Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/003—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/0005—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor characterised by the material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/04—Extrusion blow-moulding
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
  • C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L27/12—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
  • C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L27/12—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
  • C08L27/16—Homopolymers or copolymers or vinylidene fluoride
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/048—Encapsulation of modules
  • H01L31/0481—Encapsulation of modules characterised by the composition of the encapsulation material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
  • H01L31/042—PV modules or arrays of single PV cells
  • H01L31/048—Encapsulation of modules
  • H01L31/049—Protective back sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
  • C08J2327/16—Homopolymers or copolymers of vinylidene fluoride
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
  • C08L33/04—Homopolymers or copolymers of esters
  • C08L33/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
  • C08L33/10—Homopolymers or copolymers of methacrylic acid esters
  • C08L33/12—Homopolymers or copolymers of methyl methacrylate
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy

Definitions

• the present invention relates to a composition
• a composition comprising a fluoropolymer and two white inorganic fillers, said composition being intended for the production of monolayer films of small thickness, opaque to visible light and to UV rays, used in particular in the field of photovoltaic cells.
• the rear part of the cell must be protected by a polymer film to prevent its degradation by ultraviolet (UV) rays and the penetration of moisture.
• the protective film must have thermal stability in volume or size to prevent thermal expansion and in particular shrinkage during assembly of the cells.
• the assembly of the photovoltaic cells is done by bonding the different layers with a solvent-based adhesive, followed by rolling. The use of solvents in the adhesives can cause penetration of these solvents into the film.
• the cells are assembled at high temperature (> 130 ° C.) and possibly using a corona type surface oxidation treatment. When the protective film is based on fluoropolymer, this treatment can lead to yellowing and degradation of the mechanical properties thereof.
• PVDF polyvinylidene difluoride
• UV, UV absorbers and / or mineral fillers are incorporated therein.
• a fluorinated polymer such as a fluoride polymer or copolymer of vinylidene (PVDF)
• HF Hydrogen fluoride
• One way to implement these charges with eg PVDF is to introduce these inorganic fillers using an acrylic masterbatch.
• the inorganic fillers are dispersed in a polymer or copolymer of methyl methacrylate (PMMA), then this masterbatch is mixed with the PVDF in the molten state.
• PMMA methyl methacrylate
• the presence of a PMMA generates drawbacks such as a limitation of the dimensional stability of the film obtained in temperature, a lower thermal resistance, a characteristic odor of the acrylic during the assembly of the cells and a lower UV stability in comparison with a Pure PVDF.
• a film comprising a tripartite fluorinated polymer / acrylic polymer / inorganic filler composition is for example described in document WO 2009101343.
• the proportion of acrylic polymer ranges from 5 to 45 parts per 100 parts of composition.
• compositions based on fluorinated polymers and containing a single inorganic filler for preparing films opaque to UV and visible radiation while maintaining very good dimensional stability properties at the temperatures used for the manufacture of a backsheet and subsequently a photovoltaic panel comprise a fluorinated polymer and zinc oxide (ZnO), said filler being present in said composition in a mass proportion of 5 to 50%.
• ZnO zinc oxide
• the use of this filler makes it possible, on the one hand, to avoid the addition of acrylic polymers in the fluoropolymer and, on the other hand, to use processing temperatures that are compatible with the extrusion blow molding process.
• a monolayer film namely of the order of 220 to 260 ° C, which avoids the degradation of the fluoropolymer.
• the use of zinc oxide makes it possible to obtain a film opaque to ultraviolet radiation and visible at a thickness of 20 ⁇ . It has been found that the use of zinc oxide as the only white inorganic filler does not make it possible to obtain a transmittance of less than 30% at visible range wavelengths, for thin layers with a thickness of less than 20%. ⁇ . However, some applications, particularly in the field of photovoltaic modules, require film thicknesses of less than 20 ⁇ .
• the present invention therefore proposes to provide fluorinated polymeric compositions which make it possible to produce films of small thickness (less than 20 ⁇ ), opaque to UV and visible radiation and which contain little or no acrylic polymers.
• the invention relates to a composition consisting of at least one fluorinated polymer and two white inorganic fillers, characterized in that said changes are zinc oxide and titanium oxide, in that they are present in a mass proportion ranging from 5 to 30% and from 3 to 7.5% respectively (limits included), and in that said composition furthermore comprises, in addition, up to 5% by weight of acrylic polymer these percentages being calculated with respect to the total weight of the composition.
• the content by weight of acrylic polymer is therefore greater than 0% and less than 5% relative to the total weight of the composition.
• the invention also relates to the process for obtaining the said formulation, the film obtained from this formulation and its use in the photovoltaic field as a protective film of a PET substrate used as rear protection for photovoltaic panels. More particularly, the invention relates to a photovoltaic cell whose rear panel is coated with a film as described above. According to yet another aspect, the invention relates to the various methods for manufacturing the aforementioned monolayer film.
• the invention relates to a polymeric composition
• a polymeric composition comprising at least one fluorinated polymer and two pigments based on zinc and titanium, the simultaneous presence of which makes it possible to obtain, for thin films made from said composition, a UV opacity up to a wavelength of 395 nm, while having a very good opacity in the visible with a transparency less than 25% at 450 nm, with excellent thermal stability and a yellowness index (YI) less than 4.
• YI yellowness index
• Xi is H or F
• X 2 and X 3 denote H, F, Cl, a fluorinated alkyl group of formula C n F m H p - or a fluorinated alkoxy group C n F m H p O-, n being an integer between 1 and 10, m an integer between 1 and (2n + 1), p being 2n + 1m.
• HFP hexafluoropropylene
• TFE tetrafluoroethylene
• VDF vinylidene fluoride
• the diolefins containing fluorine for example diolefms such as perfluorodiallyl ether and perfluoro-1,3-butadiene.
• the fluorinated polymers that can be used in the composition according to the invention are chosen from:
• TFE polytetrafluoroethylene
• ETFE ethylene-tetrafluoroethylene copolymer
• TFE / PMVE copolymers tetrafluoroethylene-perfluoro (methyl vinyl) ether copolymer
• TFE / PEVE tetrafluoroethylene-perfluoro (ethyl vinyl) ether copolymer
• TFE / PPVE tetrafluoroethylene-perfluoro (propyl vinyl) ether copolymer
• E / TFE / HFP ethylene-tetrafluoroethylene-hexafluoropropylene terpolymers
• homo- or copolymers of VDF in particular PVDF and VDF-HFP copolymers
• CTFE homo- or copolymers of CTFE, in particular PCTFE (polychlorotrifluoroethylene) and ⁇ -CTFE (ethylene-chlorotrifluoroethylene copolymer).
• PCTFE polychlorotrifluoroethylene
• ⁇ -CTFE ethylene-chlorotrifluoroethylene copolymer
• the fluoropolymer is a homopolymer of VDF or a copolymer of VDF and at least one other fluorinated monomer.
• the fluorinated comonomer copolymerizable with VDF is chosen for example from vinyl fluoride; trifluoroethylene (VF3); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro (alkyl vinyl) ethers such as perfluoro (methyl vinyl) ether (PMVE), perfluoro (ethyl vinyl) ether (PEVE) and perfluoro (propyl vinyl) ether (PPVE); perfluoro (1,3-dioxole); perfluoro (2,2-dimethyl-1,3-dioxole) (PDD), and mixtures thereof.
• VF3 trifluoroethylene
• CTFE chlorotrifluoroethylene
• TFE tetrafluoroethylene
• HFP hexafluoropropylene
• perfluoro (alkyl vinyl) ethers
• the fluorinated comonomer is chosen from chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene (VF3) and tetrafluoroethylene. (TFE), and mixtures thereof.
• CTFE chlorotrifluoroethylene
• HFP hexafluoropropylene
• VF3 trifluoroethylene
• TFE tetrafluoroethylene.
• the mono-monomer is advantageously HFP because it copolymerizes well with VDF and provides good thermomechanical properties.
• the copolymer comprises only VDF and HFP.
• the fluoropolymer is a homopolymer of VDF (PVDF) or a VDF copolymer such as VDF-HFP containing at least 50% by weight of VDF, advantageously at least 75% by weight of VDF and preferably at least 90% by weight. mass of VDF.
• VDF VDF
• VDF-HFP VDF-HFP containing at least 50% by weight of VDF, advantageously at least 75% by weight of VDF and preferably at least 90% by weight. mass of VDF.
• VDF VDF
• VDF-HFP a VDF copolymer such as VDF-HFP containing at least 50% by weight of VDF, advantageously at least 75% by weight of VDF and preferably at least 90% by weight. mass of VDF.
• the fluoropolymer has a viscosity ranging from 100 Pa.s to 3000 Pa.s, the viscosity being measured at 230 ° C., at a shear rate of 100 s -1 using a capillary rheometer.
• this type of polymer is well suited to extrusion, preferably the polymer has a viscosity ranging from 500 Pa.s to 2900 Pa.s.
• the first white inorganic filler is zinc oxide (ZnO). It has a function of opacifier in the field of UV / visible, and acts as a solar filter so that the film prepared from the composition according to the invention is an opaque film, mainly by diffusion / reflection of UV rays, but also visible light.
• the ZnO content in the composition is between 5 and 30% by weight, advantageously between 10 and 20% by weight (limits included) relative to the total weight of the composition.
• the second white inorganic filler is titanium dioxide ( ⁇ O2). Like zinc oxide, titanium oxide has a function of opacifier in the field
• UV / visible plays a role of solar filter so that the film prepared from the composition according to the invention is an opaque film, mainly by diffusion / reflection of UV rays, but also to visible light.
• the TiO 2 content in the composition is between 3 and 7.5% by weight, advantageously between 3 and 6% by weight (limits included) relative to the total weight of the composition.
• the acrylic polymer is a homopolymer of methyl methacrylate (MMA) or a copolymer containing at least 50% by weight of MMA and at least one other monomer copolymerizable with MMA.
• Comonomer copolymerizable with MMA are alkyl (meth) acrylates, acrylonitrile, butadiene, styrene, isoprene.
• the acrylic polymer (homopolymer or copolymer of MMA) comprises, by weight, from 0 to 20% and preferably 5 to 15% of a (C 1 -C 8) alkyl (meth) acrylate, which is preferably the acrylate of methyl and / or ethyl acrylate.
• the acrylic polymer can be functionalized, that is to say that it contains, for example, acid, acid chloride, alcohol, anhydride functions.
• the functionality is in particular the acid function provided by the acrylic acid comonomer. It is also possible to use a neighboring two-functional acrylic acid monomer which can dehydrate to form an anhydride.
• the proportion of functionality may be from 0 to 15% by weight of the MMA polymer.
• the invention also relates to a method of manufacturing said composition, which comprises several steps.
• a first master batch containing zinc oxide (referred to as "master mix A”) is prepared by melt blending ZnO into a fluoropolymer having a viscosity of less than 1000 Pa.s at 230 ° C. for a shear of 100s-l. This makes it possible to obtain a good state of dispersion of the zinc oxide particles in the fluoropolymer.
• masterbatch B which is an acrylic masterbatch, is prepared by melt blending the Ti0 2 into an acrylic matrix. The TiO 2 content of this masterbatch B must be greater than 50% by weight, in order to maintain the final acrylic polymer level below 5%.
• the masterbatch A is then dispersed in a more viscous fluorinated matrix which makes it possible to obtain good mechanical properties before and after thermal aging.
• To this mixture is added the masterbatch B.
• the product thus obtained is then extruded so as to produce the thin films according to the invention.
• the invention in another aspect, relates to a monolayer film made from the composition described above.
• This film is opaque to UV and visible radiation while retaining very good dimensional stability properties at the temperatures used for the manufacture of a backsheet ("backsheet”) and subsequently a photovoltaic panel.
• o in the machine direction between 200 and 300;
• o in the cross direction between 180 and 270;
• o in the machine direction between 20 and 70;
• o in the cross direction between 10 and 60;
• o in machine direction less than or equal to 0.5;
• o in the cross direction less than or equal to 0.5.
• This film is opaque to UV and visible radiation and has a long-term stability, as shown by the damp heat test at 85 ° C and 85% humidity for 2000h, and by the UV aging.
• the film according to the invention does not have an acrylic odor.
• the film according to the invention can be manufactured by blown film extrusion ("blown film”) at a temperature ranging from 220 to 260 ° C.
• blown film blown film extrusion
• This technique consists in coextruding, generally from bottom to top, a thermoplastic polymer through an annular die.
• the extrudate is simultaneously pulled longitudinally by a pulling device, usually in rolls, and inflated by a constant volume of air trapped between the die, the pull system and the wall of the sheath.
• the inflated sheath is cooled generally by an air blowing ring at the outlet of the die.
• the nature of the first white inorganic filler (ZnO) and the presentation of the second white inorganic filler (TiO 2 ) in an acrylic matrix make it possible to obtain the film by the extrusion-blowing technique at temperatures of 220-260 ° C without causing degradation of the fluoropolymer present in said composition.
• This allows to keep intact the particular properties of this fluoropolymer, namely its very good resistance to weather, UV radiation and visible light, and chemicals.
• the film can also be manufactured by flat extrusion or "cast film”; this process consists in stretching a sheet or a polymer film in the air between a flat die and a thermostatic roll. It makes it possible to manufacture sheets of thickness between 0.2 mm and 2 mm and films with a thickness of less than 0.2 mm.
• Another method used to manufacture the film according to the invention is the casting-evaporation or "solvent casting” process. This is a process where pigments and a polymer are dissolved. This solution which contains the dissolved polymer and the dispersed pigments is then deposited on a support. The solvent is then evaporated under vacuum and heated to allow formation of the film containing the pigments. The support is then removed and the film wound. The final thickness of the film depends on the thickness of the deposited solution and its solids content.
• the subject of the invention is the use of this film for the manufacture of the rear face in a photovoltaic panel.
• the film according to the invention undergoes at first on both sides a surface treatment of Corona type. Then, it is hot rolled on each side of a PET sheet previously induced with adhesive. One of the faces of the laminate thus obtained is then pressed onto a film of the EVA type, the other face of the latter being glued against a cleaned glass plate.
• This structure can be used as a backsheet in a photovoltaic cell.
• the film according to the invention is opaque (low transmission of visible light and UV rays) and also has a protection against oxygen penetration.
• the structure retains a beautiful aesthetic appearance of film (no yellowing over time) as well as excellent fire resistance.
• the fluoropolymer-based film according to the invention has good heat resistance (low shrinkage in volume when subjected to high temperatures) as well as excellent resistance to solvents present in the adhesives and adhesives used for the construction of photovoltaic cells, and more particularly the back panel of the cells. This structure is therefore perfectly suited to protect the rear panel of photovoltaic cells (backsheet).
• the film according to the invention is opaque to UV radiation (up to 395 nm) and very slightly transparent in the visible (the transmittance is less than 25% at 450 nm), and this for a film of lower thickness at 20 ⁇ and having a density of less than 2100 kg / m3.
• the resulting film also has a yellowness index of less than 4.
• the shrinkage of the film is measured according to the ISO 11501 standard. A piece of 20cm x 20cm square film is placed in a ventilated oven at 150 ° C for 30min. Then, the dimensions are measured again. The shrinkage is then evaluated by the variation of each of the dimensions, relative to the initial dimension.
• the UV accelerated aging test is carried out in QUV, applying to the sample the following conditions: 8 hours of QUV B 313 (UV-B lamps at 313 nm) at 60 ° C, 0.89 W / m 2 / nm then 4 hours at 45 ° C, with condensation of water on the sample. This test is performed for 2000 hours.
• the test is performed in a climatic chamber where a temperature of 85 ° C and 85% humidity are maintained. After 2000 h, the samples are taken and analyzed.
• This masterbatch A is mixed in a BUSS co-kneader at 230.degree. C. (speed of the comaraxer 200 rpm and speed of the recovery screw 60 rpm) with another homopolymer of the company ARKEMA, the KYNAR 740 (MFI from 3 to 230 ° C. under 10 kg, viscosity 2000 Pa.s at 230 ° C. under 100 sec -1) and with an acrylic masterbatch (the masterbatch B composed of 40% BSMA PMMA 505 from the company ARKEMA and 60 % Ti0 2 of type R960).
• the mixture thus produced contains 54.2% of Kynar 740, 8.3% of masterbatch B and 37.5% of masterbatch A. Its mass composition is as follows: 15% ZnO, 4.98% Ti0 2 and 3 , 32% acrylic.
• the product thus obtained is then extruded on a sheath extrusion line from Dr. Collin GmbH, Ebersberg, Germany.
• the extrusion temperature is 240 ° C
• the inflation rate is 2.5.
• the produced film has a width of 250 mm and a thickness of 18 ⁇ and a density of 2.01. This film exhibits a total opacity in the UV zone up to 395 nm and a transmittance of 22% at 450 nm.
• This film is then laminated on a biaxially oriented PET of 250 ⁇ using a glue from the company BOSITK, a mixture of HBTS EPS 877 and BOSCODUR 1621. A thickness of 8 ⁇ of adhesive is used and post-crosslinking is carried out for 60 hours.
• This master mix A is mixed in a BUSS co-kneader at 230 ° C. (speed of the comaraxer 200 rpm and speed of the recovery screw 60 rpm) with another homopolymer of the company ARKEMA KYNAR 740 (MFI 3 at 230 ° C. under 10 kg, viscosity 2000 Pa.s at 230 ° C. under 100 s-1) and with a masterbatch B composed of 40% BSMA PMMA 505 from the company ARKEMA and 60% TiO 2 of type R960.
• the mixture thus produced contains 50.8%> Kynar 740, 11.7% masterbatch mixture B and 37.5% masterbatch A. Its composition by weight is as follows: 15% ZnO, 7.02% Ti0 2 and 4.68% acrylic.
• the product thus obtained is then extruded on a sheath blowing extrusion line from Dr. Collin GmbH.
• the extrusion temperature is 240 ° C
• the inflation rate is 2.5.
• the produced film has a width of 250 mm and a thickness of 18 ⁇ and a density of 2.02.
• This film has a total opacity in the UV zone up to 395 nm and a transmittance of 18% at 450 nm.
• This film is then laminated on a biaxially oriented PET of 250 ⁇ using a glue from the company BOSITK, a mixture of HBTS EPS 877 and BOSCODUR 1621.
• a thickness of 8 ⁇ of adhesive is used and post-crosslinking is carried out for 60 h at 60 ° C.
• This masterbatch A ' is mixed in a BUSS co-kneader at 230 ° C. (speed of the comixer 200 rpm and speed of the recovery screw 60 rpm) with another homopolymer of the company ARKEMA KYNAR 740 (MFI from 3 to 230 ° C. under 10 kg, viscosity 2000 Pa.s at 230 ° C. under 100 sec -1).
• the mixture thus produced contains 50% of Kynar 740 and 50% of masterbatch A '.
• the product thus obtained is then extruded on a sheath blowing extrusion line from Dr. Collin GmbH.
• the extrusion temperature is 240 ° C
• the inflation rate is 2.5.
• the produced film has a width of 250 mm and a thickness of 18 ⁇ and a density of 2.00.
• This film has a total opacity in the UV zone up to 375 nm and a transmittance of 18% at 450 nm.
• This film is then laminated on a bioriented PET of 250 ⁇ using a glue of the company
• BOSITK mixture of HBTS EPS 877 and BOSCODUR 1621.
• a thickness of 8 ⁇ of adhesive is used and post-crosslinking is carried out for 60 h at 60 ° C of the laminate. After this step of firing the adhesive, an adhesion of 8 N / cm is measured.
• the laminate obtained is then placed in a climatic chamber at 85 ° C. and 85% relative humidity. After 2000 h no delamination is obtained and no yellowing is observed. This same laminate after a UV aging test as described above has totally lost its opacity in the visible and UV range, and a strong yellowing is observed.

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• 2010
  • 2010-10-13 FR FR1058328A patent/FR2966158B1/fr not_active Expired - Fee Related
• 2011
  • 2011-09-30 US US13/879,138 patent/US20130319510A1/en not_active Abandoned
  • 2011-09-30 CN CN2011800599031A patent/CN103261312A/zh active Pending
  • 2011-09-30 EP EP11779770.4A patent/EP2627705A1/de not_active Withdrawn
  • 2011-09-30 WO PCT/FR2011/052287 patent/WO2012049397A1/fr active Application Filing
  • 2011-09-30 JP JP2013533255A patent/JP2013545831A/ja not_active Withdrawn
  • 2011-09-30 KR KR1020137012054A patent/KR20130141521A/ko not_active Application Discontinuation
  • 2011-10-07 TW TW100136461A patent/TW201231539A/zh unknown

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