TW201009004A - Photovoltaic modules comprising plasticized intermediate layer films having a low polyvinyl acetate content - Google Patents

Abstract

The invention relates to the use of plasticizer-containing films based on polyvinyl acetal, wherein the polyvinyl acetal has a polyvinyl acetate content of less than 1% by weight.

Description

201009004 VI. Description of the Invention: [Technical Field] The present invention relates to the use of a plasticizer-containing amount based on an oligoethylene vinyl acetal-based amount to be contaminated with a concentrating semiconductor layer. Membrane to make a fuss module to avoid feeling [previous technology]

= The module is made of a transparent film to prevent external D or support polysilicon. Thin film solar modules: array coating, chemical vapor deposition, hybrid or wet deposition = to a photosensitive semiconductor layer on a substrate such as a transparent film or a flexible carrier film. The two-system is superimposed between a glass panel and a rigid rear cover panel made of, for example, glass or plastic. The transparent adhesive must completely surround the photosensitive semiconductor layer and its electrical connections, must be stable in UV and insensitive to moisture, and must be completely blister-free after the lamination process. Thermosetting moulding resins or systems based on cross-linkable vinyl vinyl acetate (EVA) are generally used as transparent adhesives, for example as disclosed in DE 41 22 721 C1 or DE 41 28 766 A1. . In the uncured state, these adhesive systems can be adjusted to surround the low viscosity of the 1% energy cell in a non-foaming manner. An adhesive layer having mechanical strength can be obtained after the addition of a curing agent or a crosslinking agent. The lack of these adhesive systems is 201009004. During the curing process, aggressive substances such as acids that may damage the photosensitive semiconductor layer, especially the thin film module, are usually released. Also, some molded resins tend to form bubbles or delamination due to uv irradiation after several years. An alternative to a thermosetting adhesive system is the use of a plasticizer-containing film based on polyvinyl acetal, such as polyvinyl butyral (PVB) known from the manufacture of laminated glass. The solar cell unit is covered by one or more layers of pV]B film and these films are bonded to a laminate using a desired cover material under elevated pressure and temperature. A method for producing a solar module using a PVB film is known, for example, from de ❿ 40 26 165 C2, DE 42 278 60 Al, DE 29 237 70 C2, DE 35 38 986 C2 or US 4,321,418. The use of a pvb film as a laminated safety glass in a solar module has been disclosed, for example, in DE 20 302 045 U1, EP 1617487 A1 and DE 35 389 86 C2. However, these publications do not contain any information on the mechanical, chemical and electrical properties of the PVB films used. As the efficiency of the photosensitive semiconductor layer increases and the global sales of solar modules increase, the electrical properties of the film become especially important. During the entire use of the module, it is also necessary to avoid loss of charge or even short circuit of the semiconductor layer under extreme climatic conditions such as hot zone temperature, high humidity or strong uv illumination. According to IEC 61215, PV modules are subjected to many tests (wet heat test, wet leakage current test) to reduce the leakage current of the module. It is generally known that the volume resistance (v〇iume resjstance) of a PVB film suddenly decreases as the moisture content increases, which greatly contributes to the generation of leakage current in the photovoltaic module. In the edge area of the photovoltaic module, the material used as the material for the 201009004 is exposed to environmental and environmental conditions such as high ambient humidity. The water content of the film in the edge region may thus be greatly increased and exhibit an up-to-flat, moisture content value (about 3% by weight). Increasing the water 4 in the edge region of the film will greatly reduce the electrical resistance in this region. The moisture content does decrease toward the center of the film, but in order to avoid leakage current, it is impossible to set the photosensitive (four)-way to the edge of the module or the module.

This reduces the area of the surface being covered due to low mold and flow efficiency. An electric solar cell battery, especially a photosensitive semiconductor layer called a "film" module such as CIS (copper/indium/photocatalyte) or copper/indium/marriage/sulfide/linolenic acid sleep (CIGS) or A thin layer used as a conductive material such as (7) (transparent conductive compound) can be used as a chemical ship so that the package should be chemically inert and contain aggressive additives such as cross-linking initiators. X, the presence of water or traces of acid should be avoided. $ 【发明发明】 Technical problem: He: :: Τ 提供 提供 Τ Τ 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 Τ 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯 聚乙烯Photosensitive half (four) layer of conductive film of polyethylene film or conductive material 201009004 solution is low acetic acid content of polyglycolic acid acetate group by water gas catalytic cracking = polyethylidene group and acetic acid Therefore, the lower rot of the film of the present invention is due to the lower content of the polyvinyl acetate acetate group, but is not limited thereto. [Embodiment] The preferred embodiment of the present invention is the following laminated photovoltaic module. group:

Therefore, the subject matter of the present invention comprises a) a transparent front cover; b) - or a plurality of photosensitive semiconductor layers; c) at least one back cover comprising polyethylene acetal, wherein the polyethylene is reduced Based on this: the film-containing layer plasticizing and the agent film layer c) has less than 1% by weight of polyvinyl acetate. The polyethylene shrinkage amount used in accordance with the present invention is less than 1% by weight, preferably less than 0.55% by weight of 〇75, and most preferably less than 0.25 % by weight. Polyethyl methacrylate containing % by weight 'better than avoiding traces of acid during manufacture of the film material is another possibility to reduce 敏感性 sensitivity of the film used in accordance with the invention to a photosensitive semiconductor layer ship: such film Usually made by extrusion at elevated temperatures, the double plasticizer may decompose thermally. Also, poly B

The group may be cleaved by the diffusion of water, thereby producing acetic acid. In both cases, a trace amount of acid may corrode the photosensitive semiconductor layer. H The film used according to the invention is therefore preferably of a specific nature, and should be greater than 5 to 1 〇, preferably greater than 201009004 15 ' and preferably greater than 2 〇, 30 or more, expressed as an alkali titer. 40. However, the maximum titration of 100 should not be exceeded. As described below, the alkali titration is determined by back titration of the film and can be added by adding an organic substance such as an organic alkali metal salt having 1 to 15 carbon atoms, particularly a specific alkali salt or an alkaline earth salt such as magnesium acetate or Potassium acetate is used to adjust. The concentration of the basic compound used is usually from 0.005 to 2% by weight, most preferably from 5 to 1% by weight based on the total mixture. Φ The film used in accordance with the invention preferably has a resistivity of at least 1E + 11 ohms * cm or greater than 5E + 11 ohms * cm at 23 ° C and 85% RH ambient humidity, preferably at least 5E + 12 ohms * The resistivity of centimeters or 1E+13 ohms* is optimally at least 5E+13 or at least 1E+14 ohm*cm. In order to produce a polyvinyl acetal, polyvinyl alcohol is dissolved in water, and an acid catalyst is added to carry out an acetal reaction with an aldehyde such as butyraldehyde. The settled polyethylene acetal is separated, rinsed to neutral, selectively suspended in an aqueous medium to be tested, rinsed again to neutral, and dried. The acid used in the acetal reaction must be neutralized again after the reaction has taken place. If an excessive amount of test (for example, NaOH, KOH or Mg(〇H)2) is used, the test titration is increased quantitatively, and the addition of the alkaline substance can be completely or partially abandoned. The polyvinyl alcohol content of the polyethylene acetal can be adjusted by adjusting the amount of the aldehyde used in the acetalization reaction. The acetal reaction can also be carried out using other or several acids (e.g., valeraldehyde) having 2 to 10 carbon atoms. The film based on the plasticizer-containing polyethylene shrinkage preferably comprises uncrosslinked polyvinyl butyral (PVB) obtained by the reaction of 201009004 polyvinyl alcohol with butanal acetal. Crosslinked polyvinyl acetals, especially crosslinked polyvinyl butyral (PVB), can also be used. For example, in EP 1527107 B1 and WO 2004/063231 A1 (thermally self-crosslinking carboxyl-containing polyvinyl acetals), EP 1606325 A1 (poly-baked polybutadiene) and WO 03/020776 A1 ( Suitable crosslinked polyethylene acetals are described in the polyvinyl acetal crosslinked with acetic acid. All of these patent applications are incorporated herein by reference. It is also within the scope of the present invention to use a ternary filament of hydrolyzed vinyl acetate/ethylene oligopolymer as a polyethylation. This pure · ς, at 98% of the moles and contains the acetylene system ^

Kuraray Europe GmbH's "Exceval" category). Further, it is also possible to use, in the scope of the present invention, a polyvinyl alcohol prepared from an unsaturated monomer which is additionally ethylated with ethyl ruthenium acetate. The copolymer is decomposed within the scope of the present invention, and a polyethylene scale mixture of pure polyethylene polymerization degree or degree of hydrolysis can be used. 3. Different polyethylene acetals contain units derived from ethylene vinyl alcohol in addition to acetal units. The acetic acid vinegar and the ground used in accordance with the invention have a polyethylene glycol content of less than 22% by weight, less than decene _ preferably 18% by weight, less than 16% by weight or 15% by weight, and less than 5% by weight. The weight % ° polyethyl alcohol content should not be less than 12% by weight. The degree of acetalization below 14 can be calculated from the polyvinyl alcohol content and the residual. The residual acetate content 201009004 The enamel film preferably has a maximum % plasticizer content, 32% by weight, 30% by weight, 40% by weight, 35% by weight, 戋22% by weight. / Helmet / 〇, 26% by weight, 24 weights /. The secondary ϋ reset/〇, in order to make the film processing amount should not be less than 15% by weight (the film of the plasticizer 5 or the photovoltaic module can be packaged in each of the bases (4)). Roots - Suitable compounds or compounds of the film used according to the invention: (iv) are selected from the group consisting of Φ Φ : 〇 馼 已 已 曰 曰 曰 曰 曰 曰 曰 曰 - - - - - - - - - - - - - - - - - - a mixture of hexylhexyl hexanoate, a mixture of hexanyl hexanoate, agglomerate and adipic acid of adipic acid and a cycloaliphatic or squamous chain;酽锢.龃—w. force- 酉夂 酉夂 裱 裱 裱 裱 裱 或 或 或 或 或 或 或 或 或 或 或 或 或 或 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力 力) vinegar HTfS 曰 or 4 - multivalent lipid lysate or aromatic _ or vinegar with: „ group substituent oligo-ethylene glycol i: di-pure. Diethyl-alcohol with linear or branched aliphatic or cycloaliphatic Group carboxylic acid=bei, diethylene glycol bis(2-ethylhexanoic acid triethylene glycol bis(2-ethylhexanide-diethyl-alcohol bis(2ethylbutyl(tetra))), tetraethylene glycol Bis-indole, diethylene glycol bis-n-heptanoate, triethylene diheptan:; r-based / or dipropylene glycol benzoic acid; = group: medium B - with (four) family fragrant surface alcohol (four) (four), Qin B Benzyl) vinegar (talk, dish acid triethyl vinegar, Wei diphenyl 2_ethyl = 201009004 ester and / or linonic acid Tricorsyl Phosphate - an ester of citric acid, succinic acid and/or fumaric acid selected from one or more of the following groups of compounds, particularly suitable as a plasticizer for films used in accordance with the invention: Di(2-ethylhexyl) diester (DOS), di(2-ethylhexyl) adipate (D0A), dihexyl adipate (DHA), dibutyl sebacate (DBS) , triethylene glycol bis-n-heptanoate (3G7), tetraethylene glycol bis-n-heptanoate (4G7), triethylene glycol bis(2-ethylhexanoate) (3G0 or 3G8) , tetraethylene glycol bis(n--2-ethylhexanoate) (4G0 or 4G8), di(2-butoxyethyl) adipate (DBEA), di(2-butoxy) adipate Ethyl ethoxyethyl) vinegar (DBEEA), di(2-butoxyethyl) phthalate (DBES), di(2-ethylhexyl) g (DOP), ortho Diisodecyl phthalate (DINP), triethylene glycol diisononate, triethylene glycol bis(2-propylhexanoate), bis(2-ethylhexyl) phosphate (T0F), Diisodecyl 1,2-cyclohexanecarboxylate (DINCH) and dipropylene glycol benzoate are especially suitable for use as thin in accordance with the present invention. The plasticizer of the film is a plasticizer having the following characteristics: the polarity represented by the formula 100xO/(C+H) is less than or equal to 9.4, wherein 0, C and Η represent oxygen, carbon and hydrogen atoms in each molecule. The following table shows the plasticizers and their formulas 100xO/(C+H) values applicable according to the invention. Table 1 Name Polarity Value Di(2-ethylhexyl) sebacate (DOS) 5.3 1, Diisodecyl 2-cyclohexanecarboxylate (DINCH) 5.4 Di(2-ethylhexyl) adipate (DOA) 6.3 201009004 Di(2-ethylhexyl) vinegar (DOP) 6.5 —_Three_ Ethylene glycol bis(2-propylhexanoate) 8.6--triethylene glycol bis-isodecanoate 8.6 A _Mansan 1 Sa 2-2 Butoxyethyl ester (DBES) 9.4 -~ alcohol Bis-ethylhexanoate) (3G8) 9.4 Furthermore, the ion mobility and hence the resistivity depending on the water content of the film can be changed by the addition of SiO 2 , especially gas phase ruthenium dioxide. The plasticizer-containing film based on the polyethylene shrinkage comprises 0.001 to 15% by weight, preferably 2 to 5% by weight, of SiO 2 . Further, the film according to the present invention may further contain conventional additives such as, for example, an oxidation stabilizer, a uv stabilizer, a dye, a pigment, and an anti-caking agent. The manufacture and composition of a film based on a polyethylene acetal is theoretically described, for example, in EP 185 863 B, EP 1 118 258 Bl, WO 02/102591 Al, EP 1 118 258 B1 or EP 387 148 B1. The photovoltaic module is fabricated by welding a film to obtain a photosensitive semiconductor layer with no bubbles and no streaks. In a variant of the photovoltaic module according to the invention, the photosensitive semiconductor layer is applied to the back cover d) by, for example, evaporation, chemical vapor deposition, sputtering or wet deposition, and by at least one film c) And joined to the transparent front cover a). In another variant, the photosensitive semiconductor layer is applied to the transparent front cover a) and is joined to the back cover d) by at least one film. In a further variant of the invention, a photovoltaic module is obtained by embedding a photosensitive semiconductor layer between two thin layers C) and bonding to the cover sheets a) and d) in this manner. The thickness of the plasticizer-containing film based on polyvinyl acetal is usually 201009004 0.38, 0.5 bu 0.76, 1.14, 1.52 or 2.28 mm. The film used in accordance with the present invention during the lamination process will fill voids present in the photosensitive semiconductor layer or its electrical connections. The transparent front cover a) is usually made of glass or PMMA. The back cover d) of the photovoltaic module according to the present invention may be constructed of glass, plastic or metal or a composite thereof; at least one of the supports may be transparent. One or both of the cover sheets may also be designed as a laminated glass (i.e., a laminated layer made of at least two glass sheets and to a PVB film) or an insulating glass having a gas gap. Naturally, a combination of these measures can also be used. © The photosensitive semiconductor layer used in the module does not need to have any special characteristics. Single crystal, polycrystalline or amorphous systems can be used. In the case of a thin film solar module, the photosensitive semiconductor layer is directly applied to the support. The photosensitive semiconductor layer cannot be packaged here. In this case, a support (for example, a back sheet) having a photosensitive semiconductor layer deposited thereon, a polyvinyl acetal-based plasticizer-containing film, and a transparent cover will be included. The composite of the panels is bonded and then bonded or laminated at elevated temperatures. In another example, the photosensitive semiconductor layer can be deposited onto the transparent cover sheet a) and then assisted by the plasticizer film based on the polyvinyl acetal to be spotted or laminated to the back sheet. For the thus obtained composite laminate layer, a pre-laminated layer may be pre-manufactured or not fabricated using a method well known to those skilled in the art. The so-called autoclave treatment is carried out at an elevated pressure of about 10 to 15 bar and a temperature of 130 to 145 ° C for more than about 2 hours. For example, 12 201009004 According to EP 1 235 683 B1, the vacuum bag or vacuum ring process is operated at about 2 〇〇 _ and 130 to 145 ° C. A true splicer is preferably used to fabricate a photovoltaic module in accordance with the present invention. It consists of a heatable and vacuumable chamber in which the laminated glass can be laminated in 30 to 60 minutes. It has been confirmed that the actually reduced pressure is from 0.01 to 300 mbar and the temperature is from 1 Torr to 2 〇〇〇c, most preferably from 130 to 160 °C. ❹ Alternatively, the assembled composite as described above may be pressed into a module according to the invention between at least one pair of rollers between 6 〇 and 15 〇〇c. Such devices are known in the art of laminating glass and typically have at least one heating conduit upstream or downstream of the first compression device in a device having two pressing apparatus. INDUSTRIAL APPLICABILITY The present invention is further characterized by a plasticizer-containing film c) having a polyvinyl acetate content of less than 1 and a polyethylene-based shrinkage-based composition, or a preferred embodiment. Use in the manufacture of photovoltaic modules. The photovoltaic module according to the invention can be used as an exterior element, a roof area, a winter garden covering, a soundproof wall, a balcony or a handrail element or a window element. Measurement procedure The volumetric resistance measurement of the film was carried out according to mNIEC 6〇〇93 under the conditions of at least 24 hours after the film was at a defined temperature and ambient humidity (23 ° C and 85 ° / RH). Measurements were carried out using a Model 302 132 plate electrode from Fetronic GmbH and a resistivity meter IS0_Digi 5kv from Amprobe. The test voltage is 2.5 kV, and the waiting time after the application of the test voltage to the acquisition amount is 60 seconds. In order to ensure sufficient contact between the plate and the film of the measuring electrode, the surface roughness Rz of the film should not be greater than 10 μm when measured according to DIN EN ISO 4287, ie the original surface of the PVB film is subjected to a resistivity amount if necessary It must be flattened with heat and reemboss before measurement. The polyvinyl alcohol and polyvinyl acetate content of the polyvinyl acetal is determined in accordance with ASTM D 1396-92. The analysis of the metal ion content was carried out using an atomic absorption spectrum (AAS). The water or moisture content of the film is determined by the Karl Fischer method. This singular method can be performed on both the unlaminated film and the laminated photovoltaic module as a function of the distance from the edge of the film. Alkali titer A 3 to 4 gram plasticizer-containing polycondensation film/valley was used in a 100 ml ethanol/THF (80:20) mixture using a magnetic stirrer. Add 丨〇ml of diluted hydrochloric acid (4). G1 mol/L) to the above solution, and then use a titrator to prepare the TBAH solution in the 2-propanol (4) Molybdenum/L) The sample was subjected to potentiometric titration and _ blank titration was performed. The titration system is calculated in the following manner: ^疋里-HC1 ml of gas sample per 100 g sample (4) _TBAH sample χ just removed the weight of the stalk handle) The hot flash test is carried out according to IEC 61646. Example degree, where two 1:1 = = == estimated film _ 201009004 According to TCF 85 C and 85% humidity for 1000 hours (similar to root, damp heat test). Visually apply the grade of 1 to 5 to apply the lingering silk, where 丨(4) is the best ^ means the worst state 0. Right use PVB based film with low polyvinyl acetate vinegar content (according to The present invention), (iv) has not been affected, for example, significant, original reflection and penetration. Based on PVB with oligoethylacetate acetate ❹ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ This type of film is suitable for the manufacture of photovoltaic modules, especially for the manufacture of chemically sensitive film modules. The use of a film other than the present invention causes "blinding" and partial deterioration of the aluminum coating film. Such films are not suitable for the manufacture of photovoltaic modules. The amounts in Tables 2 and 3 are shown in % by weight based on the combined weight of pvB and plasticizer. 3G8 represents triethylene glycol diethylhexanoate), RA represents the residual acetate content of φ and AT represents the alkali titer. AEROSIL 130 and TINUVIN 328 are commercially available from Evonik Degussa and CIBA, respectively. The corrosion state of the aluminum coating film was evaluated by the above-described visual inspection method, and the volume resistance was measured in accordance with DIN IEC 60093 after the film was subjected to conditions of 85% humidity and 23 ° C and was measured in ohm* centimeters. Table 2 Example Comparative Example 1 Example 1 Comparative Example 2 Example 2 Declared High RA Low RA High RA and Low AT Very Low RA PVB 78 78 76 78 15 201009004 PVOH-Content PVB 18.0 18.0 18.0 18.0 RA PVB 3.2 0.8 3.2 0.1 3G8 22 22 24 22 AEROSIL 130 - - - - TINUVIN 328 0.15 0.15 0.15 0.15 MgAc2*4H20 - - 0.0125 - AT PVB 5 5 5 5 AT film 3 3 20 3 Corrosion 5 3 4 1 Volume resistivity 2.9E+12 2.5E+ 12 3.2E+11 4.0E+12 Table 3 Example Example 3 Example 4 Describes low RA and high AT Low RA and adds SiO 2 PVB 76 76 PVOH-content PVB 18.0 18.0 RAPVB 0.8 0.8 3G8 24 24 AEROSIL 130 - 1.5 TINUVIN 328 0.15 0.15 MgAc2*4H20 0.0125 0.0500 AT PVB 5 5 AT film 20 27 Corrosion state 2 1 Volume resistivity 4.5E+11 6.5E+12 16 201009004 [Simplified description] No [Main component symbol description] None

Claims (1)

201009004 VII • Patent application scope: L kinds of photovoltaic modules, including one of the following laminates: a) - transparent front cover; b) one or more photosensitive semiconductor layers; c) at least one with polyvinyl acetal a base plasticizer-containing film; and d) a back cover, characterized in that the polyvinyl acetal used in the plasticizer-containing film c) has less than 1% by weight of polyvinyl acetate. 2. A photovoltaic module according to claim 1 of the invention, characterized in that the plasticizer-containing film c) based on polyethylene acetal has a plasticizer content of at most 4% by weight. The photovoltaic module according to any one of claims 1 to 2, characterized in that the plasticizer-containing film c) based on polyvinyl acetal is at 85 〇/〇RH/23 °C. The volumetric resistance is greater than 1E+11 ohm*cm in the ambient atmosphere. 4. A photovoltaic module according to any one of claims 1 to 3, characterized in that the plasticizer-containing film c) based on a polyvinyl acetal is more than a base titer of 5. " 5. The photovoltaic module according to any one of claims 4 to 4 is characterized in that the polyvinyl acetal has a polyvinyl alcohol content of less than 22% by weight, as reviewed. The photovoltaic module of any one of the five items, the special IS 18 201009004 is characterized in that the plasticizer-containing film C) based on polyvinyl acetal comprises a metal carboxylate having 1 to 15 carbon atoms as a base. The photovoltaic module according to any one of claims 1 to 6, wherein the plasticizer-containing film based on the polyvinyl acetal comprises 0.001 to 5% by weight of Si〇2. 8. The photovoltaic module according to any one of claims 1 to 7, wherein the photosensitive semiconductor layer is applied to the cover d) by at least one. The base plasticizer film c) is bonded to the transparent front cover a). 9. The photovoltaic module according to any one of the items i to 7 of the present invention, characterized in that the photosensitive semiconductor layer is applied to The transparent front cover a) and comprising at least one plasticizer based on polyvinyl acetal The film module c) is bonded to the back cover d). The photovoltaic module according to any one of claims 7 to 7 is characterized in that the photosensitive semiconductor layer b) is embedded in two Between the crusts c) and in this way joined to the cover plate and d). The use of a plasticizer film based on polyvinyl acetal for the manufacture of photovoltaic modules, wherein the polyvinyl acetal has a weight less than 丨% polyvinyl acetate content. 12' Use of a photovoltaic module according to any one of the claims 2-3 to as an exterior element, roof area, winter garden cover, soundproof wall, balcony or Handrail element or window area component 19 201009004 IV. Designation of representative figure: (1) The representative figure of the case is: (No) picture. (2) The symbol of the symbol of this representative figure is simple: No. 5. If there is a chemical formula in this case , please reveal the chemical formula that best shows the characteristics of the invention: