1 which consists essentially of styrene acrylonitrile (SAN) and contains 0% reinforcing fibers. The absence of the reinforcing fibers leads to hollow profile spacers 13.3 and 13.4, which have a lower mechanical stability than those with reinforcing fibers. Surprisingly, the stability of the entire insulating glass unit I is not impaired and a stable insulating glass unit I is obtained. The second polymer hollow profile spacers 13.3 and 13.4 are transparent and do not contain any desiccant filling. The filling of the first two polymer hollow profile spacers 13.1 and 13.2 is sufficient to absorb the moisture from the inner space 8 between the panes. The second polymer hollow profile spacers 13.3 and 13.4 contain a transparent barrier film 6. The details of a suitable transparent barrier film 6 are for example in FIG Figure 5 shown. In the outer space 7 between the panes, a transparent silicone is attached as a transparent secondary sealant 28.1. The transparent silicone 28.1 is arranged around the circumference so that there are no material incompatibilities between different secondary sealants. This embodiment is also easier to produce in terms of production than combining different secondary sealing means 28. The transparent silicone along the second sides 14.3 and 14.4 in combination with the transparent polymeric hollow profile spacers 13.3 and 13.4 leads to an insulating glass unit I with two sides 14.3 and 14.4, along which an unobstructed view of the objects behind the insulating glass unit I is possible even in the edge area is. The insulating glass unit I thus has a maximum transparent area. Only along the first sides 14.1 and 14.2 does an edge bond with the first polymer hollow profile spacers 13.1, 13.2 block the view through the edge region of the insulating glass unit I.

Figure 2 shows a door II according to the invention for a refrigerated shelf. The door II comprises two horizontal frame elements 30.1 and 30.2 and an insulating glass unit I, the structure of which in cross section in Figure 1 is shown schematically. The horizontal frame elements 30.1 and 30.2 are arranged along the first sides 14.1 and 14.2 of the insulating glass unit I. The two horizontal frame elements 30.1 and 30.2 hide the view of the first polymer hollow profile spacers 13.1 and 13.2 and the edge bond with primary and secondary sealing means. The corner connectors 25 are also hidden by the edge bond. The horizontal frame elements 30.1 and 30.2 are formed from a 0.3 mm thick stainless steel sheet. The frame elements 30.1 and 30.2 increase the stability of the door II. The horizontal frame element 30.2 is at the top when the door II is installed vertically in a refrigerated shelf or at the rear when the door II is installed horizontally. The horizontal stainless steel sheet 30.2 surrounds the first and second disks 11 and 12 and thus protects the edges of the disks from damage. The horizontal frame element 30.1, which would be arranged at the bottom after installation in a refrigerated shelf or at the front when installed in a freezer, is constructed in exactly the same way as the upper or rear frame element 30.2. The horizontal frame elements 30.1 and 30.2 are glued to the insulating glass unit I. Fastening means such as hinges can be attached to the horizontal frame elements 30.1 and 30.2 when installed in a refrigerated shelf or rails when used as a sliding door in a freezer. A door handle 31, which is glued to the first pane 11, enables the door II to be opened and closed easily. Thanks to the combination of first and second polymeric hollow profile spacers the insulating glass unit I so stable that the forces that act on the insulating glass unit I when the door II is opened do not adversely affect the insulating glass unit I.

Figure 3 shows a cross section of an insulating glass unit I according to the invention in the edge area. The structure of the insulating glass unit I is basically the same along all four sides. Differences occur between the first and second polymeric hollow profile spacers. The picture shows a hollow profile spacer filled with desiccant 21, which is only arranged along the first sides, as in FIG Figure 1 is shown. The description of the figure is generally not based on a particular polymeric hollow profile spacer. The first pane 11 is connected to the first side wall 2.1 of the polymeric hollow profile spacer 13 via a transparent primary sealing means 27.1, and the second pane 12 is attached to the second side wall 2.2 via the transparent primary sealing means 27.1. The transparent primary sealant 27.1 contains a transparent crosslinking polyisobutylene. The inner space 8 between the panes is located between the first pane 11 and the second pane 12 and is delimited by the glazing interior wall 3 of the spacer 13. In the case of the first polymer hollow profile spacers 13.1 and 13.2, the cavity 5 is filled with a desiccant 21, for example molecular sieve. The cavity 5 is connected to the inner space 8 between the panes via openings in the interior wall 29 of the glazing. A gas exchange takes place through the openings 29 between the cavity 5 and the inner space between the panes 8, the desiccant 21 absorbing the humidity from the inner space 8 between the panes. The first pane 11 and the second pane 12 protrude beyond the side walls 2.1 and 2.2 so that an outer space 7 between the panes is created, which is located between the first pane 11 and the second pane 12 and is delimited by the outer wall of the hollow profile spacer 4. The outer space 7 between the panes is filled with a transparent secondary sealant 28.1. The transparent secondary sealant 28.1 is, for example, a silicone. Silicones absorb the forces acting on the edge seal particularly well and thus contribute to the high stability of the insulating glass unit I. The first pane 11 and the second pane 12 are made of soda-lime glass with a thickness of 3 mm each.

Figure 4 shows a cross section of a polymeric hollow profile spacer 13.1, 13.2 suitable for an insulating glass unit I according to the invention. The polymeric hollow profile spacer 13 comprises a polymeric base body with a first Side wall 2.1, a side wall 2.2 running parallel to it, a glazing interior wall 3 and an outer wall 4. The glazing interior wall 3 runs perpendicular to the side walls 2.1 and 2.2 and connects the two side walls. The outer wall 4 lies opposite the glazing interior wall 3 and connects the two side walls 2.1 and 2.2. The outer wall 4 runs essentially perpendicular to the side walls 2.1 and 2.2. The sections of the outer wall 4.1 and 4.2 closest to the side walls 2.1 and 2.2 are, however, inclined at an angle of approximately 45 ° to the outer wall 4 in the direction of the side walls 2.1 and 2.2. The angled geometry improves the stability of the hollow profile spacer 13 and enables better bonding with a barrier film 6. The wall thickness d of the hollow profile is 1 mm. The hollow profile 1 has, for example, a total height h _G of 6.5 mm and a width b of 16 mm. The outer wall 4, the glazing interior wall 3 and the two side walls 2.1 and 2.2 enclose the cavity 5. The cavity 5 can accommodate a desiccant 21. The polymeric base body 1 contains styrene-acrylic-nitryl (SAN) and, in the case of the first polymeric hollow profile spacer, additionally about 35% by weight of glass fiber. A gas- and vapor-tight barrier film 6, which improves the tightness of the spacer 13, is attached to the outer wall 4 and approximately half of the side walls 2.1 and 2.2. The barrier film 6 can be attached to the polymeric base body 1 with a polyurethane hotmelt adhesive, for example. As an alternative to a barrier film 6, a barrier coating 9 can also be applied. This can be applied directly to the polymer base, for example in a vacuum coating process.

Figure 5 shows a cross section through a transparent barrier film 6, which is suitable to be attached to a transparent first polymeric hollow profile spacer 13.1, 13.2. The transparent barrier film 6 is a multilayer film made of polymeric layers 19 and ceramic layers 20. The polymeric layers consist essentially of 12 μm thick polyethylene films and the ceramic layers of a 40 nm thick SiO _x layer. Two polymer layers 19 are arranged alternately with two ceramic layers 20. The alternating arrangement has the advantage that defects in one of the ceramic layers 20 can be compensated for by the other layers. A total of three ceramic layers 20 and three polymer layers 19 are part of the barrier film. Two of the ceramic layers 20 are connected directly via an adhesive layer 18, for example a 3 μm thick layer of polyurethane adhesive. Through this arrangement all ceramic layers 20 protected by polymer layers 19 against mechanical damage from the outside. The transparent barrier film 6 shown can be produced particularly easily by connecting three polyethylene films, each _{coated with an SiO x} layer, via two adhesive layers 18.

Figure 6 shows a cross section through a further embodiment of a transparent barrier film 6, which is suitable to be attached to a transparent first polymeric hollow profile spacer 13.1, 13.2. The transparent barrier film 6 is a multilayer film with two polymer layers 19, which essentially consist of polyethylene terephthalate (PET), and two ceramic layers 20, each of which consists of 30 nm thick silicon oxide (SiO _x ) layers. The production of the barrier film 6 can advantageously take place by gluing two PET films coated _{with SiO x.} The adhesive layer 18 is, for example, a 3 μm thick polyurethane adhesive layer. Such a barrier film 6 with an external ceramic layer 20 is preferably glued to the hollow profile spacer in such a way that the polymeric layer 19 faces the hollow profile spacer and the ceramic layer 20 faces the external environment or the secondary sealant. In this arrangement, the ceramic layer can serve as an adhesion promoter, since the adhesion of the usual secondary sealants to a ceramic layer is improved compared to the adhesion to a polymer layer.

Measurement of compressive strength

Figure 7 shows a perspective cross-section of a polymer base body 1 and the essential parameters for measuring the compressive strength of a polymer hollow profile spacer. The height of the side wall h _S , the length L of a piece of the hollow profile spacer and the direction of the force F, which acts when measuring the compressive strength, are also shown. The compressive strength describes the stability of the polymeric hollow profile spacer in the transverse direction. To measure the compressive strength, a polymeric base body 1 is arranged with the first side wall 2.1 on a non-movable contact surface 40. This can be in the orientation as in Figure 6 shown, or the polymer base body 1 can be placed with the first side wall 2.1 on the pressing surface 40 so that the in Figure 6 The arrangement shown is rotated 90 ° counterclockwise. A piece of polymeric base body 1 of length L is selected for the measurement. In the example shown, the sections 4.1 and 4.1 of the outer wall 4 closest to the side walls are angled. Accordingly, the area with which the polymeric base body 1 with the The contact surface 40 is in contact, defined by the length L and the height h _{S of} a side wall 2. The area L xh _S on the second side wall 2.2 is characterized by a fine checkered pattern. When measuring the compressive strength, the polymer base body 1 to be measured is clamped and then compressed at a defined test speed by exerting a force F on the entire surface L xh _{S of} the second side wall. The maximum force F _max that can be exerted on the polymeric base body 1 before the polymeric base body 1 breaks or collapses is measured. When the exerted force F is plotted against the deformation during the measurement, the force F increases continuously up to a point F _max , from which the curve suddenly drops. At this point the measurement is canceled.

Example:

A door according to the invention is equipped with four polymer hollow profile spacers, as in FIG Figures 1 and 2 shown. The door is rectangular and the first and second panes are each 80 cm x 180 cm. A transparent butyl was used as the primary sealant and a transparent silicone was used as the secondary sealant. The first two polymeric hollow profile spacers are filled with molecular sieve, while the second polymeric hollow profile spacers do not contain any desiccant. The inner space between the panes was filled with an inert gas, in this case argon.
The polymer base bodies of the first and second hollow profile spacers have the following dimensions:
Wall thickness d = 1 mm; Width b = 16 mm; Total height h _G = 6.5 mm; Height of the side walls h _S = 4.5 mm
The polymer base bodies of the first polymer hollow profile spacers essentially consist of styrene-acrylic-nitrile (SAN) with a glass fiber content of around 35%. The polymer base bodies of the second polymer hollow profile spacers essentially consist of styrene-acrylic-nitrile (SAN) and have a proportion of reinforcing fibers of 0%.
The compressive strength of the polymer base bodies of the first and second polymer hollow profile spacers were measured as described above and the following values were obtained for measurements on pieces of length L = 10 cm at a test speed of 2 mm / min each: F _max / L Base body SAN with 35% glass fiber 410 N / cm Base body SAN 295 N / cm

The compressive strength F _max / L of the second polymer hollow profile spacers is accordingly about 28% lower than that of the first polymer hollow profile spacers. The influence of the barrier layer or barrier film applied to the base body on the compressive strength values can be neglected.

Comparative example:

A door with four polymer hollow profile spacers, each containing a base body with SAN and 35% glass fiber content, was otherwise installed analogously to the door in the example. In this case, the compressive strengths of all polymer hollow profile spacers are as high as those of the first polymer hollow profile spacers in the example.

Comparison example - comparison example

Both doors were built into a refrigerated shelf with an inside temperature of - 18 ° C and an outside temperature of 20 ° C. The doors were automatically opened and closed again 10,000 times on a test bench. After closing, the doors were kept closed for at least 90 seconds so that the temperature in the interior of the refrigerated shelf did not become too hot during the test. Then the insulating glass units of the example door and the comparative example door were examined. The external appearance of both doors was unscathed. The edge seal was intact and the panes were not fogged up from the inner space between the panes. In addition, a dew point determination was carried out as described in DIN EN 1279. Both doors reached a dew point of below -60 ° C, which corresponds to the requirements for such insulating glazing according to DIN EN 1279. In addition, the argon content was determined by gas chromatography. This was around 90% in both cases, which corresponds to the requirements for a gas-filled insulating glass unit. The sealing and stability of the edge seal of the example and comparative example is therefore excellent on both sides. Accordingly, the insulating glass unit with second polymeric hollow profile spacers without reinforcing fibers has just as great a stability as the design according to the prior art with reinforcing fibers in all hollow profile spacers.

List of reference symbols

I.

Insulating glass unit

II

Door for a refrigerated cabinet

1

polymer base

2

side walls

2.1

first side wall

2.2

second side wall

3

Glazing interior wall

4th

Outer wall

4.1, 4.2

the sections of the outer wall closest to the side walls

5

cavity

6th

transparent barrier film

7th

outer space between the panes

8th

inner space between the panes

9

Barrier coating

10

circumferential spacer frame

11

first slice

12th

second disc

13th

polymeric hollow profile spacers

13.1, 13.2

Hollow profile spacers along the first sides 14.1 and 14.2

13.3, 13.4

Hollow profile spacers along the second sides 14.3 and 14.4

14.1, 14.2

two opposite first sides of the insulating glass unit I

14.3, 14.4

two opposite second sides of the insulating glass unit I

18th

Adhesive layer

19th

polymeric layer of the transparent barrier film

20th

ceramic layer of the transparent barrier film

21

Desiccant

25th

Corner connector

27

primary sealant

27.1

transparent primary sealant

28

secondary sealant

28.1

transparent secondary sealant

29

Openings in the interior wall of the glazing

30.1, 30.2

horizontal frame elements

31

Door handle

40

Contact surface

b

Width of a hollow profile spacer

d

Wall thickness of a hollow profile spacer

hG

Total height of a hollow profile spacer

hS

Height of a side wall of a hollow profile spacer

L.

Length of a piece of hollow profile spacer

F.

Force acting in the direction of the arrow

Claims (11)

1. Insulating glass unit (I) suitable for a refrigeration unit, at least comprising a first pane (11), a second pane (12) spaced at a distance from the first pane, a peripheral spacer frame (10) between the first pane (11) and the second pane (12), and an inner interpane space (8), which is delimited by the spacer frame (10) and the first pane (11) and the second pane (12), wherein

   - the spacer frame (10) comprises four hollow-profile spacers (13.1, 13.2, 13.3, 13.4), which are, in each case, secured between the first pane (11) and the second pane (12) along one of four sides (14.1, 14.2, 14.3, 14.4) of the insulating glass unit (I) via a primary sealant (27),

   - two first hollow-profile spacers (13.1, 13.2) are arranged along two opposing first sides (14.1, 14.2) of the insulating glass unit (I), and two second hollow-profile spacers (13.3, 13.4) are arranged along two opposing second sides (14.3, 14.4) of the insulating glass unit (I), characterized in that

   - the four hollow-profile spacers are polymeric hollow-profile spacers, and that

   - the first polymeric hollow-profile spacers (13.1, 13.2) contain 5% to 50% reinforcement fibers,

   - the second polymeric hollow-profile spacers (13.3, 13.4) contain 0% to 0.5% reinforcement fibers,

   and that the compressive strength of the second polymeric hollow-profile spacers (13.3, 13.4) is lower by 20% to 40% than that of the first polymeric hollow-profile spacers (13.1, 13.2).
2. Insulating glass unit (I) according to claim 1, wherein the second polymeric hollow-profile spacers (13.3, 13.4) are implemented transparent.
3. Insulating glass unit (I) according to one of claims 1 or 2, wherein the polymeric hollow-profile spacers (13.1, 13.2, 13.3, 13.4) comprise at least one polymeric main body (1), which at least comprises:

   - a first side wall (2.1); a second side wall (2.2) arranged parallel thereto;

   - a glazing interior wall (3) arranged perpendicular to the side walls (2.1, 2.2), which connects the side walls (2.1, 2.2) to one another;

   - an outer wall (4), which is arranged substantially parallel to the glazing interior wall (3) and connects the side walls (2.1, 2.2) to one another;

   - a cavity (5), which is enclosed by the side walls (2.1, 2.2), the glazing interior wall (3), and the outer wall (4),

   wherein a desiccant (21) is contained at least in the cavity (5) of one of the first polymeric hollow-profile spacers (13.1, 13.2) and the cavity (5) of the two second polymeric hollow-profile spacers (13.3, 13.4) is free of desiccant (21).
4. Insulating glass unit (I) according to one of claims 1 through 3, wherein the first polymeric hollow-profile spacers (13.1, 13.2) include, as reinforcement fibers, 15% to 40% glass fibers, preferably 20% to 35% glass fibers.
5. Insulating glass unit (I) for a refrigeration unit according to one of claims 1 through 4, wherein the first polymeric hollow-profile spacers (13.1, 13.2) and the second polymeric hollow-profile spacers (13.3, 13.4) are secured on the first pane (11) and the second pane (12) via a transparent primary sealant (27), and the outer interpane space (7) facing the external surroundings is filled with a transparent secondary sealant (28).
6. Insulating glass unit (I) according to one of claims 1 through 5, wherein at least the two second polymeric hollow-profile spacers (13.3, 13.4) include in each case on their outer wall (4) a gas-tight and vapor-tight transparent barrier in the form of a transparent barrier film (6) or a transparent barrier coating (9).
7. Insulating glass unit (I) according to claim 6, wherein the transparent barrier film (6) is a multilayer film, which includes at least one polymeric layer (19) and one ceramic layer (20).
8. Insulating glass unit (I) according to one of claims 6 or 7, wherein the transparent barrier film (6) includes at least one polymeric layer (19) and at least two ceramic layers (20), which are arranged alternatingly with the at least one polymeric layer (19).
9. Door (II) for a refrigeration unit at least comprising an insulating glass unit (I) according to one of claims 1 through 8 and two horizontal frame elements (30.1, 30.2), wherein

   - the horizontal frame elements (30.1, 30.2) are arranged along the first sides (14.1, 14.2) of the insulating glass unit (I) such that the first polymeric hollow-profile spacers (13.1, 13.2) are concealed,

   - the second polymeric hollow-profile spacers (13.3, 13.4) are implemented transparent,

   - at least the second polymeric hollow-profile spacers (13.3, 13.4) are secured via a transparent primary sealant (27), and

   - a transparent secondary sealant (28) is arranged along the second sides of the insulating glass unit (I) in the outer interpane space (8).
10. Method for producing an insulating glass unit (I) for a refrigeration unit according to one of claims 1 through 8, wherein at least

    - one first pane (11) and one second pane (12) are provided,

    - one spacer frame (10) at least comprising two first hollow-profile polymeric spacers (13.1, 13.2) and two second hollow-profile polymeric spacers (13.3, 13.4) is provided,

    - Mounting the first pane (11) and the second pane (12) on the spacer frame (10) via a primary sealant (27), wherein an inner interpane space (8) and an outer interpane space (7) are created,

    - Filling the outer interpane space (8) with a secondary sealant (28),

    - wherein a transparent primary sealant (27.1) and a transparent secondary sealant (28.1) are applied at least along the two first sides (14.1, 14.2).
11. Use of the insulating glass unit (I) according to one of claims 1 through 8 as a door in a refrigerator display case or in a freezer display case.

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