Abstract: To provide a modified polytetrafluoroethylene excellent in breaking strength. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a monomer represented by formula (1), wherein the content of the units based on a monomer represented by formula (1) is from 10 to 500 mass ppm, to all units in the modified polytetrafluoroethylene, and the standard specific gravity is from 2.155 to 2.175, CH2?CR1-L-R2??Formula (1): wherein R1 represents a hydrogen atom or an alkyl group, L represents a single bond, —CO—O—*, —O—CO—*, or —O—, * represents a bonding position to R2, and R2 represents a hydrogen atom, an alkyl group, or a nitrile group.

Abstract: To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

Abstract: A method for producing a modified polytetrafluoroethylene, the method including: polymerizing tetrafluoroethylene in an aqueous medium in which a polymer having units based on a fluorine-free monomer is present. The fluorine-free monomer is a monomer represented by formula (1): CH2?CR1-L-R2, where R1 is a hydrogen atom or an alkyl group, L is a single bond, —CO—O—*, —O—CO—* or —O—, * is a bonding position to R2, and R2 is an alkyl group. To the total amount of tetrafluoroethylene supplied to the polymerization, a proportion of the polymer is from 0.001 to 0.050 mass %.

Abstract: To provide a method for producing an aqueous dispersion of polytetrafluoroethylene, whereby formation of fluorinated oligomers as byproducts is little and CFT of a coating film to be formed is large. A method for producing an aqueous dispersion of polytetrafluoroethylene, which comprises step A1 of polymerizing a non-fluorinated monomer in an aqueous medium to obtain a solution 1 containing a polymer comprising units based on said non-fluorinated monomer, step A2 of conducting polymerization of tetrafluoroethylene in said solution 1 without substantially adding a surfactant to said solution 1, to obtain an aqueous emulsion containing polytetrafluoroethylene particles, and step A3 of adding a nonionic surfactant to said aqueous emulsion, and then concentrating said aqueous emulsion to obtain an aqueous dispersion of polytetrafluoroethylene, wherein the amount of said non-fluorinated monomer used is at most 200 mass ppm to the amount of said tetrafluoroethylene supplied to the polymerization system.

Abstract: To provide a coated body excellent in weather resistance and excellent also in pressure marking resistance. The coated body comprises a substrate, an undercoating film, a prescribed intermediate coating film and a top coating film formed by curing a top coating material comprising the following components (1) to (3), in this order: (1) a fluorinated polymer having hydroxy groups or carboxy groups; (2) a curing agent for curing the fluorinated polymer; and (3) a prescribed ultraviolet absorber.

Abstract: To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no C6-34 fluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

Abstract: To provide a modified polytetrafluoroethylene excellent in breaking strength. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a monomer represented by formula (1), wherein the content of the units based on a monomer represented by formula (1) is from 10 to 500 mass ppm, to all units in the modified polytetrafluoroethylene, and the standard specific gravity is from 2.155 to 2.175, CH2?CR1-L-R2??Formula (1) wherein R1 represents a hydrogen atom or an alkyl group, L represents a single bond, —CO—O—*, —O—CO—*, or —O—, * represents a bonding position to R2, and R2 represents a hydrogen atom, an alkyl group, or a nitrile group.

Abstract: To provide a modified PTFE excellent in heat resistance. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a fluorine-free monomer, wherein the endothermic amount ratio R calculated by a prescribed method is at least 0.65.

Abstract: To provide a novel method for producing a modified PTFE. The method for producing a modified polytetrafluoroethylene comprises polymerizing tetrafluoroethylene in an aqueous medium in which a polymer comprising units based on a fluorine-free monomer is present.

Abstract: A method for producing a fluorinated copolymer solution polymerizing a monomer mixture of a fluoro-olefin (A), a monomer (B) having a crosslinkable group and a monomer (C) having no fluorine atom and no crosslinkable group in the presence of an organic solvent and a compound having two or more piperidyl group represented by the formula (1):

Abstract: To provide a coated body excellent in weather resistance and excellent also in pressure marking resistance. The coated body comprises a substrate, an undercoating film, a prescribed intermediate coating film and a top coating film formed by curing a top coating material comprising the following components (1) to (3), in this order: (1) a fluorinated polymer having hydroxy groups or carboxy groups; (2) a curing agent for curing the fluorinated polymer; and (3) a prescribed ultraviolet absorber.

Abstract: To provide a method for producing a fluorinated copolymer solution having good storage stability and having good dryability of a coating film when made into a coating composition. A monomer mixture comprising a fluoro-olefin (A), a monomer (B) having a crosslinkable group and a monomer (C) having no fluorine atom and no crosslinkable group, is polymerized in the presence of an organic solvent and a compound having a piperidyl group represented by the formula (1), wherein the molar ratio of the total molar amount of piperidyl groups contained in the compound having a piperidyl group to the total molar amount of monomers in the monomer mixture, is from 0.00105 to 0.00380: In the formula (1), each of R1, R2, R3 and R4 which are independent of one another, is a hydrogen atom, a methyl group or a hydroxy group, and Y is a hydrogen atom, an oxy radical group, an alkyl group, an alkoxy group, an aryl group or a hydroxy group.