Opaque insulating glazing laminate, insulating structure, and method

Abstract

The present invention is related to an opaque insulating low vacuum glazing laminate, comprising at least one inner glass sheet, at least one outer glass sheet, and at least one insulating structure arranged between the inner and outer glass sheets. The insulating structure comprises at least one enveloped aerogel vacuum layer, wherein the aerogel layer is enveloped in at least one metal-based foil. The invention is also related to a method for forming an insulating structure for use in an insulating glazing laminate and a method of forming an insulating glazing laminate.

Description

[0001] Opaque insulating glazing laminate, insulating structure, and method

[0002] The present invention is related to an opaque insulating glazing laminate. The invention is further related to the use or intended use of an insulating structure in an insulating glazing. The invention is further related to a method for forming the insulating structure and a method for forming an opaque insulating glazing.

[0003] Insulation is becoming increasingly important in recent years due to global warming trends. Effective insulation is crucial for maintaining comfortable temperatures and reducing energy consumption in various applications, including architectural and building industry, and automotive industry.

[0004] In the building industry, well-insulated buildings can significantly reduce heating and cooling costs, contributing to overall energy efficiency. Similarly, in the automotive sector, proper insulation is essential for maintaining comfortable cabin temperatures and improving the performance of vehicles, particularly those utilizing solar panels which tend to generate excess heat.

[0005] Insulating glazing units have been developed to address these challenges.

[0006] However, traditional deep vacuum glazing, while highly effective, presents several drawbacks. The manufacturing process for deep vacuum glazing is complex and expensive, making it less accessible for widespread adoption. Additionally, deep vacuum glazing is particularly susceptible to quality degradation over time due to the potential loss of vacuum, which can significantly reduce its insulating properties. Deep vacuum, typically characterized by pressures below 1*10-3mbar, offers excellent thermal insulation properties due to the near absence of gas molecules that can conduct heat. However, achieving and maintaining such low pressures requires specialized manufacturing techniques and materials that can withstand the substantial pressure differential. Vacuum insulating glazing (VIG) consists of two panes of glass spaced apart, with the space between the panes being evacuated. Such glazing is known, for example, from EP1978199A1.

[0007] There is a need for an improved insulating glazing solution that can provide effective thermal insulation without relying on deep vacuum technology. Such a solution would ideally offer comparable insulating performance while being more cost-effective to produce and more resilient to long-term degradation.

[0008] It is therefore a first objective of the present invention to improve insulating glazing which is easier to manufacture.

[0009] It is a second objective to provide an insulating glazing which is able to maintain consistent insulating properties over time

[0010] It is a third objective to provide insulating glazing which can be produced on large scale.

[0011] The present invention thereto proposes an opaque insulating glazing laminate, comprising at least one inner glass sheet, and at least one outer glass sheet, at least one insulating structure having a top side and bottom side, wherein said insulating structure is arranged between the inner glass sheet and the outer glass sheet, preferably wherein at least one bonding layer is arranged between the bottom side of the insulating structure and the inner glass sheet, and preferably wherein at least one bonding layer is arranged between the top side of the insulating structure and the outer glass sheet, and wherein the insulating structure comprises at least one (enveloped) aerogel vacuum layer, wherein said (enveloped) aerogel layer is enveloped in at least one metal or metal-based foil or envelop. The top side of the insulating structure is facing towards the outer glass sheet (or the bonding layer between the insulating structure and outer glass sheet). The bottom side of the insulating structure is facing towards the inner glass sheet (or the bonding layer between the insulating structure and the inner glass sheet).

[0012] The insulating structure contributes significantly to the objectives of the present invention. The insulating glazing laminate is preferably a low-vacuum type glazing laminate. An insulating glazing that does not require deep vacuum may offer several advantages, including easier manufacturing processes, reduced production costs, and improved long-term reliability. This type of glazing may be better suited for a wide range of applications, from residential and commercial buildings to various types of vehicles, including those with integrated solar panels. First of all, the aerogel structure provides for efficient maintenance of the vacuum, which is in part due to the porosity in the aerogel layer. By enveloping the aerogel layer in the metal foil, the vacuum can be preserved in a more efficient manner in the aerogel layer without leaking of vacuum pressure out of the laminate. The use of an aerogel vacuum layer enveloped in a metal-based foil therefore provides several advantages that address the objectives of easier manufacturing and suitability for mass production. By arranging the insulating structure between the inner glass sheet and outer glass sheet it can be achieve that a relatively light insulating structure can be designed. Via the bonding layers the sealing of the insulating structure may be enhanced.

[0013] According to the invention, the aerogel layer may be, and preferably is evacuated, whereby the insulation unit forms a type of vacuum insulation glazing. The aerogel vacuum layer offers excellent insulating properties without requiring a deep vacuum. This characteristic significantly simplifies the manufacturing process compared to traditional deep vacuum glazing, which requires expensive and complicated sealing techniques. The aerogel, being a highly porous material with low density, inherently provides good thermal insulation. When combined with a low to mid-level vacuum (which may be easier to achieve and maintain than a deep vacuum), the insulating performance can be further enhanced. By avoiding the need for deep vacuum, the manufacturing process becomes more forgiving and less prone to failures due to vacuum loss. This may result in higher yield rates and reduced production costs, both of which are crucial factors for mass production.

[0014] The metal-based foil envelope serves multiple purposes. It acts as a barrier to maintain the vacuum within the aerogel layer, which is beneficial for preserving the insulating properties over time. The metal-based nature of the foil may, although not the primary purpose, provide additional benefits such as reflecting radiant heat and potentially improving the overall thermal performance of the glazing laminate.

[0015] The opaque insulating glazing as described throughout all embodiments may be applied in the automotive industry. Especially suitable to be applied as roof pane in vehicles, particularly cars. This was surprisingly found particularly beneficial in combination with a solar panel in the roof panel. The solar panel in this respect is typically arranged between the outer glass sheet and the insulating structure. The solar panel may be adhered to the glass sheet and insulating structure via one or more, preferably polymer, bonding layers, such as TPU and / or EVA and / or PVB. Yet, the present invention may alternatively or additionally be applied in the building industry where it may particularly be suitable in fagade-material. The insulating glazing as described in the embodiments provides for an appearance which in terms of reflective properties is similar to the glass. Hence from an architectural perspective use can be made of a material which is glass, but also offering great insulating properties. For the purposes of the invention, the term inner glass sheet refers to the sheet facing the interior. The outer glass sheet refers to the sheet facing the external environment. The outer glass sheet and the inner glass sheet each have a surface on the outside and a surface on the inside and a circumferential side edge surface running between them. For the purposes of the invention, the outer surface refers to the main surface which is intended to face the external environment in the installed position. For the purposes of the invention, the interior surface refers to the main surface which is intended to face the interior of the laminate in the installed position. The surface of the outer sheet on the interior side and the surface of the inner disc on the exterior side face each other and are connected to each other.

[0016] Instead, or in addition, of the aerogel layer, it is imaginable that the aerogel vacuum layer is formed by a foamed material, such as a silica nanofoam, which is also highly porous. The vacuum layer may also be formed by other low density and high porous material layers. It is also imaginable that instead and / or in addition of the metal based foil, another material is used. For example, any material suitable for enveloping the aerogel (or other material) layer and to maintain a vacuum and withstand the temperatures during the laminating process may suffice. The pores in the aerogel layer may be filled with air (corresponding to the negative pressure prevailing in the insulation structure). The aerogel layer according to the invention can also be referred to as a layer made of an aerogel or based on an aerogel. For the purposes of the invention, porosity refers to the proportion of the volume of the pores in relation to the total volume of the aerogel. The aerogel layer according to the invention is preferably formed from an aerogel or on the basis of an aerogel which has a porosity of 50% to 99.98%, particularly preferably of 80% to 99%, very particularly preferably of 85% to 98%. The porosity can be determined by gas absorption. The pore size of the aerogel is preferably from 1 nm to 50 nm, particularly preferably from 10 nm to 40 nm. This refers in particular to the diameter of the typically approximately spherical pores. It is conceivable that some thermoplastics material may be applicable provided they are able to withstand the temperatures of a laminating process. At least one, preferably all bonding layers, are preferably formed from at least one thermoplastic film. The thickness of each film is preferably from 0.2 mm to 1 mm. For example, films with standard thicknesses of 0.38 mm or 0.76 mm can be used. The aerogel layer may comprise one or more distancers or pillars, preferably arranged in an array or matrix, to maintain an even distance, preferably mutual parallel position, between the inner and outer glass sheets.

[0017] According to some embodiments of the invention, the aerogel layer is evacuated in order to increase the thermal insulation effect of the aerogel. The insulating glazing laminate is therefore a type of vacuum insulating glazing. This means that in the space between the inner glass sheet and the outer glass sheet, in particular in the insulating structure in which the aerogel layer is arranged, there is a negative pressure, i.e. a pressure which is lower than the ambient pressure. The pressure in the intermediate space is preferably at most 100 mbar, particularly preferably at most 10 mbar. For example, the pressure can be from 0.01 mbar to 100 mbar, preferably from 0.1 mbar to 10 mbar.

[0018] The insulating glazing therefore is a vacuum glazing in particular a mid- or low- vacuum glazing, wherein a pressure between the inner glass sheet and outer glass sheet, in particular in the aerogel layer, is situated between approximately 0.01 mbar and 110 mbar, preferably between 1 mbar and 100 mbar, more preferably between 5 mbar and 50 mbar. Yet these values of the lower boundary or upper boundary may also be 5 mbar, 15 mbar, 85 mbar, and / or 90 mbar. The vacuum may be applied in advance, i.e. during manufacturing of the insulating structure. However it is also conceivable that according to some embodiments the vacuum is applied during the laminating process which typically occurs under an increased temperature and a lower(ed) pressure. The latter is especially beneficial as it allows to skip an entire processing step, namely applying the vacuum which is (especially for deep-vacuum) rather complex and prone to failure as the seal requires very high standards. Typically such seals are required to be impermeable since otherwise the deep vacuum cannot be maintained causing a significant loss of insulating capabilities. Since the present invention allows to provide good insulating properties it is possible to make use of alternative seal solutions, such as permeable seals. Not only does this render the insulating structure much easier to manufacture, it still allows for good insulating properties due to the porous structure of the aerogel. The at least one metal foil causes the insulating glazing to become opaque, i.e. does not allow any transparency. The light transmission of the vehicle roof window is preferably less than 2%, in particular 0%.

[0019] It was found that there is a relationship between the 'free distance' a molecule in a layer can travel without colliding to another molecule to the minimum functional pressure of a VIG. Increasing the free distance can be done by either increasing the total distance or space between the walls, which leads to unacceptable total thicknesses of the glazing laminate. Alternatively, the free distance can be increased by adding "walls” or “pores”, like an aerogel would do. In regular deep vacuum glass, a distance between the glass sheet of approximately 5-25mm is present, between which a vacuum is maintained of above 1 mbar. The vacuum needs to be maintained in order to avoid the free distance of the molecules to increase too much and to render the insulation worse. In the present invention, it is preferred that the maximum distances of adjacent or opposing “walls” of the pores is approximately 5nm - 100 nm, preferably 10nm - 50nm, This results in a significantly better insulation even with values of a mid or low vacuum. For example, it was found that a deep vacuum (0.001 mbar) glazing having a spacing of 0.2mm between glass sheets showed equivalent insulating properties compared to a laminate according to the invention which has a wall distance or pore pitch of 30nm, and a vacuum of 6.6 mbar. Hence, a pressure which is roughly a factor 1000 more provides the same insulating properties. This was found to be related to the pore diameter, or wall distance, or the length of free travel of a molecule. This distance as said is preferably between 5nm - 5000 nm, preferably 5 nm - 2500 nm, more preferably 5 nm - 1000 nm, most preferably 10nm - 50nm. Yet, the specific pore distance can be adjusted according to the desired vacuum pressure. I.e., if a lower pore size is used, the pressure level of vacuum needs to be less deep. If, on the other hand the pore size is relatively large, the vacuum needs to be deeper.

[0020] The at least one envelop may be at least partially, preferably entirely, formed by an aluminium foil. The use of aluminium foil may form a barrier for air to enter into the aerogel layer enveloped by said foil, and as such may contribute to maintain the vacuum in the aerogel layer. Such an aluminium foil may be an aluminium barrier foil. Preferably, the metal foil, in particular the aluminium foil, is provided with an adhesive on one side. Preferably said adhesive is a temperature activated adhesive. The temperature activated adhesive may be especially beneficial in case the vacuum is applied during the laminating process since it allows to simultaneously vacuum and seal the envelop during laminating, which speeds up the production process significantly. The adhesive applied to the metal foil will ensure proper adhesion of the metal foil to the aerogel layer. It is conceivable that the metal foil, in addition to the adhesive, comprises a protective layer, arranged on a side of the metal foil facing away from the adhesive side. This way, the metal, such as the aluminium, may be protected and prevent corrosion. The protective layer may be thermoplastic layer which is able to resist higher temperatures compared to the temperature activated adhesive.

[0021] The envelop preferably covers substantially all (side) edges of the aerogel layer, and preferably forms at least a portion of the top side and bottom side of the insulating structure. By covering at least the (side) edges of the aerogel layer, it is achieved that loss of the vacuum is further prevented. Typically, loss of vacuum in vacuum glazing occurs via the path of least resistance, which most frequently is the shortest distance to the outside of the laminate. Hence, by covering the edges of the aerogel layer, a good seal of the edges from the outside can be achieved, thereby improving the ease of maintaining the vacuum. By using the aerogel layer it is possible to use only low or medium vacuum while still achieving great insulating properties. This has to do with the porous structure of the aerogel layer, causing the air particles to be entrapped within the porous structure of the aerogel layer. Therefore, less particles will “meet” contributing to an improved insulation, even with lower levels of vacuum where increased number of particles is present over deep vacuum.

[0022] The envelop may comprises at least one opening in the top side and / or bottom side. The at least one opening preferably stretches over an area of approximately 300 cm2 to 2,500 cm2, preferably approximately 900 cm2. It was found that providing an opening in the envelop allows to apply the vacuum during the laminating process. That is, during the laminating typically the temperature of the laminating chamber (such as an autoclave) is increased and the temperature may be decreased (towards vacuum). It has been surprisingly found that by arranging an opening in the envelop this allows the laminating conditions to apply the low- or mid- vacuum to the glazing. During laminating process the air can be removed from the aerogel layer via the opening. By also increasing the temperature it is possible to seal the vacuumed glazing immediately in the same process step. Due to the increased temperature, the bonding layer which is situated between the top and / or bottom side of the laminate and the respective glass sheet allows to seal the opening. The specified surface areas of the opening(s) specifically allows for easy application of the vacuum, whilst reducing the risk of loss of vacuum.

[0023] Preferably, the at least one opening is arranged at a central portion of the top side or bottom side. Here, central shall be understood as at a distance from all edges. By arranging the opening centrally it can be ensured that the bonding layer, during the laminating process, sufficiently seals the opening to prevent loss of vacuum after the laminate is formed. This way of sealing was found only possible under the use of low- or mid-vacuum since otherwise the loss of vacuum would be too big to maintain the insulating properties. The seal of the opening was found to be especially good when Thermoplastic Polyurethane (TPU) was used as a bonding layer, at least the bonding layer adjacent to the side of the envelop having the opening. Yet, at least one bonding layer and / or all bonding layers may be composed out of Ethylene-Vinyl Acetate (EVA) and / or Thermoplastic Polyurethane (TPU). Alternatively polyvinyl butyral (PVB). Preferably, the layer adjacent to the side of the insulating structure having the opening is composed out of TPU.

[0024] The thickness of the aerogel layer can be selected according to the requirements of the specific application. The requirements may be based on the application. For example, as a roof pane in automotive industry it may be preferred to have a thinner aerogel layer to maintain more cabin space, whilst in the building industry thickness may not be a strict requirement as the thickness of the aerogel layer marginally adds weight. In particular, the thermal conductivity of the aerogel (which in turn depends on the material, density and porosity), the heat absorption of the composite pane (which in turn depends on the other components of the composite pane, in particular the material, thickness and degree of tinting of the outer pane, the inner pane and the connecting layers) and the desired heat input play a role. The first glass sheet and second glass sheet may extend beyond a perimeter of the insulating structure. This may contribute to maintaining the vacuum, and therefore the insulating properties. By preventing, or reducing, the chance that the insulating structure is exposed along the perimeter of the glazing laminate the seal may be improved and hence it may be more difficult for air to leak into the insulating structure.

[0025] Parts of the metal foil are sealed together, such that the envelop of the insulating structure is formed, preferably wherein at least a part of at least one seal extends over at least part of the circumference, or side edges, of the insulating structure, at least once initially applied. The seal may be, and preferably is, arranged on the parts of the metal foil extending beyond the edges of the aerogel layer. Hence, it is preferred that the metal foil extends beyond the perimeter or edges of the aerogel layer, such that at least one seal is formed in the part of the metal foil which extends beyond the perimeter or edges of the aerogel layer. Here, the metal foil layers situated on either side of the aerogel layer may be mutually adhered.

[0026] Preferably, at least one seal is formed by the adhesive, preferably temperature activated adhesive on the metal foil. To this end, the seal may be applied prior to laminating, particularly when the insulating structure is vacuumed prior to laminating, or may be sealed during the laminating process.

[0027] The envelop may be formed out of two separate metal foils, which are applied to either side of the aerogel layer. If an opening is applied, it is conceivable that this is applied prior to applying the foils or after. The seal is preferably formed along the perimeter of the mutually touching metal foils, preferably at a small distance from the perimeter. However, it is also conceivable that the envelop is formed by a single metal foil, which is folded over the aerogel layer. The folded metal foil may be folded as a half fold, a tri fold, a double parallel fold, a roll fold, a (single or double) gate fold, a gate trifold. If an opening is applied, this may be provided prior to folding or after folding of the envelop. The seal is preferably arranged on edges of the metal foils that are mutually touching. The seal may be positioned at a small distance from the perimeter of the foil. This structure for enveloping was found particularly beneficial as it allows for a simple way to form the insulating structure. Preferably, at least one seal is arranged in the part of the metal foil which extends beyond the perimeter of the aerogel layer, which allows for easy application of the seal. The part of the metal foil(s) extending beyond the perimeter or edges of the aerogel, or the seal, has a width situated between 0.5 cm and 10.0 cm, preferably between 1.0 and 5.0 cm, more preferably 2.0 cm. It was found that this allows for easy of application of the seal. Moreover, by making this part slightly larger than required for the seal it is possible to fold over the part inwardly to abut the laminate. Preferably, at least a portion of the aforementioned part extending beyond the aerogel layer or the seal is folded inwardly, such that at least a part of the inwardly folded part or seal extends substantially parallel to, and preferably also adjacent to, the top side or bottom side of the insulating structure. The folded over portion may also be double folded, to create a labyrinth seal towards the aerogel layer. This may put the seal at a larger distance with respect to the edge of the glazing laminate which increases the capability to maintain the vacuum. Not only that, it also allows for make an improved seal along the sides of the insulating structure, harder for air to leak into the vacuum. It is imaginable that the folded over part is sealed or adhered to the exterior of the envelop, to ensure the folded part stays folded.

[0028] Preferably, at least two (preferably separate) seals are formed on the metal foil, and wherein at least two seals extend in different directions, preferably orthogonally. It is also conceivable that at least one seal extends in a diagonal direction, or at an angle with respect to one of the side edges of the insulating structure or aerogel layer. Preferably, at least two seals overlap and / or intersect. For example, in the case of a half fold based metal foil, the ends of the foil may “meet” or abut on or above an upper side or lower side of the aerogel, where a first seal is provided. The second pair of seals is provided along the other ends of the foil which are beyond the perimeter or edge of the aerogel. The first and second seal are extending in orthogonal direction. Then first the seal on or above the upper side or lower side of the aerogel is folded over, subsequently the pair of second seals are folded inwardly, to overlap with the folded first seal. Optionally, before folding the second pair of seals inwardly, the ends of the second pair of seals is folded diagonally. This way of enveloping the aerogel layer may be compared to a gift wrap. Preferably, all exposed seals in the enveloped configuration are situated at a distance within the perimeter of the aerogel layer. As such, an improved longevity of the vacuum can be assured. It is imaginable that the metal foil is wrapped over the aerogel layer, such that the ends of the foil along two opposing edges in the wrapped configuration partially overlap with each other, and wherein at least one seal is arranged in the overlapping area of the metal foil.

[0029] At least one side of the inner glass sheet and / or at least one side of the outer glass sheet may be provided with a low-e coating. Preferably, the low-e coating is provided on a side of the outer glass sheet facing towards the insulating structure and / or on a side of the inner glass sheet facing away from the insulating structure. Alternatively, the low-e coating can also be provided on the side of the outer glass sheet facing away from the insulating structure and / or the side of the inner glass sheet facing towards the insulating structure. If however, no low-e coating is applied, but the metal foil is an aluminium foil this already yields similar advantages as aluminium is able to reflect infrared light. This may further contribute to the insulating properties of the glazing laminate without requiring complicated manufacturing steps. If a solar panel is provided, it is preferred to use an Ag 1, Ag2 of Ag3 coating rather than a low-e coating. The marginally lower yield of the solar panel due to this coating is compensated by the increased temperature reduction of the solar panel

[0030] The present invention is further related to the use and / or intended use of the insulating structure as defined in any embodiment above, in particular for use in an insulating glazing laminate. The same benefits as explained in relation to the glazing apply mutatis mutandis to the insulating structure.

[0031] The present invention is further related to a method for forming an insulating structure for use in an insulating glazing laminate, in particular the insulating glazing laminate according to any of the embodiments defined, comprising the steps of:

[0032] A) Providing at least one aerogel layer having a top side and a bottom side; B) wrapping the at least one aerogel layer provided during step A) in a metal foil, such that the aerogel layer is enveloped by the metal foil;

[0033] C) Sealing the envelop. Preferably, wherein during step C), at least one seal is formed by a heat activated adhesive. During step B), the aerogel layer may be wrapped in a single metal foil, wherein the metal foil is larger, in particular in width and length, than the aerogel layer. Preferably, step B) comprises adjoining two ends of the metal foil above a top side or bottom side of the aerogel layer. This allows that during step C) at least one seal may be provided along the adjoining two ends of the metal foil. During step C), at least one seal may be, preferably at least two seals are, provided along a first side edge, preferably a first and second side edge, of the enveloped aerogel layer. A part of the envelop, in particular where the at least one seal is provided, is folded. Preferably, wherein the method comprises the step of providing at least one opening in the metal foil on a top side or bottom side of the envelop, in particular such that the insulating structure can be vacuumed during the laminating process. This allows to skip the step of pre-vacuuming the insulating structure which is beneficial to the manufacturing speed. During laminating process, which may be under a (partial) vacuum, air can be removed from the laminate, in particular the insulating structure, via the opening provided. Said opening is thereto preferably provided in a central portion of the envelop. It is also conceivable that, in addition or as alternative, the envelop, prior to step C), is brought under vacuum and sealed during step C), preferably under vacuum, such that the insulating structure is pre-vacuumed. This may simplify the lamination process whilst ensuring similar insulating properties.

[0034] The present invention is further related to a method of forming an insulating glazing laminate, in particular the insulating glazing laminate according to any of the embodiments, comprising the steps of:

[0035] i) forming an insulating structure as defined in the method above, or providing an insulating structure comprising at least one aerogel layer enveloped in a metal foil;

[0036] ii) providing the insulating structure between a pair of bonding layers;

[0037] iii) arranging the laminate formed during step ii) between a pair of glass sheets; iv) applying heat during lamination to form the insulating glazing laminate. It is noted that the method of forming the insulating structure for use in an insulating glazing laminate may be integrally incorporated in accordance to the one or more embodiments defined, within the method for forming the insulating glazing laminate. To this end it is preferred that the steps for forming the insulating structure are performed prior to, instead of, or simultaneously with, step i). It is conceivable that during step iv) a vacuum is applied during the lamination to vacuum the insulating structure during lamination. In the latter case it is preferred that the insulating structure comprises at least one opening in the envelop, such that the vacuum of the lamination process allows to remove air from the insulating structure via said opening. It allows to form the desired low- or mid-vacuum which provides the beneficial insulation in a simpler manner. The benefits that are explained with respect to the insulating structure apply mutatis mutandis to the method. Optionally, the method comprises the step, prior to step iv), of providing a solar panel in the laminate, wherein said solar panel is preferably arranged between the outer glass sheet and the insulating structure. Preferably a bonding layer is arranged between the solar panel and the outer glass sheet and between the solar panel and the insulating structure.

[0038] The present invention is further related to an automotive vehicle comprising at least one opaque glazing laminate according to the invention, preferably wherein the glazing laminate is a roof window laminate. More preferably, the opaque glazing laminate is preferably provided with at least one solar panel in the glazing laminate. If the glazing laminate is an opaque automative roof glazing laminate, the laminate is preferably curved, more preferably double curved.

[0039] The present invention will hereinafter be further elucidated based on the following non-limitative figures, wherein:

[0040] - Figure 1 shows a non-limitative embodiment of the window laminate according to an embodiment

[0041] - Figure 2 shows the steps for forming the insulating structure according to an embodiment;

[0042] - Figure 3 shows a non-limitative example of the improved functioning of the present invention compared to deep vacuum glazing.

[0043] Figure 1 shows a non-limitative embodiment of the opaque insulating glazing laminate 1 according to an embodiment. The laminate 1 comprises an outer glass sheet 4 and an inner glass sheet 2. Between the inner 2 and outer glass sheet 1 an insulating structure 4 is provided. The insulating structure is connected between the inner 2 and outer glass sheet 1 by means of a pair of bonding layers 5, 6. One bonding layer 6 is arranged between the top side 4a of the insulating structure 4 and the outer glass sheet 1, the other bonding layer 6 is arranged between a bottom side 4b of the insulating structure 4 and the inner glass sheet 1. In this embodiment, the sides of the insulating structure 4 do not stretch all the way up to the edges of the glass sheets, and hence the glass sheets 1, 2 extend beyond the edge of the insulating structure 4. This causes or allows the bonding layers 5, 6 to locally surround or wrap around the entire insulating structure during the laminating process. The insulating structure 4 in this embodiment is formed by an aerogel layer 7, which is enveloped 8 in an aluminium foil layer. In this embodiment, the ends of the foil 8 are sealed 9 which seal 9 is formed by a temperature activated adhesive. Optionally, a solar panel 13 is arranged in the laminate, which for illustrative purposes is shown in the figure. If a solar panel 13 is provided, it is imaginable that an additional bonding layer is provide between the solar panel 13 and the outer glass sheet 3. Optionally, obscuration bands 10 can be provided. The obscuration bands 10 are typically formed by a ceramic material, mostly a black ceramic material. Particularly they may be used when the glazing laminate 1 is used as a roof glazing for the automotive industry. Additionally, the obscuration band 10 may contribute to mask the presence of the solar panel 13, to make it appear as a single dark outer side of the laminate 1. The obscuration band 10 is completely optional, especially when used in building material. Alternatively, the entire surface may be provided with dark or black ceramic to give the laminate 1 a shiny black appearance.

[0044] For illustrative purposes, the insulating structure 4 is shown from a top or bottom side besides the glazing laminate 1. This allows to show that the enveloped insulating structure 4 comprises at least one opening 14 in the foil 8, through which opening 8 in the aluminium foil 8 the aerogel layer 7 is visible. The opening in the envelop 8 which is formed by the metal foil 8 is very beneficial for the production. Especially in combination with the bonding layer being TPU. The opening 14 allows for forming a medium or low vacuum during the laminating process, for example in an autoclave. Via the opening 14 air can be sucked out of the glazing laminate 1 during the laminating process by bringing the laminate under medium or low vacuum. That is, at the beginning of the laminating process, the layers are simply stacked, without being sealed. During the laminating process the pressure is reduced causing air to be sucked out of the laminate 1 (and therefore out of the aerogel layer 7 via the opening 14. Since the laminating process also involves increasing the heat, the bonding layers 4, 5, of which one is situated over the opening 14, the opening 14 is sealed by the bonding layer 5, 6 covering the opening after the laminating process is finished. Therefore, it is not only possible to skip an entire process step compared to deep vacuum glazing laminates which normally require applying a deep vacuum. It also becomes possible to use simple sealing techniques. The envelop formed by metal foil 8 according to the invention can be sealed via a temperature activated adhesive. By using the aerogel layer 7 it is possible to use only low or medium vacuum while still achieving great insulating properties. This has to do with the porous structure of the aerogel layer, causing the air particles to be entrapped within the porous structure of the aerogel layer 7. Therefore, less particles will “meet” contributing to an improved insulation, even with lower levels of vacuum where increased number of particles is present over deep vacuum. It was surprisingly found that by using a TPU bonding layer over the opening 14 the insulating structure performed comparable to without an opening 14. Hence, good insulating properties could be obtained in a much simpler way which yields that this product and the process can be used to industrialize the vacuum glazing. It was found that since the opening 14 is arranged on a central portion of the envelop, hardly any air was able to leak into the enveloped aerogel layer 7 via that opening 14.

[0045] Figures 2A-2C show the steps of forming the insulating structure 4 according to an embodiment of the invention. In step A), it is shown that a metal foil 8, in particular aluminium foil is provided. The aerogel layer 7 is positioned onto a side of the foil 8. The foil 8 may be provided with a temperature activated adhesive. In that case, the aerogel 7 is preferably provided onto the adhesive layer. As can be seen in step B), the foil 8 is wrapped around the aerogel layer 7 such that the foil ends meet on the top side 7a of the aerogel layer 7. The foil ends may overlap on the top side 7a of the aerogel layer 7. Preferably a first seal 15 is arranged along the overlapping ends. By arranging the seal 15, the foil 8 forms a find of wrap around the aerogel layer 7, which is open from the two ends. These ends need to be closed of which is shown in figure 2C. IT is imaginable that along the entire end the meeting foil ends 8 are sealed by a second seal 11, then the same can be done on the other side to entirely the envelop the aerogel layer 7. After arranging the seal 11, the corner ends of the seal can be folded diagonally on both sides. This seal 11 can be folded over the envelop inwardly and optionally sealed a second time to be adhered to the top or bottom side of the envelop. The resulting envelop structure can be seen in the last step. The seals 11, 15 preferably extend in different directions. Together, the seals 11, 15 ensure that along the entire perimeter of the aerogel layer 7 no air can leak into the enveloped insulating structure 4. The seals can be formed by temporary and locally heating up the metal foil 8 such that the temperature activated adhesive is activated locally to form the seal 11, 15. By folding the sealed aera inwardly, to be adjacent to the top or bottom side of the envelop it can be achieved that the length of the seal is effectively increased.

[0046] Figure 3 shows an indicative graph of the results obtained with the laminate according to the invention. On the vertical axis the over insulating value, U, is shown which has the unit of [W per square meter Kelvin], The U-value can be obtained by dividing one over the sum of the thermal resistances. A lower U-value means that the insulation is better. The higher the U-value the worse the insulation is. No explicit values are shown, as graph is intended to provide an overall indication of the performance of the current invention versus the level of vacuum. The horizontal axis depicts the pressure in the unit of [mbar], and therefore the horizontal axis reflects the level of vacuum. The lower the pressure, the deeper the vacuum is. The graph shows three lines, wherein the solid line reflects conventional deep-vacuum glazing. The convention deep vacuum glazing has an internal vacuum above or around 99.9% vacuum and requires highly technical seals to prevent the deep vacuum from being lost. The vacuum is accommodated between two spaced apart glass sheets. As can be seen, the conventional type deep vacuum glazing has a bad insulating value up to just before 0.1 mbar vacuum, where a sudden jump in the U-value is observed. Hence, conventional deep vacuum glazing has a real low U-value provided that the deep vacuum is entirely maintained within the laminate. That is, there is no room for errors in the seal as otherwise the deep vacuum will drop below the 0.1 mbar. In addition to conventional deep vacuum glazing, two variants according to the invention are shown in the graph. It was observed that with using the insulating structure with aerogel it is possible to maintain very good insulating values, reflected by the low U-value even up to lower vacuums. Hence, there is much more room for loss of vacuum whilst still keeping good insulating properties. Alternatively, it may be possible to use less deep vacuum, which enables the usage of very simple sealing techniques as described throughout this application. This simplifies the production process and also reduces the costs of the insulating glazing laminates substantially. It was found that good insulating properties could be maintained up to approximately 100 to 110 mbar. Hence the seals that can be used to maintain the vacuum have to withstand the pressures of 100 to 110 mbar, rather than 0.1 mbar which is a significantly deeper vacuum and much harder to withstand the pressure differences compared to the ambient outside pressure compared to the 100mbar. Therefore, simpler seals can be used to simplify the production process. Also, the 100mbar vacuum can be achieved easily during the production process by providing an insulating structure with an opening.

[0047] The above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts, including inventive details, may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the above-described inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application and / or alternative embodiment.

[0048] The ordinal numbers used in this document, like “first”, “second”, and “third” are used only for identification purposes. Hence, the use of expressions like a “second” component, does therefore not necessarily require the co-presence of a “first” component. By "complementary" or “co-acting” components is meant that these components are configured to co-act with each other. However, to this end, these components do not necessarily have to have complementary forms. The verb “comprise" and conjugations thereof used in this patent publication are understood to mean not only “comprise”, but are also understood to mean the phrases “contain”, “substantially consist of’, “formed by” and conjugations thereof.

Claims

Claims1. Opaque insulating glazing laminate, comprising- at least one inner glass sheet, and at least one outer glass sheet;- at least one insulating structure having a top side and bottom side, wherein said insulating structure is arranged between the inner glass sheet and the outer glass sheet, wherein at least one bonding layer is arranged between the bottom side of the insulating structure and the inner glass sheet, and wherein at least one bonding layer is arranged between the top side of the insulating structure and the outer glass sheet;wherein the insulating structure comprises at least one aerogel vacuum layer, wherein said aerogel layer is enveloped in at least one metal foil.

2. Opaque insulating glazing laminate according to claim 1, wherein the insulating glazing is a vacuum glazing, wherein a pressure between the inner glass sheet and outer glass sheet, in particular in the aerogel layer, is situated between approximately 0.01 mbarand 110 mbar, preferably between 1 mbar and 100 mbar, more preferably between 5 mbar and 50 mbar.

3. Opaque insulating glazing laminate according to claim 1 or 2, wherein the at least one envelop is at least partially formed by an aluminium foil.

4. Opaque insulating glazing laminate according to claim 3, wherein an adhesive, preferably a temperature activated adhesive, is provided onto said aluminium foil.

5. Opaque insulating glazing laminate according to any of the preceding claims, wherein the envelop covers substantially all edges of the aerogel layer, and forms at least a portion of the top side and bottom side of the insulating structure.

6. Opaque insulating glazing laminate according to any of the preceding claims, wherein the envelop comprises at least one opening in the top side and / or bottom side.

7. Opaque insulating glazing laminate according to claim 6, wherein the at least one opening stretches over an area of approximately 300 cm2 to 2,500 cm2, preferably approximately 900 cm2.

8. Opaque insulating glazing laminate according to claim 6 or 7, wherein the at least one opening is arranged at a central portion of the top side or bottom side.

9. Opaque insulating glazing laminate according to any of the preceding claims, wherein at least one bonding layer and / or all bonding layers are composed out of Ethylene-Vinyl Acetate (EVA) and / or Thermoplastic Polyurethane (TPU).

10. Opaque insulating glazing laminate according to any of the preceding claims, wherein the first glass sheet and second glass sheet extend beyond a perimeter of the insulating structure.

11. Opaque insulating glazing laminate according to any of the preceding, wherein parts of the metal foil are sealed together, such that an envelop is formed, wherein at least a part of at least one seal extends over at least part of the circumference of the insulating structure.

12. Opaque insulating glazing laminate according to claim 11, wherein the metal foil extends beyond the perimeter of the aerogel layer, and wherein at least one seal is formed in the part of the metal foil which extends beyond the perimeter of the aerogel layer.

13. Opaque insulating glazing laminate according to claim 12, wherein at least one seal is arranged in the part of the metal foil which extends beyond the perimeter of the aerogel layer14. Opaque insulating glazing laminate according to any of the claims 11 - 13, wherein the seal has a width situated between 0.5 cm and 10.0 cm, preferably between 1.0 and 5.0 cm, more preferably 2.0 cm.

15. Opaque insulating glazing laminate according to any of the claims 11 - 14, wherein at least a portion of the seal is folded inwardly, such that at least a part of the inwardly folded seal extends substantially parallel to, and preferably also adjacent to, the top side or bottom side of the insulating structure.

16. Opaque insulating glazing laminate according to any of the claims 11 - 15, wherein at least two seals are formed on the metal foil, and wherein at least two seals extend in different directions, preferably orthogonally.

17. Opaque insulating glazing laminate according to claim 16, wherein at least two seals overlap and / or intersect.

18. Opaque insulating glazing laminate according to any of the claims 11 - 17, wherein all exposed seals in the enveloped configuration are situated at a distance within the perimeter of the aerogel layer.

19. Opaque insulating glazing laminate according to any of the preceding claims, wherein at least one side of the inner glass sheet and / or at least one side of the outer glass sheet is provided with a low-e coating.

20. Opaque insulating glazing laminate according to claim 19, wherein the low-e coating is provided on a side of the outer glass sheet facing towards the insulating structure and / or on a side of the inner glass sheet facing away from the insulating structure.

21. Use or intended use of the insulating structure as defined in any of the preceding claims for use in an insulating glazing laminate.

22. Method for forming an insulating structure for use in an insulating glazing laminate, in particular the insulating glazing laminate according to any of the claims 1-20, comprising the steps of:A) Providing at least one aerogel layer having a top side and a bottom side;B) wrapping the at least one aerogel layer provided during step A) in a metal foil, such that the aerogel layer is enveloped by the metal foil; C) Sealing the envelop.

23. Method according to claim 22, wherein during step C), at least one seal is formed by a heat activated adhesive.

24. Method according to claim 22 or 23, wherein during step B), the aerogel layer is wrapped in a single metal foil, wherein the metal foil is larger, in particular in width and length, than the aerogel layer.

25. Method according to claim 24, wherein step B) comprises adjoining two ends of the metal foil above a top side or bottom side of the aerogel layer.

26. Method according to claim 25, wherein during step C) at least one seal is provided along the adjoining two ends of the metal foil.

27. Method according to any of the claims 22-26, wherein during step C), at least one seal is, preferably at least two seals are, provided along a first side edge, preferably a first and second side edge, of the enveloped aerogel layer.

28. Method according to claim 26 or 27, wherein a part of the envelop where at least one seal is provided is folded.

29. Method according to any of the claims 22-28, wherein the method comprises the step of providing at least one opening in the metal foil on a top side or bottom side of the envelop.

30. Method according to any of the claims 22-29, wherein the envelop, prior to step C), is brought under vacuum and sealed during step C), preferably under vacuum, such that the insulating structure is pre-vacuumed.

31. Method of forming an insulating glazing laminate, in particular the insulating glazing laminate according to any of the claims 1-20, comprising the steps of:i) Forming an insulating structure as defined in any of the claims 22-30, or providing an insulating structure comprising at least one aerogel layer enveloped in a metal foil;ii) Providing the insulating structure between a pair of bonding layers;iii) Arranging the laminate formed during step ii) between a pair of glass sheets;iv) Applying heat during lamination to form the insulating glazing laminate.

32. Method according to claim 31, wherein during step iv) a vacuum is applied during the lamination to vacuum the insulating structure during lamination.

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