Patent Application
20170298680
The invention relates to a spacer for insulating glazing units, a method for production thereof, an insulating glazing unit, and use thereof.
The thermal conductivity of glass is lower by roughly a factor of 2 to 3 than that of concrete or similar building materials. However, since panes are designed significantly thinner than comparable elements made of brick or concrete, buildings frequently lose the greatest share of heat via external glazing. The increased costs necessary for heating and air-conditioning systems make up a part of the maintenance costs of the building that must not be underestimated. Moreover, as a consequence of more stringent construction regulations, lower carbon dioxide emissions are required. Insulating glazing units are an important approach to a solution for this. Primarily as a result of increasingly rapidly rising prices of raw materials and more stringent environmental protection constraints, it is no longer possible to imagine the building construction sector without insulating glazings. Consequently, insulating glazing units constitute an increasingly greater share of outward-directed glazings. Insulating glazing units include, as a rule, at least two panes of glass or polymeric materials. The panes are separated from one another by a gas or vacuum space defined by a spacer. The thermal insulating capacity of insulating glass is significantly higher than for single plane glass and can be further increased and improved in triple glazings or with special coatings. Thus, for example, silver-containing coatings enable reduced transmittance of infrared radiation and thus reduce the heating of a building in the summer. In addition to the important property of thermal insulation, optical and aesthetic characteristics increasingly play an important role in the area of architectural glazing.
In addition to the nature and the structure of the glass, the other components of an insulating glazing unit are also of great significance. The seal and especially the spacer have a major influence on the quality of the insulating glazing unit.
The thermal insulating properties of insulating glazing units are quite substantially influenced by the thermal conductivity in the region of the edge seal, in particular of the spacer. With conventional spacers made of aluminum, the formation of a thermal bridge at the edge of the glass occurs due to the high thermal conductivity of the metal. This thermal bridge results, on the one hand, in heat losses in the edge region of the insulating glazing unit and, on the other, with high atmospheric humidity and low outside temperatures, in the formation of condensation on the inner pane in the region of the spacer. In order to solve these problems, thermally optimized, so-called “warm edge” systems, in which the spacers are made of materials with lower thermal conductivity, for instance, plastics, are increasingly used.
A challenge with the use of plastics is the proper sealing of the spacer. Leaks within the spacer can otherwise easily result in a loss of an inert gas between the insulated glazings. In addition to a poorer insulating effect, leaks can also easily result the penetration of moisture into the insulating glazing unit. Condensation formed by moisture between the panes of the insulating glazing unit quite significantly degrades the optical quality and, in many cases, makes replacement of the entire insulating glazing unit necessary. A possible approach for the improvement of the seal and an associated reduction of the thermal conductivity is the application of a barrier foil on the spacer. This foil is usually affixed on the spacer in the region of the outer seal. Customary foil materials include aluminum or high-grade steel, which have good gas tightness. At the same time, the metal surface ensures good adhesion of the spacer to the sealing compound.
WO2013/104507 A1 discloses a spacer with a polymeric main body and an insulation film. The insulation film contains a polymeric film and at least two metallic or ceramic layers, which are arranged alternatingly with at least one polymeric layer, with the outer layers preferably being polymeric layers. The metallic layers have a thickness of less than 1 μm and must be protected by polymeric layers. Otherwise, in the automated processing of spacers, damage of the metallic layers easily occurs during assembly of the insulating glazing units.
EP 0 852 280 A1 discloses a spacer for multipane insulating glazing units. The spacer comprises a metal foil with a thickness less than 0.1 mm on the adhesive bonding surface and glass fiber content in the plastic of the main body. The outer metal foil is exposed to high mechanical stresses during the further processing in the insulating glazing unit. In particular, when spacers are further processed on automated production lines, damage to the metal foil and thus degradation of the barrier effect easily occur.
The object of the invention consists in providing a spacer for an insulating glazing unit, which can be produced particularly economically and enables good sealing with, at the same time, simpler assembly and thus contributes to improved long-term stable insulation action.
The object of the present invention is accomplished according to the invention by a spacer in accordance with the independent claim 1. Preferred embodiments are apparent from the subclaims. A method for producing a spacer according to the invention, an insulating glazing unit according to the invention, and use thereof according to the invention are apparent from further independent claims.
The spacer for multipane insulating glazing according to the invention comprises at least one polymeric main body and a multilayer insulation film. The main body comprises two pane contact surfaces running parallel to one another, an adhesive bonding surface, and a glazing interior surface. The pane contact surfaces and adhesive bonding surfaces are connected to one another directly or, alternatively, via connection surfaces. The preferably two connection surfaces preferably have an angle from 30° to 60° relative to the pane contact surfaces. The insulation film is situated on the adhesive bonding surface or on the adhesive bonding surface and the connection surfaces. The insulation film comprises at least one metal-containing barrier layer, one polymeric layer, and one metal-containing thin layer. In the context of the invention, “a thin layer” refers to a layer with a thickness of less than 100 nm. The metal-containing barrier layer has a thickness of 1 μm to 20 μm and seals the spacer against gas and moisture loss. The metal-containing barrier layer faces the adhesive bonding surface and is bonded to the adhesive bonding surface directly or via an adhesion promoter. In the context of the invention, the layer facing the adhesive bonding surface is the layer of the insulation film that is the least distant of all layers of the insulation film from the adhesive bonding surface of the polymeric main body. The polymeric layer has a thickness of 5 μm to 80 μm and serves for additional sealing. At the same time, the polymeric layer protects the metal-containing barrier layer against mechanical damage during storage and automated assembly of the insulating glazing unit. The metal-containing thin layer has a thickness of 5 nm to 30 nm. It was surprising that by means of such a thin metal-containing layer, an additional barrier effect can be obtained. The metal-containing thin layer is adjacent the polymeric layer, which is particularly advantageous from the standpoint of production technology, since such foils can be produced separately and are economically available.
Thus, the invention provides a spacer that has low thermal conductivity due to low metal content, that is outstandingly sealed by a multilayer barrier, and that is, additionally, economical to produce in large quantities due to the simple structure of the insulation film. In addition, the metal-containing barrier layer is very well protected by the polymeric layer such that no damage to the otherwise sensitive metal-containing barrier layer can occur.
The insulation film preferably comprises the metal-containing barrier layer, the polymeric layer, and the metal-containing thin layer. Already with these three layers, a very good seal is obtained. The individual layers can be bonded by adhesives.
In a preferred embodiment of the spacer according to the invention, the metal-containing thin layer is on the outside and thus faces away from the polymeric main body. According to the invention, the outer layer is, of all the layers of the insulation film, the farthest from the adhesive bonding surface of the polymeric main body. Thus, the metal-containing thin layer faces the sealing layer in the finished insulating glazing unit. The layer sequence in the insulation film, starting from the adhesive bonding surface, is thus: Metal-containing barrier—polymeric layer—metal-containing thin layer. In this arrangement, the thin layer serves not only as an additional barrier against gas loss and moisture penetration but also assumes, at the same time, the role of an adhesion promoter. The adhesion of this thin layer to the customary materials of the outer seal is so outstanding that an additional adhesion promoter can be dispensed with.
In an alternative embodiment, the polymeric layer is on the outside such that the layer sequence in the insulation film starting from the adhesive bonding surface is metal-containing barrier layer—metal-containing thin layer—polymeric layer. In this arrangement, the metal-containing barrier layer is also protected against damage.
In another preferred embodiment, the insulation film includes at least a second metal-containing thin layer. Another metal-containing thin layer improves the barrier effect. Preferably, the metal-containing thin layer is on the outside such that it acts as an adhesion promoter. Particularly preferred is a layer sequence in the insulation film starting from the adhesive bonding surface: metal-containing barrier layer—metal-containing thin layer—polymeric layer—metal-containing thin layer. In this arrangement, the barrier effect is further improved by the second metal-containing thin layer and, at the same time, the outside metal-containing thin layer acts as an adhesion promoter.
The metal-containing thin layer is preferably deposited by a PVD process (physical vapor deposition). Coating methods for films with metal-containing thin layers in the nanometer range are known and are, for example, used in the packaging industry. The metal-containing thin layer can be applied on a polymeric film, for example, by sputtering in the required thickness between 5 nm and 30 nm. Then, this coated film can be laminated with a metal-containing barrier layer in a thickness in the μm-range and, thus, the insulation film for the spacer according to the invention can be obtained. Such coating can be done on one or both sides. Thus, surprisingly, starting from a readily available product, an insulation film, which, in combination with the polymeric main body, delivers a spacer with outstanding sealing, can be obtained in one production step.
Preferably, the insulation film is applied on the adhesive bonding surface, the connection surfaces, and a part of the pane contact surfaces. In this arrangement, the adhesive bonding surfaces and the connection surfaces are completely covered by the insulation film and, in addition, the pane contact surfaces are partially covered. Particularly preferably, the insulation film extends over two-thirds or one-half of the height h of the pane contact surfaces. In this arrangement, a particularly good seal is obtained, since in the finished insulating glazing unit, the insulation film overlaps with the sealant, that is situated between the panes and the pane contact surfaces. Thus, possible diffusion of moisture into the pane Interior and diffusion of gases into or out of the pane Interior can be prevented.
The metal-containing barrier layer preferably contains aluminum, silver, copper, and/or alloys or mixtures thereof. Particularly preferably, the metal-containing layer contains aluminum. Aluminum foils are characterized by particularly good gas tightness. The metallic layer has a thickness of 5 μm to 10 μm, particularly preferably of 6 μm to 9 μm. It was possible to observe particularly good tightness of the insulation film within the layer thicknesses mentioned. Since the metal-containing barrier layer in the structure according to the invention is protected by a polymeric layer, compared to spacers customary in the trade (ca. 30 μm to 100 μm thickness of the metal-containing layers), thinner metal-containing layers can be used, by which means the thermal insulating properties of the spacer are improved.
The metal-containing thin layer preferably contains metals and/or metal oxides. In particular, metal oxides produce good adhesion to the materials of the outer seal when the thin layer is on the outside. Particularly preferably, the metal-containing thin layer is made of aluminum and/or aluminum oxide. These materials produce good adhesion and have, at the same time, a particularly good barrier effect.
The metal-containing thin layer preferably has a thickness of 10 nm to 30 nm, particularly preferably of 15 nm. In such a thickness, a good additional barrier effect is obtained without a degradation of the thermal properties due to formation of a thermal bridge.
In a preferred variant, the insulation film is bonded to the adhesive bonding surface via a non-gassing adhesive, such as, for example, a polyurethane hot-melt adhesive that cures under humidity. This adhesive produces particularly good adhesion between the glass-fiber-reinforced polymeric main body and the metal-containing barrier layer and avoids the formation of gases that diffuse through the spacer into the pane Interior.
The insulation film preferably has gas permeation of less than 0.001 g/(m2 h).
The insulation film can be applied on the main body, for example, glued. Alternatively, the insulation film can be coextruded together with the main body.
The polymeric layer preferably includes polyethylene terephthalate, ethylene vinyl alcohol, polyvinylidene chloride, polyamides, polyethylene, polypropylene, silicones, acrylonitriles, polyacrylates, polymethylmethacrylates, and/or copolymers or mixtures thereof.
The polymeric layer preferably has a thickness of 5 μm to 24 μm, particularly preferably 12 μm. With these thicknesses, the metallic barrier layer lying thereunder is particularly well protected.
The main body preferably has, along the glazing interior surface, a width b of 5 mm to 45 mm, particularly preferably 8 mm to 20 mm. The precise diameter is governed by the dimensions of the insulating glazing unit and the desired size of the intermediate space.
The main body preferably has, along the pane contact surfaces, an overall height g of 5.5 mm to 8 mm, particularly preferably 6.5 mm.
The main body preferably contains a desiccant, preferably silica gels, molecular sieves, CaCl2, Na2SO4, activated carbon, silicates, bentonites, zeolites, and/or mixtures thereof. The desiccant can be incorporated both inside a central hollow space or into the glass-fiber-reinforced polymeric main body itself. The desiccant is preferably contained inside the central hollow space. The desiccant can then be filled immediately before the assembly of the insulating glazing unit, Thus, a particularly high absorption capacity is ensured in the finished insulating glazing unit. The glazing interior surface preferably has openings that enable absorption of the atmospheric humidity by the desiccant contained in the main body.
The main body preferably contains polyethylene (PE), polycarbonates (PC), polypropylene (PP), polystyrene, polyester, polyurethanes, polymethylmethacrylates, polyacrylates, polyamides, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), preferably acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylester (ASA), acrylonitrile-butadiene-styrene polycarbonate (ABS/PC), styrene-acrylonitrile (SAN), PET/PC, PBT/PC, and/or copolymers or mixtures thereof.
The main body is preferably glass fiber reinforced. The coefficient of thermal expansion of the main body can be varied and adjusted through the selection of the glass fiber content. By adjustment of the coefficient of thermal expansion of the main body and of the insulation film, temperature related stresses between the different materials and flaking of the insulation film can be avoided. The main body preferably has a glass fiber content of 20% to 50%, particularly preferably of 30% to 40%. The glass fiber content in the main body simultaneously improves the strength and stability.
The invention further includes an insulating glazing unit comprising at least two panes, a spacer according to the invention arranged peripherally between the panes in the edge region of the panes, a sealant, and an outer sealing layer, A first pane lies flat against the first pane contact surface of the spacer and a second pane lies flat against the second pane contact surface. A sealant is applied between the first pane and the first pane contact surface and between the second pane and the second pane contact surface. The two panes protrude beyond the spacer such that a peripheral edge region, which is filled with an outer sealing layer, preferably a plastic sealing compound, is created. The edge space is positioned opposite the inner pane interspace and is bounded by the two panes and the spacer. The outer sealing layer is in contact with the insulation film of the spacer according to the invention. The outer sealing layer preferably contains polymers or silane-modified polymers, particularly preferably polysulfides, silicones, RTV (room temperature vulcanizing) silicone rubber, HTV (high temperature vulcanizing) silicone rubber, peroxide vulcanizing silicone rubber, and/or addition vulcanizing silicone rubber, polyurethanes, butyl rubber, and/or polyacrylates. The panes contain materials such as glass and/or transparent polymers. The panes preferably have optical transparency of >85%, In principle, different geometries of the panes are possible, for example, rectangular, trapezoidal, and rounded geometries. The panes preferably have a thermal protection coating. The thermal protection coating preferably contains silver. In order to be able to maximize energy saving possibilities, the insulating glazing unit can be filled with a noble gas, preferably argon or krypton, which reduce the heat transfer value in the insulating glass unit interspace.
The invention further includes a method for producing a spacer according to the invention comprising the steps
The polymeric main body is produced by extrusion. The insulation film is produced in another step. First, for this, a polymeric film is metallized in a PVD process. By this means, the structure comprising a polymeric layer and a metal-containing thin layer necessary for the insulation film is obtained. This process is already used extensively for the production of films in the packaging industry such that the layer structure comprising a polymeric layer and a metal-containing thin layer can be produced economically. In a further step, the metallized polymeric layer is laminated with the metal-containing barrier layer. For this, a thin metal film (corresponding to the metal-containing barrier layer) is bonded to the prepared metallized polymeric layer by lamination.
The metal-containing barrier layer can be applied both on the polymeric layer and on the metal-containing thin layer. In the first case, the metal-containing thin layer is on the outside in the finished insulation film and can thus serve, after application on the spacer, as an adhesion promoter for the material of the outer seal. In the second case, the metal-containing thin layer is on the inside and is thus protected against damage.
Die insulation film is preferably affixed on the adhesive bonding surface of the polymeric main body via an adhesive.
The invention further includes the use of the spacer according to the invention in multipane glazing units, preferably in insulating glazing units.
In the following, the invention is explained in detail with reference to drawings. The drawings are purely schematic representations and not true to scale. They in no way restrict the invention. The figures depict:
The structure of the insulation film 10 according to the invention reduces the thermal conductivity of the insulation film compared to insulation films that are made exclusively of an aluminum foil since the thicknesses of the metal-containing layers of the insulation film 10 according to the invention are thinner, Insulation films that are made of only an aluminum foil have to be thicker since aluminum foils with thicknesses under 0.1 mm are highly sensitive to mechanical damage, which can occur, for example, during automated installation in an insulating glazing unit. A spacer 1 provided with said insulation film 10 according to the invention and the glass-fiber-reinforced polymeric main body 2 has thermal heat conductivity of 0.29 W/(m K). A prior art spacer, in which the insulation film 10 according to the invention is replaced by a 30-μm-thick aluminum layer, has a thermal heat conductivity of 0.63 Wi(m K). This comparison shows that, despite lower overall metal content, with the structure according to the invention of the spacer made of a polymeric main body and insulation film, higher mechanical resistance and equivalent impermeability (against gas and moisture diffusion) with, at the same time, lower heat conductivity can be obtained, which significantly increases the efficiency of an insulating glazing unit.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14186342.3 | Sep 2014 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/071452 | 9/18/2015 | WO | 00 |
