Method for manufacturing a photovoltaic module

Abstract

A method for manufacturing a photovoltaic module (1), the photovoltaic module (1) comprising at least a first layer and a second layer fixed to each other by a sealant, the method comprising the following steps: - providing a laminating device (33); - arranging the first layer in the laminating device (33); - arranging a sealant material manufactured by the following steps on the first layer: - providing a base resin comprising a silane-modified polyolefin and having a melting point below 90°C; - forming a mixture of the base resin and an additive comprising a cross-linking catalyst, the cross-linking catalyst being present in a ratio of 0.01 to 5 parts per 100 parts of the resin; - melting the mixture at a temperature between 90°C and 190°C, preferably between 160°C and 180°C, and extruding the mixture to form the sealant material; - arranging the second layer on the sealant material; - laminating the first layer, the second layer and the sealant material under the application of heat and pressure, the heat being applied at a temperature between 60°C and 125°C, preferably between 60°C and 100°C, more preferably between 70°C and 90°C, thereby cross-linking the base resin.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic devices, and more particularly to a method for manufacturing a photovoltaic module suitable for use with highly temperature-sensitive photovoltaic devices. Background Art

[0002] Photovoltaic (PV) devices, also known as solar panels, photovoltaic modules, etc., are usually made by laminating multiple components together under heat and pressure in a laminating device, the individual components being fixed together by a sealant layer that completely covers the components and adheres to external materials, such as the so-called front cover (usually glass) and the back cover (usually a back sheet or back glass). Such sealant layers are usually based on thermoplastic and / or cross-linking resins, such as ethylene vinyl acetate (EVA), silicones, urethanes, polyvinyl butyral (PVB), thermoplastic silicone elastomers (TPSE), ionomers, polyolefins (PO) or any other convenient polymer.

[0003] Standard lamination temperatures are about 130°C to 170°C at pressures up to 1 bar, and lamination times vary between about 5 minutes and 2000 minutes, more typically 5 to 60 minutes. During this time, the sealant resin softens and / or crosslinks, bonding it to the adjacent layers, which may be, for example, the back or front cover and the photovoltaic cell itself or any other paired layers. For example, document WO 2012 / 082261 describes crosslinking silane-grafted polyolefin sealants for PV applications, these formulations requiring a lamination temperature of at least 130°C.

[0004] Such temperatures and pressures are compatible with most standard PV cell technologies (e.g. thin-film silicon, crystalline silicon, and germanium-based cells), but are generally incompatible with perovskite-based, organic, and dye-sensitized cells. Batteries) employ photosensitive dyes adsorbed onto titanium dioxide films and use liquid or gel-based electrolytes that can be damaged if heated above about 90° C. As a result, they are not compatible with conventional lamination techniques.

[0005] "Perovskite" is an organic metal halide material, and its chemical formula is generally written as ABX 3 , where A is an inorganic or organic cation, such as Cs, CH 3 NH 3 or HC(NH 2 ) 2 , B is a metal such as tin or lead, and X is a halogen atom such as iodine, bromine or chlorine. An example of such a material is methylammonium lead trihalide (CH 3 NH 3 PbX 3), cesium formyl ammonium lead trihalide (CsH 2 NCHNH 2 PbX 3 ) and methylammonium tin triiodide (CH 3 NH 3 Sn 3 These compounds are taken from calcium titanium oxide (CaTiO 3 ) and when illuminated, electron-hole pairs are generated, which can be separated by sandwiching the perovskite absorber layer between an electron-transporting n-type layer and a hole-transporting p-type layer, with the perovskite acting as an intrinsic (i) layer, thus forming a PIN or NIP junction, similar to its silicon counterpart. Perovskite materials are also temperature sensitive, although they can tolerate maximum lamination temperatures of up to 120°C or even 150°C. However, lamination at lower temperatures has certain other advantages, such as reduced energy consumption.

[0006] Simply using known, softer encapsulant materials that allow lamination (but not cross-linking) at lower temperatures is unsatisfactory since PV modules may reach temperatures in excess of 80°C in use. Such encapsulants will soften at higher use temperatures and be subject to the risk of mechanical creep due to any forces applied by mounting or clamping devices, weight of module sub-elements, etc. Module debonding may therefore also occur.

[0007] It is therefore an object of the present invention to propose a method for manufacturing photovoltaic modules that is compatible with the lamination of dye-sensitized, perovskite and other temperature-sensitive photovoltaic technologies, thereby enabling their processing using conventional lamination equipment and methods. Summary of the invention

[0008] More specifically, the present invention relates to a method for manufacturing a photovoltaic module comprising at least a first layer and a second layer fixed to each other by a sealant, the method comprising the following steps:

[0009] -Provide laminating equipment, such as vacuum bag laminators;

[0010] - placing the first layer in the laminating device, the first layer being for example a front sheet, a back sheet or any other layer, either alone or as part of an existing prefabricated PV module or a part thereof;

[0011] - providing on the first layer a sealant material produced by the steps of: (a) providing a base resin comprising a silane-modified polyolefin (such as an ethylene-containing copolymer), the base resin having a melting point below 90°C, (b) forming a mixture of the base resin and an additive comprising a crosslinking catalyst, the crosslinking catalyst being present in a proportion of 0.01-5 parts per 100 parts of the resin, (c) melting the mixture at a temperature between 90°C and 190°C, preferably between 160°C and 180°C, and (d) extruding the mixture to form the sealant material, which can then be placed on the first layer as a sheet and / or powder;

[0012] - providing said second layer on said encapsulant material, said second layer being for example a photovoltaic conversion device, an internal front sheet forming part of an existing PV module or any other suitable layer,

[0013] - laminating the first layer, the second layer and the sealant material under application of heat and pressure, the heat being applied at a temperature between 60°C and 125°C, preferably between 60°C and 100°C, more preferably between 70°C and 90°C, thereby crosslinking the base resin.

[0014] During lamination at temperatures up to 125°C, the sealant resin described above may be at least partially cross-linked, thereby producing mechanical properties suitable for use in PV modules, i.e. sufficient rigidity and creep resistance at the highest expected use temperature (i.e. around 85°C, or even up to 105°C to increase the safety margin). Cross-linking may also be performed or continued after the module has been laminarized. Thus, this combination of a particular sealant with a lower than normal lamination temperature is suitable for use when laminating PV modules containing temperature-sensitive PV cells (e.g. perovskite-based, organic or dye-sensitized cells) in conventional lamination equipment. In addition, the reduced processing temperature during lamination reduces energy consumption. It should be noted that one of the above-mentioned first and second layers may form part of an existing prefabricated PV module (on which the other layer is laminated), or may be a separate layer of the PV module.

[0015] In an alternative method of the present invention, the method comprises the following steps:

[0016] - providing a laminating device;

[0017] - arranging said first layer (as described above) in said laminating device,

[0018] - providing on the first layer a sealant material produced by: (a) providing a base resin in powder form, the base resin comprising a silane-modified polyolefin (such as an ethylene-containing copolymer) and having a melting point below 90° C., (b) mixing the base resin powder and an additive in powder form to form the sealant material, the additive comprising a cross-linking catalyst present in the sealant material in a proportion of 0.01 to 5 parts per 100 parts of the resin (based on the total sealant material mixture);

[0019] - providing said second layer (as described above) on said sealant material,

[0020] - laminating the first layer, the second layer and the sealant material under application of heat and pressure, the heat being applied at a temperature between 60°C and 125°C, preferably between 60°C and 100°C, more preferably between 70°C and 90°C, thereby crosslinking the base resin.

[0021] During lamination at temperatures up to 125°C, even if the particles of catalyst and base resin are discrete, the resin is cross-linked in the same manner as described above, resulting in mechanical properties suitable for PV modules, namely sufficient rigidity and creep resistance at the highest expected use temperature (i.e. around 85°C, or even up to 105°C to increase the safety margin). Therefore, this method can be used when laminating PV modules including temperature-sensitive PV cells (such as perovskite-type or dye-sensitized cells) in conventional lamination equipment. In addition, the reduced processing temperature during lamination reduces energy consumption. Again, it should be noted that one of the above-mentioned first and second layers can form part of an existing prefabricated PV module (on which the other layer is laminated), or can be a separate layer of the PV module.

[0022] Advantageously, the base resin has a complex viscosity of less than 15,000 Pa.s at 85° C. and less than 10,000 Pa.s at 100° C. before lamination.

[0023] Advantageously, the base resin exhibits a tan delta value greater than 0.8 at 85°C and a tan delta value greater than 1.0 at 100°C before lamination.

[0024] The aforementioned properties impart good processability to the resulting sealant material.

[0025] Advantageously, the mixture further comprises other additives, the other additives comprising at least one of the following: antioxidant; UV absorber; UV stabilizer; pigment particles. The other additives may be mixed and / or kneaded with the base resin at the same time as the catalyst or in a separate step before the mixture is mixed and / or kneaded with the catalyst.

[0026] Advantageously, the catalyst comprises one or more of the following: boric acid; metallocene catalyst; constrained geometry catalyst; chain shuttling catalyst; multi-site catalyst, such as Ziegler-Natta catalyst or Phillips catalyst. Such crosslinking catalysts may include carboxylates of metals (e.g., cobalt, tin, zinc, iron, lead, etc.), dialkyltin mercaptides, stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous acetate, stannous octoate, zinc octoate, organic bases (e.g., ethylamine, dibutylamine or hexylamine), inorganic acids (e.g., sulfuric acid) or organic acids (e.g., toluenesulfonic acid, stearic acid and maleic acid).

[0027] Advantageously, after said lamination step, said sealant material exhibits a complex viscosity at 85°C of greater than 15000 Pa.s and a complex viscosity at 100°C of greater than 10000 Pa.s.

[0028] Advantageously, after said lamination step, said sealant material exhibits a tan delta value at 85°C of less than 1.0 and a tan delta value at 100°C of less than 1.2.

[0029] These properties are sufficient to provide the required structural stability and creep resistance at the required use temperature immediately after lamination. As crosslinking further develops after lamination, the creep resistance of the sealant layer will be further improved.

[0030] Such photovoltaic modules are naturally suitable for incorporation into or on building structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further details of the present invention will become more apparent upon reading the following description in conjunction with the following drawings, which depict:

[0032] Figure 1 : A schematic cross-sectional view of a photovoltaic module manufactured according to the present invention;

[0033] Figure 2 : A schematic cross-sectional view of another photovoltaic module manufactured according to the present invention;

[0034] Figure 3 : Schematic diagram of a method for manufacturing a photovoltaic module;

[0035] Figure 4-7 : A schematic diagram of a method for manufacturing a sealant material according to the present invention; and

[0036] Figure 8 : Schematic diagram of a building structure equipped with PV modules. DETAILED DESCRIPTION

[0037] It should be noted in the following that, unless it is explicitly stated that a particular layer is disposed directly on an adjacent layer, one or more intermediate layers may also exist between the layers. Therefore, by default, "on" should be interpreted as "directly or indirectly on". In addition, the patterns of certain layers, connectors, etc. are not shown because they are well known to the skilled person.

[0038] Figure 1 The classical construction of a photovoltaic module 1 is shown, comprising a front sheet 3 on the light incident side of the module 1 intended to be illuminated in use (indicated in the figure by a sun symbol), and a back sheet 11 on the side of the module 1 opposite to the front sheet 3. The front sheet 3 may be glass, transparent ceramic, polymer or any other convenient substantially transparent material, while the back sheet may be metal, glass, ceramic, polymer or any other convenient material. The front sheet 3 may be structured and may be provided with a coating. One of the front sheet 3 and the back sheet 11 may represent a "first layer" in the sense of the present invention, and the layer encapsulated to the first layer by the sealant layer corresponds to a "second layer" in the sense of the present invention. Alternatively, any two specific layers of the PV module construction that are encapsulated together may represent the first layer and the second layer in the sense of the present invention, or any of the first layer and the second layer may form part of an existing prefabricated PV module (to which one or more further layers are to be laminated).

[0039] The photovoltaic conversion device 7 is located between the front sheet 3 and the back sheet 11, and includes one or more PV cells (including NIP, PIN, NP or PN junctions) patterned and interconnected as is well known. The PV cells can be based on thin film silicon, crystalline silicon, germanium, perovskite, dye-sensitized cells or any other type of PV technology, which are suitable for generating electrical energy from light incident on the light incident side of the PV module 1 and entering the photoelectric active site of the PV conversion device 7. Although the present invention is particularly suitable for packaging PV modules containing dye-sensitized and perovskite cells, it can also be applied to any PV cell technology.

[0040] The PV conversion device 7 is encapsulated on its light incident side by a front sealant layer 5, which seals it to the front sheet 3, and on its back side by a rear sealant layer 11. The latter seals the PV conversion device 15 to the back sheet 19, although it can actually form the back sheet itself. The thickness of each sealant layer 13, 17 is typically 200μm to 1mm. In addition, multiple front encapsulation layers 3 can be stacked on top of each other. The front and / or rear sealant layers 5, 9 are specially made according to the present invention and will be described in more detail below.

[0041] It should be noted that other intermediate layers may be provided between the layers shown and that these need not be flat but may have curved or more complex surfaces. In such cases, the use of a powdered sealant material, either by itself or in combination with a film thereof, may be advantageous to ensure that all details of the shape are filled with sealant.

[0042] Figure 2 Another variant of the structure of a PV module 1 is shown, which is manufactured by laminating a front sheet 3 onto an existing prefabricated PV module 17 with the help of a front sealant 5. The other layers 7, 9 and 11 are as previously specified. As a result, the original front sheet and the front sealant of the prefabricated module 17 become the internal front sheet 13 and the other sealant layer 15, respectively. The description about the rear sealant 9 and the rear sheet 11 applies the same as before. This structure makes it possible to functionalize the front side of an existing module 17 by means of a front sheet 3 that is structured, printed, includes the desired additives, includes filters such as disclosed in EP2994940, US2017 / 123122 or US2017 / 033250, or displays similar functions.

[0043] Figure 3 A method for manufacturing a PV module 1 according to the invention is schematically illustrated.

[0044] A layer stack 31 comprising at least layers 3, 5, 7 and 9 and any other layers present is assembled in a laminating device 33. Figure 2 In the case of an embodiment of the present invention, the layer stack comprises a prefabricated PV module 17, onto which the front sealant layer 5 and the front sheet 3 (and any other desired layers) have been applied. It should be noted that the layer stack 31 can be assembled in the laminating device 33 with the light incident side of the final PV module facing downwards or upwards, this orientation determining which specific layers are the "first" and "second" layers in the sense of the present invention. Furthermore, one or more sealant layers 5, 9 can be applied to the layer stack 31 as a film and / or powder.

[0045] The laminating device may be a vacuum bag laminator, a roll laminator or any other convenient type. The laminating device 33 then applies heat and pressure at a lower temperature than normal, in particular between 60 and 125°C, preferably between 60 and 100°C, further preferably between 70 and 90°C, and a pressure of up to 2 bar (usually substantially 1 bar) for an appropriate period of time (e.g. 20 to 2000 minutes), which fuses and crosslinks the individual sealant layers, thereby assembling the final PV module 1.

[0046] As a result, the PV module 1 of the present invention can be manufactured in conventional PV processing equipment without the need for dedicated equipment. Furthermore, the reduced processing temperature reduces energy consumption in manufacturing.

[0047] In order to allow lamination to be performed at temperatures below the normal temperatures mentioned above, while maintaining the desired mechanical properties of the sealant after lamination and in use, the at least one sealant layer 5, 9 is manufactured as described in detail below.

[0048] The one or more sealant layers 5, 9 in question are formed from a silane-modified polyolefin base resin, such as polyethylene or other vinyl polymers or copolymers, or a mixture of such polymers. Such base resins are mixed with silane crosslinking agents that have been grafted onto the polymer molecules and are commercially available from companies such as Padanaplast, Dow, Evonik and others. In the following, certain specific formulations will be referred to by their manufacturer's index, which does not vary for a specific formulation. Reproducibility by a skilled person is thus ensured.

[0049] Such base resins can generally be prepared by processing one or more polyolefins (such as polyethylene, polypropylene, or ethylene or propylene with a C 3 -C 10 The base resin can be obtained by melt processing one or more polyolefins in the presence of a compound containing a hydrolyzable silane group and a compound capable of generating free radicals. However, since such base resins are readily available from several manufacturers, the technician only needs to select a suitable resin without synthesizing it himself.

[0050] The base resin ideally has the following properties prior to lamination:

[0051] parameter value density <![CDATA[<0.92g / cm 3 ]]> Melting point <90℃ Complex viscosity at 85℃ <15000Pa.s and> 1000Pa.s Complex viscosity at 100°C <10000Pa.s and> 500Pa.s Tanδ at 85℃ >0.8, ideally <10, or even <5 Tanδ at 100℃ >1, ideally <10, or even <5

[0052] [Table 1]

[0053] For reference, complex viscosity is the frequency-dependent viscosity function measured during forced harmonic oscillation of shear stress and is defined as the complex modulus divided by the angular frequency, where the complex modulus represents the overall resistance of the material to deformation, whether the deformation is recoverable (i.e., elastic) or non-recoverable (i.e., viscous). This is measured using a dynamic dynamic mode rheometer or similar tool in the present case at a frequency of 1 Hz and 10% strain. Tan δ, also known as the "loss tangent," is the phase tangent representing the ratio of the viscous modulus (G") to the elastic modulus (G') and quantifies the presence and degree of elasticity in the fluid. Also at a frequency of 1 Hz and 10% strain, Tan δ values ​​less than 1.0 indicate predominantly elastic (i.e., solid-like) behavior, and values ​​greater than 1 indicate predominantly viscous (i.e., liquid-like) behavior.

[0054] The density ranges stated represent optimum values ​​for the base resin in terms of crystallinity and melting point, which ensures that the sealant can melt at lower lamination temperatures, and the viscosity and tan delta values ​​are important values ​​reflecting the processability of the sealant under standard lamination conditions. Specific commercial examples of resins having these properties are given in the following examples, but a person skilled in the art knows how to select other resins by referring to the properties given in the appropriate material data sheets. In essence, it has been shown that polymers having the stated properties are laminable at the desired temperature, while those with parameters outside these ranges are generally unsuitable.

[0055] The base resin is combined with a crosslinking catalyst at a concentration of 0.01 phr to 5 phr. The catalyst may include boric acid, a metallocene catalyst, a restricted geometry catalyst, a chain shuttle catalyst, a multi-center catalyst (such as a Ziegler-Natta or Phillips catalyst) as a water source, or any other type of catalyst suitable for catalyzing the crosslinking of polyolefin molecules by silane and water, wherein the water may be ambient water and / or provided by boric acid or similar compounds that decompose and release water when heated. The catalyst may be provided as a powder or liquid solution, or may have been incorporated into a catalyst masterbatch with a polymer. Examples of such catalysts are: carboxylates of metals (such as cobalt, tin, zinc, iron, lead, etc.), dialkyltin mercaptides, stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, stannous acetate, stannous octoate, zinc octoate, an organic base (such as ethylamine, dibutylamine or hexylamine), an inorganic acid (such as sulfuric acid) or an organic acid (such as toluenesulfonic acid, stearic acid and maleic acid).

[0056] In the following, the catalyst preparations are likewise referred to by their manufacturer's indices, which do not vary for a particular recipe, thus ensuring reproducibility for the skilled person.

[0057] Other additives such as antioxidants, UV absorbers and / or UV stabilizers may be added to the sealant base resin, for example, in a concentration of 0.1% to 5%. In addition, the sealant may also contain pigment particles as other additives. Such particles may be present, for example, in a concentration of 0.01 to 10 phr or weight %, preferably 0.1-1 phr or weight %, and have a size of 100nm to 1 μm, most particularly 300-700nm, most particularly 400-600nm. Note that pigment particles are discrete particles, which are different from colorants that are dispersed in the sealant at the molecular level or sealants made of already colored materials. As examples of suitable pigments, titanium dioxide or zinc oxide particles can be used to produce a white color. The color of the color can be obtained by using various iron oxides (such as Fe for red). 2 O 3 , or FeO(OH) for yellow) to produce yellow, orange, red and brown. Blue can be produced by, for example, complex sulfur-containing sodium silicate or Prussian blue. Such pigment particles 21 absorb a portion of the visible light incident on the PV device 1 to produce the desired color, and also scatter the light, which provides a uniform color and helps to hide various features of the PV conversion device 15, such as its patterning, the traces of electrical interconnections between the individual cells, the edges of the individual cells, the color mismatch between the individual cells and the rear sealant 17 and / or the rear sheet 19, etc.

[0058] The mixture of base resin and catalyst (plus any other additives) may be compounded and then extruded through a twin screw extruder or other form of extruder at a temperature of 90°C to 190°C, preferably 140°C to 180°C, preferably 160°C to 180°C, preferably 165°C to 175°C to form a film or any other convenient form (such as a cylinder) of sealant material, which may then be ground into a powder. Figure 4 As schematically illustrated in FIG. 1 , a base resin, a catalyst formulation (which includes a catalyst powder, a solution or a catalyst masterbatch including a catalyst already compounded with a polymer) are mixed, compounded and extruded. Figure 5 Another variation of the process is schematically shown, in which the base resin is first mixed and compounded with other additives (such as UV absorbers, UV stabilizers and / or antioxidants) and then extruded, and the resulting mixture is subsequently mixed and compounded with a catalyst formulation (as described above) and extruded.

[0059] Using conventional extrusion methods, the relatively short residence time of the melt in the extruder before it solidifies ensures that relatively few crosslinks occur in the polymer. However, some may indeed occur, but there is no problem. In the case of the problem of excessive crosslinking in the extruder, the technician can easily modify the extrusion parameters (temperature, extrusion pressure, extrusion flow rate, etc.) to solve the problem through routine experiments. As mentioned above, the sheet and / or powder can therefore be placed in the layer stack 31 in the laminating device 33. After applying heat and pressure, the silane crosslinks the polymer molecules in the presence of water (possibly from other ingredients such as boric acid or catalysts) at the laminating temperature, thereby hardening the sealant material and bonding to adjacent layers.

[0060] In another variation, the base resin and any additives other than the catalyst may be compounded and extruded at the above temperature into a form such as a cylinder and then ground into a powder. The base resin powder may then be mixed with a catalyst powder containing the catalyst material (alone or compounded with a polymer) and optionally other additives such as antioxidants, UV absorbers and / or UV stabilizers, such as Figure 6 Schematically shown. This powder may have a particle size of 1 to 1000 μm, preferably 1 to 100 μm. The resulting powder mixture constitutes the sealant material of the present invention. Figure 7 In another variation of the method schematically shown in , the base resin (which may be in powder, granules or any other convenient form) and other additives as described above are first mixed, kneaded and extruded, and the resulting mixture is then crushed into a powder. The latter powder is then mixed with the above-mentioned catalyst in powder form (with or without a polymer component) to form a sealant material powder.

[0061] This powder mixture can then be placed in a layer stack 31 as described above and heat is applied between 60°C and 125°C, preferably between 60°C and 100°C, more preferably between 60°C and 85°C, and a pressure of 0.5 to 2 bar, and as the ingredients soften and combine, the catalyst will interact with the base resin to crosslink the polymers of the base resin in the same manner as if the catalyst was mixed with the base material and then extruded.

[0062] After lamination, the resulting sealant has the following improved properties to provide the required strength and creep resistance in use:

[0063] parameter value Complex viscosity at 85℃ >15000Pa.s Complex viscosity at 100°C >10000Pa.s Tanδ at 85℃ <1.0 Tanδ at 100℃ <1.2

[0064] [Table 2]

[0065] Reproduced below are a number of test results which demonstrate that the method of the present invention achieves the desired results and provide specific examples of particular combinations of materials that can achieve the desired effects.

[0066] Example 1

[0067]

[0068] [Table 3]

[0069] Table 3 details the formulation of this example, where "phr" refers to parts per hundred parts of resin. Antioxidants and UV stabilizers were first compounded into an additive masterbatch at 170°C by a twin-screw extruder. The mixture of base resin, catalyst masterbatch, and additive masterbatch was then extruded into a 0.5 mm thick film at 170°C by a single-screw extruder. The extruded film was then tested in a series of characterization steps.

[0070] The film was first laminated between two glass sheets, each 3 mm thick, at 85°C in a standard flatbed vacuum bag laminator with a total cycle time of 60 minutes. The resulting laminate had no voids or other visible defects. The post-lamination peel strength between the foil and the glass was measured to be in excess of 10 N / mm, as measured by a standard 90° peel test using a standard tensile testing machine. The laminated glass sheets were then subjected to a standard creep test at 85°C and 85% relative humidity, showing a creep strength equivalent to 15 kg / m 2 The laminate showed no creep after 100 hours under the weight of the glass.

[0071] Example 2

[0072]

[0073] [Table 4]

[0074] Table 4 details the formulation for this example. Antioxidants, UV absorbers, and UV stabilizers were first compounded into an additive masterbatch at 170°C via a twin screw extruder. The mixture of base resin (in this case, it comprised a 50:50 blend of two different resins as shown in the table), catalyst masterbatch, and additive masterbatch was then extruded into a 0.5 mm thick film via a single screw extruder at 170°C. The extruded film was then tested in a series of characterization steps.

[0075] The film was first laminated between two glass plates, each 3 mm thick, at 85°C in a standard flatbed vacuum bag laminator with a total cycle time of 60 minutes. The resulting laminate had no voids and other visible defects. The peel strength between the foil and the glass after lamination was measured to be in excess of 5 N / mm by the standard 90° peel test as described above. The laminated glass plates were then subjected to a standard creep test (described above) at 85°C and 85% relative humidity, showing no creep after 100 hours.

[0076] Example 3

[0077]

[0078] [Table 5]

[0079] Table 5 details the formulation of this example. Antioxidants, UV absorbers and UV stabilizers were first compounded into an additive masterbatch at 170°C by a twin-screw extruder. The mixture of base resin, catalyst masterbatch and additive masterbatch was then extruded into a 0.5 mm thick film by a single screw extruder at 170°C. The extruded film was then tested in a series of characterization steps.

[0080] The film was first laminated between two glass plates, each 3 mm thick, at 85°C in a standard flatbed vacuum bag laminator with a total cycle time of 60 minutes. The resulting laminate had no voids and other visible defects. The peel strength between the foil and the glass after lamination was measured to be in excess of 5 N / mm by the standard 90° peel test as described above. The laminated glass plates were then subjected to the same creep test as above at 85°C and 85% relative humidity, showing no creep after 100 hours.

[0081] Example 4

[0082]

[0083]

[0084] [Table 6]

[0085] Table 6 details the formulation of this example. Antioxidants and UV stabilizers were first compounded into an additive masterbatch by a twin-screw extruder at 190°C. The mixture of base resin, catalyst masterbatch and additive masterbatch was then extruded into a 0.5 mm thick film by a single screw extruder at 190°C. The extruded film was then tested in a series of characterization steps.

[0086] The foil film was first laminated between two glass plates, each 3 mm thick, at 85°C in a standard flatbed vacuum bag laminator with a total cycle time of 60 minutes. The resulting laminate had no voids and other visible defects. The peel strength between the foil and the glass after lamination was measured to be in excess of 10 N / mm by the standard 90° peel test as described above. The laminated glass plates were then subjected to the same creep test as above at 85°C and 85% relative humidity, showing no creep after 100 hours.

[0087] As shown in the above tests, the sealant material produced by the method of the present invention can be laminated at significantly lower temperatures than conventional methods while still maintaining peel strength and creep resistance at 85° C. As a result, conventional lamination equipment and techniques can be used to assemble PV modules 1 incorporating temperature-sensitive PV cells (such as those based on perovskite or dye-sensitized technology).

[0088] at last, Figure 8 The photovoltaic module 1 of the present invention is shown mounted on the roof of a building structure 35. As an alternative, the PV module 1 can be mounted on an exterior wall, for example as a cladding, or integrated into the structure of the wall and / or roof. In general, the PV module 1 can be mounted on a building 35 or in the structure of a building 35.

[0089] Although the present invention has been described with reference to specific embodiments, modifications may be made thereto without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method for manufacturing a photovoltaic module (1), the photovoltaic module (1) comprising at least a first layer and a second layer fixed to each other by a sealant, the method The following steps are involved: - providing a laminating device (33); - arranging the first layer in the laminating device (33), - providing on said first layer a sealant material produced by: - providing a base resin comprising a silane-modified polyolefin and having a melting point below 90° C., - forming a mixture of the base resin and an additive comprising a crosslinking catalyst, the crosslinking catalyst being present in a proportion of 0.01 to 5 parts per 100 parts of the resin, - melting the mixture at a temperature between 90°C and 190°C and extruding the mixture to form the sealant material; - providing said second layer on said sealant material, - laminating the first layer, the second layer and the sealant material under application of heat and pressure, the heat being applied at a temperature between 60° C. and 125° C., thereby crosslinking the base resin, wherein, before the lamination, the base resin has a complex viscosity of less than 15,000 Pa.s at 85°C, a complex viscosity of less than 10,000 Pa.s at 100°C, a tan δ value of greater than 0.8 at 85°C, and a tan δ value of greater than 1.0 at 100°C, After the lamination, the sealant material exhibits a complex viscosity greater than 15,000 Pa.s at 85°C and greater than 10,000 Pa.s at 100°C, a tan δ value less than 1.0 at 85°C and a tan δ value less than 1.2 at 100°C.

2. The method according to claim 1, in, The sealant material is extruded as a sheet.

3. The method according to claim 1, in, Prior to providing the sealant material on the first layer, the sealant material is extruded and subsequently ground into a powder.

4. A method for manufacturing a photovoltaic module (1), the photovoltaic module (1) comprising at least a first layer and a second layer fixed to each other by a sealant, the method The following steps are involved: - providing a laminating device (33); - arranging the first layer in the laminating device (33), - providing on said first layer in powder form a sealant material produced by: - providing a base resin in powder form, said base resin comprising a silane-modified polyolefin and having a melting point below 90° C., - mixing the base resin powder and an additive in powder form to form the sealant material, the additive comprising a cross-linking catalyst present in the sealant material in a proportion of 0.01 to 5 parts per 100 parts of resin; - providing said second layer on said sealant material, - laminating the first layer, the second layer and the sealant material under application of heat and pressure, the heat being applied at a temperature between 60° C. and 125° C., thereby crosslinking the base resin, wherein, before the lamination, the base resin has a complex viscosity of less than 15,000 Pa.s at 85°C, a complex viscosity of less than 10,000 Pa.s at 100°C, a tan δ value of greater than 0.8 at 85°C, and a tan δ value of greater than 1.0 at 100°C, After the lamination, the sealant material exhibits a complex viscosity greater than 15,000 Pa.s at 85°C and greater than 10,000 Pa.s at 100°C, a tan δ value less than 1.0 at 85°C and a tan δ value less than 1.2 at 100°C.

5. The method according to claim 4, in, The base resin has a complex viscosity of less than 15,000 Pa.s at 85° C. and less than 10,000 Pa.s at 100° C. before lamination.

6. The method according to claim 4, in, The base resin exhibits a tan δ value greater than 0.8 at 85° C. and a tan δ value greater than 1.0 at 100° C. before lamination.

7. The method according to any one of claims 1 to 6, in, The mixture further comprises other additives, wherein the other additives comprise at least one of the following: an antioxidant; an ultraviolet absorber; an ultraviolet stabilizer; and pigment particles.

8. The method according to any one of claims 1 to 6, in, The catalyst comprises at least one of the following: -boric acid; - metallocene catalysts; - constrained geometry catalysts; -Chain shuttling catalysts; -Multi-center catalyst.

9. The method according to claim 8, in, The multi-site catalyst is a Ziegler-Natta catalyst or a Phillips catalyst.

10. The method according to claim 4, in, After the lamination step, the sealant material exhibits a complex viscosity at 85°C of greater than 15,000 Pa.s and a complex viscosity at 100°C of greater than 10,000 Pa.s.

11. The method according to claim 4, in, After the lamination step, the sealant material exhibits a tan delta value of less than 1.0 at 85°C and a tan delta value of less than 1.2 at 100°C.

12. A photovoltaic module (1) manufactured by the method according to any one of claims 1 to 11.

13. A building structure (35) comprising at least one photovoltaic module (1) according to claim 12.

Images