RU2508202C2 - Fluorocarbon polymer protective sheet containing powder filler - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: film incorporates first and third layers of fluorocarbon polymer moulded from the mix with water or other solvent and powder filler. Second layer is made from polyimide, polycarbonate, titanium, steel or aluminium. Films are used in electronic devices where electronic component and film are packed together.

EFFECT: higher dielectric rigidity, water resistance, opacity and reflection capacity.

30 cl, 8 ex

Description

FIELD OF TECHNOLOGY

[001] The present invention relates generally to films and multilayer films that are suitable as packaging materials having at least one particle immersed in a film, and methods for their manufacture.

BACKGROUND

[002] Multilayer films or laminates are structures that attempt to combine the properties of dissimilar layers in order to provide improved performance compared to single materials. Desirable properties for multilayer films include moisture, vapor barrier, weathering resistance, breakdown strength, electric current resistance, surface reflectivity, opacity, two-sided color, or other two-sided electromagnetic spectral effects.

[003] Up to the present invention, such laminates often result in an imbalance of properties, are expensive or difficult to handle or process. Adding material to improve one property may result in a concomitant loss of another property.

[004] In the growing field of application of protective films for packaging for electronic devices, it is imperative to provide a well-developed economic balance of the required properties. For example, protective films as a substrate for solar cells should provide a combination of properties, such as moisture protection, good dielectric strength, high opacity and / or reflectivity. Obtaining these properties in multilayer films was difficult or expensive.

[005] In particular, monitoring properties using a widely used method of adding a suitable filler has often led to the improvement of one property with the deterioration of another. For example, the addition of a light-insulating filler at the levels necessary to obtain a high level of opacity can lead to an undesirable increase in moisture and vapor permeability. Similarly, the addition of a high level of light-insulating filler may lead to an undesirable decrease in dielectric strength. In another example, the addition of filler to increase the reflection coefficient of the film may result in a multilayer film surface that does not adhere well when connected to a photovoltaic device. Previous films, as a rule, provided one or two necessary properties of protective films for electronic devices, but were not able to provide a higher level of combined protection.

[006] Moreover, when fillers are added to melt extruded multilayer films, it can be difficult to disperse them, requiring significant mixing, resulting in an increase in processing time and cost.

[007] Accordingly, there is a need for multilayer films that can be adapted to provide one or more improved properties to a photovoltaic sheet. There is also a need for multilayer films adapted for other protective applications, such as a protective wrap for applications in the field of wires or cables, or protective films for other optoelectronic devices such as OLED.

SUMMARY OF THE INVENTION

[008] The present invention discloses multilayer films and methods for producing such multilayer films that overcome one or more of the disadvantages known from the prior art. It was found that it is possible to create and use multilayer films having characteristics, for example, suitable for packaging materials for electronic devices. These films help protect components from heat, moisture, chemicals, radiation, physical damage, and general wear. Such packaging materials help electrically isolate the active components / circuits of electronic devices. Additionally, such materials provide protective cushioning to electronic devices, such as photovoltaic devices, provide pollution-preventing properties, chemical resistance, UV resistance, reflectivity, increased fire resistance, aesthetics and / or opacity.

[009] In one aspect, the invention discloses an injection composition that includes a carrier fluid; polymer resin matrix material; powder filler material; and where the polymer matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film, which includes variable percentages of the filler material, expressed in volume percent.

[010] It has been unexpectedly discovered that by selecting one or more parameters from the size of the powder filler, such as a particular filler and / or volume percentage of the filler material, the opacity of the film can be controlled, while providing an aesthetically pleasing appearance and also ensuring the integrity of the film. Typically, with the inclusion of a smaller amount of powder filler, an improvement in film integrity is observed while maintaining opacity. Lower levels of powder filler may also provide lower moisture permeability or improve dielectric strength. Therefore, in certain embodiments, it is preferable to have less than 15 volume percent of the filler present in the final film.

[011] It is interesting, however, that it was found that there is a balance of factors with a control of the volume percentage of the filler. Particle size can also affect the integrity of the film, and in some aspects, the operator will select filler material (s), where none of the individual linear particle sizes will be more than 10 microns and can be from nanometer (nm) to about 100 nm, for example 0.1 μm. In another aspect, the powder filler may have a separate size from 100 nm to 2 μm. In other aspects, some of the powder fillers may have discrete linear dimensions greater than 10 microns.

[012] The choice of the particle itself can help improve the integrity of the film and its physical properties, such as opacity, water vapor permeability, IR reflectivity, and dielectric constant. A particle may be one of, or a mixture of, particles of the following: silicon dioxide, aluminum silicates, glass granules, glass microspheres, fiberglass, particles of titanium dioxide, particles of barium titanate, calcium carbonate, zinc oxide, mica, clay, such as kaolin or others, mullite, talc, iron oxide, carbon black, zinc sulfide, barium sulfate, zinc sulfite, a number of pigments such as blue cobalt aluminate, sodium aluminosilicate, combustion inhibitors such as magnesium hydroxide, antimony trioxide, organophosphorus compounds or bromine grammed compounds or other particles suitable for the intended application. In some embodiments, the implementation of the particle size may be from about 100 nanometers (nm) to about 2 microns (microns).

[013] In another aspect, the particle may be reflective in the infrared or spectral region. Particles of this type can be effective in reducing IR absorption and subsequent heat generation in the film, while at the same time providing the same range of color alternatives in the visible spectrum. Such IR reflective pigments include Arctic Black 10C909, Black 411, Yellow 193, Brown 12 and Brown 8 from Shepherd Color Company, Cincinnati, Ohio, and V-780 Black, V-778 Black, PC-9415 Yellow, V-9248 Blue, V-13810 Red and V-12600 Camouflage Green from Ferro Corporation, Cleveland, Ohio.

[014] In another aspect, the invention discloses films from an injection composition.

[015] In another aspect, this invention discloses methods for producing films and multilayer films disclosed herein.

[016] In yet another aspect, the invention discloses a photovoltaic device that includes a photovoltaic component that is protected (for example, in contact with) with the film or multilayer film of the present invention.

[017] It should be understood that the multilayer films of this invention may include from 2 layers to about 12 layers of material. For example, multilayer films may repeat layering of the first layer and second layer, etc. An outer layer or two outer layers may be included in the construction of the multilayer film. The outer layers, for example, may be a fluoropolymer or a non-fluoropolymer. Additionally, combinations of different layers are included herein, for example, a first layer, a second layer, a third layer different from the first or second layers, and a fourth layer that is different from the first, second or third layers, etc. This layering, moreover, can be repeated if necessary for the intended application.

[018] The multilayer films typically have a dielectric breakdown strength (kV) that is greater than 3 kV, measured using the ASTM method (American Society for Testing Materials) D3755, solar energy reflection coefficient, which is more than 70% when measured using the method ASTM E424, or water vapor permeability, which is less than 20 g / m ² / day, measured using the ASTM F1249 method, in the case where the multilayer film has a thickness of from about 0.8 millimeters to about 2.0 millimeters, for example, about 1.1 inch.

[019] The present invention also provides methods for producing the multilayer films mentioned herein.

[020] In addition, an object of the present invention is an electronic device in which the electronic component is packaged in a multilayer film made in accordance with the present invention or the film is fake for such a component. Although multiple embodiments are disclosed, other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description. As will become apparent, the invention is capable of modifications in various obvious aspects, while all do not deviate from the essence and scope of this invention. Accordingly, detailed descriptions should be considered illustrative in nature and not restrictive.

DETAILED DESCRIPTION OF THE INVENTION

[021] In the description and claims, the expressions "including" and "comprising" are unlimited expressions and should be interpreted with the meaning "including, but not limited to the following. ...". These expressions include the more restrictive expressions "consisting essentially of" and "consisting of." [022] It should be noted that the singular forms used in this document and in the claims include a reference to the plural form, unless the context clearly dictates otherwise. In addition, the expressions “certain” (or “some”), “one or more” and “at least one” can be used interchangeably herein. It should also be noted that the expressions “comprising,” “including,” “characterized,” and “having” may be used interchangeably.

[023] Unless otherwise indicated, all technical and scientific expressions used herein have the same meanings as are commonly understood by one of skill in the art to which this invention pertains. All publications and patents specifically mentioned in this document are incorporated by reference in their entirety for all purposes, including the description and disclosure of chemical compounds, tools, statistical analyzes and techniques that are reported in publications that can be used in connection with this invention . All references cited in this description of the invention should be construed as indicating the level of knowledge in the art.

[024] The present invention includes various embodiments. In a first embodiment, the invention relates to an injection composition comprising:

[025] a carrier fluid;

[026] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material (polymer resin or polymer matrix);

[027] a filler powder material, where some of the particles of the filler powder material have a separate linear size of more than 10 μm; and where the polymeric matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising more than 15 volume percent of the filler material.

[028] In a second embodiment, the invention relates to an injection composition comprising:

[029] a carrier fluid;

[030] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[031] a filler powder material, where some of the particulate filler material particles have a separate linear size of more than 10 μm; and where the polymer matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising less than 15 volume percent of the filler material.

[032] In a third embodiment, the invention relates to an injection composition comprising:

[033] a carrier fluid;

[034] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[035] a powder filler material, where none of the particles of the powder filler material has a separate linear size of more than 10 microns; and where the polymer matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising less than 15 volume percent of the filler material.

[036] In a fourth embodiment, the invention relates to an injection composition comprising:

[037] a carrier fluid;

[038] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[039] a filler powder material, where some of the particulate filler material particles have a separate linear size of more than 10 μm; and where the polymeric matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising more than 15 volume percent of the filler material.

[040] In a fifth embodiment, the invention relates to an injection composition comprising:

[041] a carrier fluid;

[042] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[043] a filler powder material, where some of the particles of the filler powder material have a separate linear size of more than 10 μm; and where the polymer matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising less than 15 volume percent of the filler material.

[044] In a sixth embodiment, the invention relates to an injection composition comprising:

[045] a carrier fluid;

[046] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[047] a filler powder material, wherein none of the particulate filler material particles has a separate linear size greater than 10 μm; and where the polymeric matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising more than 15 volume percent of the filler material.

[048] In a seventh embodiment, the invention relates to an injection composition comprising:

[049] a carrier fluid;

[050] a non-fibrous, oil-fluoropolymer or fluoropolymer matrix material;

[051] a powder filler material, where none of the particles of the powder filler material has a separate linear size of more than 10 microns; and where the polymer matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising less than 15 volume percent of the filler material.

[052] After removal of the carrier, and optionally other additives discussed herein, films are obtained. Films may be part of the multilayer film designs described herein.

[053] In an eighth embodiment, the invention relates to an injection composition comprising:

[054] a carrier fluid;

[055] a non-fibrous oil fluoropolymer matrix material;

[056] a filler powder material, wherein none of the particulate filler material particles has a separate linear size greater than 10 μm; and where the polymeric matrix material and the powder filler material are included in the composition in relative amounts effective to produce a dry composite film comprising more than 15 volume percent of the filler material.

[057] It should be understood that the third layer can be placed on the second layer with the formation of the composite. The second layer is sealed by the first and third layers. The third layer may not be a fluoropolymer or a fluoropolymer, which is also obtained from a cast solution.

[058] Therefore, the present invention also discloses injection compositions, methods for producing molded multilayer films from these compositions, and multilayer films formed from these compositions. The multilayer films may include a first outer layer, as described above, containing a molded polymer in water or a solvent polymer, for example a fluoropolymer, a second inner layer, as described above, located on the first layer, the second layer containing a molded polymer in water or a solvent polymer for example, a fluoropolymer or mixtures thereof, and a filler powder material, as described above, and a third outer layer located on a second layer containing a molded polymer in water or a solvent, the polymer, as described above, for example er, a fluoropolymer, or a mixture of them.

[059] Basically, the first outer layer has a thickness of from about 0.01 millimeters to about 0.7 millimeters, more specifically from about 0.02 millimeters to about 0.4 millimeters, and most specifically from about 0.05 millimeters to about 0 , 3 millimeters.

[060] The second inner layer typically has a thickness of from about 0.1 millimeter to about 0.8 millimeter, more particularly from about 0.2 millimeter to about 0.4 millimeter, and most specifically from about 0.3 millimeter to about 0.4 millimeters.

[061] The third outer layer has, for example, a thickness of from about 0.01 millimeters to about 0.7 millimeters, more specifically from about 0.02 millimeters to about 0.4 millimeters, and most specifically from about 0.05 millimeters to about 0 , 3 millimeters.

[062] Subsequent layers, for example, the fourth and fifth layers, can have a thickness of from about 0.01 millimeters to about 0.7 millimeters, more specifically from about 0.02 millimeters to about 0.4 millimeters, and most specifically from about 0, 05 millimeters to approximately 0.3 millimeters.

[063] It is understood that the phrase "multilayer" film includes multiple layers of film (s) in contact with each other. At least two layers are present, although three layers are especially desirable. Additional layers may be included in the multilayer film, so that the multilayer film may include 4, 5, 6-12, etc. layers.

[064] It is understood that the phrase "molded polymer" means a fluoropolymer or not a fluoropolymer capable of dispersing, dissolving, suspending, emulsifying or otherwise distributed in a carrier fluid. The carrier fluid medium may be water, an organic solvent, or any other liquid in which the polymer can be dispersed, dissolved, suspended, emulsified or otherwise distributed. The carrier fluid may be a mixture of suitable fluids. Distributed in the medium of the carrier, the polymer and the medium are then capable of being placed or cast onto a carrier material to form a film. The polymer (s) can be mixed with the first carrier fluid. The mixture may include a dispersion of polymer particles in a first carrier fluid, an emulsion of polymer liquid droplets or a monomeric or oligomeric polymer precursor in a first carrier fluid, or a solution of the polymer in a first carrier fluid.

[065] The molded polymer (s) may (may) also be a monomeric or oligomeric polymer precursor distributed within the carrier fluid. Most often cast compositions are emulsions or dispersions in aqueous media.

[066] The choice of the first carrier fluid is based on the particular polymer and the form in which the material is to be incorporated into the molding composition of the present invention. If a solution is desired, the solvent for the particular fluoropolymer is selected as a carrier fluid. Suitable carriers include, for example, DMAC, NMP, cellosolve or water and the like. If a dispersion is desired, then a suitable carrier is one in which the polymer does not dissolve. The aqueous solution will be a suitable carrier fluid for dispersion of polymer particles.

[067] Most often, molded compositions are emulsions or dispersions in aqueous media. Surfactants can be used to obtain the dispersion in an amount effective to modify the surface tension of the carrier fluid so as to allow the carrier fluid to wet the filler particles. Suitable surfactants include ionic surfactants, amphoteric, cationic and nonionic surfactants.

[068] In one illustrative embodiment, a mixture of a polymer, a carrier fluid and a dispersion of filler particles in a second carrier fluid is combined to form an injection composition.

[069] Fluoropolymers are typically selected as external layers in order to provide resistance to chemical compounds, electrical insulation, resistance to weathering and / or moisture barrier.

[070] The term "fluoropolymer" is known in the art and is intended to include, for example, polytetrafluoroethylene (PTRE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), polyvinyl fluoride (PVF), tetrafluoroethylene / hexafluoropropylene (ethylene / ethylene (ethylene) / ethylene (ethylene fluoropropylene) copolymer , chlorotrifluoroethylene / vinylidene fluoride copolymer, chlorotrifluoroethylene / hexafluoropropylene, ethylene / chlorotrifluoroethylene (ECTFE) copolymers, ethylene / trifluoroethylene copolymers, ethylene / tetrafluoroethylene (ETFE) copolymers, tetrafluoroethylene / P propylene copolymers, TFE retilena / hexafluoropropylene (FEP), copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA, e.g., tetrafluoroethylene and perfluoro (propyl vinyl ether), polyvinylidene difluoride, copolymers of hexafluoropropylene / tetrafluoroethylene / vinylidene (i.e., THV) and mixtures thereof.

[071] The fluoropolymer may be melt processable, for example, as in the case of polyvinylidene difluoride; vinylidene difluoride copolymers; copolymers of tetrafluoroethylene, hexafluoropropylene and vinylidene difluoride; copolymers of tetrafluoroethylene and hexafluoropropylene; and other fluoroplastics processed in the melt; or the fluoropolymer may not be melt processable, for example, as in the case of polytetrafluoroethylene, TFE copolymers and low levels of fluorinated vinyl esters) and cured fluoroelastomers.

[072] Examples of commercially available THV polymers include those sold by Dyneon, LLC under the trade names "DYNEON THV 2030G FLUOROTHERMOPLASTIC", "DYNEON THV 220 FLUOROTHERMOPLASTIC", "DYNEON THV 340C FLUOROTHENOPLOTORENTERFLEUTENTER FLOWERTER THERMOTLASTORNTERNUTLENTER 500 THERMAL PERFORMANCE , "DYNEON THV 610G FLUOROTHERMOPLASTIC" or "DYNEON THV 810G FLUOROTHERMOPLASTIC".

[073] Examples of commercially available NTE polymers include those sold, for example, under the trade name "DYNEON FLUOROTHERMOPLASTIC HTE" (eg, "DYNEON FLUOROTHERMOPLASTIC HTE X 1510" or "DYNEON FLUOROTHERMOPLASTIC HTE X 1705") from Dyneon, LLC.

[074] Examples of commercially available vinylidene difluoride-containing fluoropolymers include, for example, those fluoropolymers that have trade names; "KYNAR" (e.g., "KYNAR 740") sold by Atofina, Philadelphia, PA .; "HYLAR" (e.g., "HYLAR 700") sold by Ausimont USA, Morristown, NJ; and "FLUOREL" (e.g., "FLUOREL FC-2178") sold by Dyneon, LLC.

[075] Examples of commercially available copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) include those sold, for example, under the trade name "Hyflon PFA" or "Hyflon MFA" from Solvay Solexis; and "Teflon PFA" by E.I. du Font de Nemours & Company.

[076] Examples of commercially available vinyl fluoride fluoropolymers include those vinyl fluoride homopolymers sold under the trade name "TEDLAR" from E.I. du Pont de Nemours & Company, Wilmington, Delaware.

[077] Examples of commercially available (TFE / P) polymers include those sold under the trade name "AFLAS" (for example, "AFLAS TFE ELASTOMER FA 100H", "AFLAS TFE ELASTOMER FA 150C", "AFLAS TFE ELASTOMER FA 150L" or "AFLAS TFE ELASTOMER FA 150P "), which are sold by Dyneon, LLC, or" VITON "(for example," VITON VTR-7480 "or" VITON VTR-7512 "), which are sold by EI du Pont de Nemours & Company, Wilmington, Delaware.

[078] Examples of commercially available ETFE polymers include, for example, those sold under the trade names "DYNEON FLUOROTHERMOPLASTIC ET 6210J", "DYNEON FLUOROTHERMOPLASTIC ET 6235" or "DYNEON FLUOROTHERMOPLASTIC ET 6240J" from Dyneon, LLC.

[079] Examples of commercially available ECTFE polymers include the Halar 350 and Halar 500 resins sold under the trade designation from Solvay Solexis Corp.

[080] Alternatively, the polymer matrix material of this invention may include a thermoplastic or thermoset polymer other than a fluoropolymer. Suitable alternative polymeric matrix materials include polyolefins and their copolymers, such as polyethylene, polypropylene, polyethylene, polymethylpentene and polybutadiene, epoxy resins, phenolic resins, cyanoic acid esters, polyesters, polyamides, polycarbonates, polyimides, polyacrylic resins, polymethacrylic resins, thermoplastics olefins, ethylene vinyl alcohol (EVOH), ethylene vinyl acetate (EVA), ethylene methacrylate (EMA), thermoplastic urethanes, thermoplastic silicones, ionomers, ethyl butyl acrylate (EVA), watering Inyl butyral (PVB), Class M ethylene propylene diene rubbers (EPDM), or mixtures thereof.

[081] The filler powder material of the present invention may include any organic or inorganic powder material. As used herein, the terms “powder” and “particles” are intended to include fibers and flakes. Suitable inorganic filler materials include, for example, glass particles, ceramic particles, metal particles, carbon particles and mineral particles. Specific examples of suitable particles and flakes include glass granules, glass microspheres, fiberglass, silica particles, carbon black, titanium dioxide particles, iron oxide particles, aluminum particles and barium titanate particles. Silica particles, in particular amorphous fused silica particles and silica particles obtained by the sol-gel process, and glass particles are useful, for example, dielectric layers of plate electric circuits, if necessary with a low dielectric constant.

[082] The shape of the filler particles, the particle size of the filler, and the particle size distribution of the filler may be important parameters regarding the characteristics of the particle-filled composite product of this invention. For example, plate-shaped pigments can cause light interference and other optical effects. Such particles may include oxide complexes as mica-coated iron or other metal (e.g., Taizhu TZ2013 violet from Wenzhou Pearlescent Pigments Co, Taizhou, China; and Xirallic T60-10 WNT crystalline silver from Merck KGaA, Darmstadt, Germany).

[083] In one embodiment of the present invention, all powder filler particles have a diameter of less than about 10 microns (microns).

[084] In an alternative preferred embodiment of the present invention, each of the filler particles has a separate linear size of not more than about 10 microns.

[085] In another embodiment, the particulate filler particles include some particles that have a separate linear size greater than 10 microns. The percentage of particles that have a separate linear size of more than 10 microns, relative to particles that have a separate linear size of less than 10 microns, can be from 0.01% to about 50%, from about 0.1% to about 20%, or from about 1% to about 10% of the total number of particles. The linear size can be from about 11 microns to about 50 microns, from about 15 microns to about 20.

[086] As indicated previously, it has been unexpectedly discovered that the inclusion of particles that have a separate linear size of more than 10 μm can help to provide unique properties to the final film. They include increased tensile strength, greater opacity (than that without large particles) or reduce water vapor permeability.

[087] Also, the particle does not need to be spherical. In one aspect, the particle may be oblong, also known as “lamellar” in the prior art.

[088] In one aspect of the present invention, each of the filler particles is essentially spherical.

[089] In another aspect of the present invention, the filler particles of the film are not uniform in size. The use of uneven particle sizes can provide an unexpected advantage in light scattering and provide a more uniform distribution of particles. Typically, the particles have an average particle size of from about 0.1 microns to about 20 microns, with about 80% of the particles having a narrow particle size range from about 0.2 microns to about 5 microns.

[090] The filler powder material can be surface-treated in order to improve moisture resistance, particle dispersion, matrix adhesion or IR reflectance, film UV resistance and / or mechanical properties of the composite film of the present invention. For example, certain forms of TiO _{2 are} passivated, otherwise they would be photocatalytic.

[091] Suitable hydrophobic coatings suitable for treating particles of the present invention may include any coating material that is thermally stable, exhibits low surface energy and increases the moisture resistance of the composite of the present invention. Suitable coating materials include traditional silane coatings, titanium coatings and zirconate coatings.

[092] The polymer matrix material of this invention is mixed with a first carrier fluid. The mixture may include a dispersion of polymer particles in a first carrier fluid, a dispersion, namely an emulsion, liquid droplets of a polymer or a monomeric or oligomeric polymer precursor in a first carrier fluid, or a solution of the polymer in a first carrier fluid.

[093] The selection of the first carrier fluid is based on the particular polymer matrix material and the form in which the polymer matrix material is to be incorporated into the molding composition of the present invention. If a solution is desired, then the solvent for the particular polymer matrix material is selected as the carrier fluid. Suitable carriers include, for example, DMAC, NMP, cellosolve or water and the like. If dispersion is desired, then a suitable carrier is one in which the matrix material is insoluble. The aqueous solution may be a suitable carrier fluid for dispersion of fluoropolymer particles.

[094] the Dispersion of the powder filler of the present invention may be in a suitable second carrier fluid in which the filler is insoluble.

[095] To obtain the dispersion, surfactants can be used in an amount effective to modify the surface tension of the second carrier fluid so that the second carrier fluid can wet the filler particles. Suitable surfactants include ionic surfactants, amphoteric, cationic and nonionic surfactants.

[096] In one illustrative embodiment, the mixture of the polymer matrix material and the first carrier fluid and the dispersion of filler particles in the second carrier fluid are combined to form an injection composition. Typically, the injection composition has from about 10 to about 90 weight percent solids (based on particles and polymer matrix), from about 20 to about 70 weight percent, or from about 25 to about 50 weight percent.

[097] The viscosity of the injection composition of the present invention can be adjusted by adding suitable viscosity modifiers. Such modifiers include polyacrylic acid compounds, vegetable gums, and cellulose-based compounds. Specific examples of suitable viscosity modifiers include polyacrylic acid, methyl cellulose, polyethylene oxide, guar gum, locust bean gum, sodium carboxymethyl cellulose, sodium alginate and tragacanth gum.

[098] Typically, the molded composition has from about 10 to about 90 weight percent solids (based on particles and / or polymer), from about 20 to about 70 weight percent, or from about 25 to about 50 weight percent.

[099] Typically, a filler powder material may be present within the cast polymer layer in a range from about 0 vol.% To about 60 vol.%.

[0100] In one aspect, a particulate filler material is present from about 2% to about 50%, for example, from about 8 vol.% To about 25 vol.% Of the total volume of the multilayer film. In another aspect, a particulate filler material is present from about 9 vol.% To about 15 vol.% Of the total volume of the multilayer film. It should be understood that subranges are included herein that fall within the range of 0% to about 60%, including ranges that are fractional. That is, from about 0.5% to about 5.5%, from about 0.6 to about 10.3%, etc. All ranges are included in this document. Enumerations of numerical ranges using finite values include all numbers related to a given range (for example, 1-5 includes 1, 1,5, 2, 2,75, 3, 3,80, 4, 5, etc.).

[0101] The viscosity of the injection composition of this invention can be adjusted by adding suitable viscosity modifiers. Such modifiers include polyacrylic acid compounds, vegetable gums, and cellulose-based compounds. Specific examples of suitable viscosity modifiers include polyacrylic acid, methyl cellulose, polyethylene oxide, guar gum, locust bean gum, sodium carboxymethyl cellulose, sodium alginate and tragacanth gum.

[0102] To obtain a film, a layer of the composition is poured onto the substrate by conventional methods, for example, by dipping, by reversing the roller, by using a knife roller, by applying a squeegee above the sheet, and by using a metering rod.

[0103] Suitable base materials include, for example, metal films, polymer films or ceramic films. Specific examples of suitable substrates include stainless steel foil, polyimide films, polycarbonate films, titanium, aluminum or fluoropolymer films.

[0104] In the injection method, which is described in detail in US patent No. 4883716, the contents of which are included in this document in its entirety, films are formed by injection molding on a conveyor belt having a low heat capacity. The carrier tape is part of an injection device. The carrier tape is immersed in a fluoropolymer matrix material / specific dispersion of the filler material in the immersion boiler at the base of the casting tower, so that a dispersion coating forms on the carrier tape. The coated carrier tape then passes through a dosing zone in which the metering slides remove excess dispersion from the coated carrier tape. After the dosing zone, the coated carrier tape passes into a drying zone at which a temperature is maintained sufficient to remove the carrier liquid from the dispersion, resulting in a dried film. The dried film carrier tape then passes to a heat treatment zone / melting zone in which the temperature is sufficient to combine or fuse the fluoropolymer and particulate in the dispersion. As a result, the carrier tape passes through the ventilation cooling chamber, from which it can be directed either to the subsequent boiler for immersion with the beginning of the formation of the next layer of the subsequent film, or to a separating device. The method can be repeated as many times as necessary, as a rule, providing up to 7 layers, for example, 5 layers, 3 of which are layers of a fluoropolymer matrix material / specific filler material, and 2 are external layers of one fluoropolymer or several fluoropolymers.

[0105] In the following injection method, the coated film can remain on the carrier substrate, so that a combined structure of the base and the cast film is obtained. Examples of this may include a fluoropolymer and a polyimide base, an aluminum base, a titanium base, a steel base or a polycarbonate base. In the following example, a separate backing film can be introduced between the applied injection composition and the carrier tape so that a molded fluoropolymer film is formed on this basis. In one example, a base, a polyimide film, an aluminum sheet, a titanium sheet, a steel sheet, or a polycarbonate film can be attached to a carrier tape, and an injection composition can be applied to the base. The injection composition can thus be applied to both surfaces of the substrate so that the substrate is coated on the upper side and the lower side. Suitable designs include, for example, a first molded fluoropolymer / aluminum / second molded fluoropolymer, which may be the same or different from a first molded fluoropolymer (e.g. PTFE / Al / PTFE), a first molded fluoropolymer / polyimide / second molded fluoropolymer, which may be the same or different from the first molten fluoropolymer (e.g., PEP / polyimide / PEP), and the first molten fluoropolymer / polycarbonate / second molded fluoropolymer, which may be the same or different from the first molded fluoropolymer (E.g., PVDF / polycarbonate / PVDF).

[0106] Other alternative warp films may be used depending on the processing temperatures required for the applied fluoropolymer injection composition. Fluoropolymer compositions with lower melting points may use lower temperature bases.

[0107] In one example, a carrier fluid and processing aids such as a surfactant and / or viscosity modifiers are removed from the cast layer by evaporation and / or thermal degradation to form a film of a polymer matrix material and a powder filler. In one aspect, a composite polymer matrix film with a powder filler material of the present invention is prepared by heating a cast film to evaporate a carrier fluid.

[0108] A film of a polymer matrix material and a powder filler may be further heated to modify the physical properties of the film. This may include subsequent film hardening.

[0109] In one aspect, the multilayer film has three layers. The first outer layer is a molded fluoropolymer, the second inner layer is a molded fluoropolymer with powder filler, which is described herein, and the third outer layer is a molded fluoropolymer. In another aspect, either of the two or both of the first and third outer layers together may comprise from about 0.01% to about 12% by volume of a powder filler, and in particular from about 0.01% to about 6% by volume .

[0110] In another aspect, the fourth layer may be located on the first layer. The fourth layer is a molded fluoropolymer, which is described in this document. In yet another aspect, the fifth layer may be located on the third layer. The fifth layer is a castable fluoropolymer as described herein. Ideally, the fourth and fifth layers are selected from copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA) or copolymers of fluorinated ethylene and propylene (FEP) or mixtures thereof. Additionally, the fourth and / or fifth layers may include mixtures of PTFE with PFA or FEP.

[0111] The fourth and fifth layers may further include a specific filler, which is described herein. Any of two or both of the fourth and fifth outer layers together may comprise from about 0.01 vol.% To about 12 vol.% Powder filler and, in particular, from about 0.01% to about 6 vol.%.

[0112] In one aspect, the outer layers of the multilayer film can be made of melt-bonded fluoropolymer. Suitable melt-bonded materials include, for example, copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether), or copolymers of fluorinated ethylene and propylene (FEP), or mixtures thereof.

[0113] The method of this invention provides films having thicknesses below about 2 millimeters, and even below about 1 millimeters, for economical production. The film thicknesses are set forth in this document in units of "millimeters", where one millimeter is equal to 0.001 inches.

[0114] In another aspect, the multilayer films of the present invention have a total thickness of from about 0.6 millimeters to about 2 millimeters, more specifically from about 0.8 to about 1.5 millimeters.

[0115] In one embodiment, these multilayer films have a dielectric breakdown strength (kV) of more than 3 kV, measured using ASTM D3755. In particular, the dielectric breakdown strength is from more than 3 kV to about 12 kV, from about 3 kV to about 7 kV, and in particular from about 4 kV to about 6 kV.

[0116] Dielectric breakdown strength is measured according to ASTM D3755, Standard Method for Testing Dielectric Breakdown Voltage and Dielectric Strength of Solid Insulating Materials in a DC Voltage Gradient.

[0117] A test sample of 5 inches × 5 inches is fixed in air between two opposing cylinders 2 inches in diameter, 1 inch in length with edges rounded to a radius of 0.25 inches. The sample is subjected to electrical voltage by applying an increasing forward voltage at the same speed of 500 V / s until an internal breakdown occurs. Dielectric breakdown is usually accompanied by an increase in current in the circuit under test, which can activate a sensor element, such as a circuit breaker or fuse. The test breakdown voltage is recorded.

[0118] In another embodiment, the multilayer films have a solar energy reflection coefficient on at least one side of the film of more than 70% as measured by ASTM E424. In particular, the reflection coefficient of solar energy on at least one side of the film is from more than 70% to about 99.9%, from about 75% to about 99%, and in particular from about 80% to about 99%.

[0119] The reflection coefficient of solar energy is measured according to ASTM E424, Standard Test Methods for the Transmission of Solar Energy and the Reflectance of (Ground) Sheet Materials. The established procedure for ASTM E424 involves the collection of data in the range from 350 to 2100 nm. Summing data from 400 to 1100 nm is a widely used version of this procedure and is the method used in this document.

[0120] A spectrophotometer with a light-measuring ball is used to measure the spectral characteristics of the test sample, 2 inches. × 2 inches, within the region of interest of interest. Smoky magnesium oxide is used as a standard for a fully reflective and scattering surface. The spectral transmittance data for air and the spectral directional reflectance data for magnesium oxide are obtained. The transmission of solar energy and reflectivity in percent, is calculated by integrating the spectral reflectivity of the standard distribution of solar energy. The transmission of solar energy is measured through the film, while reflectance is usually measured in relation to one side of the film. Opacity (%) is defined as 100% - Transmission in%.

[0121] In yet another embodiment, the multilayer films have a water vapor permeation rate of less than about 20 g / m ² / day as measured by ASTM F1249. In particular, the water vapor permeation rate is less than about 16 g / m ² / day, more particularly less than about 13 g / m ² / day, and most specifically less than about 8 g / m ² / day.

[0122] The rate of penetration of water vapor is measured according to ASTM F1249, The rate of penetration of water vapor through a plastic film and sheet material using an adjustable infrared sensor.

[0123] Test sample 4 inches. × 4 in. tightly sealed with grease and O-ring between the dry chamber and the wet chamber. Water vapor diffusing through the film is mixed with gaseous nitrogen in a dry chamber and transferred to a pressure-controlled infrared sensor. The sensor measures the proportion of infrared energy absorbed by water vapor and produces an electrical signal whose amplitude is proportional to the concentration of water vapor. The amplitude of the electrical signal is compared with that of a calibration film with a known rate of water permeability, from which the rate of moisture permeability through the test film is calculated. The test is carried out at a constant temperature and humidity, for example, at 39 ° C and 100% relative humidity. In yet another embodiment, the multilayer films have an opacity for light, which is more than about 80% when measured using the ASTM E424 method. In particular, the opacity for light is more than about 80, more specifically more than about 85, and most specifically more than about 95.

[0124] In a specific embodiment, the multilayer films described herein have a dielectric breakdown strength (kV) of more than 3 kV, measured using the ASTM D3755 method, solar energy reflection coefficient of more than 70% when measured using the ASTM E424 method, water vapor permeability less 20 g / m ² / day, measured by ASTM F1249, in the case where the multilayer film has a thickness of from about 0.7 millimeters to about 2.0 millimeters.

[0125] In another embodiment, the multilayer films have two-sided properties. For example, they may have a white, highly reflective surface on one side and a black surface on the other side. In another example, they may have a white, highly reflective surface on one side and a black, non-reflective surface on the other side. In another embodiment, they may have a white, highly reflective surface on one side and a black, reflective surface on the other side.

[0126] The color on either side of the film can be indicated by measuring the color using a standard method called the CIE L * a * b * color model. In a specific embodiment, the two-sided color films, the black side and the white side may be different. A low value of L * indicates a blacker color, while L * = 0 is the value of the most extreme black. A high value of L * indicates a whiter color, while L * = 100 is an estimate of the maximum scattered white.

[0127] The fluoropolymers used in particular for the outer layers of the multilayer films described herein are unique materials since they exhibit a remarkable range of properties such as high transparency, good dielectric strength, high purity, chemical inertness, low friction coefficient , high thermal stability, excellent resistance to weathering and UV radiation. Fluoropolymers are often used in applications requiring high performance, which often require a combination of the above properties. However, due to their low surface energy, fluoropolymers are difficult to moisten with most, if not all, of the fluoropolymer materials, either liquid or solid.

[0128] Therefore, a common problem associated with fluoropolymers is difficult adhesion to oil fluoropolymer surfaces. In addition, this problem is especially acute for fluoropolymer composite laminates in which at least one layer is not a fluoropolymer.

[0129] The present invention provides new multilayer films and methods for producing multilayer films by using suitable materials together with repeated deposition of layers followed by additional optional surface treatment. In general, the multilayer films of the present invention include an outer layer containing a modified fluoropolymer, and an inner (inner) layer (s) described (described) herein having (having) a polymer matrix / powder filler film (s).

[0130] The expression “modified fluoropolymer” is intended to include fluoropolymers that are either volume modified, or surface modified, or both first and second. Volumetric modification of the fluoropolymer includes the inclusion of a polar functional group that is incorporated or grafted into or onto the fluoropolymer skeleton. This type of modified fluoropolymer material can be used in combination with the unmodified fluoropolymer layer and the oil fluoropolymer layer or as the main fluoropolymer layer. For example, a modified maleic anhydride ETFE is useful for attaching nylon to an untreated ETFE base.

[0131] Surface modification of fluoropolymers is another method of producing a modified fluoropolymer suitable in the present invention. As a rule, polar functional groups attach to the surface of the fluoropolymer, making it more easily wettable, and provide opportunities for chemical bonding. There are several ways to functionalize the surface of a fluoropolymer, including chemical etching, physico-mechanical etching, plasma etching, corona treatment, chemical vapor deposition, or any combination thereof. In an embodiment, chemical etching includes sodium ammonium or sodium naphthalene. Illustrative physico-mechanical etching may include sandblasting and abrasive wear with silicon dioxide gas. In another embodiment, plasma etching comprises reaction plasmas such as hydrogen, oxygen, acetylene, methane, and mixtures thereof with nitrogen, argon, and helium. Corona treatment may include reactive hydrocarbon vapors such as ketones, e.g., acetone, alcohols, p-chlorostyrene, acrylonitrile, propylene diamine, anhydrous ammonia, styrene sulfonic acid, carbon tetrachloride, tetraethylene pentamine, cyclohexyl amine, tetraisopropyl titanate, decylamine, tetrahydrofuran, diethylene triamine, tertiary butylamine, ethylenediamine, toluene-2,4-diisocyanate, glycidyl methacrylate, triethylene tetramine, hexane, triethylamine, methyl alcohol, vinyl acetate, methyl isopropylamine, vinyl butyl ether, methyl methacr ylate, 2-vinylpyrrolidone, methyl vinyl ketone, xylene or mixtures thereof.

[0132] Some techniques use a combination of steps involving one of these methods. For example, surface activation can be performed using plasma or corona discharge in the presence of a species of excited gas. For example, surface activation can be accomplished by corona treatment in the presence of a solvent gas, such as acetone.

[0133] Not wanting to be limited by theory, a method was discovered to ensure strong adhesion between the layers at the interface of the modified fluoropolymer and the oil fluoropolymer (or the second modified fluoropolymer). So, each of the fluoropolymer and oil fluoropolymer forms are formed separately. Then, the fluoropolymer form is treated on the surface using the processing method described in US Pat. Nos. 3,030,290, 3255099, 3274089, 3274090, 3274091, 3275540, 3284331, 3291712, 3296011, 3391314, 3397132, 3485734, 3507763, 3676181, 4597921, 672626 which are incorporated herein in their entirety for all purposes. Further, the obtained modified fluoropolymer and oil fluoropolymer forms are brought into contact with each other, for example, by thermal lamination, with the formation of a multilayer film. Finally, the multilayer film can be subjected to UV irradiation with wavelengths in UVA; UVB and / or UVS range.

[0134] In one aspect, the surface of the fluoropolymer base is corona treated, wherein the electrode region is filled with vapors of acetone, tetrahydrofuran, methyl ethyl ketone, ethyl acetate, isopropyl acetate or propyl acetate.

[0135] A corona discharge is produced by capacitive exchange of a gaseous medium that is present between two remote electrodes, at least one of which is isolated from the gaseous medium by a dielectric barrier. Corona discharge is somewhat limited in origin by alternative currents due to its capacitive nature. This is a phenomenon with high voltage and low current, with voltages usually measured in kilovolts, and currents measured in milliamps. Corona discharges can be maintained over a wide range of pressure and frequency. Pressures from 0.2 to 10 atmospheres, as a rule, determine the limits of corona discharge and atmospheric pressures, as a rule, are preferred. Traditionally, you can use frequencies in the range from 20 Hz to 100 MHz: in particular, the ranges are from 500 Hz, especially 3000 Hz - 10 MHz.

[0136] When using dielectric barriers to isolate each of two electrodes that are remote from each other from a gaseous medium, the phenomenon of corona discharge is often called electrodeless discharge, while when using one dielectric barrier to isolate only one of the electrodes from a gaseous medium, the resulting corona discharge is often called semi-corona discharge. discharge. The expression "corona discharge" is used in this description of the invention to denote both types of corona discharge, that is, both an electrodeless discharge and a semicircular discharge.

[0137] All details regarding the corona treatment procedure are given in a number of US patents held by E.I. du Pont de Nemours and Company, USA, are described in US Pat. No. 3,366,181 and US Pat. No. 6,726,979 to Saint-Gobain Performance Plastics Corporation, which are incorporated herein by reference in their entirety. An example of the proposed methodology can be found in US patent No. 3667181 (Kowalski). The atmosphere for pressurized processing equipment is 20% acetone (by volume) in nitrogen and is constant. The outer layer of a continuously fed multilayer film or a powder-filled film, for example, is exposed to from 0.15 to 2.5 W per sq. foot of film / sheet surface. The fluoropolymer can be processed on both sides of the film / mold to increase adhesion. The material may then be placed on a non-silicone adhesive storage material. Materials that are C-processed are stored for more than 1 year without significant loss of surface wettability, binding properties and adhesion.

[0138] In another aspect, the surface of the fluoropolymer base is plasma treated. The phrase “plasma enhanced chemical vapor deposition” (PECVD) is known in the art and relates to a method that deposits thin films from a gaseous state (vapor) into a solid phase based on. There are several chemical reactions involved in this process that take place after the formation of plasma from the reaction gases. Plasma, as a rule, is created using the RF (AC) frequency or a direct current discharge between two electrodes, between which the base is placed, and the space is filled with reaction gases. Plasma is any gas in which a significant percentage of atoms or molecules is ionized, resulting in reactive ions, electrons, radicals and UV radiation.

[0139] In another illustrative embodiment, at least one major surface of the fluoropolymer layer includes colloidal silicon dioxide. Colloidal silicon dioxide is usually present in solution in an amount to provide adhesion between the first layer and the second layer. In an embodiment, colloidal silicon dioxide is present in the solution, which does not adversely affect the adhesive properties of colloidal silicon dioxide. In an example, the solution may be aqueous. Commercially available colloidal silica solution is available as Ludox®. In an embodiment, a binder solution can be used in addition to a colloidal silicon dioxide solution. Any known binder solution that is compatible with colloidal silicon dioxide is contemplated. For example, a fluoropolymer binder such as FEP or PFA can be used. Typically, a binder solution and colloidal silicon dioxide are applied in a ratio of at least about 25/75 by weight, for example, as about 40/60 by weight, for example, about 50/50 by weight, or even about 75/25 by weight.

[0140] The multilayer films of the present invention can be used to protect, in particular, electronic components from moisture, weathering, heat, radiation, physical damage and / or to isolate the component. Examples of optoelectronic components include, but are not limited to, packaging for crystalline silicon photovoltaic modules, amorphous silicone thin photovoltaic modules, CIGS, DSC, OPV or CdTe OLED, LED, LCD, printed circuit boards, non-rigid displays and printed wiring boards .

[0141] Any of the disclosed layers may contain conventional formulation additives, including antioxidants, UV blockers, UV stabilizers, sterically hindered amine stabilizers, hardeners, crosslinkers, additional pigments, processing aids and the like.

[0142] The multilayer films described above provide certain advantages that are generally not found by other multilayer films. For example, the incorporation of a polyimide layer plays the role of a good dielectric insulating material, since it has a nominal value of approximately 7,000 volts / millimeter dielectric breakdown strength. The polyimide material also provides excellent thermal stability, good mechanical properties, radiation resistance, and excellent chemical resistance.

[0143] By applying a fluoropolymer directly to a polyimide, polycarbonate, aluminum, titanium or steel film, the integrity of the joint between two dissimilar materials provides an advantage over the laminated structure. For example, a coated multilayer film will not have air gaps or bubbles between layers, which can cause delamination or the formation of electrical underpressure, which can develop partial discharge. The combination of various fluoropolymers (on one or both sides of the substrate, for example, polyimide, polycarbonate, aluminum, titanium or steel) can be specified using a multiple dipping process to impart the desired characteristics to the final multilayer film. Additionally, as indicated above, particles can be added to form an opaque film that provides enhanced reflectivity and overall photovoltaic module efficiency. The powder material may be applied during the coating process as part of a fluoropolymer injection composition or after that with a high temperature, highly pigmented coating, such as those that can be seen on the barcode label.

[0144] The invention will be further described with reference to the following non-limiting Examples. It will be apparent to those skilled in the art that many changes can be made to the described embodiments without departing from the scope of the invention. Thus, the scope of the present invention should not be limited by the embodiments described herein, but only by the embodiments described in the claims and equivalents of such embodiments. Unless otherwise indicated, all percentages are by weight.

[0145] Examples

[0146] Obtaining molded fluoropolymer films

[0147] General procedure for casting films

[0148] (a) An aqueous dispersion is obtained with organic or inorganic fillers, such as white pigment (TiO ₂ , ZnO, or others described herein).

[0149] (b) An aqueous dispersion is obtained which includes a film-forming polymer material selected from any of those described in the description of this invention, and in particular a fluoropolymer. This dispersion may comprise the aqueous dispersion described in step (a).

[0150] (c) The carrier tape can then be immersed in the dispersion described in step (b) so that a dispersion coating is formed on the carrier tape.

[0151] (d) A coated carrier tape is passed through a dosing zone to remove excess dispersion.

[0152] (e) After passing through the dosing zone, the coated carrier is dried to remove water from the dispersion.

[0153] (f) The dried coated carrier is then heated to a temperature sufficient to solidify the dispersion, where the carrier tape is formed from a material with low heat capacity having chemical and spatial stability at the temperature of solidification of the dispersion and the adhesion between the carrier tape and the dispersion, which does not exceed the ultimate shear stress of the hardened fluoropolymer film.

[0154] (g) Step (c) - Step (f) can be repeated as necessary for injection multilayer films. At least one of the dispersion coatings will contain the dispersion described in steps (a) or (b).

[0155] (h) Optionally, the film is removed from a carrier (such as polyimide).

[0156] (i) Optionally, the multilayer film may be C-treated on one side or both sides or otherwise so that the surface can be treated so that it becomes adhesive.

[0157] Dispersion:

[0158] Dispersion of PTFE with 22 vol. % TiO ₂

[0159] Mix 3384 g of a PTFE dispersion (Daikin, 59% solids), 1772 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 1400 deionized water for 30 minutes. Add 32 g of the modified fluoroalkyl surfactant (Ciba, 60% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0160] Dispersion of PTFE with 14.8 vol.% TiO ₂

[0161] Mix 3000 g of a PTFE dispersion (Daikin, 59% solids), 990 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 800 deionized water for 30 minutes. Add 24 g of modified surfactant (Ciba, 60% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0162] Dispersion of PTFE with 12% TiO ₂

[0163] Mix 1532 g of a PTFE dispersion (Daikin, 59% solids), 400 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 550 deionized water for 30 minutes. Add 10 g of modified surfactant (Ciba, 60% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0164] Dispersion of PTFE with 38 vol. % TiO ₂

[0165] Mix 3000 g of a PTFE dispersion (Daikin, 60% solids), 3440 g of a TiO ₂ suspension (DuPont R-900 TiO ₂ , 60% solids) and 3500 g of deionized water for 30 minutes. Add 50 g of the modified fluoroalkyl surfactant (Ciba, 60% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0166] Dispersion of PTFE with 4 vol. % TiO ₂

[0167] Mix 7659 g of a PTFE dispersion (Daikin, 60% solids), 666 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 1625 g of deionized water for 30 minutes. Add 50 g of the modified fluoroalkyl surfactant (Ciba, 60% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0168] Dispersion of PTFE with 41 vol. % TiO ₂

[0169] Mix 550 g of a PTFE dispersion (Daikin, 60% solids), 826 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 600 g of deionized water for 30 minutes. Add 10 g of modified fluoroalkyl surfactant (Ciba, 60% solids) and 13.2 g of acrylic copolymer (Rohm and Haas, 100% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0170] Dispersion of PTFE with 28 vol. % TiO ₂

[0171] Mix 3970 g of a PTFE dispersion (Daikin, 60% solids), 2870 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 3110 g of deionized water for 30 minutes. Add 50 g of modified fluoroalkyl surfactant (Ciba, 60% solids) to the mixture. Filter the solution through a 10 micron sieve.

[0172] Dispersion of PTFE with 3 vol. % TiO ₂

Mix 728 g of a PTFE dispersion (Daikin, 60% solids), 105 g of a suspension of TiO ₂ (DuPont R-900 TiO ₂ , 60% solids) and 172 g of deionized water for 30 minutes. Add 5 g of modified fluoroalkyl surfactant (Ciba, 60% solids) to the mixture. Filter the solution through a 10 micron sieve.

[0173] Dispersion of PTFE with 2 vol.% Carbon black

[0174] Mix 816 g of a PTFE dispersion (Daikin, 60% solids), 33 g of a suspension of carbon black (Aqua black, TOKAI, 30% solids) and 143 g of deionized water for 30 minutes. Add 5 g of modified fluoroalkyl surfactant (Ciba, 60% solids) and 3 grams of acrylic copolymer (Rohm and Haas, 100% solids) to the mixture. Filter the solution through a 10 micron sieve.

[0175] Pure dispersion PTFE without filler

[0176] Mix 796 g of a PTFE dispersion (Daikin, 59% solids) and 157 deionized water for 30 minutes. Filter the solution through a 10 micron sieve.

[0177] Net dispersion of PFA without filler

[0178] Mix 1480 g of a PFA dispersion (DuPont, 58-62% solids) and 2520 g of deionized water for 30 minutes. Add 10 g of modified non-ionic surfactant (DuPont, 50% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0179] Pure dispersion of FEP without filler

[0180] Mix 1000 g of a FEP dispersion (DuPont, 41% solids) and 450 g of deionized water for 30 minutes. Add 2.25 g of the modified non-ionic surfactant (DuPont, 50% solids) to the mixture and mix for an additional 10 minutes. Filter the solution through a 10 micron sieve.

[0181] The following films were obtained according to the General procedure:

[0182] Example 1

[0183] Using the above General procedure and method, a four-layer film was obtained with the following design:

PTFE with 22.0 vol.% TiO ₂ PTFE with 22.0 vol.% TiO ₂ PTFE with 22.0 vol.% TiO ₂ FEP (without filler)

[0184] Total film thickness: 1.1 millimeters

[0185] Example 2

[0186] Using the above General procedure and method, a five-layer film was obtained with the following design:

PTFE (without filler) PTFE with 14.8 vol.% TiO ₂ PTFE with 14.8 vol.% TiO ₂ PTFE with 14.8 vol.% TiO ₂ FEP (without filler)

[0187] Total film thickness: 1.1 millimeters

[0188] Example 3

PTFE with 12 vol.% TiO ₂ PTFE c 12 o6.% TiO ₂ PTFE c 12 o6.% TiO ₂ FEP (without filler)

[0189] The total film thickness of 1.1 millimeters

[0190] The following properties were measured:

Example Transmission (%) Opacity (%) Dielectric Breakdown Strength (kV) one 7.4 92.6% 1.65 2 9.8 90.2 3.91 3 9.5 90.5 4.04 Tedlar (PV2111) 12.9 87.1 3.00

[0191] Tedlar PV2111 is a commercial film sold by DuPont and is used for layering a PV substrate. The film thickness is 1.0 millimeter.

[0192] A dielectric breakdown value of> = 3.00 kV is generally considered acceptable for a 1 millimeter PV substrate film.

[0193] Test methods:

[0194] Dielectric breakdown strength measurements were generally performed according to ASTM D149 using a dielectric measuring instrument QC101A, Beckman. Films were placed between circular electrodes having a diameter of 0.25 inches. The ramp DC voltage was then applied at a constant rate of change (typically 500 V / s), starting at zero volts. The voltage at which a burn through of the film thickness was observed was recorded as the dielectric breakdown voltage.

[0195] Light transmission was measured according to ASTM E424 using a Color-Eye® 7000A spectrophotometer, Gretag Macbeth. The wavelength scanning region was 400 nm - 750 nm. The background correction was scanned, leaving the empty and reflective standard for transmittance measurement in the reflectivity camera. The films were then loaded into the chamber to measure the transmittance of the accessory and the% of total transmittance (diffusion + uniform transmittance) was determined. % Opacity = 100% -% Transmission.

[0196] Example 4

[0197] Using the general procedure and method described above, a five-layer film was obtained with the following construction:

Composition Thickness (millimeters) PFA - No Filler 0.10 PTFE - no filler 0.35 PTFE with 38 vol.% TiO ₂ 0.35 PTFE with 4 vol.% TiO ₂ 0.20 FEP - No Filler 0.10 Total (9.6 vol.% TiO ₂ ) 1.10

[0198] Example 5

[0199] Using the above General procedure and method, a five-layer film was obtained with the following design:

Composition Thickness (millimeters) PFA - No Filler 0,03 PTFE - no filler 0.35 PTFE c 41 vol.% TiO ₂ 0.35 PTFE without filler 0.25 FEP - No Filler 0,03 Total (11.6 vol.% TiO ₂ ) 1.01

[0200] Example 6

[0201] Using the above General procedure and method, a three-layer film was obtained with the following construction:

Composition Thickness (millimeters) PTFE with 22 vol.% TiO ₂ 0.35 PTFE with 22 vol.% TiO ₂ 0.35 FEP - No Filler 0.20 Total (16.4 vol.% TiO ₂ ) 0.90

Measured Properties

Dielectric strength (kV) Opacity (%) SPVP (g / m ² / day) Reflectance (%) Example 4 6.1 81.91 7.72 77.91 Example 5 4.9 83.04 10.5 78.53 Example 6 1,6 85.47 127 81.28

[0202] Example 7

[0203] Using the general procedure and method described above, a five-layer film was obtained with the following construction:

Composition Thickness (millimeters) PFA-free filler 0.05 PTFE - no filler 0.25 PTFE with 28 vol.% TiO ₂ 0.40 PTFE with 3 vol.% TiO ₂ 0.25 FEP - No Filler 0.05 Total (10.5 vol.% TiO ₂ ) 1,0 Dielectric strength (kV) Opacity (%) SPVP (g / m ² / day) Reflectance (%) Example 7 3.98 80.79 12.7 76.39

Example 8

[0204] Using the above General procedure and method, a five-layer film was obtained with the following design:

Composition Thickness (millimeters) PFA - No Filler 0.05 PTFE - no filler 0.25 PTFE with 28 vol.% TiO ₂ 0.40 PTFE with 2 vol.% Carbon black 0.15 FEP - No Filler 0.05 Total (10.9 vol.% TiO ₂ ) 0.90

Dielectric strength (kV) SPVP (g / m ² / day) Opacity (%) Reflectance (%) Color L * A * B * (L *) Side 1 Side 1 Side 2 Ex 8 3.0 fourteen 98.8 67.7 87.1 7.7

[0205] Examples 4-8 were investigated as follows: dielectric breakdown strength was measured according to ASTM D3755, Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Insulating Materials in a DC Voltage Gradient. Solar reflectance was measured according to ASTM E424, Standard Test Methods for Solar Transmittance and Reflectance of (Ground) Sheet Materials; the rate of penetration of water vapor was measured according to ASTM F1249, the Rate of penetration of water vapor through a plastic film and sheet material using an adjustable infrared sensor; and opacity was measured according to ASTM E424.

[0206] Although the invention has been described with reference to preferred embodiments, those skilled in the art will understand that changes can be made in detail without departing from the spirit and scope of the invention. All references cited in this description of the invention are incorporated herein in their entirety. Those skilled in the art will understand, or will be able to ascertain, using a simple experiment, many equivalents to the specific embodiments of the invention specifically described herein. It is intended that such equivalents be included within the scope of the claims.

Claims (30)

1. Multilayer packaging film, including:
a first layer comprising a fluoropolymer cast from a mixture with water or another solvent, and a powder filler material;
a second layer having upper and lower sides selected from polyimide, polycarbonate, titanium, steel or aluminum; and
a third layer containing a fluoropolymer cast from a mixture with water or another solvent, and a powder filler material, where the first layer is located on the upper side and the third layer is located on the lower side of the second layer; each of the castable fluoropolymers of the first and third layers is independently selected from polytetrafluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl fluoride, copolymer of tetrafluoroethylene / hexafluoropropylene / ethylene, copolymer of chlorotrifluoroethylene / ethylene trifluoroethylene copolymer copolymers / tetrafluoroethylene, copolymers of tetrafluoroethylene / hexafluoropropylene, copolymers of tetrafluoroethylene and perfluoro (a alkyl vinyl ether) or mixtures thereof. 2. The multilayer film according to claim 1, in which each of the powder fillers is independently selected from particles of silicon dioxide, glass granules, glass microspheres, glass fibers, particles of titanium dioxide, particles of barium titanate, calcium carbonate, zinc oxide, mica, clay, talc, iron oxide, carbon black, zinc sulfide, barium sulfate, zinc sulfite, cobalt blue aluminate, sodium aluminosilosilicate, magnesium hydroxide, antimony trioxide, organophosphorus compounds, brominated compounds or mixtures thereof. 3. The multilayer film according to claim 1, where each of the fluoropolymers is independently selected from polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA), ethylene / tetrafluoroethylene copolymers (ETFE), fluorinated ethylene and propylene copolymers (FEP), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) or mixtures thereof, and the powder filler of the fluoropolymer layers is titanium dioxide. 4. The multilayer film according to claim 1, in which the dielectric breakdown strength (kV) is more than 3 kV when measured using the ASTM method D3755. 5. The multilayer film according to claim 1, in which the reflection coefficient of solar energy is more than 70% when measured using the ASTM E424 method. 6. The multilayer film according to claim 1, in which the rate of penetration of water vapor is less than approximately 20 g / m ² / day when measured using the ASTM method F1249. 7. An electronic device, including:
The electronic component and the multilayer film according to claim 1, wherein the electronic component and the multilayer film are packaged together. 8. The electronic device according to claim 7, in which the multilayer film is a substrate for the electronic component. 9. A multilayer packaging film, including:
a first layer comprising a fluoropolymer cast from a mixture with water or another solvent, and a powder filler material; and
a second layer having upper and lower sides selected from polyimide, polycarbonate, titanium, steel or aluminum, where the first layer is located on one side of the second layer, and each of the castable fluoropolymers of the first and third layers is independently selected from polytetrafluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl fluoride, tetrafluoroethylene / hexafluoropropylene / ethylene copolymer, chlorotrifluoroethylene / vinylidene fluoride copolymer, chlorotrifluoroethylene / hexafluoropropylene copolymers, chlorotrifluoroethylene / ethyl on ethylene / trifluoroethylene copolymers, ethylene / tetrafluoroethylene copolymers, tetrafluoroethylene / hexafluoropropylene copolymers, tetrafluoroethylene and perfluoro (alkyl vinyl ether) copolymers, or mixtures thereof. 10. The multilayer film according to claim 9, in which the powder filler is selected from particles of silicon dioxide, glass granules, glass microspheres, glass fibers, particles of titanium dioxide, particles of barium titanate, calcium carbonate, zinc oxide, mica, clay, talc, iron oxide, carbon black, zinc sulfide, barium sulfate, zinc sulfite, blue cobalt aluminate, sodium aluminosulfosilicate, magnesium hydroxide, antimony trioxide, organophosphorus compounds, brominated compounds or mixtures thereof. 11. The multilayer film according to claim 9, in which the fluoropolymer is selected from polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA), copolymers of ethylene / tetrafluoroethylene (ETFE), copolymers of fluorinated ethylene and propylene (FEP), polyvinylidene fluoride PVDF), polychlorotrifluoroethylene (PCTFE) or mixtures thereof, and the powder filler of the fluoropolymer layer is titanium dioxide. 12. The multilayer film according to claim 9, in which the dielectric breakdown strength (kV) is more than 3 kV when measured using the ASTM method D3755. 13. The multilayer film according to claim 9, in which the reflection coefficient of solar energy is more than 70% when measured using the ASTM E424 method. 14. The multilayer film according to claim 9, in which the rate of penetration of water vapor is less than approximately 20 g / m ² / day when measured using the ASTM method F1249. 15. An electronic device, including:
The electronic component and the multilayer film according to claim 9, wherein the electronic component and the multilayer film are packaged together. 16. The electronic device according to clause 15, in which the multilayer film is a substrate for the electronic component. 17. A method of obtaining a multilayer film, comprising the steps of applying the injection composition to a base of polyimide, polycarbonate, titanium, steel or aluminum, where the injection composition includes:
carrier;
a fluoropolymer cast from a mixture with water or another solvent; and powder filler material; and each of the castable fluoropolymers of the first and third layers is independently selected from polytetrafluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl fluoride, copolymer of tetrafluoroethylene / hexafluoropropylene / ethylene, copolymer of chlorotrifluoroethylene / vinylidene fluorofluoromethylene copolymers copolymers of copolymers of ethylene / tetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymers, tetrafluoroethylene copolymers and perfluoro (alkyl vinyl ether) or mixtures thereof. 18. The method according to 17, further comprising the step of drying the multilayer film. 19. The method according to 17, in which the powder filler is selected from particles of silicon dioxide, glass granules, glass microspheres, glass fibers, particles of titanium dioxide, particles of barium titanate, calcium carbonate, zinc oxide, mica, clay, talc, iron oxide, carbon carbon black, zinc sulfide, barium sulfate, zinc sulfite, cobalt blue aluminate, sodium aluminosulfosilicate, magnesium hydroxide, antimony trioxide, organophosphorus compounds, brominated compounds or mixtures thereof. 20. The method according to 17, in which the fluoropolymer is selected from polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA), copolymers of ethylene / tetrafluoroethylene (ETFE), copolymers of fluorinated ethylene and propylene (FEP), polyvinylidene fluoride (PVD ), polychlorotrifluoroethylene (PCTFE) or mixtures thereof, and the powder filler of the fluoropolymer layer is titanium dioxide. 21. The method according to 17, in which the dielectric breakdown strength (kV) is more than 3 kV when measured using the ASTM method D3755. 22. The method according to 17, in which the reflection coefficient of solar energy is more than 70% when measured using the method of ASTM E424. 23. The method according to 17, in which the rate of penetration of water vapor is less than approximately 20 g / m ² / day when measured using method ASTM F1249. 24. A method of obtaining a multilayer film, comprising the steps
applying the first injection composition to the upper side of the base of polyimide, polycarbonate, titanium, steel or aluminum, where the first injection composition includes:
carrier;
a fluoropolymer cast from a mixture with water or another solvent; and
powder filler material;
applying the second injection composition to the lower side of the base of polyimide, polycarbonate, titanium, steel or aluminum, where the second injection composition includes:
carrier;
a fluoropolymer cast from a mixture with water or another solvent; and
powder filler material; and
each of the castable fluoropolymers of the first and third layers is independently selected from polytetrafluoroethylene, polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinyl fluoride, copolymer of tetrafluoroethylene / hexafluoropropylene / ethylene, copolymer of chlorotrifluoroethylene / ethylene trifluoroethylene copolymer copolymers / tetrafluoroethylene, copolymers of tetrafluoroethylene / hexafluoropropylene, copolymers of tetrafluoroethylene and perfluoro (a alkyl vinyl ether) or mixtures thereof. 25. The method according to paragraph 24, further comprising the step of drying the multilayer film. 26. The method according to paragraph 24, in which each of the powder fillers are independently selected from particles of silicon dioxide, glass granules, glass microspheres, glass fibers, particles of titanium dioxide, particles of barium titanate, calcium carbonate, zinc oxide, mica, clay, talc, oxide iron, carbon black, zinc sulfide, barium sulfate, zinc sulfite, blue cobalt aluminate, sodium aluminosilosilicate, magnesium hydroxide, antimony trioxide, organophosphorus compounds, brominated compounds or mixtures thereof. 27. The method according to paragraph 24, in which each of the fluoropolymers are independently selected from polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoro (alkyl vinyl ether) (PFA), ethylene / tetrafluoroethylene copolymers (ETFE), fluorinated ethylene and propylene copolymers (FEP), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) or mixtures thereof, and the powder filler of the fluoropolymer layer is titanium dioxide. 28. The method according to paragraph 24, in which the dielectric breakdown strength (kV) is more than 3 kV when measured using the ASTM method D3755. 29. The method according to paragraph 24, in which the reflection coefficient of solar energy is more than 70% when measured using the method of ASTM E424. 30. The method according to paragraph 24, in which the rate of penetration of water vapor is less than approximately 20 g / m ² / day when measured using method ASTM F1249.