Abstract: A fluororubber composition including a polyol-crosslinkable fluororubber; a cross-linking accelerator comprising a quaternary ammonium salt; and a polyol crosslinking agent; wherein the weight ratio X (quaternary ammonium salt/polyol crosslinking agent) between the cross-linking accelerator and the polyol crosslinking agent is in a range of 0.40 to 0.60; and a production method of a cross-linked fluororubber product, comprising the steps of: previously polyol-crosslinking, as required, the fluororubber composition; and subsequently heat treating the polyol-crosslinked composition, in a temperature range of 200° C. to 300° C. for 0.1 to 48 hours. The fluororubber composition has surface has a lower friction coefficient, and the surface roughness of the cross-linked fluororubber product can be increased without applying a treatment to a mold.

Abstract: A membrane humidifier assembly includes a first flow field plate adapted to facilitate flow of a first gas thereto and a second flow field plate adapted to facilitate flow of a second gas thereto. A polymeric membrane is disposed between the first and second flow fields and adapted to permit transfer of water from the first flow field plate to the second flow field plate. The polymeric membrane includes a polymer having perfluorocyclobutyl groups and a pendant side chain having a protogenic group.

Abstract: Copolymers prepared by copolymerization of at least one fluorinated vinyl ether are provided. In one embodiment, the at least one fluorinated vinyl ether comprises ethylene directly substituted at an olefinic carbon atom with a moiety —OR* and optionally substituted with one, two, or three additional nonhydrogen substituents, wherein R* comprises a fluorinated alkyl moiety substituted with a protected or unprotected hydroxyl group, and further wherein an atom within R* may be (i) taken together with one of the additional nonhydrogen substituents, if present, or (ii) directly bound to an olefinic carbon atom, to form a ring. The polymers are useful, for example, in lithographic photoresist compositions, particularly chemical amplification resists. In a preferred embodiment, the polymers are substantially transparent to deep ultraviolet (DUV) radiation, and are thus useful in DUV lithographic photoresist compositions.

Abstract: The present invention provides a fluorinated polymer excellent in the crosslinking reactivity, crosslinked rubber physical properties and chemical resistance, and its crosslinked rubber. A fluorinated polymer comprising repeating units (a) based on at least one monomer selected from the group consisting of ethylenic unsaturated compounds each having a hydroxyphenyl group, repeating units (b) based on at least one fluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, 3,3,3-trifluoropropene, 1,3,3,3-tetrafluoropropene, 1,1,2-trifluoroethylene, vinyl fluoride, 1,2-difluoroethylene and CF2?CF—O—Rf (wherein Rf is a C1-8 saturated perfluoroalkyl group or a perfluoro(alkoxyalkyl) group) and, if necessary, repeating units (c) based on at least one hydrocarbon monomer selected from the group consisting of ethylene, propylene and CH2?CH—O—R1.

Abstract: The present invention provides a protective backing sheet for photovoltaic modules. The backing sheets of the current invention possess excellent weather resistance, heat resistance, color retention, adhesion between layers and encapsulant, and scratch resistance. The backing sheet can minimize the deterioration in the performance of the solar module due to moisture permeation. It also can achieve desirable photoelectric conversion efficiency over a long period of time. Additionally the described backing sheet, or alternatively referred to backskin, can be made in an aesthetically pleasing form.

Abstract: A proton conductive graft polymer comprises at least a structure unit of a sulfonated polymer side chain covalently attached to a hydrophobic perfluorocyclobutane polymer main chain. The sulfonated condensation polymer side chain has a high local ion exchange capacity while the main polymer chain is substantially free of sulfonic acid group. A membrane made from the graft polymer can provide good mechanical properties and high proton conductivity at wide range of humidity and temperatures.

Abstract: A sulfonated aromatic perfluorocyclobutane block copolymer comprises a hydrophobic perfluorocyclobutane ether chain segment and a hydrophilic sulfonated perfluorocyclobutane ether chain segment. The sulfonated perfluorocyclobutane copolymer may be used to make proton conductive membranes and membrane electrode assemblies in fuel cells. Processes of making the block copolymer through thermal coupling reactions are also disclosed.

Abstract: In one embodiment, a copolymer comprises a sulfonatable segment covalently linked to an un-sulfonatable segment through an organic linking group. The sulfonatable group segment may be sulfonated through direction sulfonation or sulfonation through a spacer molecule. In another embodiment, a copolymer comprises a sulfonated segment and an unsulfonated segment. A membrane electrode assembly and a fuel cell may be produced using the copolymer.

Abstract: A polymer for ion conductor applications includes a polymer segment having a perfluorocyclobutyl moiety and a polymer segment not having such a moiety. One of these polymer segments is sulfonated to improve ionic conductivity. Fuel cells incorporating the ion conducting polymers are provided.

Abstract: Disclosed herein is a crosslinked fluoropolymer network formed by the free radical initiated crosslinking of a diacrylate fluoropolymer The diacrylate copolymer is of formula CH2?CR?COO—(CH2)n—R—(CH2)n—OOCR??CH2, wherein R is selected from the group consisting of i) an oligomer comprising copolymerized units of vinylidene fluoride and perfluoro(methyl vinyl ether), ii) an oligomer comprising copolymerized units of vinylidene fluoride and hexafluoropropylene, iii) an oligomer comprising copolymerized units of tetrafluoroethylene and perfluoro(methyl vinyl ether), and iv) an oligomer comprising copolymerized units of tetrafluoroethylene and a hydrocarbon olefin, R? is H or —CH3, n is 1-4 and wherein said oligomer has a number average molecular weight of 1000 to 25,000 daltons. The source of the free radicals may be a photoinitiator or an organic peroxide.

Abstract: This invention relates to a process comprising contacting an polymerization reactor effluent with a fluorinated hydrocarbon and thereafter recovering olefin polymer, where the fluorinated hydrocarbon is present at 5 volume % to 99 volume % based upon the volume of the effluent and the fluorinated hydrocarbon, and where the polymerization is a continuous polymerization of at least 75 mole % of hydrocarbon monomers, based upon the total moles of monomer present in the reactor.

Abstract: A tetrafluoroethylene/hexafluoropropylene copolymer has improved moldability in melt extrusion molding, especially with significant reduction of defects in high-speed extrusion coating of an electrical wire. The tetrafluoroethylene/hexafluoropropylene copolymer is obtained by polymerization of at least tetrafluoroethylene and hexafluoropropylene selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and a third monomer without mixing with the resin which has the melting point with the difference of 20 degree C. and more from the melting point of the tetrafluoroethylene/hexafluoropropylene copolymer; and has a complex viscosity of from 2.0×I03 to 10.0×I03 Pa*s and a storage modulus of from 0.1 to 3.5 Pa*s in melt viscoelasticity measurement under the condition of atmosphere temperature of 310 degree C. and angular frequency of 0.01 radian/second. The tetrafluoroethylene/hexafluoropropylene copolymer can be used in an electrical wire as a coating on a conductive core.

Abstract: Chain end functionalized fluoropolymers are disclosed exhibiting good chemical reactivity high breakdown electric field (E>100 MV/m) and high dielectric constants (i.e., ?>10). The polymers can be prepared by functional initiators and from a variety of fluoromonomers including vinylidene difluoride together with one or more additional monomers. The polymers can be combined with other dielectric materials to form composites having uniform composition and morphology.

Abstract: Fluoroelastomer gum or crumb is isolated from fluoroelastomer dispersions by the addition of a water-soluble polymeric coagulating agent to the dispersion. This coagulating agent comprises either a homopolymer of ethylene oxide (CH2CH2O—) or a copolymer of ethylene oxide. Specific examples of such copolymers include, but are not limited to ethylene oxide-propylene oxide copolymers and ethylene oxide-butylene oxide copolymers. The viscosity average molecular weight (Mv), determined by rheology, of the coagulant polymer must be at least 500,000 and preferably greater than 2,000,000.

Abstract: A process for the preparation of a fluoroolefin polymer, including the step of: contacting in a reaction zone: an initiator; CF3CF?CH2, and optionally, at least one ethylenically unsaturated comonomer capable of copolymerizing therewith; wherein the contacting is carried out at a temperature, pressure and length of time sufficient to produce the fluoroolefin polymer.

Abstract: The present invention provides a fluorocopolymer capable of giving electric wires excellent in electric characteristics even when it is used in high-speed electric wire covering molding. The present invention is a fluorocopolymer comprising tetrafluoroethylene [TFE]-derived copolymerized units and hexafluoropropylene [HFP]-derived copolymerized units, which has a following characteristics (a) and (b). (a) A thermal melting curve obtained by primary heating in differential scanning calorimetry shows a melting point within the range of 240 to 280° C. and a melting point peak portion area accounts for at least 60% of heats of fugion area. (b) The product of a MFR (g/10 minutes) and a resin pressure (MPa) is not larger than 40.

Abstract: The present invention provides an aqueous emulsion resin composition which comprises: (a) a resin composition containing at least one fluoroolefin polymer having crosslinkable group(s) at a terminus and/or a side chain of its molecule and at least one non-fluoroolefin polymer having crosslinkable group(s) at a terminus and/or a side chain of its molecule; and (b) at least one curing agent selected from the group consisting of isocyanates, melamines, hydrazides, carbodiimides, silanes and epoxides; and provides an aqueous emulsion resin compositions containing at least one chemically bonded product of a fluoroolefin polymer and a non-fluoroolefin polymer bonded to each other via at least one covalent bond at a terminus and/or a side chain of the molecules wherein one or both of the fluoroolefin polymer and the non-fluoroolefin polymer have crosslinkable group(s).

Abstract: Interpolymers of 1-99 mol % vinyl fluoride and 99-1 mol % of at least one highly fluorinated monomer such as tetrafluoroethylene are disclosed. The interpolymers are characterized by the presence of ionic end groups and are prepared by polymerizing VF and fluorinated monomer in water with water-soluble free-radical initiators such as azoamidine initiators or persulfate initiators at temperatures within the range of 60 to 100° C. and reactor pressures within the range of 1 to 12 MPa (145 to 1760 psi). The invention further provides for protective self-supporting films and coatings formed from nonaqueous dispersions of the interpolymers, both for use on the surfaces of substrates including metal, plastic, ceramic, glass, concrete, fabric and wood.

Abstract: A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula: [R1—On-L-A?] Y+ wherein: R1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A? is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y+ is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R1—On-L- is not greater than 6 atoms.

Abstract: Crosslinkable fluoropolymers and crosslinked fluoropolymers prepared from select fluorinated monomers by dimerization and trimerization. Also disclosed are proton conductive membranes of these crosslinked fluoropolymers.

Abstract: In a process for the manufacture of fluoroelastomers, a water-soluble polymeric coagulant is employed that is an aqueous solution of polyethylene oxide homopolymer or copolymer having a viscosity average molecular weight of 500,000 or greater.

Abstract: Amorphous copolymers comprising 50-80 mole percent of monomer units derived from tetrafluoroethylene and 20 to 50 mole percent of monomer units derived from 1,2,3,3,3-pentafluoropropylene are provided.

Abstract: A true tetrafluoroethylene (TFE) copolymer of the fine powder type is provided, wherein the copolymer contains polymerized comonomer units of at least one comonomer other than TFE in concentrations of at least or exceeding 1.0 weight percent, and which can exceed 5.0 weight percent, wherein the copolymer is expandable, that is, the copolymer may be expanded to produce strong, useful, expanded TFE copolymeric articles having a microstructure of nodes interconnected by fibrils. Articles made from the expandable copolymer may include tapes, membranes, films, fibers, and are suitable in a variety of end applications, including medical devices.

Abstract: The present invention relates to the process of extruding melt drawing fluoropolymer onto conductor to form insulated conductor at a line speed of at least 533 m/min and having no more than 10 sparks and no more than 2 lumps/13.7 km of insulated conductor under conditions that comprise an adequate process window to allow for these results to be obtained at different conditions within the process window. The invention identifies the critical parameters for achieving this process window, namely melt flow rate of the fluoropolymer, preferably being 30±3 g/10 min, and the melt temperature of the extruding/melt-drawing step, preferably being 393° C.±6° C.

Abstract: A micropowder composition containing a granular PTFE micropowder, a fine powder PTFE micropowder, and a fine powder molding resin provides mixtures with fluoroelastomers containing copolymerized and alternating units of tetrafluoroethylene and propylene that provide molded articles having improved surface smoothness characteristics and tear resistance on molding. Processes for mixing additives with fluoroelastomers by adding or mixing the fluoroelastomer with the additives in the presence of micropowder PTFE compositions.

Abstract: The invention relates to a polyvinylidene fluoride polymer having an ultra-high molecular weight, and unexpected physical properties. The ultra-high molecular weight polymer is clear, has a lower melting point, reduced crystallinity, excellent impact resistance, and a high elongation at the yield point. The ultra-high molecular weight polyvinylidene fluoride can be alone, or blended with other polymers, in final applications and articles.

Abstract: The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.

Abstract: A fluoropolymer block copolymer containing a hydrofluorocarbon and a polyamide-based crosslinking agent crosslinked at a temperature above about 500° F. (about 260° C.). The crosslinked-block copolymer has compatibility with both non-hydrofluorocarbon-based fluoropolymers and engineered resins. Additionally, the block copolymer has unexpectedly high temperature stability, higher than each of the individual components.

Abstract: The present invention relates to a partially-crystalline copolymer comprising tetrafluoroethylene, hexafluoropropylene in an amount corresponding to HFPI of from about 2.8 to 5.3, and preferably from about 0.2% to 3% by weight of perfluoro(alkyl vinyl ether), said copolymer having less than about 50 ppm alkali metal ion, having a melt flow rate of within the range of about 30±3 g/10 min, and having no more than about 50 unstable endgroups/106 carbon atoms and which can be extruded at high speed onto conductor over a broad polymer melt temperature range to give insulated wire of high quality.

Abstract: The present invention provides a fluoropolymer capable of giving fluorine-containing molded materials and laminates excellent in moldability, productivity, interlaminar bonding and stress cracking resistance, in particular stress cracking resistance upon contacting with various liquid chemicals, without impairing such characteristics intrinsic in fluororesins as chemical resistance, solvent resistance, weathering resistance, antifouling properties, liquid chemical impermeability and nonstickiness. The present invention provides a fluoropolymer which is an oligomer-containing or oligomer-free fluoropolymer, wherein said oligomer has a molecular weight not higher than 10,000 and amounts to not more than 0.05% by mass relative to the fluoropolymer.

Abstract: Provided is a method of manufacturing a perhalogenated elastomer comprising using an onium compound to coagulate a latex comprising polymer particles, the polymer particles consisting essentially of interpolymerized units of one or more perhalogenated comonomer(s) and at least one cure site monomer, wherein the coagulation is performed essentially free of metal ions and metal salts. Also provided is an elastomeric composition comprising a curable perhalogenated elastomer comprising interpolymerized units derived from a nitrogen-containing cure site monomer and coagulated with an onium compound, wherein the elastomer is capable of curing without adding further components and wherein the composition is essentially free of metal ions and metal salts. Also provided are fluoropolymer articles and methods of making fluoropolymer compositions and articles.

Abstract: The present invention relates to a partially-crystalline copolymer comprising tetrafluoroethylene, hexafluoropropylene in an amount corresponding to hexafluoropropylene index (HFPI) of from about 2.8 to 5.3, and preferably from about 0.2% to 3% by weight of perfluoro(alkyl vinyl ether), said copolymer being polymerized and isolated in the absence of added alkali metal salts, having a melt flow rate of within the range of about 30±3 g/10 min, and having no more than about 50 unstable endgroups/106 carbon atoms can be extruded at high speed onto conductor over a broad polymer melt temperature range to give insulated wire of high quality.

Abstract: The present invention provides a fluorine-containing resin being excellent in mold-processability and providing an electric wire jacket having excellent flame retardance, low smoke releasing property, flexibility and mechanical properties. The fluorine-containing resin is a resin for an electric wire jacket substantially comprising, as a resin component, only a fluorine-containing copolymer having a MFR of 11 to 27 g/10 min and comprising tetrafluoroethylene and a perfluoro ethylenically unsaturated compound represented by the formula: CF2?CF—Rf1, wherein Rf1 represents —CF3 and/or —ORf2; Rf2 represents a perfluoroalkyl group having 1 to 5 carbon atoms. The present invention also provides an electric wire jacket.

Abstract: The present invention relates to the reduction of oligomer content of melt-processible fluoropolymer so that the fluoropolymer has at least 25 ppm less oligomer than the as-polymerized fluoropolymer.

Abstract: A process is disclosed for the manufacture of CHClF2 which involves contacting CHCl3, HF and pentavalent antimony catalyst in the liquid phase; passing reactor vapor effluent to a reflux column to produce a reflux column vapor effluent of CHClF2 and HCl; passing the reflux column vapor effluent to a condenser to produce a condenser liquid effluent of CHClF2 and a condenser vapor effluent of CHClF2 and HCl; passing the condenser liquid effluent to the reflux column upper end; and recovering CHClF2 from the condenser vapor effluent.

Abstract: The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.

Abstract: Amorphous hydrofluoroolefin telomers are prepared by a free-radical polymerization process conducted at high temperature and pressure in the presence of non-monomeric chain transfer agent.

Abstract: Interpolymers of 1-99 mol % vinyl fluoride and 99-1 mol % of at least one highly fluorinated monomer such as tetrafluoroethylene are disclosed. The interpolymers are characterized by the presence of ionic end groups and are prepared by polymerizing VF and fluorinated monomer in water with water-soluble free-radical initiators such as azoamidine initiators or persulfate initiators at temperatures within the range of 60 to 100° C. and reactor pressures within the range of 1 to 12 MPa (145 to 1760 psi). The invention further provides for protective self-supporting films and coatings formed from nonaqueous dispersions of the interpolymers, both for use on the surfaces of substrates including metal, plastic, ceramic, glass, concrete, fabric and wood.

Abstract: Chain end functionalized fluoropolymers are disclosed exhibiting good chemical reactivity high breakdown electric field (E>100 MV/m) and high dielectric constants (i.e., ?>10). The polymers can be prepared by functional initiators and from a variety of fluoromonomers including vinylidene difluoride together with one or more additional monomers. The polymers can be combined with other dielectric materials to form composites having uniform composition and morphology.

Abstract: A heat sealable tape of a copolymer of tetrafluoroethylene and at least about 15% by weight of a highly fluorinated monomer. The copolymer has a melt viscosity of no greater than about 1000 Pa·S at 372° C. and an application temperature of no greater than about 250° C. The invention further provides for a seam formed from two sections of sheet material, especially fabric, wherein each sheet has at least one fluoropolymer surface. The sections are sealed one to the other by application of heat sealable composition over one fluoropolymer surface of each section. The heat sealable composition comprises a copolymer of tetrafluoroethylene and at least about 15% by weight of a highly fluorinated monomer, the copolymer having a melt viscosity of no greater than about 1000 Pa·S at 372° C. and an application temperature of no greater than about 250° C.

Abstract: The present invention relates to a method for producing a fluorocopolymer which comprises a polymerization reaction of a fluorine-containing ethylenic monomer with a fluorovinyl ether derivative represented by the following general formula (I): CF2?CF—O—[CF2CF(CF3)O]n—(CF2)m-A??(I) (wherein n represents an integer of 0 to 3, m represents an integer of 1 to 5, and A represents —SO2X or —COOY; X represents a halogen atom or —NR1R2; R1 and R2 are the same or different and each represents a hydrogen atom, an alkali metal, an alkyl group or a sulfonyl-containing group and Y represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) to give a fluorocopolymer, said fluorine-containing ethylenic monomer being a perhaloethylenic monomer represented by the following general formula (II): CF2?CF—Rf1??(II) (wherein Rf1 represents a fluorine atom, a chlorine atom, Rf2 or ORf2; Rf2 represents a straight or branched perfluoroalkyl group having 1 to 9 carbon atoms, which may have an ether oxygen atom(s)) a

Abstract: Provided is a method of manufacturing a perhalogenated elastomer comprising using an onium compound to coagulate a latex comprising polymer particles, the polymer particles consisting essentially of interpolymerized units of one or more perhalogenated comonomer(s) and at least one cure site monomer, wherein the coagulation is performed essentially free of metal ions and metal salts. Also provided is an elastomeric composition comprising a curable perhalogenated elastomer comprising interpolymerized units derived from a nitrogen-containing cure site monomer and coagulated with an onium compound, wherein the elastomer is capable of curing without adding further components and wherein the composition is essentially free of metal ions and metal salts. Also provided are fluoropolymer articles and methods of making fluoropolymer compositions and articles.

Abstract: The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.

Abstract: Melt-processible, thermoplastic poly(tetrafluoroethylene) (PTFE) compositions are disclosed and methods for making and processing same. Additionally, products comprising these compositions are described.

Abstract: Fluoropolymers are made by admixing tetrafluoroethylene, hexfluoropropylene, and vinylidene fluoride; reacting the reaction admixture to generate a set of fluoropolymeric oligomers; irradiating the fluoropolymeric oligomeric precursor admixture (preferably with electron beam radiation) to form free radical sites on individual fluoropolymeric oligomers of the set and generate thereby a set of free radical oligomer derivatives in the fluoropolymeric oligomeric precursor admixture; and reacting the fluoropolymeric oligomeric precursor admixture to derive the fluoropolymer compound from the free radical oligomer derivatives. In a second approach, fluoropolymers are made by admixing tetrafluoroethylene, hexfluoropropylene, and vinylidene fluoride and irradiating the admixture.

Abstract: The present invention provides an ambient temperature curable fluoroelastomer coatings and coated articles to provide improved elongation, and adhesion to substrates especially flexible elastomeric substrates. The curable coating mixture is a mixture of two parts, part A containing a solution of a fluoroelastomer containing a specified acid number, and the other part B providing a curing component which is a mono-primary amine containing silane or condensate.

Abstract: The present invention relates to the reduction of oligomer content of melt-processible fluoropolymer so that the fluoropolymer has at least 25 ppm less oligomer than the as-polymerized fluoropolymer, the reduction being obtained by melting the fluoropolymer forming a surface of molten fluoropolymer and regenerating this surface, contacting the regenerating surface with inert gas, and devolatilizing the resultant molten fluoropolymer.

Abstract: A fluororubber sealant composition includes 100 parts by weight of a fluororubber, which is a copolymer having a cross-linking site derived from a bromine-containing and/or iodine-containing compound, capable of crosslinking with peroxide and having a component unit composition comprising 20 to 23% by mol of a perfluoromethyl vinylether component unit, 60 to 70% by mol of a vinylidene fluoride component unit, 10 to 20% by mol of a tetrafluoroethylene component unit, 0 to 10% by mol of hexafluoropropylene component unit (based on 100% of the total of the above component units), and a small amount of a bromide and/or iodide unsaturated fluorohydrocarbon component unit as a crosslinking site based on 100% by mol of the total of the above component units; and further comprising, based on 100 parts by weight of the fluororubber, 2 to 50 parts by weight of a bituminous fine powder; 0.5 to 6 parts by weight of an organoperoxide; and 1 to 10 parts by weight of a polyfunctional monomer.

Abstract: The invention relates to high purity fluoropolymers and processes for making such materials. These polymers are particularly suited for applications in the semiconductor industry. The process comprises removal of unstable polymer end groups by fluorination and removal of heavy metal impurities by extraction with an aqueous acid medium.

Abstract: A tetrafluoroethylene/hexafluoropropylene copolymer with high drawability is provided. Also provided is a process employing the polymer and an article coated with the polymer.