Electronic telecommunication article and coated substrate and method of making the same

Abstract

An electronic telecommunications article is described, comprising a layer of fluoropolymer composition comprising an uncrosslinked fluoropolymer containing at least 80, 85, or 90 wt% of a polymeric unit comprising one or more unsaturated perfluorinated alkyl ethers. In a general embodiment, the uncrosslinked fluoropolymer contains at least 10, 20, or 30 wt.% of one or more unsaturated perfluorinated alkyl ethers. The uncrosslinked fluoropolymer may be characterized as amorphous. The uncrosslinked fluoropolymer is soluble in fluorinated solvents. Coating (e.g., copper) substrates, methods, and compositions are also described.

Description

Summary of the Invention

[0001] In one embodiment, an electronic telecommunications article is described comprising a layer of fluoropolymer composition comprising an uncrosslinked fluoropolymer containing at least 80, 85, or 90 wt% of a polymeric unit comprising one or more unsaturated perfluorinated alkyl ethers. In a general embodiment, the uncrosslinked fluoropolymer contains at least 10, 20, or 30 wt.% of one or more unsaturated perfluorinated alkyl ethers. The uncrosslinked fluoropolymer may be characterized as amorphous. The uncrosslinked fluoropolymer is soluble in fluorinated solvents.

[0002] In another embodiment, a method for manufacturing a coated substrate is described, comprising: Provides a fluoropolymer composition comprising a fluoropolymer containing at least 80, 85, or 90% by weight of a polymeric unit comprising one or more unsaturated perfluorinated alkyl ethers; and applies the fluoropolymer composition to a substrate.

[0003] In one embodiment, the fluoropolymer composition further comprises a fluorinated solvent; and the method further comprises removing the fluorinated solvent after applying the fluoropolymer composition to the substrate. The fluorinated solvent may be a partially fluorinated ether, such as 3-ethoxyperfluorinated 2-methylhexane or 3-methoxyperfluorinated 4-methylpentane.

[0004] In another embodiment, a coated article is described, comprising (e.g., copper) a substrate and a fluoropolymer composition comprising an uncrosslinked fluoropolymer containing at least 80, 85, or 90% by weight of a polymeric unit perfluorinated monomer comprising one or more unsaturated perfluorinated alkyl ethers;

[0005] The fluoropolymer compositions described herein may optionally further comprise crystalline fluoropolymers, silica, glass or quartz fibers, thermally conductive fillers, or combinations thereof. Crystalline fluoropolymers may exist as particles ranging in size from submicron to larger than 1 micrometer.

[0006] It also describes fluoropolymer compositions and coating solutions, which contain such fluoropolymer compositions dissolved in fluorinated solvents. Simple Explanation of the Diagram

[0007] 100: Fluoropolymer membrane 120: Silicon wafer 125: Passivation layer 150: Fluoropolymer portion 175: Part of the fluoropolymer layer 200: Integrated Circuits 300: Fluoropolymer membrane 310: Passivation layer 320: Silicon Chip 360: Electrode Patterning 620: Core 630: Coating layer 640: Coating 650: Reinforced Fiber 660: Outer Sheath

[0008] [Figure 1] is a schematic cross-sectional view of a patterned fluoropolymer layer; [Figure 2] is a perspective view of an illustrative printed circuit board (PCB) including integrated circuits; Figures 3A and 3B are illustrative cross-sectional views of the fluoropolymer passivation layer and the insulating layer; [Figure 4] is a plan view of an illustrative antenna for a mobile computer device; Figures 5A and 5B are perspective views of an illustrative antenna of a telecommunications tower; [Figure 6] is an illustrative cross-sectional view of an optical fiber cable. Implementation Electronic telecommunications items

[0009] The description herein refers to certain fluoropolymer compositions (e.g., films and coatings) intended for use in electronic and telecommunications articles. As used herein, "electronic" means a device that uses the electromagnetic spectrum (e.g., electrons, photons); and "telecommunications" refers to the transmission of symbols, signals, messages, text, writing, images, and sounds, or information of any nature, by means of wires, radio, optics, or other electromagnetic systems.

[0010] Polyimide materials are widely used in the electronics and telecommunications industries. The structure of poly-oxydiphenylene-pyromellitimide ("Kapton") is as follows:

[0011] Polyimide film exhibits good insulating properties, with a dielectric constant ranging from 2.78 to 3.48 at room temperature at 1 Hz and a dielectric loss between 0.01 and 0.03.

[0012] Perfluoropolymers can have substantially lower dielectric constants and dielectric loss properties than polyimides, which is particularly important for fifth-generation cellular network ("5G") products. For example, the fluoropolymer compositions described herein can have dielectric constants (Dk) less than 2.75, 2.70, 2.65, 2.60, 2.55, 2.50, 2.45, 2.40, 2.35, 2.30, 2.25, 2.20, 2.15, 2.10, 2.05, 2.00, and 1.95. In some embodiments, the dielectric constant is at least 2.02, 2.03, 2.04, and 2.05. Furthermore, the fluoropolymer compositions described herein may have low dielectric losses, typically less than 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002, 0.001, 0.0009, 0.0008, 0.0007, 0.0006, 0.0005, 0.0004, or 0.0003. In some embodiments, the dielectric loss is at least 0.00022, 0.00023, 0.00024, or 0.00025. Dielectric properties (e.g., constant or loss) can be determined according to the test methods described in the examples. Generally, the dielectric constant and dielectric loss increase with the increase in the number of non-fluorine atoms (e.g., the increase in the number of carbon-hydrogen and / or carbon-oxygen bonds).

[0013] However, perfluoropolymers have not yet been used to replace polyimide in various electronic and telecommunications articles, at least in part due to the lack of perfluoropolymer materials that can bond with certain substrates (such as copper), especially at lower temperatures. Therefore, the aforementioned perfluoropolymer compositions are suitable as substitutes for polyimide in various electronic and telecommunications articles.

[0014] In one embodiment, the electronic telecommunications article is an integrated circuit, or in other words, a silicon wafer or microchip, that is, a microelectronic circuit array formed by fabricating various electrical and electronic components (resistors, capacitors, transistors, etc.) on a semiconductor material (silicon) wafer. Various integrated circuit designs have been described in the literature.

[0015] In some embodiments, particularly when a thin fluoropolymer film needs to be applied to a substrate, the method includes applying a coating solution (e.g., spin coating) to the substrate. The coating solution comprises a fluorinated solvent and a fluoropolymer. The method generally includes removing the fluorinated solvent (e.g., by evaporation). In this embodiment, the substrate in contact with the solvent, or its coated surface (e.g., SiO2), is substantially insoluble in the fluorinated solvent of the coating solution. Furthermore, the method generally includes recovering, or in other words, reusing, the fluorinated solvent of the coating solution.

[0016] In some embodiments, the fluoropolymer may be characterized as a patterned fluoropolymer layer. The patterned fluoropolymer can be formed by any suitable additive or subtractive process known in the art. Referring to FIG1, in one embodiment, a method of forming a patterned fluoropolymer layer is described, comprising: applying a fluoropolymer film 100 to a substrate (e.g., a silicon wafer 120, a surface thereon coated with a passivated (e.g., SiO2) layer 125, or copper); and selectively removing portions of the fluoropolymer film. For example, portions 175 of the fluoropolymer layer may be removed using various methods (such as laser ablation). Fluoropolymer portions 150 remain, thereby forming a patterned fluoropolymer layer.

[0017] Patterned fluoropolymer layers can be used to fabricate other layers, such as circuits with patterned electrode materials. Suitable electrode materials and deposition methods are known in the art. Such electrode materials include, for example, inorganic or organic materials, or composites of both. Exemplary electrode materials include: further dispersions or pastes of polyaniline, polypyrrole, poly(3,4-ethylenedioxythiophene), or doped conjugated polymers, graphite, or metal particles (such as Au, Ag, Cu, Al, Ni, or mixtures thereof), as well as sputtered or evaporated metals (such as Cu, Cr, Pt / Pd, Ag, Au, Mg, Ca, Li, or mixtures thereof), or metal oxides (such as indium tin oxide (ITO), F-doped ITO, GZO (gallium-doped zinc oxide), or AZO (aluminium-doped zinc oxide)). Organometallic precursors can also be used and deposited from the liquid phase.

[0018] In another embodiment, a (e.g., patterned) fluoropolymer layer may be disposed on a metal (e.g., copper) substrate during the manufacture of a printed circuit board (PCB). An illustrative perspective view of a printed circuit board is depicted in FIG2. A printed circuit board (or PCB) is used to mechanically support and electrically connect electronic components using conductive paths, conductive rails, or signal traces etched from a (e.g., copper) metal sheet laminated on a non-conductive substrate. Such boards are generally made of insulating materials, such as glass fiber reinforced (glass fiber) epoxy resin or paper reinforced phenolic resin. Electrical paths are generally formed by forming a patterned fluoropolymer layer on the surface of the (e.g., copper) metal substrate, as previously described. In some embodiments, portions of the fluoropolymer are removed to form conductive (e.g., copper) paths. The fluoropolymer remains, disposed between the conductive (e.g., copper) paths of the printed circuit board. Solder is used to mount components onto these board surfaces. In some embodiments, the printed circuit board further includes integrated circuitry 200, as illustrated in FIG2. Printed circuit board assemblies are used in almost every electronic device, including computers, computer printers, televisions, and mobile phones.

[0019] In another embodiment, the fluoropolymer layer, or in other words, the fluoropolymer film as described herein, can be used as an insulating layer, passivation layer, and / or protective layer in the fabrication of integrated circuits.

[0020] Referring to FIG3A, in one embodiment, a thin fluoropolymer film 300 (e.g., generally having a thickness of less than 50, 40, or 30 nm) may be disposed on a passivation layer 310 (e.g., SiO2), which is disposed on an electrode patterned silicon wafer 320.

[0021] Referring to Figure 3B, in another embodiment, a thicker fluoropolymer film 300 (e.g., typically having a thickness of at least 100, 200, 300, 400, or 500 nm) may be disposed on an electrode patterned silicon wafer 320. In this embodiment, the fluoropolymer layer may function as both a passivation layer and an insulating layer. Passivation uses a thin coating to provide electrical stability by isolating the transistor surface from the electrical and chemical conditions of the environment.

[0022] In another embodiment, the fluoropolymer film described herein can be used as one of the substrates for an antenna. The transmitter's antenna emits (e.g., at a high frequency) energy into space, while the receiver's antenna captures this energy and converts it into electrical energy.

[0023] Patterned electrodes for an antenna can also be formed by photolithography. Screen printing, flexographic printing, and inkjet printing can also be used to form electrode patterns as known in the art. Various antenna designs for (e.g., mobile) computing devices (smartphones, tablets, laptops, desktops) have been described in the literature. Figure 4 illustrates a representative split-ring monopole antenna with the following dimensions in micrometers.

[0024] The low-dielectric fluoropolymer films and coatings described herein can also be used as insulation and protective layers for transmitter antennas in cell towers and other (e.g., outdoor) structures. There are two main types of antennas used in cell towers. Figure 5A illustrates a representative omnidirectional (e.g., dipole) antenna used for transmitting / receiving in any direction. Figure 5B illustrates a representative directional antenna used for transmitting / receiving only in a specific desired direction, such as circular and rectangular horn antennas.

[0025] In another embodiment, the low-dielectric fluoropolymer composition described herein can also be used in optical fiber cables. Referring to Figure 6, an optical fiber cable generally comprises five main components: a core 620 typically made of highly pure (e.g., silica) glass, a cladding 630, a coating (e.g., a first inner protective layer) 640, reinforcing fibers 650, and an outer sheath (i.e., a second outer protective layer) 660. The cladding functions to provide a lower refractive index at the core interface to cause reflection within the core, allowing light waves to be transmitted through the fiber. A coating is typically present on the cladding to reinforce the fiber core, help absorb shocks, and provide additional protection against excessive bending of the cable. The low-dielectric fluoropolymer composition described herein can be used as the cladding, coating, outer sheath, or a combination thereof.

[0026] In other embodiments, the low-dielectric fluoropolymer films and coatings described herein can also be used in flexible cables and as an insulating film on electromagnetic wires. For example, in a laptop, the cable connecting the main logic board to the display (which bends every time the laptop is turned on or off) can be a low-dielectric fluoropolymer composition with copper conductors as described herein.

[0027] Electronic and telecommunications items are generally not among the sealed components of equipment used in wafer and chip manufacturing.

[0028] Those skilled in the art will understand that the low-dielectric fluoropolymer compositions described herein can be used in a variety of electronic and telecommunications articles, particularly as a substitute for polyimide, and that such applications are not limited to the specific articles described herein. Fluoroplastics

[0029] The uncrosslinked fluoropolymer comprises a fluoropolymer that is predominantly or solely derived from perfluorinated comonomers, including one or more of tetrafluoroethylene (TFE) and unsaturated (e.g., alkenyl, vinyl) perfluorinated alkyl ethers. As used herein, "predominantly" means that at least 80, 85, or 90% by weight of the fluoropolymer polymer units are derived from such perfluorinated comonomers, such as tetrafluoroethylene (TFE), and one or more unsaturated perfluorinated alkyl ethers, based on the total weight of the fluoropolymer. In some embodiments, the fluoropolymer comprises at least 81, 82, 83, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, or 97% by weight or more of such perfluorinated comonomers based on the total weight of the fluoropolymer. The fluoropolymer may contain at least 40, 45, or 50% by weight of TFE-derived polymer units. In some embodiments, the maximum amount derived from the TFE polymer unit is no more than 60% by weight or 55% by weight.

[0030] In some advantageous embodiments, one or more unsaturated perfluorinated alkyl ether systems are selected from the following general formulas: Rf-O-(CF2)n-CF=CF2, where n is 1 (allyl ether) or 0 (vinyl ether), and Rf represents a perfluoroalkyl residue, which may be inserted with an oxygen atom once or more. Rf may contain up to 10 carbon atoms, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Rf preferably contains up to 8 carbon atoms, more preferably up to 6 carbon atoms, and most preferably 3 or 4 carbon atoms. In one embodiment, Rf has 3 carbon atoms. In another embodiment, Rf has 1 carbon atom. Rf may be straight-chain or branched, and may or may not contain cyclic units. Specific examples of Rf include residues having one or more ether functionalities, including but not limited to: -(CF2)-O-C3F7, -(CF2)2-O-C2F5, -(CF2)r3-O-CF3, -(CF2-O)-C3F7, -(CF2-O)2-C2F5, -(CF2-O)3-CF3, -(CF2CF2-O)-C3F7, -(CF2CF2-O)2-C2F5, -(CF2CF2-O)3-CF3,

[0031] Other specific examples of Rf include residues that do not contain ether functionality, and include, but are not limited to, -C4F9; -C3F7, -C2F5, -CF3, wherein the C4 and C3 residues may be branched or straight, but are preferably straight.

[0032] Unsaturated perfluorinated alkyl groups may contain allyl or vinyl groups. Both have C-C double bonds. Perfluorinated vinyl groups are CF2=CF-; perfluorinated allyl groups are CF2=CFCF2-.

[0033] Suitable examples of perfluorinated alkyl vinyl ethers (PAVE) and perfluorinated alkyl allyl ethers (PAAE) include, but are not limited to, perfluorinated (methyl vinyl) ether (PMVE), perfluorinated (ethyl vinyl) ether (PEVE), perfluorinated (n-propyl vinyl) ether (PPVE-1), perfluorinated-2-propoxypropyl vinyl ether (PPVE-2), perfluorinated-3-methoxy-n-propyl vinyl ether, perfluorinated-2-methoxy-ethyl vinyl ether, CF2=CF-O-CF2-O-C2F5, CF2=CF-O-CF2-O-C3F7, CF3-(CF2)2-O-CF(CF3)-CF2-O-CF(CF3)-CF2-O-CF=CF2, and their allyl ether homologues. Specific examples of allyl ethers include CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-(CF3)3-O-CF3. Further examples include, but are not limited to, the vinyl ethers described in European Patent Application EP 1,997,795 B1.

[0034] In some embodiments, (e.g., amorphous) fluoropolymers comprise at least one allyl ether polymeric unit, such as alkyl vinyl ethers CF2=CFCF2OCF2CF2CF3. Such fluoropolymers are described in WO 2019 / 161153, which is incorporated herein by reference.

[0035] The perfluorinated alkyl ethers described above are commercially available, for example from Anles Ltd., St. Petersburg, Russia and other companies, or can be prepared according to the methods described in U.S. Patent No. 4,349,650 (Krespan) or EP 1,997,795 or by such modifications known to those skilled in the art.

[0036] Fluoropolymers generally comprise polymeric units derived from one or more unsaturated perfluorinated alkyl ethers (PAVE) (e.g., PMVE, PAAE, or combinations thereof), in an amount of at least 10, 15, 20, 25, 30, 45, or 50% by weight of the total monomeric units of the fluoropolymer. When the amount of polymeric units derived from one or more unsaturated perfluorinated alkyl ethers is less than 30 wt.%, amorphous fluoropolymers generally comprise other comonomers, such as HFP, to reduce crystallinity. In some embodiments, the fluoropolymer comprises no more than 50, 45, 40, or 35% by weight of polymeric units derived from one or more unsaturated perfluorinated alkyl ethers (PMVE, PAAE, or combinations thereof) of the total monomeric units of the fluoropolymer. The molar ratio of units derived from TFE to those derived from the aforementioned perfluorinated alkyl ethers may be, for example, from 1:1 to 5:1. In some embodiments, the molar ratio is in the range of 1.5:1 to 3:1.

[0037] In some embodiments, one or more unsaturated perfluorinated alkyl ethers comprise unsaturated cyclic perfluorinated alkyl ethers, such as 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxane. The amorphous fluoropolymers primarily comprise or comprise only (e.g., repeatedly) the following: polymeric units derived from two or more perfluorinated comonomers, including tetrafluoroethylene (TFE) and one or more unsaturated cyclic perfluorinated alkyl ethers, such as 2,2-bis(trifluoromethyl)-4,5-difluoro-1,3-dioxane, are commercially available as "TEFLON™ AF", "CYTOP™", and "HYFLON™".

[0038] Fluoropolymers containing sufficient amounts of polymer units of one or more unsaturated perfluorinated alkyl ethers are generally amorphous fluoropolymers. As used herein, amorphous fluoropolymers are materials that are essentially non-crystalline or do not possess a distinct melting point (peak value), as determined by differential scanning calorimetry according to DIN EN ISO 11357-3:2013-04 under a nitrogen flow and a heating rate of 10 °C / min. Generally, amorphous fluoropolymers have glass transition temperatures (Tg) of less than 26 °C, less than 20 °C, or less than 0 °C, and for example, from -40 °C to 20 °C, or from -50 °C to 15 °C, or from -55 °C to 10 °C. Fluoropolymers generally have a Mooney viscosity (ML 1+10, at 121 °C) of about 2 to about 150, for example, from about 10 to 100, or from 20 to 70. For amorphous polymers containing cyclic perfluorinated alkyl ether units, the glass transition temperature is generally at least 70°C, 80°C, or 90°C, and can range up to 220°C, 250°C, 270°C, or 290°C. The MFI (297°C / 5kg) is between 0.1 and 1000 g / 10 min.

[0039] The fluorine content of fluoropolymers is generally at least 60, 65, 66, 67, 68, 69, or 70 wt.%, and generally not greater than 76, 75, 74, or 73 wt.%. The fluorine content can be achieved by appropriately selecting the comonomers and their amounts.

[0040] These highly fluorinated amorphous fluoropolymers generally do not dissolve to at least 1 wt.% in hydrogen-containing organic liquids at room temperature and standard pressure (for example, they are insoluble in any of methyl ethyl ketone (“MEK”), tetrahydrofuran (“THF”), ethyl acetate, or N-methylpyrrolidone (“NMP”).

[0041] Amorphous and crystalline fluoropolymers can be prepared by methods known in the art, such as total polymerization, suspension polymerization, solution polymerization, or aqueous emulsion polymerization. (See, for example, EP 1,155,055; U.S. Patent No. 5,463,021; WO 2015 / 088784 and WO 2015 / 134435) Various emulsifiers can be used as described in the art, including, for example, 3H-perfluoro-3-[(3-methoxy-propoxy)propionic acid. For example, the polymerization process can be carried out by free radical polymerization of the monomer alone or as a solution, emulsion, or dispersion in an organic solvent or water. Seeded polymerization may or may not be used. Curable fluoroelastomers that can be used also include commercially available fluoroelastomers, particularly perfluoroelastomers.

[0042] Fluoroelastomers can have a single-peak, bi-peak, or multi-peak weight distribution. Fluoropolymers may or may not have a core-shell structure. Core-shell polymers are polymers in which the composition of the comonomer, or the ratio of the comonomers, or the reaction rate is changed to produce a shell with different compositions when polymerization is nearing completion (generally after at least 50 mol% of the comonomer has been consumed).

[0043] The fluoropolymer layer comprises an uncrosslinked (e.g., amorphous) fluoropolymer. The uncrosslinked fluoropolymer of the coated substrate or article is soluble in a fluorinated solvent. This fluorinated solvent will be described in more detail later. In some embodiments, the fluorinated solvent is a partially fluorinated ether, such as 3-ethoxyperfluorinated 2-methylhexane or 3-methoxyperfluorinated 4-methylpentane. Soluble means that at least 10, 15, 20, 25, or 30 wt.% of the uncrosslinked fluoropolymer is soluble in the fluorinated solvent. [Optional curing sites & modifiers]

[0044] The fluoropolymer layer comprises an uncrosslinked (e.g., amorphous) fluoropolymer. The uncrosslinked fluoropolymer lacks the crosslinking effect of a chemical curing agent that renders the fluoropolymer insoluble in fluorinated solvents. Therefore, the fluoropolymer composition described herein lacks a chemical curing agent and / or its (multiple) fluoropolymers lack curing sites that react with such chemical curing agents. It should be understood that in the absence of a fluoropolymer with curing sites, a chemical curing agent will not cause crosslinking. It should also be understood that in the absence of a chemical curing agent, a fluoropolymer with curing sites will not cause crosslinking. Therefore, in the absence of a chemical curing agent, (multiple) fluoropolymers may optionally contain one or more curing sites. Alternatively, in the absence of a fluoropolymer with curing sites, the fluoropolymer composition may optionally contain a chemical curing agent.

[0045] In general embodiments, the fluoropolymer composition lacks a chemical curing agent, as described in WO 2021 / 091864, which is incorporated herein by reference. Therefore, the fluoropolymer lacks chemical curing agents such as peroxides, amines, vinyl unsaturated compounds; and amino organosilicon esters or ester equivalents. The fluoropolymer composition also lacks one or more compounds containing electron-donating groups (such as amines) combined with vinyl unsaturated groups.

[0046] In general embodiments, the fluoropolymer(s) of the fluoropolymer composition also lack curing sites, such as iodine, bromine, chlorine, nitriles, and amidine, amidine salts, imines, amides, and ammonium salts. However, fluoropolymers containing such curing sites are commercially available. Therefore, some exemplary compositions include such curing sites, even if these curing sites do not react with chemical curing agents to chemically crosslink with the fluoropolymer. Furthermore, including curing sites (such as nitriles) can improve the adhesion of the fluoropolymer composition to a substrate.

[0047] Curing sites are functional groups that react in the presence of a curing agent or curing system to crosslink the polymer. Curing sites are generally introduced by copolymerizing curing site monomers, which already contain functional comonomers of the curing site or its precursors. One indicator of crosslinking is that the dried and cured coating composition is insoluble in the fluorinated solvent of the coating.

[0048] Curing sites can be introduced into the polymer using curing site monomers (i.e., functional monomers), functional chain transfer agents, and initiating molecules, as further described in WO 2021 / 091864. Fluoroelastomers may contain curing sites that are reactive to more than one class of curing agents.

[0049] Fluoroelastomers contain curing sites that function as side groups in the main chain or at the terminal positions. Curing sites within the fluoropolymer main chain can be introduced by using suitable curing site monomers. Curing site monomer systems contain one or more monomers that can act as curing sites, or contain precursors that can be converted into curing sites.

[0050] In some embodiments, the fluoropolymer includes halogen-cured sites, i.e., curing sites containing iodine, bromine, or chlorine. When present, the amount of iodine, bromine, or chlorine, or combinations thereof, in the fluoropolymer is between 0.001 and 5% by weight, preferably between 0.01 and 2.5% by weight, or between 0.1 and 1% by weight, or between 0.2 and 0.6% by weight, relative to the total weight of the fluoropolymer. In one embodiment, the curable fluoropolymer contains iodine between 0.001 and 5% by weight, preferably between 0.01 and 2.5% by weight, or between 0.1 and 1% by weight, more preferably between 0.2 and 0.6% by weight, based on the total weight of the fluoropolymer.

[0051] In some embodiments, the fluoropolymer comprises: a nitrile-containing curing site and corresponding amidine, amidine salt, imine, amide, and ammonium salt. Fluoropolymers having nitrile-containing curing sites are known, such as those described in U.S. Patent Nos. 6,720,360 and 7,019,082. When present, the amount of the nitrile-containing curing site comonomer is generally at least 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5% by weight, and generally not more than 10% by weight; the above are based on the total weight of the fluoropolymer.

[0052] Fluoropolymers may or may not contain units derived from at least one modifying monomer. The modifying monomer can introduce branched sites into the polymer structure. Generally, the modifying monomer is a diene, diene ether, or polyether. Diolefins and diene (poly)ethers can be perfluorinated, partially fluorinated, or non-fluorinated. Preferably, they are perfluorinated. Suitable perfluorinated diene ethers include those represented by the following general formulas: CF2=CF-(CF2)nO-(Rf)-O-(CF2)m-CF=CF2, where n and m are independently 1 or 0, and Rf represents a perfluorinated straight-chain or branched, cyclic or acyclic aliphatic or aromatic hydrocarbon residue, which may be inserted through one or more oxygen atoms and contains up to 30 carbon atoms. Particularly suitable perfluorinated diene ethers are divinyl ethers represented by the following formula: CF2 = CF - O - (CF2)nO - CF = CF2 where n is an integer between 1 and 10, preferably 2 to 6, for example, n can be 1, 2, 3, 4, 5, 6, or 7. More preferably, n represents a non-even integer, such as 1, 3, 5, or 7.

[0053] Further specific examples include diene ethers according to the following general formula CF2 = CF - (CF2)nO - (CF2)pO - (CF2)m - CF = CF2 where n and m are independently 1 or 0, and p is an integer from 1 to 10 or from 2 to 6. For example, n can be chosen to represent 1, 2, 3, 4, 5, 6, or 7, preferably 1, 3, 5, or 7.

[0054] Further suitable perfluorinated diene ethers can be represented by the following formula: CF2=CF-(CF2)pO-(RafO)n(RbfO)m-(CF2)q-CF=CF2, where Raf and Rbf are different straight-chain or branched perfluoroalkyl groups with 1 to 10 carbon atoms, particularly 2 to 6 carbon atoms, and may or may not be inserted with one or more oxygen atoms. Raf and / or Rbf may also be perfluorinated phenyl or substituted phenyl; n is an integer between 1 and 10, and m is an integer between 0 and 10, preferably m is 0. In addition, p and q are independently 1 or 0.

[0055] In another embodiment, the perfluorinated diene ether can be represented by the formula just described, wherein m, n, and p are zero, and q are 1 to 4.

[0056] The modified monomers can be prepared by methods known in the art and are commercially available from sources such as Anles Ltd., St. Petersburg, Russia.

[0057] Preferably, no or only a small amount (e.g., ethylene-based unsaturated) of modifying monomers is used. The typical amount, based on the total weight of the fluoropolymer, includes 0 to 5% by weight, or 0 to 1.4% by weight. For example, the modifier may be present in an amount from about 0.1% to about 1.2% by weight, or from about 0.3% to about 0.8% by weight, based on the total weight of the fluoropolymer. Combinations of modifiers may also be used. Furthermore, in general embodiments, the fluoropolymer composition comprises no more than 8, 7, 6, 5, 4, 3, 2, 1, or 0.1 wt% of polymeric units containing (e.g., (meth)acrylate) esters.

[0058] Fluoropolymers may contain partially fluorinated or non-fluorinated comonomers and combinations thereof, although this is not preferred. Typical partially fluorinated comonomers include, but are not limited to, 1,1-difluoroethylene (vinyl difluoroethylene, VDF) and vinyl fluoride (VF), or trifluorochloroethylene, or trichlorofluoroethylene. Examples of non-fluorinated comonomers include, but are not limited to, ethylene and propylene. In general embodiments, the fluoropolymer composition contains no more than 8, 7, 6, 5, 4, 3, 2, 1, or 0.1 wt.% of polymeric units derived from non-fluorinated or partially fluorinated monomers, based on the total weight of the fluoropolymer. Method for manufacturing coating solutions and optional crystalline fluoropolymers

[0059] In one embodiment, the uncrosslinked (e.g., amorphous) fluoropolymer is a coagulated latex. Coagulation can be carried out, for example, by cooling (e.g., freezing) the blended latex or by adding a suitable salt (e.g., magnesium chloride) or inorganic acid. Cooling is particularly desirable for coatings intended for semiconductor manufacturing and for applications where the introduction of salt may be undesirable. The method further includes optionally washing the coagulated fluoropolymer particles. The washing step can substantially remove emulsifiers or other surfactants from the mixture and can help obtain a well-mixed blend of substantially non-agglomerated dry particles. In some embodiments, the surfactant level in the resulting dry particle mixture can be, for example, less than 0.1% by weight, less than 0.05% by weight, or less than 0.01% by weight. The method further includes drying the coagulated latex mixture. The coagulated latex mixture can be dried by any suitable means, such as air drying or oven drying. In one embodiment, the coagulated latex mixture can be dried at 100°C for 1 to 2 hours. The fluoropolymer particles derived from the coagulated latex have a submicron size. The size range of submicron fluoropolymer particles can be approximately 50 to approximately 1000 nm, or approximately 50 to approximately 400 nm, or approximately 50 to approximately 200 nm.

[0060] In some embodiments, the dried coagulated latex can be dissolved in a fluorinated solvent suitable for dissolving (e.g., amorphous) fluoropolymer particles to form a stable coating composition.

[0061] In some embodiments, the fluoropolymer composition lacks crystalline fluoropolymers. However, the fluoropolymer composition of the fluoropolymer layer may optionally further include crystalline fluoropolymers, provided that their presence does not impair the solubility of the fluoropolymer (e.g., amorphous) in the fluorinated solvent. The crystalline fluoropolymers may be present in particles.

[0062] When a coating solution of a fluoropolymer (e.g., amorphous) that is soluble in a fluorinated solvent and an insoluble crystalline fluoropolymer particle is applied to a substrate and dried, the amorphous polymer remains soluble in the same fluorinated solvent as long as the dried coating has not been heated to the point that the amorphous and crystalline fluoropolymers co-crystallize with each other.

[0063] Various crystalline fluoropolymers (e.g., particles) can be used, including mixtures of different crystalline fluoropolymers (e.g., particles). Crystalline fluoropolymer particles generally have high crystallinity and therefore a distinct melting point (maximum peak value), as determined by differential scanning calorimetry according to DIN EN ISO 11357-3:2013-04 under a nitrogen flow and a heating rate of 10°C / min. Therefore, crystalline fluoropolymers (e.g., particles) are generally thermoplastic.

[0064] For example, crystalline fluoropolymers (e.g., particles) may include fluoropolymers having a Tm of at least 100, 110, 120, or 130°C. In some embodiments, crystalline fluoropolymers (e.g., particles) may include fluoropolymers having a Tm of no more than 350, 340, 330, 320, 310, or 300°C.

[0065] Crystalline fluoropolymers (e.g., particles) generally have a fluorine content greater than about 50 percent by weight. Furthermore, fluoropolymers (e.g., particles) may include fluoropolymers having a fluorine content between about 50 and about 76 percent by weight, between about 60 and about 76 percent by weight, or between about 65 and about 76 percent by weight.

[0066] Representative crystalline fluoropolymers include, for example, perfluorinated fluoropolymers such as 3M™ Dyneon™ PTFE dispersions TF 5032Z, TF 5033Z, TF 5035Z, TF 5050Z, TF 5135GZ, and TF 5070GZ; and 3M™ Dyneon™ Fluorothermoplastic Dispersions PFA 6900GZ, PFA 6910GZ, FEP 6300GZ, THV 221, THV 340Z, and THV 800. Other suitable fluoropolymers (e.g., particles) are available from suppliers such as Asahi Glass, Solvay Solexis, and Daikin Industries, and will be familiar to those skilled in the art.

[0067] Commercially available aqueous dispersions typically contain up to 5 to 10 wt.% nonionic and / or ionic surfactants. These surfactants are substantially removed by washing away the aggregated mixture. Residual surfactant concentrations of less than 1, 0.05, or 0.01 wt.% may be present. Using "polymerized" aqueous fluoropolymer latexes is generally more convenient because they do not contain such high levels of nonionic / ionic surfactants.

[0068] As previously mentioned, crystalline fluoropolymers have melting points that can be determined by DSC. Crystallinity depends on the choice and concentration of the polymerizing monomers in the fluoropolymer. For example, PTFE homopolymers (containing 100% TFE units) have a melting point (Tm) higher than 340°C. Adding comonomers (such as unsaturated (per)fluorinated alkyl ethers) lowers the Tm. For example, when a fluoropolymer contains about 3 to 5 wt.% of such comonomer units, the Tm is about 310°C. As another example, when a fluoropolymer contains about 15 to 20 wt.% HFP polymerizing units, the Tm is about 260 to 270°C. As yet another example, when a fluoropolymer contains 30 wt.% of (per)fluorinated alkyl ethers (e.g., PMVE) or other polymerizing units of (various) comonomers that reduce crystallinity, the fluoropolymer no longer has a melting point detectable by DSC and is therefore characterized as amorphous.

[0069] In some embodiments, the crystalline fluoropolymer (e.g., particles) contains at least 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or about 100 wt.% of TFE polymeric units. The crystalline fluoropolymer (e.g., particles) generally has a larger amount of TFE polymeric units than the first amorphous fluoropolymer. More generally, the crystalline fluoropolymer (e.g., particles) contains at least 70, 75, 85, 90, 95, or about 100 wt.% of TFE polymeric units. Furthermore, the crystalline fluoropolymer (e.g., particles) generally contains a lower concentration of unsaturated (per)fluorinated alkyl ethers (e.g., PMVE) than the amorphous fluoropolymer. In general embodiments, the crystalline fluoropolymer particles contain less than 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, or 5 wt.% of (fully)fluorinated alkyl ether polymeric units.

[0070] In some embodiments, the crystalline fluoropolymer is a copolymer formed from monomers comprising tetrafluoroethylene (“TFE”), hexafluoropropylene (“HFP”), and difluoroethylene (“VDF”, “VF2”). The monomer structures of these constituent components are shown below: TFE:CF2=CF2 (1) VDF:CH2=CF2 (2) HFP:CF2=CF-CF3 (3)

[0071] In some embodiments, the crystalline fluoropolymer is composed of at least two constituent monomers (HFP and VDF), and in some embodiments it is composed of all three constituent monomers in different amounts.

[0072] Tm depends on the amounts of TFE, HFP, and VDF. For example, a fluoropolymer containing approximately 45 wt.% TFE polymeric units, approximately 18 wt.% HFP polymeric units, and approximately 37 wt.% VDF polymeric units has a Tm of approximately 120°C. As another example, a fluoropolymer containing approximately 76 wt.% TFE polymeric units, approximately 11 wt.% HFP polymeric units, and approximately 13 wt.% VDF polymeric units has a Tm of approximately 240°C. By increasing the number of HFP / VDF polymeric units while decreasing the number of TFE polymeric units, the fluoropolymer becomes amorphous. For an overview of crystalline and amorphous fluoropolymers, see: Ullmann's Encyclopedia of Industrial Chemistry (7th Edition, 2013 Wiley-VCH Verlag. 10. 1002 / 14356007.a11 393 pub 2) Chapter: Fluoropolymers, Organic.

[0073] In some embodiments, the crystalline fluoropolymer contains very few or no VDF polymeric units. The amount of VDF polymeric units is no more than 5, 4, 3, 2, or 1 wt.% of the total crystalline fluoropolymer.

[0074] In some embodiments, the crystalline fluoropolymer comprises HFP polymerization units. The amount of HFP polymerization units may be at least 1, 2, 3, 4, or 5 wt.% of the total crystalline fluoropolymer. In some embodiments, the amount of HFP polymerization units is not greater than 15, 14, 13, 12, 11, or 10 wt.% of the total crystalline fluoropolymer.

[0075] In some embodiments, the crystalline fluoropolymers of the compositions described herein contain little or no vinylidene (VDF) (i.e., CH2=CF2) or VDF coupled to hexafluoropropylene (HFP) polymeric units. The VDF polymeric units may undergo dehydrofluorination (i.e., HF elimination reaction) as described in US2006 / 0147723. This reaction is limited by the number of polymeric VDF groups coupled to HFP groups contained in the fluoropolymer.

[0076] When present, the coating composition or fluoropolymer layer contains at least 5, 10, or 15 weight percent, ranging from about 50, 55, 60, 65, 70, 75, or 80 weight percent of crystalline fluoropolymer (e.g., particles) and about 20, 30, 40, or 50 to about 90 or 95 weight percent of (e.g., amorphous) uncrosslinked fluoropolymer. In some embodiments, the coating composition contains about 10 to about 30 weight percent of crystalline fluoropolymer (e.g., particles) and about 90 to about 70 weight percent of (e.g., amorphous) uncrosslinked fluoropolymer.

[0077] In some embodiments, fluoropolymer particles may be characterized as "agglomerates" (e.g., latex particles), meaning weak associations between primary particles (such as particles held together by charge or polarity). During the preparation of the coating solution, agglomerates generally physically break down into smaller entities (such as primary particles). In other embodiments, fluoropolymer particles may be characterized as "aggregates," meaning strongly bonded or molten particles, such as covalently bonded or thermally bonded particles prepared by processes such as sintering, arcing, flame hydrolysis, or plasma. During the preparation of the coating solution, aggregates generally do not break down into smaller entities (such as primary particles). "Primary particle size" refers to the average diameter of a single (non-agglomerated, non-agglomerated) particle.

[0078] In some embodiments, the fluoropolymer composition comprises fluoropolymer particles having a particle size greater than 1 micrometer. In general embodiments, the fluoropolymer particles have an average particle size not greater than 75, 70, 65, 60, 55, 50, 45, 35, 30, 30, 25, 20, 15, 10, or 5 micrometers. In some embodiments, the particle size of the fluoropolymer particles is smaller than the thickness of the fluoropolymer coating or fluoropolymer film. The average particle size is generally reported by the supplier. The particle size of the fluoropolymer particles in the fluoropolymer coating or fluoropolymer film can be determined by microscopy.

[0079] In some embodiments, the fluoropolymer particles comprise a mixture of particles, including fluoropolymer particles having a particle size greater than 1 micrometer and fluoropolymer particles having a particle size of 1 micrometer or less. In some embodiments, the submicron fluoropolymer particle size range may be about 50 to about 1000 nm, or about 50 to about 400 nm, or about 50 to about 200 nm.

[0080] The weight ratio of fluoropolymer particles with a diameter greater than 1 micrometer to fluoropolymer particles with a diameter of 1 micrometer or smaller generally ranges from 1:1 to 10:1. In some embodiments, the weight ratio of the larger to the smaller fluoropolymer particles is at least 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1.

[0081] Crystalline fluoropolymers (e.g., particles) are insoluble in fluorinated solvents. Crystalline fluoropolymers (e.g., particles) are also insoluble in non-fluorinated organic solvents, such as methyl ethyl ketone (“MEK”), tetrahydrofuran (“THF”), ethyl acetate, or N-methylpyrrolidone (“NMP”). “Insoluble” means that the fluoropolymer soluble in fluorinated solvents is less than 1, 0.5, 0.1, 0.01, or 0.001 wt.%. Fluoropolymer coating composition

[0082] The fluoropolymer coating composition contains at least one fluorinated solvent. The solvent is capable of dissolving amorphous fluoropolymers. Crystalline fluoropolymers (e.g., particles) are insoluble in fluorinated solvents. The amorphous polymer of the fluoropolymer composition of the coated substrate or article remains soluble in the fluorinated solvent.

[0083] Fluoropolymer coating compositions can be prepared by mixing fluoropolymers, optional additives, and fluorinated solvents. In some embodiments, amorphous fluoropolymers are first dissolved in a fluorinated solvent, followed by the addition of crystalline fluoropolymer particles and other additives.

[0084] The fluorinated solvent is generally present in an amount of at least 25% by weight of the total weight of the coating composition. In some embodiments, the solvent is present in an amount of at least 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%, or greater of the total weight of the coating composition.

[0085] The fluoropolymer coating composition typically contains at least 0.01, 0.02, 0.03, 0.03, 0.04, 0.04, 0.05, 0.06, 0.7, 0.8, 0.9, or 1% by weight of the total coating composition. In some embodiments, the fluoropolymer coating composition contains at least 2, 3, 4, or 5% by weight of the fluoropolymer. In some embodiments, the fluoropolymer coating composition contains at least 6, 7, 8, 9, or 10% by weight of the fluoropolymer. The fluoropolymer coating composition typically contains no more than 50, 45, 40, 35, 30, 25, or 20% by weight of the total coating composition. Therefore, the coating composition may contain various concentrations of (e.g., amorphous) fluoropolymers soluble in fluorinated solvents.

[0086] The optimal amounts of solvent and fluoropolymer can vary depending on the end application. For example, to provide a thin coating, a very diluted solution of fluoropolymer in a solvent is desirable, for example, the amount of fluoropolymer can be from 0.01% to 5% by weight. Furthermore, for spray coating applications, a low-viscosity coating composition may be preferable to a high-viscosity solution. The concentration of fluoropolymer in the solution affects the viscosity and can be adjusted accordingly. An advantage of this disclosure is that solutions with high concentrations of fluoropolymer can also be prepared, yet still provide a low-viscosity, transparent liquid composition.

[0087] In some embodiments, the fluoropolymer coating composition may be a liquid. The liquid may have a viscosity of, for example, less than 2,000 mPas at room temperature (20°C + / - 2°C). In other embodiments, the fluoropolymer coating solution composition is a paste. The paste may have a viscosity of, for example, from 2,000 to 100,000 mPas at room temperature (20°C + / - 2°C).

[0088] The solvent is a liquid under ambient conditions and generally has a boiling point greater than 50°C. Preferably, the solvent has a boiling point below 200°C, allowing it to be easily removed. In some embodiments, the solvent has a boiling point below 190, 180, 170, 160, 150, 140, 130, 120, 110, or 100°C.

[0089] The solvents are partially or fully fluorinated. Therefore, the solvents are non-aqueous. Various partially or fully fluorinated solvents are known, including perfluorocarbons (PFCs), hydrochlorofluorocarbons (HCFCs), perfluoropolyethers (PFPEs), and hydrofluorocarbons (HFCs), as well as fluorinated ketones and fluorinated alkylamines.

[0090] In some embodiments, the solvent has a global warming potential (GWP, 100-year ITH) of less than 1000, 900, 800, 700, 600, 500, 400, 300, 200, or 100. The GWP is generally greater than 0 and may be at least 10, 20, 30, 40, 50, 60, 70, or 80.

[0091] As used in this paper, GWP is a relative value of the global warming potential of a compound based on its structure. The GWP of a compound, as defined by the Intergovernmental Panel on Climate Change (IPCC) in 1990 and updated in subsequent reports, is calculated as the warming effect caused by the release of 1 kg of the compound relative to the warming effect caused by the release of 1 kg of CO2 over a specified integration time horizon (ITH). The F series represents the radiative forcing per unit mass of compound (the change in the flux of radiation penetrating the atmosphere due to the IR absorption of this compound), the Co series represents the atmospheric concentration of the compound at the initial time, the τ series represents the atmospheric lifetime of the compound, the t series represents time, and the x series represents the compound of interest.

[0092] In some embodiments, the solvent comprises a partially fluorinated ether or a partially fluorinated polyether. The partially fluorinated ether or polyether may be linear, cyclic, or branched. Preferably, it is branched. More preferably, it comprises non-fluorinated alkyl groups and perfluorinated alkyl groups, and more preferably, the perfluorinated alkyl groups are branched.

[0093] In one embodiment, the partially fluorinated ether or polyether solvent corresponds to the following formula: In Rf-OR, Rf is a perfluorinated or partially fluorinated alkyl or (poly)ether group, and R is a nonfluorinated or partially fluorinated alkyl group. Generally, Rf can have 1 to 12 carbon atoms. Rf can be a primary, secondary, or tertiary fluorinated or perfluorinated alkyl residue. This means that when Rf is a primary alkyl residue, the carbon atom bonded to the ether atom contains two fluorine atoms and is bonded to another carbon atom of the fluorinated or perfluorinated alkyl chain. In this case, Rf corresponds to Rf 1-CF2-, and the polyether can be described by the general formula: Rf 1-CF2-OR.

[0094] When Rf is a secondary alkyl residue, the carbon atom bonded to the ether atom is also bonded to a fluorine atom and two carbon atoms of part and / or perfluorinated alkyl chains, and Rf corresponds to (Rf 2Rf 3)CF-. Polyethers correspond to (Rf 2Rf 3)CF-OR.

[0095] When Rf is a tertiary alkyl residue, the carbon atom bonded to the ether atom is also bonded to three carbon atoms of three partially fluorinated and / or perfluorinated alkyl chains, and Rf corresponds to (Rf 4Rf 5Rf 6)-C-. Polyethers correspond to (Rf 4Rf 5Rf 6)-C-OR. Rf 1; Rf 2; Rf 3; Rf 4; Rf 5; Rf 6 correspond to the definition of Rf and are perfluorinated or partially fluorinated alkyl groups, which may be inserted once or more via an ether oxygen. They may be linear, branched, or cyclic. Combinations of polyethers may also be used, as well as combinations of primary, secondary, and / or tertiary alkyl residues.

[0096] Examples of solvents containing partially fluorinated alkyl groups include C3F7OCHFCF3 (CAS No. 3330-15-2).

[0097] An example of a solvent containing perfluorinated (poly)ethers in Rf is C3F7OCF(CF3)CF2OCHFCF3 (CAS No. 3330-14-1).

[0098] In some embodiments, the fluorinated ether solvent corresponds to the following formula: CpF2p+1-O-CqH2q+1, where q is an integer from 1 to 5, such as 1, 2, 3, 4, or 5, and p is an integer from 5 to 11, such as 5, 6, 7, 8, 9, 10, or 11. Preferably, CpF2p+1 is a branch chain. Preferably, CpF2p+1 is a branch chain, and q is 1, 2, or 3.

[0099] Representative solvents include, for example, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane and 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecano-2-(trifluoromethyl)hexane. These solvents are available, for example, under the trade name NOVEC from 3M Company, St. Paul, MN.

[0100] Fluorinated (e.g., ethers and polyethers) solvents can be used alone or in combination with other solvents that may be fluorinated or non-fluorinated. When non-fluorinated solvents are combined with fluorinated solvents, the concentration of non-fluorinated solvent relative to the total amount of solvent is generally less than 30, 25, 20, 15, 10, or 5 wt% . Representative non-fluorinated solvents include ketones, such as acetone, MEK, methyl isobutyl ketone, methyl pentyl ketone, and NMP; ethers, such as tetrahydrofuran, 2-methyltetrahydrofuran, and methyltetrahydrofurfuryl ether; esters, such as methyl acetate, ethyl acetate, and butyl acetate; and cyclic esters, such as δ-valerolactone and γ-valerolactone.

[0101] The term "stable" as used herein refers to coating compositions containing fluorinated solvents, meaning that the coating composition remains homogeneous when stored in a sealed container at room temperature for at least 24 hours. In some embodiments, the coating composition remains stable for one week or longer. "Homogeneous" means that the coating composition, immediately after shaking, does not exhibit visible separation of precipitates or visible stratification when placed in a 100 ml glass container and allowed to stand at room temperature for at least 4 hours. additive

[0102] Compositions containing curable fluoroelastomers may further contain additives as known in the art. Examples include acid acceptors. These acid acceptors can be inorganic acid acceptors or blends of inorganic and organic acid acceptors. Examples of inorganic acceptors include magnesium oxide, lead oxide, calcium oxide, calcium hydroxide, lead hydrogen phosphate, zinc oxide, barium carbonate, strontium hydroxide, calcium carbonate, hydrotalcite, etc. Organic acceptors include epoxy resins, sodium stearate, and magnesium oxalate. Particularly suitable acid acceptors include magnesium oxide and zinc oxide. Blends of acid acceptors may also be used. The amount of acid acceptor usually depends on the nature of the acid acceptor used. Generally, the amount of acid acceptor used is between 0.5 and 5 parts per 100 parts of fluoropolymer.

[0103] Fluoropolymer compositions may contain other additives, such as stabilizers, surfactants, ultraviolet ("UV") absorbers, antioxidants, plasticizers, lubricants, fillers, and processing aids, which are generally used in the processing or compounding of fluoropolymers, provided that they have sufficient stability for the intended use conditions. Specific examples of additives include carbon particles, such as carbon black, graphite, and soot. Other additives include, but are not limited to, pigments, such as iron oxide and titanium dioxide. Other additives include, but are not limited to, clay, silicon dioxide, barium sulfate, silica, glass fiber, or other additives known in the art.

[0104] In some embodiments, the fluoropolymer composition comprises silica, glass fiber, thermally conductive particles, or a combination thereof. Any amount of silica and / or glass fiber and / or thermally conductive particles may be present. In some embodiments, the amount of silica and / or glass fiber is at least 0.05, 0.1, 0.2, or 0.3 wt.% of the total solids of the composition. In some embodiments, the amount of silica and / or glass fiber is not greater than 5, 4, 3, 2, or 1 wt.% of the total solids of the composition. Low concentrations of silica can be used to thicken the coating composition. Furthermore, low concentrations of glass fiber can be used to improve the strength of the fluoropolymer film. In other embodiments, the amount of glass fiber may be at least 5, 10, 15, 20, 25, 35, 40, 45, or 50 wt.% of the total solids of the composition. The amount of glass fiber is generally not greater than 55, 50, 45, 40, 35, 25, 20, 15, or 10 wt.%. In some embodiments, the glass fibers have an average length of at least 100, 150, 200, 250, 300, 350, 400, 450, or 500 micrometers. In some embodiments, the glass fibers have an average length of at least 1, 2, or 3 mm and generally no greater than 5 or 10 mm. In some embodiments, the glass fibers have an average diameter of at least 1, 2, 3, 4, or 5 micrometers and generally no greater than 10, 15, 30, or 25 micrometers. The glass fibers may have an aspect ratio of at least 3:1, 5:1, 10:1, or 15:1.

[0105] In some embodiments, the fluoropolymer composition does not contain inorganic oxide particles (e.g., silica). In other embodiments, the fluoropolymer composition includes inorganic oxide particles (e.g., silica and / or thermally conductive). In some embodiments, the amount of inorganic oxide particles (e.g., silica and / or thermally conductive) is at least 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 wt.% of the total solids of the composition. In some embodiments, the amount of inorganic oxide particles (e.g., silica and / or thermally conductive) is no more than 90, 85, 80%, 75, 70, or 65 wt.% of the total solids of the composition. Various combinations of silica and thermally conductive particles may be used. In some embodiments, the total amount of inorganic oxide particles (e.g., silica and thermally conductive) or the amount of specific types of silica particles (e.g., fused silica, fuming silica, glass bulbs, etc.) or thermally conductive particles (e.g., boron nitride, silicon carbide, alumina, aluminum trihydrate) is no greater than 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 wt.% of the total solids of the composition. Higher concentrations of inorganic oxide particles (e.g., silica) can be advantageous for further reducing dielectric properties. Therefore, compositions including inorganic oxide particles (e.g., silica) can have lower dielectric properties than compositions containing only fluoropolymers.

[0106] In some embodiments, the inorganic oxide particles (e.g., silica) and / or glass fibers have a dielectric constant of no greater than 7, 6.5, 6, 5.5, 5, 4.5, or 4 at 1 GHz. In some embodiments, the inorganic oxide particles (e.g., silica) and / or glass fibers have a loss factor of no greater than 0.005, 0.004, 0.003, 0.002, or 0.0015 at 1 GHz.

[0107] In some embodiments, the composition comprises inorganic oxide particles or glass fibers primarily consisting of silica. In some embodiments, the amount of silica is generally at least 50, 60, 70, 75, 80, 85, or 90 wt.% of the inorganic oxide particles or glass fibers. In some embodiments, the amount of silica is generally at least 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or greater (e.g., at least 99.5, 99.6, or 99.7) wt.% silica. Higher silica concentrations generally result in lower dielectric constants. In some embodiments, the silica particles (e.g., molten) may further comprise low concentrations of other metal / metal oxides, such as Al₂O₃, Fe₂O₅, TiO₂, K₂O, CaO, MgO, and Na₂O. In some embodiments, the total amount of such metal / metal oxides (e.g., Al₂O₃, CaO, and MgO) is independently no greater than 30, 25, 20, 15, or 10 wt.%. In some embodiments, the inorganic oxide particles or glass fibers may contain B₂O₃. The amount of B₂O₃ may range up to 25 wt.% of the inorganic oxide particles or glass fibers. In other embodiments, (e.g., fuming) silica particles may further contain low concentrations of additional metal / metal oxides such as Cr, Cu, Li, Mg, Ni, P, and Zr. In some embodiments, the total amount of such metals or metal oxides is no greater than 5, 4, 3, 2, or 1 wt.%. In some embodiments, silica may be described as quartz. The amount of non-silica metals or metal oxides can be determined by inductively coupled plasma mass spectrometry. (e.g., silica) inorganic oxide particles are generally dissolved in hydrofluoric acid and distilled at low temperature to H₂SiF₆.

[0108] In some embodiments, inorganic particles may be characterized as "aggregates," meaning weak associations between primary particles (such as particles held together by charge or polarity). During the preparation of the coating solution, aggregates generally physically break down into smaller entities (such as primary particles). In other embodiments, inorganic particles may be characterized as "aggregates," meaning strongly bonded or molten particles, such as covalently bonded or thermally bonded particles prepared by processes such as sintering, arcing, flame hydrolysis, or plasma. During the preparation of the coating solution, aggregates generally do not break down into smaller entities (such as primary particles). "Primary particle size" refers to the average diameter of a single (non-aggregated, non-cohesive) particle.

[0109] (For example, silica) particles can have various shapes, such as spherical, elliptical, straight-chain, or branched. Molten and fuming silica aggregates are more often branched. The size of the aggregate is usually at least 10 times the size of the primary particles in the discrete fraction.

[0110] In other embodiments, the particles (e.g., silica) may be characterized as glass bubbles. The glass bubbles may be prepared from soda lime borosilicate glass. In this embodiment, the glass may contain approximately 70 percent silica (silicon dioxide), 15 percent alkali (sodium oxide), and 9 percent lime (calcium oxide), and smaller amounts of various other compounds.

[0111] In some embodiments, the inorganic oxide particles may be characterized as (e.g., silica) nanoparticles having an average or median particle size of less than 1 micrometer. In some embodiments, the average or median particle size of the (e.g., silica) inorganic oxide particles is 500 or 750 nm. In other embodiments, the average particle size of the (e.g., silica) inorganic oxide particles may be at least 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 micrometers. In some embodiments, the median particle size is not greater than 30, 25, 20, 15, or 10 micrometers. In some embodiments, the composition contains very little or no (e.g., colloidal silica) nanoparticles having a particle size of 100 nanometers or smaller. The concentration of nanoparticles (e.g., colloidal silica) is generally less than (10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 wt.%). Inorganic oxides (e.g., silica particles) may contain a normal particle size distribution with a single peak or a particle distribution with two or more peaks.

[0112] In some embodiments, no more than 1 wt.% of inorganic oxide particles (e.g., silica) have a particle size greater than or equal to 3 or 4 micrometers. In some embodiments, no more than 1 wt.% of inorganic oxide particles (e.g., silica) have a particle size greater than or equal to 5 or 10 micrometers. In other embodiments, no more than 5, 4, 3, 2, or 1 wt.% of particles have a particle size greater than 45 micrometers. In some embodiments, no more than 1 wt.% of particles have a particle size in the range of 75 to 150 micrometers.

[0113] In some embodiments, the average or median particle size refers to the "primary particle size," which is the average or median particle size of discrete, non-aggregated, non-cohesive particles. For example, the particle size of colloidal silica or glass bubbles is generally the average or median particle size. In a preferred embodiment, the average or median particle size refers to the average or median diameter of the aggregate. The particle size of inorganic particles can be measured using a transmission electron microscope. The particle size of fluoropolymer coating solutions can be measured using dynamic light scattering.

[0114] In some embodiments, (e.g., silica) inorganic particles have a specific gravity in the range of 2.18 to 2.20 g / cc.

[0115] Aggregate particles, such as those in the case of fuming and molten (e.g., silica) particles, may have a lower surface area than primary particles of the same size. In some embodiments, (e.g., silica) particles have a BET surface area in the range of about 50 to 500 m² / g. In some embodiments, the BET surface area is less than 450, 400, 350, 300, 250, 200, 150, or 100 m² / g.

[0116] In some embodiments, inorganic nanoparticles may be characterized as colloidal silica. It should be understood that unmodified colloidal silica nanoparticles typically contain hydroxyl or silanol functional groups on the nanoparticle surface and are generally characterized as hydrophilic.

[0117] In some embodiments, inorganic particles (e.g., silica aggregates) and especially colloidal silica nanoparticles are surface-treated with hydrophobic surface-treatment agents. Common hydrophobic surface-treatment agents include compounds such as alkoxysilanes (e.g., octadecyltriethoxysilane), silazanes, or siloxanes. Various hydrophobic fuming silicas are commercially available from AEROSIL™, Evonik, and various other suppliers. Representative hydrophobic fuming silicas include AEROSIL™ grades R 972, R 805, RX 300, and NX 90 S.

[0118] In some embodiments, (e.g., silica aggregates), the inorganic particles are surface-treated with fluorinated alkoxysilane compounds. These compounds generally contain perfluoroalkyl or perfluoropolyether groups. The perfluoroalkyl or perfluoropolyether groups generally have no more than 4, 5, 6, 7, or 8 carbon atoms. The alkoxysilane group can be bonded to the alkoxysilane group using various divalent linking groups, including alkylene groups, carbamates, and -SO2N(Me)-. Some representative fluorinated alkoxysilanes are described in U.S. Patent Nos. 5,274,159 and WO 2011 / 043973, which are incorporated herein by reference. Other fluorinated alkoxysilanes are commercially available.

[0119] In some embodiments, the fluoropolymer composition includes thermally conductive particles.

[0120] In some embodiments, the thermally conductive inorganic particles are preferably non-conductive materials. Suitable non-conductive, thermally conductive materials include ceramics, such as metal oxides, hydroxides, oxyhydroxides, silicates, borides, carbides, and nitrides. Suitable ceramic fillers include, for example, silicon oxide, zinc oxide, alumina trihydrate (ATH) (also known as hydrated alumina, alumina, and aluminum trihydroxide), aluminum nitride, boron nitride, silicon carbide, and beryllium oxide. Other thermally conductive fillers include carbon-based materials, such as graphite, and metals, such as aluminum and copper. Combinations of different thermally conductive materials can be used. Such materials are non-conductive, i.e., have an electron band gap greater than 0 eV, and in some embodiments, at least 1, 2, 3, 4, or 5 eV. In some embodiments, such materials have an electron band gap not greater than 15 or 20 eV. In this embodiment, the composition may optionally further comprise low concentrations of thermally conductive particles having an electron band gap of less than 0 eV or greater than 20 eV.

[0121] In an advantageous embodiment, the thermally conductive particles comprise a material having a bulk thermal conductivity > 10 W / m*K. The thermal conductivity of some representative inorganic materials is illustrated in the table below. Thermally conductive materials

[0122] In some embodiments, the thermally conductive particles comprise (multiple) materials having an overall thermal conductivity of at least 15 or 20 W / m*K. In other embodiments, the thermally conductive particles comprise (multiple) materials having an overall thermal conductivity of at least 25 or 30 W / m*K. In still other embodiments, the thermally conductive particles comprise (multiple) materials having an overall thermal conductivity of at least 50, 75, or 100 W / m*K. In still other embodiments, the thermally conductive particles comprise (multiple) materials having an overall thermal conductivity of at least 150 W / m*K. In general embodiments, the thermally conductive particles comprise (multiple) materials having an overall thermal conductivity of no more than about 350 or 300 W / m*K.

[0123] Thermally conductive particles can be obtained in various shapes, such as spherical and needle-like, and can be irregular or plate-like. In some embodiments, the thermally conductive particles are crystals, generally having a geometric shape. For example, hexagonal boron nitride crystals are commercially available from Momentive. Furthermore, alumina trihydrate is described as a hexagonal plate. Combinations of particles with different shapes can be used. Thermally conductive particles typically have an aspect ratio of less than 100:1, 75:1, or 50:1. In some embodiments, thermally conductive particles have an aspect ratio of less than 3:1, 2.5:1, 2:1, or 1.5:1. In some embodiments, substantially symmetrical (e.g., spherical, hemispherical) particles can be used.

[0124] Boron nitride particles can be purchased from 3M through the retailer "3MTM Boron Nitride Cooling Fillers".

[0125] In some embodiments, the boron nitride particles have a total density of at least 0.05, 0.01, 0.15, or 0.03 g / cm³, and up to about 0.60, 0.70, or 0.80 g / cm³. The surface area of ​​the boron nitride particles may be <25, <20, <10, <5, or <3 m² / g. The surface area is generally at least 1 or 2 m² / g.

[0126] In some embodiments, the particle size d (0.1) of the boron nitride (e.g., plate) particles is in the range of about 0.5 to 5 micrometers. In some embodiments, the particle size d (0.9) of the boron nitride (e.g., plate) particles is at least 5, and ranges up to 20, 25, 30, 35, 40, 45, or 50 micrometers. Method for manufacturing fluoropolymer compositions and coated substrates

[0127] In some embodiments, a method of manufacturing a coated substrate is described, comprising: providing a fluoropolymer composition comprising (e.g., an amorphous) fluoropolymer; and applying the fluoropolymer composition to the substrate. The fluoropolymer composition may comprise optional crystalline fluoropolymers (e.g., particles) and other additives, as previously described.

[0128] In some embodiments, the fluoropolymer composition further comprises a fluorinated solvent; and the method further comprises removing the fluorinated solvent after applying the fluoropolymer composition to the substrate.

[0129] The fluoropolymer coating composition described herein can be adjusted (by solvent content) to allow for a viscosity that can be applied by various coating methods, including but not limited to spraying or printing (e.g., but not limited to ink printing, 3D printing, screen printing), painting, dipping, roller coating, bar coating, dip coating, and solvent casting.

[0130] The solvent can be reduced or completely removed, for example, by evaporation, drying, or by boiling. After the solvent is removed, the composition can be characterized as "dried". The coated substrate can be dried at or above the boiling point of the fluorinated solvent. Amorphous fluoropolymers are soluble in the fluorinated solvent of the coating solution; crystalline fluoropolymers (e.g., particles) are insoluble in the fluorinated solvent of the coating solution.

[0131] In some embodiments, the method further includes heating a substrate containing a fluoropolymer composition to a temperature above the melting temperature of the fluoropolymer particles to sinter the polymer particles.

[0132] In other embodiments, the method includes thermally extruding a fluoropolymer composition onto a substrate. Fluoropolymers can be combined with optional materials in conventional rubber processing equipment to provide solid mixtures, i.e., solid polymers containing additional components, also referred to in the art as "compounds". Typical equipment includes rubber mills, internal mixers (such as Banbury mixers), and mixing extruders. During mixing, the components and additives are uniformly distributed throughout the resulting fluoropolymer "compound" or polymer sheet. The compound is then preferably crushed, for example by cutting it into smaller fragments, and then dissolved in a solvent.

[0133] In yet another embodiment, the method includes laminating a fluoropolymer film onto a substrate using heat and pressure. The fluoropolymer film can be heat-laminated at temperatures ranging from 120°C to 350°C. In some embodiments, the fluoropolymer film can be heat-laminated at temperatures below 325°C or 300°C. In some embodiments, the fluoropolymer film can be heat-laminated at temperatures not exceeding 290, 280, 270, 260, 250, 240, 230, 220, 210, or 200°C. Lower temperatures are suitable for bonding heat-sensitive substrates and reducing manufacturing energy costs.

[0134] When the method involves heating, the composition lacks crystalline fluoropolymers (e.g., particles) or the temperature is insufficient to co-crystallize the amorphous fluoropolymers with the crystalline fluoropolymers (e.g., particles). The lack of co-crystallization can be evident in the composition having 100% or less of a normalized crystallinity, as described in co-submission 83758US002.

[0135] The composition can be used to impregnate, print (e.g., screen print) onto, or coat (e.g., by spraying, painting, dip coating, roller coating, bar coating, solvent casting, paste coating) a substrate. The substrate can be organic, inorganic, or a combination thereof. Suitable substrates can include any solid surface and can include substrates selected from: glass, plastics (e.g., polycarbonate), composites, metals (stainless steel, aluminum, carbon steel), metal alloys, wood, paper, etc. If the composition contains pigments (e.g., titanium dioxide, or black fillers such as graphite or soot), the coating can be colored; if the pigments or black fillers are absent, the coating can be colorless.

[0136] Before coating, the surface of the substrate can be pretreated with adhesives and primers. For example, applying an adhesive or primer can improve the adhesion of the coating to the metal surface. Examples include commercially available primers or adhesives, such as those from the brand name CHEMLOK.

[0137] Fluoropolymers exhibit good adhesion to a variety of substrates, such as glass, polycarbonate, and metals like copper. In some embodiments, the substrate has an average peak-to-valley height surface roughness (Rz) of about 1 to 1.5 micrometers. In some embodiments, the Rz of the substrate is not greater than 1.5, 2, 2.5, or 3 micrometers. In some embodiments, the Rz of the substrate is not greater than 5, 4, 3, 2, or 1.5 micrometers. For example, in some embodiments, the T-peel coefficient of the copper foil is at least 5, 6, 7, 8, 9, or 10 N / mm, and at most 15, 20, 25, 30, or 35 N / mm or greater, as determined by the test methods described in the examples.

[0138] In some embodiments, the dried fluoropolymer composition has hydrophobic and oleophobic properties, as determined by contact angle measurement (as determined according to the test method described in the examples). In some embodiments, the static, advancing, and / or receding contact angles with water may be at least 100, 105, 110, 115, 120, or 125 degrees, and generally not greater than 130 degrees. In some embodiments, the advancing and / or receding contact angles with hexadecane may be at least 60, 65, 70, or 75 degrees.

[0139] As used herein, the term "partially fluorinated alkyl" refers to an alkyl group in which some, but not all, of the hydrogen atoms bonded to the carbon chain have been replaced by fluorine. For example, the F2HC- or FH2C- groups are partially fluorinated methyl groups. The term "partially fluorinated alkyl" also covers alkyl groups in which at least one hydrogen atom has been replaced by fluorine, and the remaining hydrogen atoms have been partially or completely replaced by other atoms (e.g., other halogen atoms, such as chlorine, iodine, and / or bromine). For example, residues of the formula F2ClC- or FHClC- are also partially fluorinated alkyl residues.

[0140] "Partially fluorinated ether" refers to an ether containing at least one partially fluorinated group, or an ether containing one or more perfluorinated groups and at least one non-fluorinated group or at least one partially fluorinated group. For example, F2HC-O-CH3, F3C-O-CH3, F2HC-O-CFH2, and F2HC-O-CF3 are examples of partially fluorinated ethers. The term "partially fluorinated alkyl" also covers ether groups in which at least one hydrogen atom has been replaced by fluorine, and the remaining hydrogen atoms have been partially or completely replaced by other atoms (e.g., other halogen atoms, such as chlorine, iodine, and / or bromine). For example, ethers of the formula F2ClC-O-CF3 or FHClC-O-CF3 are also partially fluorinated ethers.

[0141] The terms "perfluorinated alkyl" or "perfluoro alkyl" are used herein to describe alkyl groups in which all hydrogen atoms bonded to the alkyl chain have been replaced by fluorine atoms. For example, F3C- represents perfluoromethyl.

[0142] "Perfluorinated ether" is an ether in which all hydrogen atoms have been replaced by fluorine atoms. An example of a perfluorinated ether is F3C-O-CF3.

[0143] The following examples are provided to further illustrate this disclosure, but are not intended to limit this disclosure to the specific examples and embodiments provided. Example

[0144] Unless otherwise stated, all parts, percentages, ratios, etc., in the examples and the remainder of this specification are by weight. Unless otherwise indicated, all other reagents are obtained from or available from precision chemical suppliers such as Sigma-Aldrich Company, St. Louis, Missouri, or can be synthesized by known methods. Table 1 (below) lists the materials used in the examples and their sources. Test methods Test method for measuring the dielectric resonator after separation (at 25 GHz)

[0145] All measurements of the separated dielectric resonators were performed near 25 GHz according to standard IEC 61189-2-721. Thin materials or films were inserted between two fixed dielectric resonators. The resonant frequency and quality factor of the cylinders are affected by the presence of the sample, allowing direct calculation of the complex dielectric constant (dielectric constant and dielectric loss). The geometry of the separated dielectric resonator fixture used in our measurements was designed by QWED in Warsaw, Poland. This 25 GHz resonator operates in TE01d mode, which has only an azimuthal electric field component, ensuring the electric field remains continuous at the dielectric interface. The dielectric constant component in the sample plane was measured using the separated dielectric resonator. Critically coupled loop coupling was used in all of these dielectric resonator measurements. This 25 GHz split post resonator measurement system was combined with a Keysight VNA (vector network analyzer, PNA 8364C, 10 MHz-50 GHz). Calculations were performed using QWED's commercial Split Post Resonator Software to provide a powerful tool for determining the complex electric permittivity of each sample at 25 GHz. T-peeling measurement test method

[0146] The T-peel test was performed using an INSTRON electromechanical universal testing machine, employing the ASTM D1876 standard method for "peel resistance of adhesives," more commonly known as the "T-peel" test. Peel data were generated using an Instron™ 1125 universal testing instrument (Norwood, MA) equipped with a Sintech Tester 20 (MTS Systems Corporation, Eden Prairie, MN). Sample preparation is as follows.

[0147] Perfluoropolymer films / sheets are obtained by hot-pressing corresponding condensed or co-condensed fluoropolymers sandwiched between two PTFE release sheets. The film is pressed between the heating plates of a Wabash hydraulic press at different temperatures (according to the table below), and then immediately transferred to a cold press. After cooling to room temperature by "cold pressing," the resulting sample sheet is peeled off from the PTFE sheet. The resulting film is cut into coupons, which are then laminated with two Cu foil coupons to obtain a sandwich structure (with a perfluoropolymer composite film in the middle). The laminated sample is then heated between the heating plates of a Wabash hydraulic press at 200 to 250°C for 30 minutes and immediately transferred to a cold press. After cooling to room temperature by "cold pressing," the resulting sample is subjected to a T-peel test. The laminated sample is pressed and cut into strips with a width of 1.0 to 1.5 cm for the T-peel measurement.

[0148] The perfluoropolymer coating solutions in Table 5 were individually applied to copper substrates. The resulting coated substrates were dried at room temperature and then heated at 80 to 165°C for 10 to 30 minutes. Coated copper samples were laminated onto uncoated or coated copper test pieces for hot lamination at various temperatures (as described in Table 5 below). The laminated samples were then heated at 200°C for 30 minutes between the heated plates of a Wabash hydraulic press and immediately transferred to a cold press. After cooling to room temperature by cold pressing, the resulting samples were subjected to a T-peel test. The laminated samples were pressed and cut into strips 1 cm wide for the T-peel measurement. Solubility test method

[0149] The sample material (10 wt.%, according to Table 6) was coated onto a glass substrate and then dried at 120°C for 5 minutes. The coated glass substrates were then individually heated at 150°C, 200°C, or 300°C for 10 minutes each. The sample was then peeled off the glass slide, the film was immersed in HFE-7500, and sealed in a glass vial. The vial was then thoroughly sealed with PTFE tape and a paraffin film. The vial was then shaken overnight at room temperature to determine if the film had dissolved. The solubility results are recorded in Table 6. Example General Procedure - Preparation of Amorphous Perfluoropolymer Coating Solution

[0150] PFE was dissolved / dispersed in HFE-7300 by cutting the fluoropolymer material into small pieces and placing them in separate glass jars, then adding HFE-7300 solvent to each jar. The containers were then thoroughly sealed with PTFE tape and a paraffin film. The solution was subjected to vigorous shaking overnight (~12 hours) to achieve complete homogenization, thus obtaining PFE in the HFE-7300 solution.

[0151] The solution prepared above was applied to a copper foil substrate using a 24-gauge Meyer rod, or simply poured onto a pad to obtain a thicker coating sample. The resulting coating on the copper foil was typically dried overnight at room temperature or cured at 120 to 165°C for 20 to 105 minutes. The coated copper substrate can be used for measurements of copper adhesion and Dk / Df (Table 5). General Procedure - Fluoropolymer Membrane Preparation

[0152] The agglomerated perfluoropolymer powder or adhesive is pressed into a film / sheet using a hot laminator. Each of the agglomerated fluoropolymer powder or adhesive is placed between two PTFE release sheets and hot-pressed (according to Tables 2, 3, and 4, based on the melting point of the perfluoroplastic resin) between the heating plates of a Wabash hydraulic press for 30 minutes, followed by quenching with a cold press. After cooling to room temperature by "cold pressing," the resulting sample is ready for use.

[0153] The resulting sheets / films are used for Dk / Df and CTE measurements, and for bonding to Cu substrates. Some aggregated polymers may also contain inorganic fillers. These are obtained by agglomerating polymers in the presence of inorganic fillers. **C = Comparison Example** ***EX = Example

[0154] Examples 1 to 19 are also soluble in HFE-7500.

[0155] All references, patents, and patent applications cited in the foregoing patent applications are incorporated herein by reference in their entirety. In the event of any inconsistency or conflict between the incorporated references and this application, the information provided above shall prevail. The foregoing is intended to enable those skilled in the art to implement the disclosed embodiments and should not be construed as limiting the scope of the invention, which is defined by the scope of the patent applications and all their equivalents.

Claims

1. An electronic telecommunications article comprising a layer of fluoropolymer composition comprising an uncrosslinked fluoropolymer comprising at least 80% by weight of a polymeric unit comprising one or more unsaturated perfluorinated alkyl ethers, wherein the content of the one or more unsaturated perfluorinated alkyl ethers is at least 10% by weight.

2. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition is a substrate, a patterned layer, an insulating layer, a passivation layer, a coating layer, a protective layer, or a combination thereof.

3. The electronic telecommunications article as claimed in item 1, wherein the article is an integrated circuit or a printed circuit board.

4. The electronic telecommunications article as claimed in item 1, wherein the article is an antenna.

5. Electronic telecommunications articles as claimed in item 4, wherein the article is a computing device or an antenna of an outdoor structure.

6. The electronic telecommunications article as claimed in item 1, wherein the article is an optical cable.

7. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition has: i) a dielectric constant (Dk) of less than 2.75; ii) a dielectric loss of less than 0.01; or a combination thereof.

8. The electronic telecommunications article of claim 1, wherein the uncrosslinked fluoropolymer comprises 40 to 60% by weight of TFE polymeric units based on the total weight of the uncrosslinked fluoropolymer.

9. The electronic telecommunications article of claim 1, wherein the uncrosslinked fluoropolymer comprises at least 20% by weight of one or more polymeric units of unsaturated perfluorinated alkyl ethers.

10. The electronic telecommunications article of claim 1, wherein the uncrosslinked fluoropolymer comprises at least 30% by weight of one or more unsaturated perfluorinated alkyl ether polymeric units.

11. The electronic telecommunications article of claim 1, wherein the unsaturated perfluorinated alkyl ether of the uncrosslinked fluoropolymer has the following general formula: Rf-O-(CF2)n-CF=CF2, wherein n is 1 or 0, and Rf is a perfluorinated alkyl or perfluorinated ether group.

12. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition comprises HFP polymeric units.

13. The electronic telecommunications article as claimed in claim 1, wherein the uncrosslinked fluoropolymer is amorphous.

14. The electronic telecommunications article of claim 1, wherein the uncrosslinked fluoropolymer is soluble in a fluorinated solvent.

15. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition further comprises a crystalline fluoropolymer.

16. The electronic telecommunications article of claim 15, wherein the crystalline fluoropolymer contains a greater amount of TFE polymeric units than the amorphous fluoropolymer.

17. The electronic and telecommunications articles of claim 15, wherein the particle size range of the crystalline fluoropolymer is from submicron particles to particles with a diameter greater than 1 micrometer.

18. The electronic telecommunications article of claim 15, wherein the crystalline fluoropolymer is insoluble in non-fluorinated organic solvents.

19. The electronic and telecommunications articles of claim 14, wherein the fluorinated solvent is a partially fluorinated ether, 3-ethoxyperfluorinated 2-methylhexane, or 3-methoxyperfluorinated 4-methylpentane.

20. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition comprises not more than 5% by weight of polymeric units derived from non-fluorinated or partially fluorinated monomers and / or comprises not more than 5% by weight of ester-containing linkages.

21. The electronic telecommunications article of claim 1, wherein the uncrosslinked fluoropolymer further comprises a cured portion selected from nitrile, iodine, bromine, chlorine, nitrile, and amidine.

22. The electronic telecommunications article as claimed in claim 1, wherein the fluoropolymer composition lacks crosslinking by a chemical curing agent.

23. The electronic telecommunications article of claim 1, wherein the fluoropolymer composition further comprises silica, glass or quartz fiber, thermally conductive filler, or a combination thereof.

24. The electronic telecommunications article of claim 23, wherein the silica is fuming silica, fused silica, glass bulb, or a combination thereof.

25. The electronic telecommunications article of claim 23, wherein the fuming or molten silica has an aggregate particle size of at least 500 nm.

26. The electronic telecommunications article of claim 23, wherein the silica comprises a hydrophobic surface treatment, which optionally comprises a fluorinated alkoxysilane compound.

27. The electronic telecommunications article of claim 23, wherein the silica is present in an amount of at least 10% by weight, based on the total amount of the fluoropolymer composition.

28. A method of manufacturing a coated substrate, comprising: providing a fluoropolymer composition comprising: an uncrosslinked fluoropolymer comprising at least 80% by weight of polymeric units comprising one or more unsaturated perfluorinated alkyl ethers, the content of the one or more unsaturated perfluorinated alkyl ethers being at least 10% by weight; and optionally a crystalline fluoropolymer; and applying the fluoropolymer composition to a copper substrate.

29. The method of claim 28, wherein the fluoropolymer composition further comprises a fluorinated solvent; and the method further comprises removing the fluorinated solvent after the fluoropolymer composition has been applied to the copper substrate.

30. The method of claim 29, wherein the uncrosslinked fluoropolymer is soluble in the fluorinated solvent of the coating solution, and the optional crystalline fluoropolymer is insoluble in the fluorinated solvent.

31. The method of claim 30, wherein the fluorinated solvent is a partially fluorinated ether, 3-ethoxyperfluorinated 2-methylhexane, or 3-methoxyperfluorinated 4-methylpentane.

32. A coated substrate comprising: a copper substrate; and a fluoropolymer composition disposed on the copper substrate, wherein the fluoropolymer composition comprises an uncrosslinked fluoropolymer, the uncrosslinked fluoropolymer comprising at least 80% by weight of a polymeric unit comprising one or more unsaturated perfluorinated alkyl ethers, the content of the one or more unsaturated perfluorinated alkyl ethers being at least 10% by weight.

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