Abstract: The present invention relates to a gas phase process for polymerizing one or more hydrocarbon monomer(s) in the presence of a catalyst system and a fluorinated hydrocarbon, where the fluorinated hydrocarbon is present at a partial pressure of 6.9 to 348 kPa in the reactor and the reactor temperature is from 30 to 120° C.

Abstract: A vinylidene fluoride-based resin film including polyvinylidene fluoride whose average spherocrystal diameter is less than 0.1 ?m that is a detection limit or lower by observation using a transmission electron microscope is provided, the average spherocrystal diameter being obtained by shaping a vinylidene fluoride-based resin in a molten state by sandwiching the resin between rollers or metal belts so as to let it cool down. Thereby, a vinylidene fluoride-based resin film and a vinylidene fluoride-based resin multilayered film having excellent transparency, weather resistance, chemical resistance, break resistance and formability are provided.

Abstract: Methods for producing elastomers or elastomeric compositions are provided. One or more C4 to C7 isoolefins and one or more comonomers can be polymerized in the presence of a diluent comprising one or more hydrofluorocarbons to provide a slurry comprising polymer product, unreacted monomer and the diluent. The slurry can be extruded to separate at least a portion of the diluent from the polymer product. The separated diluent can be recycled for polymerizing the one or more C4 to C7 isoolefins.

Abstract: Disclosed are partially fluorinated and fully fluorinated polymers that are substantially transparent to ultraviolet radiation at wavelengths from approximately 150 nanometer to 260 nanometers.

Abstract: To provide a fluorinated polymer which enables to reduce the amount of residual ink on partition walls and to form an ink layer having high uniformity in film thickness, and a negative photosensitive composition. A fluorinated polymer which is a copolymer made of at least two monomers each having an ethylenic double bond, and which has a side chain having a C20 or lower alkyl group in which at least one of its hydrogen atoms is substituted by a fluorine atom (provided that the alkyl group may contain an etheric oxygen atom between carbon atoms) and a side chain having at least two ethylenic double bonds per side chain.

Abstract: A fluorecopolymer which comprises repeating units (a) based on tetrafluoroethylene, repeating units (b) based on perfluoro(methyl vinyl ether) and repeating units (c) based on perfluoro(propyl vinyl ether) in a molar ratio of (a)/(b)/(c) of 40-70/3-57/3-57. The fluorocopolymer is a perfluoroelastomer which is excellent in low temperature characteristics, heat resistance and chemical resistance.

Abstract: The invention provides a polymer having (a) at least one repeat unit derived from an ethylenically unsaturated compound having at least one fluorine atom covalently attached to an ethylenically unsaturated carbon atom; and (b) at least one repeat unit derived from an ethylenically unsaturated cyclic compound of structure: (I) wherein n is 0, 1, or 2; and R2 to R4 are independently H; C1-C10 alkyl or alkoxy, optionally substituted by halogen or ether oxygens; or C6-C20 aryl. These polymers can be used in making photoresist compositions and coated substrates.

Abstract: A fluorocopolymer and film thereof exhibiting excellent transparency and mechanical strength at ambient and elevated temperatures, wherein the fluorocopolymer includes polymerized units based on ethylene (E), tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and perfluoro(alkyl vinyl ether) (PFAV), wherein the molar ratio of polymerized units based on E/TFE is from 10/90 to 60/40, the content of polymerized units based on HFP is from 0.2 to 0.9 mol % based on the total number of polymerized units, and the content of polymerized units based on PFAV is from 0.1 to 1.0 mol % based on the total number of polymerized units.

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: Perfluoroelastomers that contain high levels (i.e. about 40 mole percent or more) of perfluoro(alkyl vinyl ether) copolymerized units can form stable blends with higher levels of perfluoropolyethers than can perfluoroelastomers that contain lower levels of perfluoro(alkyl vinyl ether) units. Thus, the former blends have better low temperature properties than the latter.

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: The present invention provides a process for preparing a fluorine-containing elastomer in a high productivity comparable to that of non-iodine transfer polymerization process by carrying out an iodine transfer polymerization at high pressure. The present invention also provides a fluorine-containing elastomer prepared by this process, and fluorine-containing molded articles. The process is a batch copolymerization process conducted under conditions that the reduced temperature of the critical constant is at least 0.95 and the reduced pressure of the critical constant is at least 0.80 wherein the reduced temperature and the reduced pressure are calculated using the Peng-Robinson formula from the critical temperature, the critical pressure and the composition ratio of each of the monomers in the gaseous phase in a reaction vessel, in which ethylenically unsaturated compounds containing at least one fluoroolefine are copolymerized in the presence of a compound having the formula: Rf1.

Abstract: Blends of PVDF (polyvinylidene fluoride) homopolymer or copolymer with ABC triblock copolymers are useful for manufacturing parts which may be sheets, film, tubes, rods, centrifugal pump components and containers. The PVDF comprises a fraction of non-transferred chains of very high molar mass which are insoluble in the usual solvents for PVDF, such as DMF (dimethylformamide), DMSO (dimethyl sulphoxide) and NMP (N-methylpyrrolidone), the polymer fraction associated with these high-mass chains having a dynamic viscosity of greater than 50 kpoise at 230° C., and at a shear rate of 100 s1, and has spherulites with a size between 0.5 and 4?m.

Abstract: Disclosed is a method for producing a fluorine-containing elastomer polymer which is excellent in productivity and crosslinkability. Specifically disclosed is a method for producing a fluorine-containing elastomer polymer wherein a fluorine-containing monomer is polymerized in an aqueous solvent in the presence of an emulsifying agent containing a fluorine-containing vinyl group and a chain transfer agent. This method for producing a fluorine-containing elastomer polymer is characterized in that the emulsifying agent containing a fluorine-containing vinyl group is composed of a compound having a radically polymerizable unsaturated bond and a hydrophilic group in a molecule.

Abstract: Provided is a method comprising polymerizing at least one fluorinated monomer in an aqueous emulsion polymerization in the presence of a carbosilane surfactant having at least one hydrophobic part, wherein the hydrophobic part has at least one silicon atom, and having at least one hydrophilic part, with the proviso that the carbosilane contains no Si—O bonds.

Abstract: A fluorocopolymer film formed by molding at a molding temperature of at most 320° C. a fluorocopolymer comprising repeating units based on ethylene, repeating units based on tetrafluoroethylene, repeating units based on hexafluoropropylene and repeating units based on a fluoroalkyl vinyl ether represented by CF2?CFORf (wherein Rf represents a C1-10 fluoroalkyl group), having a molar ratio of the repeating units based on ethylene/the repeating units based on tetrafluoroethylene of from 10/90 to 60/40, a content of the repeating units based on hexafluoropropylene to the total repeating units of from 0.1 to 20 mol % and a content of the fluoroalkyl vinyl ether to the total repeating units of from 0.1 to 10 mol %, and having a volumetric flow rate of from 0.1 to 30 mm3/sec at 297° C.

Abstract: Fluorine-containing emulsifiers can be removed from fluoropolymer dispersions by adding to the dispersion a non ionic emulsifier, removing the fluorine-containing emulsifier by contact with an anion exchanger and separating the dispersion from the anion exchanger. The resulting dispersions can be concentrated and used for coating applications.

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: 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: The present invention provides a process for preparing a fluorine-containing polymer having few branched chains and little weight change in high temperatures, which is a new process wherein composition distribution substantially does not occur. The fluorine-containing polymer is prepared by a batch copolymerization process conducted under conditions of reduced temperature of at least 0.95 and reduced pressure of at least 0.80 of the critical constant calculated from critical temperature, critical pressure and composition ratio of each monomer in the gaseous phase of the reaction vessel using the Peng-Robinson formula.

Abstract: The present invention provides an aqueous non-melt processible polytetrafluoroethylene dispersion comprising non-melt processible polytetrafluoroethylene particles in an amount between 30 and 70% by weight based on the total weight of the dispersion and one or more non-ionic surfactants and wherein at least a part of said non-melt processible polytetrafluoroethylene particles comprise polytetrafluoroethylene polymer chains having repeating units comprising ionic groups. The invention further provides a method for obtaining the dispersions.

Abstract: A fluoropolymer composition comprising a fluoropolymer with a particle size distribution having a ratio of the mode to D95 of 0.75 or greater and wherein when the fluoropolymer is a copolymer consisting of interpolymerized units derived from tetrafluoroethylene and perfluoro(propyl vinyl) ether, the fluoropolymer has less than 60 unstable endgroups per million carbon atoms; coated articles comprising the fluoropolymer; and methods for making the same.

Abstract: The invention provides surfactant-containing cosmetic, dermatological, and pharmaceutical agents comprising at least one water-soluble or water-swellable copolymer obtainable by free-radical copolymerization of A) acryloyldimethyltaurine and/or acryloyldimethyltaurates, B) optionally, one or more further olefinically unsaturated, noncationic comonomers, C) optionally, one or more olefinically unsaturated, cationic comonomers, D) optionally, a silicon-containing component(s), E) optionally, a fluorine-containing component(s), F) optionally, one or more macromonomers, G) the copolymerization taking place if desired in the presence of at least one polymeric additive, H) with the proviso that component A) is copolymerized with at least one component selected from one of the groups D) to G).

Abstract: Provided are a polymer compound having high transparency for use in a photoresist composition for microfabrication of the next generation, a resist composition using the polymer compound as a base polymer, and a dissolution inhibitor agent composed of the polymer compound. To ensure etching resistance, an alicyclic group is introduced into a side chain portion. Hydrogen atoms on the ring of the alicyclic group are highly fluorinated to ensure transparency to light of 157 nanometer wavelength, represented by an adsorption coefficient equal to or less than 3.0 ?m?1. As the alicyclic group, a polycyclic group is preferably used. Hydrogen atoms are highly fluorinated by preferably substituting all hydrogen atoms on the ring by fluorine atoms, that is, forming a perfluoroalicyclic group. The resist composition is formed by using the polymer compound as a base polymer and further, the dissolution inhibitor agent is formed of the polymer compound.

Abstract: A process comprising polymerizing tetrafluoroethylene in an aqueous emulsion in the presence of a non-telogenic surfactant having an anionic portion with the general formula (I): Rf—O-L-CO2— ??(I) wherein Rf is selected from a partially fluorinated alkyl group, a perfluorinated alkyl group, a partially fluorinated alkyl group interrupted by one or more oxygen atoms, and a perfluorinated alkyl group interrupted by one or more oxygen atoms, wherein Rf has from 1 to 10 carbon atoms; and L is an alkylene group having the general formula (CX2)n wherein each X is independently selected from Rf, fluorine, and hydrogen and n is selected from 1 to 5, with the proviso that the surfactant contains at least one unit selected from a —CH2— unit and a —CHF— unit. Also provided are aqueous dispersions comprising these surfactants and methods of coating substrates with the aqueous dispersions.

Abstract: This invention provides a fluorine-containing copolymer having a repeat unit derived from at least one fluorinated olefin and a repeat unit derived from at least one polycyclic ethylenically unsaturated monomer having pendant hydroxyl or esterified hydroxyl groups, and optionally other repeat units, typically derived from an acrylate. These polymers have high transparency at short wavelengths such as 193 nm and 157 nm, and provide good plasma etch resistance and adhesive properties. Also provided are photoresist compositions and substrates coated therewith.

Abstract: Anionic species are removed from aqueous dispersions of ionic fluoropolymers using anion exchange resins. In some embodiments, cationic species are also removed using cation exchange resins.

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: This invention concerns radiation durable organic compositions which are well-suited for use in 157 nm lithography by virtue of their high transparency and excellent radiation durability, and to a process for the preparation thereof.

Abstract: The present invention provides a method of preparing an aqueous dispersion of poly(perfluorovinyl ether) homopolymers. The present invention further relates to a method of making an aqueous fluoropolymer dispersion comprising bicomponent particles of poly(perfluorovinyl ether) homopolymers and a second fluoropolymer. The dispersions of the present invention may be used for rendering fibrous substrates oil repellent, water repellent and/or stain repellent without altering the looks and feel of the substrate.

Abstract: The invention provides a surfactant-free cosmetic, dermatological, and pharmaceutical agents comprising at least one copolymer obtainable by free-radical copolymerization of A) acryloyldimethyltaurine and/or acryloyldimethyltaurates, B) optionally, one or more further olefinically unsaturated, noncationic comonomers, C) optionally, one or more olefinically unsaturated, cationic comonomers, D) optionally, one or more silicon-containing component(s), E) optionally, one or more fluorine-containing component(s), F) optionally, one or more macromonomers, G) the copolymerization taking place if desired in the presence of at least one polymeric additive, H) with the proviso that component A) is copolymerized with at least one component selected from one of the groups D) to G).

Abstract: An aqueous non-melt processible polytetrafluoroethylene dispersion having non-melt processible polytetrafluoroethylene particles in an amount of 30 to 70% by weight and an amount of non-ionic surfactant between 2 and 15% by weight based on the weight of polytetrafluoroethylene solids. The dispersion is free of fluorinated surfactant or contains fluorinated surfactant in amounts of not more than 200 ppm based on the amount of polytetrafluoroethylene solids. At least part of the non-melt processible polytetrafluoroethylene particles comprise an effective amount of ionic end groups in the polytetrafluoroethylene polymer chains.

Abstract: The invention relates to uses of comb polymers of acryloyldimethyltaurine and/or acryloyldimethyltaurates in cosmetic, pharmaceutical and dermatological applications as thickeners, dispersing agents, suspending agents, emulsifiers, stabilizers, solubilizers, conditioning agents, consistency-giving agents, lubricants, bonding agents and/or conditioners. The comb polymers of the present invention comprise at least one copolymer.

Abstract: An aqueous semi-batch polymerization process is disclosed for the manufacture of dipolymers of tetrafluoroethylene and 3,3,3-trifluoropropene that contain between 45 and 95 mole percent tetrafluoroethylene and between 5 and 55 mole percent 3,3,3-trifluoropropene.

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: A fluorocopolymer which comprises (A) polymerized units based on tetrafluoroethylene, (B) polymerized units based on ethylene and (C) polymerized units based on itaconic anhydride or citraconic anhydride, wherein the molar ratio of (A)/(B) is from 20/80 to 80/20, and the molar ratio of (C)/((A)+(B)) is from 1/10000 to 5/100, and which has a volume flow rate of from 1 to 1000 mm3/sec. The fluorocopolymer is excellent in the fuel barrier properties and in the adhesive properties to a non-fluorinated polymer.

Abstract: Melt-fabricable, tough copolymer of tetrafluoroethylene and fluorinated vinyl ether is produced in a suspension polymerization process by copolymerizing tetrafluoroethylene and fluorinated vinyl ether in a pressurized, agitated reaction vessel which contains aqueous medium, free radical initiator, and a telogen, the aqueous medium being essentially free of fluorine containing organic solvent. The contents of the reaction vessel are agitated during polymerization sufficiently to coagulate copolymer of tetrafluoroethylene and fluorinated vinyl ether. The melt-fabricable, tough copolymer having a melt viscosity of less than about 1×106 Pa·S is isolated directly from the reaction vessel.

Abstract: A process for producing an elastic fluorocopolymer, which comprises emulsion-polymerizing at least one fluoromonomer (a) selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and a perfluorovinyl ether represented by CF2?CF—O—Rf (wherein Rf is a C1-8 perfluoroalkyl group or a perfluoro(alkoxyalkyl) group), a vinyl ester monomer (b) represented by the formula CR1R2?CR3COOCH?CH2 (wherein each of R1 and R2 which are independent of each other, is a hydrogen atom, a C1-10 alkyl group or a C1-10 alkoxyalkyl group containing an etheric oxygen atom, and R3 is a hydrogen atom, a fluorine atom or a methyl group), and as the case requires, at least one hydrocarbon monomer (c) selected from the group consisting of ethylene, propylene and a vinyl ether represented by CH2?CH—O—R4 (wherein R4 is a C1-8 alkyl group or an alkoxyalkyl group), in an aqueous medium to produce an elastic fluorocopolymer latex, adjusting the pH of the elastic fluorocopolymer latex to from 1 to 9, and c

Abstract: The invention relates to cosmetic and dermatological hair treatment compositions comprising at least one copolymer. The copolymer is obtained by free-radical copolymerization of A) acryloyldimethyltaurine and/or acryloyldimethyltaurates, and B) optionally, one or more further olefinically unsaturated, noncationic comonomers, C) optionally, one or more olefinically unsaturated, cationic comonomers, D) optionally, one or more silicon-containing component(s), E) optionally, one or more fluorine-containing component(s), F) optionally, one or more macromonomers, G) optionally, the copolymerization taking place in the presence of at least one polymeric additive, H) with the proviso that component A) is copolymerized with at least one component selected from one of the groups D) to G).

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: Unsintered poly(tetrafluoroethylene) resin feeds are treated with ionizing radiation in an absorbed dose of no more than 1,000 Gy at room temperature in air so that only the melting temperature of the resin feeds is shifted toward the lower end without changing the quantities of heat of fusion and crystallization.

Abstract: Sulphonic fluorinated ionomers crosslinked by radical crosslinking of: A) crosslinkable sulphonic fluorinated ionomers, having equivalent weight 380–1300 g/eq and comprising: from 48% to 85% by moles of monomeric units deriving from tetrafluoroethylene (TFE); from 15% to 47% by moles of fluorinated monomeric units containing sulphonyl groups —SO2F; from 0.01% to 5% by moles of monomeric units deriving from a bis-olefin of formula: wherein: m=2–10, preferably 4–8; R1, R2, R5, R6, equal to or different from each other, are H or C1–C5 alkyl groups; B) a fluorinated compound as crosslinking radical initiator; C) a fluorinated bis-olefin of structure (I) as crosslinking agent; the radical crosslinking being carried out at a temperature in the range 250° C.–310° C., preferably 260° C.–300° C.

Abstract: The present invention provides a polyvinylidene fluoride copolymer capable of forming a uniform film, a solution of the copolymer and a thin film comprising the polyvinylidene fluoride copolymer. The polyvinylidene fluoride copolymer of the present invention is characterized in that the ratio of the scattered-light intensity (I) for a 15% solution of the polyvinylidene fluoride copolymer in dimethylformamide solvent to the scattered-light intensity (I0) for dimethylformamide, (I/I0), is 10 or lower. The polyvinylidene fluoride copolymer solution comprises the polyvinylidene fluoride copolymer and an organic solvent capable of dissolving the copolymer.

Abstract: A fluorocopolymer which comprises (a) polymerized units based on tetrafluoroethylene and/or chlorotrifluoroethylene, (b) polymerized units based on a fluorinated monomer (excluding tetrafluoroethylene and chlorotrifluoroethylene) and (c) polymerized units based on at least one member selected from the group consisting of itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride, wherein (a) is from 50 to 99.8 mol %, (b) is from 0.1 to 49.99 mol %, and (c) is from 0.01 to 5 mol %, based on ((a)+(b)+(c)), and which has a volume flow rate of from 0.1 to 1000 mm3/sec.

Abstract: The present invention is generally directed to perfluoroalkylated fluorene polymers. It further relates to a process for preparing the polymers and devices that are made with the polymers.

Abstract: A process for producing low molecular weight, granular polytetrafluoroethylene or modified polytetrafluoroethylene by suspension polymerization of pressurized tetrafluoroethylene in an agitated reaction vessel. The polymerization is conducted in aqueous medium in the presence of a free radical initiator, and a telogen. The reaction vessel is agitated during polymerization sufficiently to coagulate the polytetrafluoroethylene or modified polytetrafluoroethylene. Low molecular weight granular polytetrafluoroethylene or modified polytetrafluoroethylene having a melt viscosity of less than about 1×106 Pa·S powder is isolated directly from the reaction vessel.

Abstract: The present invention has for its object to provide a method of producing fluoropolymers with high productivity under comparatively low temperature and low pressure conditions which are conducive to reduced cost of commercial-scale production equipment. The present invention is directed to a method of producing a fluoropolymer which comprises polymerizing a radical polymerizable monomer in a defined reaction-field, said radical polymerizable monomer comprising a fluorine-containing ethylenic monomer and said defined reaction-field being in supercriticality-expression state with a monomer density [?m]-monomer critical density [?0] ratio of [?m/?0] not less than 1.1.

Abstract: Highly ozone-resistant molding/shaped articles inclusive of piping materials and joints for use in semiconductor production lines, molding materials for ozone-resistant molding/shaped articles which are suited for the production of the molding/shaped articles, and ozone-resistant injection-molded articles and relevant injection-molding materials. Also disclosed is a molding material for ozone-resistant molding/shaped articles including a copolymer (A) and having a melt flow rate of 0.1–50 g/10 minute. The copolymer (A) is a copolymer including tetrafluoroethylene and a perfluorovinylether, and has not less than 3.5 mass % of a perfluorovinylether unit, a melting point of not less than 295° C., and not more than 50 of unstable terminal groups per 1×106 carbon atoms in the copolymer (A).

Abstract: An ion exchange fluorocarbon resin membrane having a storage modulus (JIS K-7244), when substituted with tributyl ammonium ions, at a temperature of not less than Tc represented by the following general equations (1-1) to (1-3) of 0.8×106 Pa or more, and a heat of crystal fusion at 270 to 350° C. of 1 J/g or less: Tc (° C.)=55+Tg (EW<750)??(1-1) Tc (° C.)=0.444×EW?278+Tg (750?EW<930)??(1-2) Tc (° C.)=135+Tg (EW?930)??(1-3) where Tg designates the peak temperature of loss tangent in the dynamic viscoelasticity measure-ment of the ion exchange fluorocarbon resin membrane (having SO3H as the ends of the side chains).

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.