Abstract: The present disclosure relates to a method of treating a substrate comprising an elastomeric material, wherein the method comprises the steps of: a) providing a composition comprising: i. at least one fluoropolymer which is a copolymer comprising at least 90% by weight, based on the total weight of the copolymer, of units derived from tetrafluoroethene (TFE) and from one or more perfluorinated alkyl ethers corresponding to the general formula (I): Rf1—O—(CF2)n—CF?CF2 (I) wherein n is 1 or 0 and Rf1 represents a perfluoroalkyl residue which is optionally interrupted once or more than once by an oxygen atom; and ii.

Abstract: Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 1×102 to 7×105 Pa·s at 380° C., having a melt viscosity of 1×102 to 7×105 Pa·s at 380° C., having an average particle size of 1.0 to 50 ?m, and containing 30 or more carboxyl groups at ends of the molecule chain per 106 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

Abstract: Powder including low molecular weight polytetrafluoroethylene having a melt viscosity of 1×102 to 7×105 Pa·s at 380° C., having a melt viscosity of 1×102 to 7×105 Pa·s at 380° C., having an average particle size of 1.0 to 50 ?m, and containing 30 or more carboxyl groups at ends of the molecule chain per 106 carbon atoms in the main chain, wherein the powder is substantially free from C8-C14 perfluorocarboxylic acids and salts thereof.

Abstract: The present invention provides a processing additive which can bring about improvements in moldability at Mooney viscosity levels at which the dispersibility in a melt-processable resin is high and which further can work at reduced addition levels. The present invention is a processing additive comprising a fluoropolymer having an acid value of not lower than 0.5 KOH mg/g.

Abstract: To provide a fluorinated coating material capable of forming a coating film excellent in water repellency and substrate adhesion. Further, to provide a method for producing the coating material, a coated article and its production method. A fluorinated coating material comprising a fluorinated polymer having the following units F, the following units 1 and the following units 2: units F: at least one type of units selected from the group consisting of units based on CF3—CH?CHF and units based on CF3—CF?CH2; units 1: at least one type of units selected from the group consisting of units having a carboxy group, units based on allyl alcohol and units based on a hydroxyalkyl allyl ether; units 2: at least one type of units selected from the group consisting of units based on a vinyl ether, units based on a vinyl ester, units based on an allyl ether (excluding a hydroxyalkyl allyl ether), units based on an allyl ester and units based on a (meth)acrylic acid ester.

Abstract: A powder coating material which has excellent blocking resistance and can form coating films excellent in water repellency is provided. The powder coating material of the present invention comprises a fluorinated polymer comprising from 20 to 80 mol % of units based on at least one species selected from the group consisting of CF3—CH?CHF and CF3—CF?CH2, from 18 to 60 mol % of units based on a monomer represented by the formula X1—Z1 (wherein X1 is a specific monovalent polymerizable group, and Z1 is a specific alkyl group, a specific cycloalkyl group or a specific aryl group) and units having a crosslinkable group.

Abstract: The present invention pertains to a fluoropolymer hybrid organic/inorganic composite, to a film comprising said fluoropolymer hybrid organic/inorganic composite and to uses of said film in various applications, in particular in electrochemical and in photo-electrochemical applications.

Abstract: Described herein is an oligomer according to formula I: (I) wherein Y is an anionic group selected from the group consisting of: sulfates, carboxylates, phosphate, phosphonate, and sulfonate, wherein each X1, X2, and X3 are independently selected from F, Cl, H, and CF3; R is a linking group; each Z1 and Z2 is independently selected from F and CF3; m is at least 2; and R1 and R2 are end groups, wherein the oligomer comprises substantially no pendant functional groups, except those selected from the group consisting of: sulfates, carboxylates, phosphate, phosphonate, and sulfonate.

Abstract: The present invention relates to a process for the preparation of a composite material comprising a vinylidene difluoride (VDF)-containing copolymer and an electrically non-conductive polymeric material, to a composite material obtainable via said process, to its use in electrochemical cells and to an electrochemical cell comprising said composite.

Abstract: Described herein is a millable fluorinated block copolymer having at least one A block and at least one B block, wherein the A block is a semi-crystalline segment comprising repeating divalent monomeric units derived from TFE, HFP and VDF; and the B block is a segment comprising repeating dilvalent monomeric units derived from HFP and VDF; and wherein the millable fluorinated block copolymer has a modulus of 0.1 to 2.5 MPa at 100° C.

Abstract: Disclosed are protective coating compositions having enhanced gloss retention properties formed by steps comprising: (i) providing one or more fluorocopolymers by copolymerization of (1) one or more hydrofluoroolefin monomer(s) selected from the group consisting of hydrofluoroethylenes, hydrofluoropropenes, hydrofluorobutenes, hydrofluoropentenes and combinations of these, (2) one or more vinyl ester monomer(s), and (3) one or more vinyl ether monomer(s), wherein at least a portion of said vinyl ether monomer is a hydroxyl group-containing vinyl ether monomer, wherein the copolymer preferably has a number average molecular weight of greater than about 10,000; (ii) providing a VOC containing carrier for said one or more fluorocopolymers; and (iii) providing a stabilizing agent comprising: a) a radical scavenger and b) an absorber of UV light; and (iv) combining said one or more fluorocopolymers with said carrier and said stabilizing agent to produce a polymeric coating composition.

Abstract: An electrolyte composition (A) containing (i) at least one aprotic organic solvent; (ii) at least one conducting salt; (iii) at least one compound of formula (I) wherein A1, A2, A3, A4, A5, and A6 are independently from each other selected from H and F, wherein at least one of the group A1, A2, A3, A4, A5, and A6 is F; R is selected from R1, and C(O)OR1, and R1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, C2-C6 alkenyl, C3-C6 cycloalkenyl, C5-C7 (hetero)aryl, and C2-C6 alkinyl, wherein alkyl, cycloalkyl, alkenyl, cycloalkenyl, (hetero)aryl, and alkinyl may be substituted by one or more F; and (iv) optionally at least one further additive.

Abstract: In an aspect, a binder composition, a cathode including the same, and a lithium battery including the cathode, wherein the binder composition includes a first fluorine containing binder including a polar functional group; a second fluorine containing binder not including a polar functional group; and a non-fluorine containing binder including a repeating unit resulting from polymerization of an acryl monomer and a repeating unit resulting from polymerization of an olefin monomer, wherein the first fluorine containing binder is a vinylidene fluoride containing binder is provided.

Abstract: The present invention pertains to a fluoropolymer hybrid organic/inorganic composite, to a process for manufacturing said fluoropolymer hybrid organic/inorganic composite and films and membranes thereof and to uses of said fluoropolymer hybrid organic/inorganic composite and films and membranes thereof in various applications.

Abstract: The present invention pertains to a hybrid fluoropolymer composition, to a process for its manufacture and to its use in the manufacture of fluoropolymer films.

Abstract: The present invention provides a composition including a fluorine-containing polymer, and excellent in heat resistance even if only a small amount of additives is added to the composition. The present invention relates to a composition, comprising: a fluorine-containing polymer (a) and a cobalt compound (b).

Abstract: This disclosure is directed to a plate design for use in variable data digital lithographic image forming devices. The disclosed plate design incorporates surface passivated carbon black filler material particles in a fluorosilicone polymer. The disclosed functionalized carbon black material compositions include hydrophobic carbon black particles surface passivated via the use of an A/B-block copolymer where the A/B block contains a pentafluorostyrene-maleimide alternating polymer and the B block contains pure pentafluorostyrene. The A/B portion allows for the polymer to adsorb onto the carbon black while the b-block acts as the stabilizer in fluorinated systems. Fine dispersions result from the addition of poly (pentafluorostyrene/Maleimide-b-pentafluorostyrene) or P(PFS/MI-b-PFS) passivated carbon black to fluorinated polymers, enhancing the physical and mechanical properties.

Abstract: Provided is a dripping inhibitor excellent in handling characteristics. The present invention provides a dripping inhibitor including a modified polytetrafluoroethylene, the inhibitor having an average particle size of 300 to 800 ?m, an apparent density of 0.40 to 0.52 g/ml, a compression ratio of 1.20 or less, an aggregate disintegration degree with 50-sec vibration of 70% or more, a cylinder extrusion pressure at a reduction ratio 1500 of 80 MPa or less, and a standard specific gravity (SSG) of 2.140 to 2.230.

Abstract: A manufacturing method for ceramic tile products comprises the steps of providing a green body and sintering the green body. The green body has a composition comprising gypsum ranging from 15 to 35% weight of the green body and a subsidiary material ranging from 65 to 85% weight of the green body.

Abstract: A sheet ejection device comprises an ejection roller pair (20) which ejects a sheet by a pressure contact portion (N) in which a first roller (21) and a second roller (22) are in pressure contact with each other. In the first roller (21), protrusions (41) that protrude in a roller diameter direction in order to push the back end of the sheet ejected with the rotation of the first roller (21) are formed. The protrusions (41) are provided in a flange (45) at a predetermined distance from the peripheral end (43a) of a cylindrical portion (42) of the first roller (21) in a sheet width direction. The distance from the center of rotation of the flange (45) to the front end (41c) of each of the protrusions (41) is equal to or less than the radius of the cylindrical portion (42).

Abstract: The invention concerns a method for preparing block copolymers, comprising a step of controlled free-radical copolymerisation of trifluoroethylene with at least one additional monomer, different from trifluoroethylene, in the presence of a chain transfer agent, said chain transfer agent being a xanthate compound, a trithiocarbonate compound or a monoiodide compound. The invention also concerns the block copolymers likely to be obtained by this method.

Abstract: The present invention is directed to partially fluorinated copolymers and the production thereof. More specifically, the copolymers, which are preferably produced by a solution polymerization process, preferably have at least three units, the first unit selected from 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene, the second unit having a polymerized monomer selected from the vinyl esters and vinyl ethers, and the third unit having a polymerized monomer derived from a hydroxyl group-containing vinyl ether. The resulting copolymer is environmentally friendly, has favorable molecular weight characteristics, and may be shipped economically in high concentration.

Abstract: A method for manufacturing a polytetrafluoroethylene fine powder characterized by including the steps of (1) preparing an aqueous dispersion containing polytetrafluoroethylene, water, and a surfactant (A); (2) coagulating the polytetrafluoroethylene in the aqueous dispersion by agitating the aqueous dispersion with a discharge flow-type impeller; (3) collecting a wet powder of the polytetrafluoroethylene; and (4) drying the wet powder of the polytetrafluoroethylene.

Abstract: Disclosed is a perfluoroelastomer composition comprising 100 parts by weight of a perfluoroelastomer containing a cyano group as a crosslinkable group, 0.2 to 5 parts by weight of a bisamidoxime compound vulcanizing agent represented by the general formula: HON?C(NH2)—(CF2)n—C(NH2)?NOH (n: an integer of 1 to 10), and 0.005 to 0.3 parts by weight of a coloring agent with a melting point of 300° C. or above. This perfluoroelastomer composition provides a colored molded product that does not form blooms under high temperature conditions of 300° C. or above, and that can be effectively used, for example, as a sealing material for semiconductor manufacturing devices.

Abstract: The LED mounting substrate of the present invention includes a thermally conductive layer (thermally conductive sheet (10)) made of a composition containing boron nitride powder and a fluororesin, and the fluororesin contains polytetrafluoroethylene. The thermally conductive layer has a thermal conductivity of 2 W/(m·K) or more. The thermally conductive layer has a reflectance of 0.80 or more at wavelengths of 380 nm, 470 nm, and 650 nm.

Abstract: Biocompatible polymeric coating compositions having nanoscale surface roughness and methods of forming such coatings are described. A polymeric biocompatible coating may be produced using a powder coating method, where one or more thermosetting polymer resins and one or more biocompatible materials are mixed and extruded, ground into microscale particles, and mixed with nanoparticles to form a dry powder mixture that may be coated onto a substrate according to a powder coating method. Alternatively, the thermosetting polymeric resin can be first extruded and ground into microscale particles, and then mixed with the biocompatible materials in particular form of nanoscale to microscale in size, and then further mixed with nanoparticles to form a dry powder mixture for coating. Bioactive materials may also be selectively added into the polymeric coating in a similar way as the biocompatible materials, either before or after the extrusion, to form a bioactive polymeric coating.

Abstract: Disclosed is a method of manufacturing an organic-inorganic composite film. The method includes co-sputtering an inorganic target and a fluorine-containing organic polymer target, thereby simultaneously depositing atoms from the inorganic target and atoms from the fluorine-containing organic polymer target on a substrate. As such, an organic-inorganic composite film is obtained. The organic-inorganic composite film includes a homogeneous, amorphous, and nonporous material composed of carbon, fluorine, oxygen and/or nitrogen, and M. M can be silicon, titanium, aluminum, chromium, or combinations thereof.

Abstract: Described herein is a method of coagulating a fluoropolymer latex comprising: providing an amorphous fluoropolymer latex; providing unmodified inorganic nanoparticles; contacting the amorphous fluoropolymer latex with a sufficient amount of unmodified inorganic nanoparticles to coagulate the amorphous fluoropolymer.

Abstract: Use in LAN cable applications, as materials for the coating of the primary cable and for the external jacket, of TFE thermoprocessable perfluoropolymers comprising perfluoroalkylvinylethers in the following amounts, expressed as percent by weight on the total of the monomers: a) 0-5.5% of perfluoromethylvinylether (PMVE); b) 0.4-4.5% of perfluoroethylvinylether (PEVE) and/or perfluoropropylvinylether (PPVE); when a) is present, then a)+b) ranges from 1.5% to 5.5% by weight on the total of the monomers; optionally c) 0-6% of hexafluoropropene (HFP); the TFE amount being the complement to 100% by weight.

Abstract: An adhesive manufacturing process, an adhesive, and an article are disclosed. The adhesive manufacturing process includes mixing THV with a polar aprotic solvent and sodium azide to form an adhesive having an azide group. The mixing is at about the melting point of the THV for a duration of at least about 24 hours. The adhesive includes THV having an azide group. The article includes a substrate and an adhesive positioned on the substrate, the adhesive comprising THV having an azide group.

Abstract: An adhesive manufacturing process, an adhesive, and an article are disclosed. The adhesive manufacturing process includes blending a lower-melt fluoropolymer having a melting point that is less than a first temperature with a fluoropolymer powder having a melting point that is greater than a second temperature to form an adhesive and applying the adhesive to a surface at the first temperature. The adhesive is configured to be exposed to the second temperature. The adhesive includes the lower-melt fluoropolymer and the fluoropolymer powder blended with the lower-melt fluoropolymer. The article includes a surface and the adhesive applied to the surface at an applying temperature.

Abstract: To provide a binder for a storage battery device whereby favorable adhesion is obtainable and swelling by an electrolytic solution can favorably be suppressed. A binder for a storage battery device, which is made of a fluorinated copolymer comprising structural units (A), structural units (B) and structural units (C), wherein the molar ratio of the structural units (C) to the total of all the structural units excluding the structural units (C) is from 0.01/100 to 3/100: structural units (A): structural units derived from a monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and chlorotrifluoroethylene; structural units (B): structural units derived from ethylene or propylene; and structural units (C): structural units derived from a C5-30 organic compound having at least two double bonds and at least one of the double bonds being a double bond of a vinyl ether group or a double bond of a vinyl ester group.

Abstract: A fluororubber composition which includes a fluororubber (A) and a carbon black (B). The fluororubber (A) is a vinylidene fluoride-based fluororubber including a structural unit (VdF unit) derived from vinylidene fluoride and a structural unit derived from at least one monomer selected from the group consisting of hexafluoropropylene (HFP), 2,3,3,3-tetrafluoro propylene, and perfluoro(alkyl vinyl ether) (PAVE). The molar ratio of the VdF unit to the structural unit derived from at least one monomer selected from the group consisting of HFP, 2,3,3,3-tetrafluoro propylene, and PAVE is 50/50 to 78/22. The fluororubber composition has a difference ?G? (G? (1%)-G? (100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G? (1%) denotes a modulus of shearing elasticity at a dynamic strain of 1%, G? (100%) denotes a modulus of shearing elasticity at a dynamic strain of 100%, and G? (1%) and G? (100%) are determined by a dynamic viscoelasticity test.

Abstract: Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a PTFE porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a fibrillable modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.

Abstract: In a first aspect, a melt-processible interpolymer consists essentially of units derived from vinyl fluoride and at least two highly fluorinated monomers, at least one of the highly fluorinated monomers introducing into the polymer a side chain of at least one carbon atom. The interpolymer has a melt flow rate in a range of from about 2 to about 250 grams per 10 minutes at a temperature of 280° C. In a second aspect, an emulsion polymerization process for preparing a melt-processible interpolymer includes polymerizing vinyl fluoride and at least two highly fluorinated monomers in water with a water-soluble free-radical initiator at a temperature in the range of from about 60 to about 100° C. and a pressure in the range of from about 1 to about 12 MPa.

Abstract: An inkjet printhead includes a front face having a polymer coating, the polymer coating including an oleophobic grafted polymer having a crosslinked fluoroelastomer and a perfluorinated polyether grafted to the crosslinked fluoroelastomer.

Abstract: Coatings includes about 60 weight percent to about 90 weight percent of one or more fluorinated polymers, about 1 weight percent to about 7 weight percent of one or more erosion resistant fillers about 3 weight percent to about 9 weight percent of one or more anticorrosive pigments, about 1 weight percent to about 4 weight percent of one or more thixotropic agents, and about 1 weight percent to about 4 weight percent of one or more porosity reducing filler materials.

Abstract: Provided is a film or sheet composed of a resin composition that includes a poly lactic acid (A), an acidic functional group-modified olefinic polymer (B) including an acidic functional group and having an acid value of 10 to 70 mg KOH/g and a weight average molecular weight of 10,000 to 80,000, a tetrafluoroethylene polymer (C), and an aromatic-condensed phosphoric acid ester-containing flame retardant (D) including a compound of General Formula (I) and in which the aromatic-condensed phosphoric acid ester-containing flame retardant (D) is included in an amount of 10 to 80 parts by weight based on 100 parts by weight of the poly lactic acid (A), and a method for manufacturing the film or sheet by melt film formation. Each sign in Formula is as described in the specification.

Abstract: Provided herein is a prohealing piezoelectric coating and the method of making and using the same.

Abstract: To provide a binder for a storage battery device, whereby good adhesion in an electrode and flexibility are obtainable, and it is possible to realize good charge and discharge characteristics when used for a secondary battery. A binder for a storage battery device, which is made of a fluorinated copolymer comprising structural units (a) derived from tetrafluoroethylene and structural units (b) derived from propylene, wherein the molar ratio (a)/(b) is from 40/60 to 50/50, and the total of the structural units (a) and (b) is at least 90 mol % in all structural units.

Abstract: Methods for preparing an electrode comprise: providing a mixture of carbon particles and a solvent and shearing the mixture to form a dispersion of the carbon particles in the solvent; adding non-fibrillated POLY(TETRAFLUOROETHYLENE) to the dispersion to provide a resultant mixture and shearing the resultant mixture until at least a portion of the poly(tetrafluoroethylene) has been fibrillated; processing the resultant mixture into a sheet; and attaching the sheet onto a current collector. Methods for preparing sheet for the electrode and composition for the sheet are also provided.

Abstract: Disclosed are methods for making emulsions and emulsions, that in some embodiments can be considered to be Pickering emulsions.

Abstract: The present invention relates to an ionic liquid-polymer gel membrane with improved gas permeability, and a preparation method thereof, and more specifically, to a membrane prepared to allow an ionic liquid to be dispersed in a polymer gel, thereby improving gas permeability. Particularly, the present invention relates to an ionic liquid-polymer gel membrane wherein membrane selectivity and permeability exceed an upper bound by increasing the amount of dispersed ionic liquid, and a preparation method thereof. The preparation method of the membrane for separating a specific gas from a mixture gas according to the present invention comprises the following steps of: mixing a polymer, an ionic liquid and PC as a solvent to prepare a mixture solution; and drying the mixture solution to remove the solvent from the mixture solution. In addition, the polymer is polyvinylidene fluoride-hexafluoropropyl copolymer (PVdF-HFP), and the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]).

Abstract: The present invention relates generally to a method for manufacturing a foamed article, which comprises providing a composition comprising a melt-processable perfluoropolymer and talc, said perfluoropolymer comprising at least 50 percent by weight of said composition and said talc comprising about 2 percent to 3 percent by weight of said composition; wherein said melt-processable perfluoropolymer is selected from the group consisting of tetrafluoroethylent/perfluoromethylvinyl ether copolymer (MFA), hexafluoropropylene/tetrafluoroethylene copolymer (FEP), and perfluroralkoxy (PFA) and any blend thereof. The composition is heated to a processing temperature of at least 600° F. at which talc functions as a foaming agent, thereby causing the foaming of said composition at a foaming rate in a range from 20% to 50% so as to form a foamed article. The talc is the only foaming agent in said composition and the foaming is achieved without gas injection.

Abstract: Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a polytetrafluoroethylene porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the modified polytetrafluoroethylene having an extrusion pressure to a cylinder, at a reduction ratio of 1600, of 70 MPa or higher.

Abstract: The invention pertain to a process for purifying a fluoropolymer dispersion, said process comprising: (i) providing an aqueous dispersion (D) of at least one fluoropolymer [polymer (F)]comprising at least one fluorinated surfactant [surfactant (FS)], having a solids content (SC) of 15% by weight or more; (ii) adding to said aqueous dispersion (D) at least one non-ionic non-fluorinated surfactant [surfactant (NS)]; (iii) adjusting said solid content (SC) to less than 10% by weight, to obtain a diluted aqueous dispersion (dD); (iv) contacting said diluted aqueous dispersion (dD) with at least one adsorbing material, so as to obtain an aqueous dispersion of polymer (F) having a content of the fluorinated surfactant (FS) of less than 1 ppm based on the total weight of solids. Still an object of the invention is an aqueous fluoropolymer dispersion comprising less than 1 ppm of fluorinated surfactant.

Abstract: A biocompatible polymeric composition for cross-linking in-situ in a wound is disclosed comprising 1) one or more polyanionic polymers such as alginates or hyaluronates, able to be cross-linked the surface of the wound and 2) one or more polycationic polymers such as chitosan or DEAE-Dextran, that assists in the solidification process as well as speeds up hemostasis without the need for applying pressure. The biocompatible polymeric composition may further comprise a cross-linking agent such as aqueous calcium chloride. The invention encompasses an initial polymeric composition, the solidified matrix cross-linked and integrated at the wound site, including the methods of using, applying, and cross-linking the composition.

Abstract: Iodine containing amorphous fluoropolymers having at least one fluoropolymer with a cure site, where the fluoropolymer has a Mooney viscosity of 2 or less (ML 1+10) at 100° C. according to ASTM D1646, and a peel strength to a roll mill of 10 dN/cm or less and methods for making such iodine containing amorphous fluoropolymers are described. Articles derived from the cured product of such iodine containing amorphous fluoropolymers are also described. Solutions, dispersions and coatings derived from such iodine containing amorphous fluoropolymers are also described.

Abstract: Embodiments in accordance with the present invention provide polymers for forming layers/films useful in the manufacture of a variety of types of optoelectronic displays. Such embodiments also provide compositions of such polymers for forming such layers/films where the formed layers/films have high transparency over the visible light spectrum.

Abstract: The invention provides a fluororubber composition able to produce a crosslinked fluororubber article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures, and a method for producing same. The fluororubber composition contains: a fluororubber (A); and carbon black (B), wherein when the aforementioned fluororubber composition is immersed for 160 hours in an extraction solvent of acetone and hexane at an acetone:hexane mass ratio of 42.29:57.71 at 40° C. and an extraction residue that is not extracted and remains as a solid is separated from the aforementioned extraction solvent and dried and then the dry weight of the extraction residue is measured, the quantity of a solvent-insoluble polymer is not lower than 5%.