Abstract: A method for producing a polytetrafluoroethylene particle, which includes subjecting tetrafluoroethylene to suspension polymerization in an aqueous medium to prepare a suspension-polymerized particle of polytetrafluoroethylene, washing and then crushing the suspension-polymerized particle or crushing the suspension-polymerized particle with washing to prepare a crushed particle, dehydrating the crushed particle to prepare a crushed particle having a water content of 40% by mass or less, and subjecting the dehydrated crushed particle to heat treatment to produce a polytetrafluoroethylene particle.

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: Provided is a fluoropolymer composition production method for producing a fluoropolymer composition containing a fluoropolymer, the method which includes polymerizing a fluoromonomer in a reactor in the presence of a fluorine-containing surfactant, a polymerization initiator, and an aqueous medium to prepare an aqueous dispersion containing a fluoropolymer; after the aqueous dispersion is prepared, removing from the reactor the fluoromonomer remaining in the reactor, or recovering the aqueous dispersion in the reactor and accommodating the aqueous dispersion in a container different from the reactor; adding a radical generator to the aqueous dispersion; and subjecting to a heat treatment the aqueous dispersion comprising the radical generator to give a fluoropolymer composition.

Abstract: A fluoropolymer composition production method for producing a fluoropolymer composition containing a fluoropolymer, the method which includes polymerizing a fluoromonomer in a reactor in the presence of a fluorine-containing surfactant, a polymerization initiator, and an aqueous medium to prepare an aqueous dispersion comprising a fluoropolymer; feeding an inert gas to the reactor; and subjecting to a heat treatment the aqueous dispersion in the reactor to give a fluoropolymer composition, wherein a temperature of the heat treatment is 35° C. or higher and a time of the heat treatment is 15 minutes or more.

Abstract: A modified polytetrafluoroethylene aqueous dispersion having low viscosity at high temperature. The modified polytetrafluoroethylene aqueous dispersion contains a modified polytetrafluoroethylene and a nonionic surfactant, has a modified polytetrafluoroethylene solid concentration of 50 to 70% by mass, is substantially free from a fluorine-containing surfactant, and has a viscosity at 55° C. of 80 mPa•s or lower, and the modified polytetrafluoroethylene contains 0.050% by mass or more and 1.00% by mass or less of a polymerized unit based on a modifying monomer.

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 composition containing a polytetrafluoroethylene, a polymer (I) containing a polymerization unit (I) based on a monomer represented by the general formula (I), a nonionic surfactant, and an aqueous medium, wherein a content of the polytetrafluoroethylene in the composition is 10% by mass or more based on the composition, and a content of the nonionic surfactant in the composition is 1.0% by mass or more based on the polytetrafluoroethylene, CX1X3?CX2R(—VZ1Z2-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.

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 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 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 method for producing a fluoropolymer aqueous dispersion having a significantly small particle size and excellent dispersion stability. The present invention relates to a method for producing an aqueous dispersion containing at least one fluoropolymer selected from the group consisting of polytetrafluoroethylene and melt-fabricable fluororesins excluding polytetrafluoroethylene. The method includes polymerizing a fluoromonomer in an aqueous medium in the presence of a fluorosurfactant and a polymerization initiator. The fluorosurfactant has a concentration in the aqueous medium of not lower than 0.8 times the critical micelle concentration of the fluorosurfactant.