Abstract: A method for producing a polytetrafluoroethylene powder, which includes subjecting tetrafluoroethylene to suspension polymerization in an aqueous medium to prepare a suspension-polymerized particle of non melt-processible polytetrafluoroethylene, drying the suspension-polymerized particle to prepare a dry particle, subjecting the dry particle to fluorine radical treatment to prepare a fluorine radical-treated particle, and crushing the fluorine radical-treated particle to produce a polytetrafluoroethylene powder. Also disclosed is a polytetrafluoroethylene formed article obtained by forming the polytetrafluoroethylene powder, as well as a polytetrafluoroethylene compression-molded article obtained by compression molding the polytetrafluoroethylene powder.

Abstract: A composition containing polytetrafluoroethylene and substantially free from a compound represented by Formula (3): (H—(CF2)8—SO3)qM2 wherein M2 is H, a metal atom, NR54 (where R5s may be the same as or different from each other and are each H or an organic group having 1 to 10 carbon atoms), an imidazolium optionally having a substituent, a pyridinium optionally having a substituent, or a phosphonium optionally having a substituent, and q is 1 or 2. Also disclosed is a molded boy including the composition.

Abstract: A method for producing an aqueous dispersion of purified polytetrafluoroethylene, the method including: removing or reducing a compound represented by Formula (1) or (2) below from an aqueous dispersion of polytetrafluoroethylene obtained using a hydrocarbon surfactant: (H—(CF2)m—COO)pM1; or??Formula (1): (H—(CF2)n—SO3)qM2.??Formula (2): Also disclosed is a composition containing polytetrafluoroethylene substantially free from a compound represented by Formula (3) below and a molded body including the composition: (H—(CF2)8—SO3)qM2.

Abstract: A method for producing a fluoropolymer, which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a polymer (1), the polymer (1) including a polymerized unit derived from a monomer CX2?CY(—CZ2—O—Rf-A), wherein X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; Rf is a C1-C40 fluorine-containing alkylene group or a C-C100 fluorine-containing alkylene group and having an ether bond; and A is —COOM, —SO3M, or —OSO3M, wherein M is —H, a metal atom, —NR74, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R7 is H or an organic group, providing that at least one of X, Y, and Z contains a fluorine atom.

Abstract: A method for producing a fluoropolymer, which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a polymer (1), the polymer (1) including a polymerized unit derived from a monomer CX2?CY(—CZ2—O—Rf-A), wherein X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; Rf is a C1-C40 fluorine-containing alkylene group or a C—C100 fluorine-containing alkylene group and having an ether bond; and A is —COOM, —SO3M, or —OSO3M, wherein M is —H, a metal atom, —NR74, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R7 is H or an organic group, providing that at least one of X, Y, and Z contains a fluorine atom.

Abstract: A method for producing a polytetrafluoroethylene powder, which includes applying an ultrasonic wave to a polytetrafluoroethylene aqueous dispersion containing polytetrafluoroethylene particles to coagulate the polytetrafluoroethylene particles.

Abstract: A water treatment method including a removal step of removing a polymer (I) containing a polymerization unit (I) based on a monomer represented by the following general formula (I) from water containing the polymer (I): CX1X3?CX2R(—CZ1Z2-A0)m??(I) wherein X1 and X3 are each independently F, Cl, H, or CF3; X2 is H, F, an alkyl group, or a fluorine-containing alkyl group; A0 is an anionic group; R is a linking group; Z1 and Z2 are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more. Further, the number average molecular weight of the polymer (I) to 0.3×104 or more. Also disclosed is a composition including the polymer (I) containing the polymerization unit (I) based on a monomer represented by general formula (I), and where the composition has a content of the polymer (I) of 250 ppm or less.

Abstract: A PTFE aqueous dispersion having low viscosity at high temperature. The PTFE aqueous dispersion contains PTFE and a nonionic surfactant, has a PTFE solid concentration of 50 to 70% by mass, is substantially free from a fluorine-containing surfactant, and has a viscosity at 55° C. of 50 mPa·s or lower. Also disclosed is a method for producing the PTFE aqueous dispersion, a coating film obtained by applying the PTFE aqueous dispersion, an impregnated film obtained by impregnating the PTFE aqueous dispersion, and a coated article containing a coating film obtained by applying the PTFE aqueous dispersion.

Abstract: A method for producing a purified fluoropolymer aqueous dispersion, which includes: (A) bringing a fluoropolymer aqueous dispersion obtained using a hydrocarbon surfactant into contact with an anion exchange resin A or a synthetic adsorbent. The anion exchange resin A has an ion-exchange group represented by the following general formula (A1): —N+R1R2R3X— wherein each of R1, R2, and R3 are the same or different, and are each a hydrogen atom or an organic group, and at least one of R1, R2, and R3 is an organic group having 3 or more carbon atoms; and X is a counter ion; or an ion-exchange group represented by the following general formula (A2): —NR4R5 wherein each of R4 and R5 are the same or different, and are each a hydrogen atom or an organic group, and at least one of R4 and R5 is an organic group having 2 or more carbon atoms.

Abstract: A composition having a breaking strength of 10.0 N or more, containing a polytetrafluoroethylene, and substantially free from a compound represented by the following general formula (3): (H—(CF2)8—SO3)qM2??General Formula (3): wherein M2 is H, a metal atom, NR54, where each R5 may be the same or different and is H or an organic group having 1 to 10 carbon atoms, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and q is 1 or 2.

Abstract: A method for producing a polytetrafluoroethylene powder, which includes applying an ultrasonic wave to a polytetrafluoroethylene aqueous dispersion containing polytetrafluoroethylene particles to coagulate the polytetrafluoroethylene particles.

Abstract: A method for removing a fluorine-containing compound from discharge water, which includes bringing discharge water containing two or more fluorine-containing compounds represented by the following general formula (1) or (2) into contact with an adsorbent so as to adsorb the two or more fluorine-containing compounds: (H—(CF2)m—COO)pM1??General Formula (1): wherein m is 3 to 19, M1 is H, a metal atom, NRb4, where Rb is the same or different and is H or an organic group having 1 to 10 carbon atoms, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and p is 1 or 2; (H—(CF2)n—SO3)qM2??General Formula (2): wherein n is 4 to 20; M2 is H, a metal atom, NRb4, where Rb is the same as above, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and q is 1 or 2.

Abstract: The present invention aims to provide a modified polytetrafluoroethylene fine powder capable of providing a stretched body having high strength, a small pore size, and excellent homogeneity. The modified polytetrafluoroethylene fine powder of the present invention has non-melt-processability, has a standard specific gravity of 2.155 or lower, includes 0.015 mol % or more of a polymer unit derived from perfluoro(methyl vinyl ether) in all the monomer units, is obtained by emulsion polymerizing tetrafluoroethylene and at least the perfluoro(methyl vinyl ether) in the presence of a fluorosurfactant having a LogPOW value of 3.4 or lower, and has an extrusion pressure of 20.0 MPa or lower.

Abstract: A method for producing a fluoropolymer, which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a polymer (1), the polymer (1) including a polymerized unit derived from a monomer CX2?CY(—CZ2—O—Rf-A), wherein X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; Rf is a C1-C40 fluorine-containing alkylene group or a C—C100 fluorine-containing alkylene group and having an ether bond; and A is —COOM, —SO3M, or —OSO3M, wherein M is —H, a metal atom, —NR74, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R7 is H or an organic group, providing that at least one of X, Y, and Z contains a fluorine atom.

Abstract: A method for producing an aqueous dispersion of purified polytetrafluoroethylene, the method including: removing or reducing a compound represented by Formula (1) or (2) below from an aqueous dispersion of polytetrafluoroethylene obtained using a hydrocarbon surfactant: Formula (1): (H—(CF2)m—COO)pM1; or Formula (2): (H—(CF2)n—SO3)qM2. Also disclosed is a composition containing polytetrafluoroethylene substantially free from a compound represented by Formula (3) below and a molded body including the composition: Formula (3): (H—(CF2)8—SO3)qM2.

Abstract: The present invention provides a polytetrafluoroethylene aqueous dispersion containing high-molecular-weight, significantly small polytetrafluoroethylene particles and having excellent dispersion stability. The present invention relates to an aqueous dispersion containing polytetrafluoroethylene particles containing a tetrafluoroethylene unit alone or a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with the tetrafluoroethylene. The polytetrafluoroethylene particles have a volume average particle size of not smaller than 0.1 nm but smaller than 20 nm, a melt flow rate of not lower than 0 g/10 min but lower than 80 g/10 min determined at 380° C. and 5 kg load, a melting point of 324° C. to 360° C., and an initial pyrolysis temperature of not lower than 400° C.

Abstract: The present invention provides a polytetrafluoroethylene powder having high dispersibility in lubricants. The polytetrafluoroethylene powder includes polytetrafluoroethylene containing a tetrafluoroethylene unit alone or a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with the tetrafluoroethylene, and has a specific surface area of 32 m2/g or larger.

Abstract: The present invention provides a modified polytetrafluoroethylene fine powder which can be processed into molded articles high in thermal stability, chemical resistance and transparency and for which the extrusion pressure can be lowered. The present invention is a modified polytetrafluoroethylene fine powder, wherein the cylinder extrusion pressure at a reduction ratio of 1600 is not higher than 50 MPa and the haze value of molded article a for measurement formed therefrom is not higher than 60.

Abstract: The present invention provides a polytetrafluoroethylene aqueous dispersion containing high-molecular-weight, significantly small polytetrafluoroethylene particles and having excellent dispersion stability. The present invention relates to an aqueous dispersion containing polytetrafluoroethylene particles containing a tetrafluoroethylene unit alone or a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with the tetrafluoroethylene. The polytetrafluoroethylene particles have a volume average particle size of not smaller than 0.1 nm but smaller than 20 nm, a melt flow rate of not lower than 0 g/10 min but lower than 80 g/10 min determined at 380° C. and 5 kg load, a melting point of 324° C. to 360° C., and an initial pyrolysis temperature of not lower than 400° C.

Abstract: The present invention provides a polytetrafluoroethylene powder having high dispersibility in lubricants. The polytetrafluoroethylene powder includes polytetrafluoroethylene containing a tetrafluoroethylene unit alone or a tetrafluoroethylene unit and a modifying monomer unit based on a modifying monomer copolymerizable with the tetrafluoroethylene, and has a specific surface area of 32 m2/g or larger.