Abstract: A method for producing a fluoropolymer dispersion where a fine particle containing a fluoropolymer is dispersed in an aqueous dispersion medium, the fluoropolymer having a sulfonic acid group, and the method including a polymerization reaction step of emulsion polymerizing a fluorovinyl ether derivative and a fluorine-containing ethylenic monomer to give a fluoropolymer precursor, a hydrolysis step of hydrolyzing, in an aqueous medium, —SO2X1, where X1 represents a halogen atom, which the fluoropolymer precursor has thereby to give the fluoropolymer, the fluorovinyl ether derivative being represented by the following general formula (II): CF2?CF—O—(CF2CFY1—O)n—(CFY2)m-A1??(II) wherein Y1, n, Y1, m and A1 are as defined herein, the fluoropolymer precursor having a fluorovinyl ether derivative unit content of 5 to 40 mole percent, and the fluoropolymer dispersion being produced without drying the fluoropolymer precursor and the fluoropolymer.

Abstract: A fluoropolymer liquid composition including a fluoropolymer liquid (A) which includes a liquid medium and a crosslinkable functional group-containing crosslinkable fluoropolymer. The fluoropolymer liquid (A) is a fluoropolymer liquid dispersion (AD) having, dispersed in a liquid dispersion medium, particles of a crosslinkable fluoropolymer (PD) containing acid/acid salt groups or organic groups capable of undergoing hydrolysis and thus being converted to carboxyl groups, or a fluoropolymer solution (AS) having, dissolved in a fluorosolvent or an alcohol/water mixed solvent, a crosslinkable fluoropolymer (PS) containing acid/acid salt groups or acid/acid salt groups precursors. Further, the crosslinkable functional group is a cyano group, —I or —Br.

Abstract: A fluoropolymer liquid composition including a fluoropolymer liquid (A) which includes a liquid medium and a crosslinkable functional group-containing crosslinkable fluoropolymer. The fluoropolymer liquid (A) is a fluoropolymer liquid dispersion (AD) having, dispersed in a liquid dispersion medium, particles of a crosslinkable fluoropolymer (PD) containing acid/acid salt groups or organic groups capable of undergoing hydrolysis and thus being converted to carboxyl groups, or a fluoropolymer solution (AS) having, dissolved in a fluorosolvent or an alcohol/water mixed solvent, a crosslinkable fluoropolymer (PS) containing acid/acid salt groups or acid/acid salt groups precursors. Further, the crosslinkable functional group is a cyano group, —I or —Br.

Abstract: The present invention provides a process for producing a fluorinated ionomer, comprising copolymerizing, in the presence of a polymerization initiator, (i) a compound represented by Formula (I) (M)1/LOSO2CFY(CF2)mO(CFXCF2O)nCF?CF2??(I) wherein M is H or a metal with a valence of L (L is 1, 2 or 3), X is F, Cl or CF3, Y is halogen, m is 1 to 5, and n is 0 to 5, (ii) tetrafluoroethylene and (iii) at least one third monomer selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, CF2?CFORf (Rf is C1 to C5 perfluoroalkyl) and ethylene. The present invention further provides a method for purifying and concentrating a fluorinated ionomer, comprising ultrafiltration or dialysis of a fluorinated ionomer solution or dispersion, and a method for forming a film of the fluorinated ionomer.

Abstract: It is an object of the present invention to provide a liquid composition which comprises an acid/acid salt group-containing polymer and from which cured articles excellent in mechanical characteristics and undergoing only slight dimensional changes depending on the moisture content can be produced by application thereof to a substrate or impregnation of a porous material therewith.

Abstract: The invention provides a fluoropolymer liquid composition comprising a fluoropolymer and a film-forming auxiliary, said fluoropolymer comprising acid/acid salt fluorovinyl ether units represented by the general formula (I): said film-forming auxiliary being an organic liquid which is compatible with water and has a boiling point higher than 100° C. but not higher than 300° C., said fluoropolymer liquid composition being a fluoropolymer dispersion composition comprising said film-forming auxiliary and a fluoropolymer fine particle comprising said fluoropolymer, said fluoropolymer fine particle containing, at the proportion of at least 25% by mass thereof, a spherical fluoropolymer fine particle, and said spherical fluoropolymer fine particle being substantially spherical.

Abstract: A fluoropolymer solid composition which contains a fine particle comprising a fluoropolymer, said fluoropolymer having an acid/acid salt group, said acid/acid salt group being a sulfonic acid group, —SO2NR17R18, a carboxyl group, —SO3NR1R2R3R4, —SO3M11/L, —COONR5R6R7R8 or —COOM21/L (in which R17 and R18 are the same or different and each represents a hydrogen atom, an alkali metal, an alkyl group or a sulfonyl-containing group, R1, R2, R3 and R4 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R5, R6, R7 and R8 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, M1 and M2 are the same or different and each represents a metal whose valence is L, and said metal whose valence is L is a metal belonging to the group 1, 2, 4, 8, 11, 12 or 13 of the periodic table); said fine particle comprising the fluoropolymer containing, at the proportion of at least 25% by mass thereof, a spherical fluoropolymer

Abstract: A process for preparing a monomer compound represented by formula (II): [wherein M represents an alkali metal or alkaline earth metal; and n is 0, 1 or 2.] by pyrolysis of a compound represented by formula (I) below: [wherein M and n are as defined above.], the pyrolysis being conducted in the presence of a catalyst which has coordinating properties to a metal ion M.

Abstract: The present invention provides a process for producing a fluorinated ionomer, comprising copolymerizing, in the presence of a polymerization initiator, (i) a compound represented by Formula (I) (M)1/LOSO2CFY(CF2)mO(CFXCF2O)nCF═CF2  (I)

Abstract: A compound of the formula (1): FSO2CFXCF2O(CFXCF2O)nCF—(CF2Y)COF in which X is a fluorine atom, a chlorine atom or a trifluoromethyl group, Y is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and n is a number of 0 to 5, preferably 0, 1 or 2, is converted to a compound of the formula (2): MOSO2CFXCF2O(CFXCF2O)2CF(CF2Y)COOM1 in which X, Y and n are the same as defined above, and M and M1 independently represent an alkali metal atom or an alkaline earth metal atom, and then a compound of the formula (2) is pyrolyzed at a temperature of 150 to 250° C. to obtain a compound of the formula (3): ASO2CFXCF2O(CFXCF2O)nCF═CF2 in which A is MO—, a hydroxyl group or a fluorine atom, and X and n are the same as defined above.

Abstract: Novel silicon-containing organic fluoropolymers which are appliable to materials over a wide range and which have excellent antifouling property. The silicon-containing organic fluoropolymer of the invention is represented by the general formula and has a number average molecular weight of from 5×102 to 1×105: wherein Rf represents perfluoroalkyl; Z represents fluoro or trifluoromethyl; a, b, c, d and e each independently represent 0 or an integer of 1 or above, provided that a+b+c+d+e is not less than 1 and the order of the repeating units parenthesized by subscripts a, b, c, d and e occurring in the formula is not limited to that shown; Y represents hydrogen or alkyl containing 1 to 4 carbon atoms; X represents hydrogen, bromo or iodo; R1 represents hydroxy or a hydrolyzable substituent group; R2 represents hydrogen or a monovalent hydrocarbon group; 1 represents 0, 1 or 2; m represents 1, 2 or 3; and n represents an integer of 2 or above.

Abstract: A novel fluorine-containing copolymer is obtained by radically copolymerizing 60 to 80% by mole of ethylene and 20 to 40% by mole of hexafluoropropylene in the presence of 0.1 to 15% by mole of tetrafluoroethylene as a comonomer, each based on the monomer mixture, under pressure of 10 to 40 kgf/cm.sup.2. A fluoroelastomer is obtained by curing the obtained copolymer. The copolymerization is carried out under mild conditions, and the fluoroelastomer obtained by curing the resulting copolymer is excellent in amine resistance.

Abstract: A polymer comprising at least one polymer chain is produced by polymerizing, in the presence of a radical generating source and an iodide compound, at least one monomer M.sub.1 having a radically polymerizable unsaturated bond between a carbon atom and an iodine atom constituting a carbon-iodine bond of the iodide compound to form at least one polymer chain between the carbon atom and the iodine atom, wherein the polymerization reaction is carried out in the presence of a monomer M.sub.2 which is different from the monomer M.sub.1 and has a larger addition reactivity with a carbon radical which is generated by cleavage of the carbon-iodine bond of the iodine compound than that of the monomer M.sub.1.

Abstract: a fluorine-containing block copolymer comprising at least one soft segment which comprises chlorotrifluoroethylene and vinylidene fluoride and at least one hard segment which comprises a fluorine-containing crystalline polymer, which copolymer has good flexibility and transparency and useful as a material for an artificial lens.

Abstract: A thermoplastic elastomer composition comprising a thermoplastic elastomeric block or graft polymer comprising at least one hard segment and at least one soft segment and a vulcanizing agent, which can be molded under high shearing stress at a temperature lower than a melting or softening point of the hard sements under shear force to give a molded article having a substantially smooth surface.

Abstract: An iodine-containing compound consisting of at least two repeating units selected from the formulae:--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a ----(CHClCF.sub.2 CF.sub.2 O).sub.b ----(CCl.sub.2 CF.sub.2 CF.sub.2 O).sub.c ----(CHFCF.sub.2 CF.sub.2 O).sub.d ----(CFClCF.sub.2 CF.sub.2 O).sub.e ----(CF.sub.2 CF.sub.2 CF.sub.2 O).sub.f --wherein a, b, c, d, e and f are each 0 or a positive integer and satisfy the following equations:2.ltoreq.a+b+c+d+e+f.ltoreq.200 and1.ltoreq.a+c+d+fand an iodine atom at at least one end of a molecule, which can provide a block copolymer which is useful as a grease.

Abstract: Modified polytetrafluoroethylene unsintered powder of which has sintering-densification indexes P.sub.10, P.sub.25 and P.sub.50 of not larger than 0.2, which is suitable for producing a porous molding article.

Abstract: A polymer of the formula:PC--[CH.sub.2 CYI--(CH.sub.2).sub.n --SiR.sub.x X.sub.3-x].sub.m (I)wherein PC is a polymer chain, X is a monovalent functional group, Y is a hydrogen atom or a lower alkyl group, R is a hydrogen atom or an inactive monovalent organic group, X is an integer of 0 to 3, m is a positive integer which is not larger than the number of ends of the polymer chain PC, and n is 0, 1 or 2, having a molecular weight of 5.times.10.sup.2 to 5.times.10.sup.6, which is relatively stable and easily handled.

Abstract: A fluorine-containing copolymer comprising repeating units derived from an olefin of the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are each a hydrogen atom or a fluorine atom, or one is a chlorine atom and the remainder are fluorine atoms, and repeating units derived from a vinylphosphonic acid derivative of the formula: ##STR2## wherein R groups are the same or different and are each an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or a phenyl group, and n is 0, 1 or 2, which has good hydrophilicity.

Abstract: An iodine-containing compound consisting of at least two repeating units selected from the formulae:--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a ----(CHClCF.sub.2 CF.sub.2 O).sub.b ----(CCl.sub.2 CF.sub.2 CF.sub.2 O).sub.c ----(CHFCF.sub.2 CF.sub.2 O).sub.d ----(CFClCF.sub.2 CF.sub.2 O).sub.e ----(CF.sub.2 CF.sub.2 CF.sub.2 O).sub.f --wherein a, b, c, d, e and f are each 0 or a positive integer and satisfy the following equations:2.ltoreq.a+b+c+d+e+f.ltoreq.200 and1.ltoreq.a+c+d+fand an iodine atom at at least one end of a molecule, which can provide a block copolymer which is useful as a grease.