Abstract: Provided is a method for producing low-molecular-weight polytetrafluoroethylene which is less likely to generate C6-C14 perfluorocarboxylic acids and salts thereof. The disclosure relates to a method for producing low-molecular-weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×102 to 7.0×105 Pa·s. The method includes (1) irradiating high-molecular-weight polytetrafluoroethylene with radiation in a substantially oxygen-free state and decomposing the high-molecular-weight polytetrafluoroethylene into a low-molecular-weight component and (2) deactivating, in a substantially oxygen-free state, at least part of main-chain radicals and end radicals generated by the irradiation and providing the low-molecular-weight polytetrafluoroethylene.

Abstract: This disclosure provides a method for producing a hydrofluoroolefin (HFO) or fluoroolefin (FO), which is a target compound, with high selectivity, without requiring a high temperature and a catalyst in a synthesis process of the target compound. Specifically, the present disclosure provides a method for producing a hydrofluoroolefin or fluoroolefin having two, three, or four carbon atoms, comprising irradiating at least one starting material compound selected from the group consisting of hydrofluorocarbons having one or two carbon atoms and hydrofluoroolefin As having two or three carbon atoms with ionizing radiation and/or an ultraviolet ray having a wavelength of 300 nm or less, with the proviso that when the at least one starting material compound is the hydrofluoroolefin A, the resulting hydrofluoroolefin is different from the hydrofluoroolefin A.

Abstract: A process for producing one or both of tetrafluoroethylene and hexafluoropropylene, which includes pyrolyzing a low molecular weight fluorine compound by continuous reaction in a microreactor.

Abstract: A pipe-joining centering device aligns, with an axial center of one pipe, an axial center of another pipe when a spigot of the other pipe is to be inserted into a socket of the one pipe. The pipe-joining centering device includes a support member configured to support an end part of the spigot. The support member is tiltable in a pipe radial direction between an inner peripheral surface of the socket and an outer peripheral surface of the spigot. The pipe-joining centering device also includes a position adjustment member configured to tilt the support member in the pipe radial direction. The support member and the position adjustment member are supported on the inner peripheral surface of the socket.

Abstract: Provided is a method for producing low-molecular-weight polytetrafluoroethylene which is less likely to generate C6-C14 perfluorocarboxylic acids and salts thereof. The disclosure relates to a method for producing low-molecular-weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×102 to 7.0×105 Pa·s. The method includes (1) irradiating high-molecular-weight polytetrafluoroethylene with radiation in a substantially oxygen-free state and decomposing the high-molecular-weight polytetrafluoroethylene into a low-molecular-weight component and (2) deactivating, in a substantially oxygen-free state, at least part of main-chain radicals and end radicals generated by the irradiation and providing the low-molecular-weight polytetrafluoroethylene.

Abstract: A process for producing one or both of tetrafluoroethylene and hexafluoropropylene, which includes pyrolyzing a low molecular weight fluorine compound by continuous reaction in a microreactor.

Abstract: A pipe-joining centering device aligns, with an axial center of one pipe, an axial center of another pipe when a spigot of the other pipe is to be inserted into a socket of the one pipe. The pipe-joining centering device includes a support member configured to support an end part of the spigot. The support member is tiltable in a pipe radial direction between an inner peripheral surface of the socket and an outer peripheral surface of the spigot. The pipe-joining centering device also includes a position adjustment member configured to tilt the support member in the pipe radial direction. The support member and the position adjustment member are supported on the inner peripheral surface of the socket.

Abstract: The present invention provides a process for producing a perfluoropolyoxyalkylene peroxide compound comprising a step of reacting a perfluoroalkene with oxygen, wherein the reaction of the perfluoroalkene with oxygen is performed in a microreactor.

Abstract: The present invention provides a process for producing a perfluoropolyoxyalkylene peroxide compound comprising a step of reacting a perfluoroalkene with oxygen, wherein the reaction of the perfluoroalkene with oxygen is performed under ultraviolet irradiation and in the presence of a fluorine source.

Abstract: The present invention provides a process for producing a perfluoropolyoxyalkylene peroxide compound comprising a step of reacting a perfluoroalkene with oxygen, wherein the reaction of the perfluoroalkene with oxygen is performed under ultraviolet irradiation and in the presence of a fluorine source.

Abstract: The present invention provides a process for producing a perfluoropolyoxyalkylene peroxide compound comprising a step of reacting a perfluoroalkene with oxygen, wherein the reaction of the perfluoroalkene with oxygen is performed in a microreactor.

Abstract: The present invention provides a novel method for producing hexafluoropropylene oxide, which can attain a high HFPO selectivity without using a phase transfer catalyst. Hexafluoropropylene (HFP), a water-soluble and aprotic organic solvent, and an aqueous solution of an oxidizing agent are introduced into a small space, thereby bringing into contact with each other and reacting hexafluoropropylene with the oxidizing agent to obtain hexafluoropropylene oxide (HFPO).

Abstract: The present invention provides a novel method for separating hexafluoropropylene oxide (HFPO) from hexafluoropropylene (HFP), which is capable of reducing the burden on the environment. A mixture including HFPO and HFP is subjected to an extractive distillation operation using, as a solvent, at least one of a fluorine-containing saturated compound represented by the general formula CnHaFb (wherein n, a and b are integers which satisfy: n=3 to 8, 0?a?2n+1, and 1?b?2n+2) thereby separating into a first fraction including HFPO and a second fraction including HFP and the solvent. At least one of 1-bromopropane and 2-bromopropane may be u as the solvent in place of the fluorine-containing saturated compound.

Abstract: The present invention provides a novel method for producing hexafluoropropylene oxide, which can attain a high HFPO selectivity without using a phase transfer catalyst. Hexafluoropropylene (HFP), a water-soluble and aprotic organic solvent, and an aqueous solution of an oxidizing agent are introduced into a small space, thereby bringing into contact with each other and reacting hexafluoropropylene with the oxidizing agent to obtain hexafluoropropylene oxide (HFPO).

Abstract: The present invention provides a novel method for separating hexafluoropropylene oxide (HFPO) from hexafluoropropylene (HFP), which is capable of reducing the burden on the environment. A mixture including HFPO and HFP is subjected to an extractive distillation operation using, as a solvent, at least one of a fluorine-containing saturated compound represented by the general formula CnHaFb (wherein n, a and b are integers which satisfy: n=3 to 8, 0?a?2n+1, and 1?b?2n+2) thereby separating into a first fraction including HFPO and a second fraction including HFP and the solvent. At least one of 1-bromopropane and 2-bromopropane may be u as the solvent in place of the fluorine-containing saturated compound.

Abstract: There is provided a process for producing hexafluoropropylene oxide which is novel and capable of achieving a higher yield. An organic phase comprising hexafluoropropylene (HFP) in an organic solvent and an aqueous phase comprising an oxygen-containing oxidizing agent in water are supplied to a small space (or microspace), preferably together with a phase transfer catalyst. The organic phase and the aqueous phase are contacted with each other in the small space, thereby reacting hexafluoropropylene (HFP) with the oxygen-containing oxidizing agent, preferably by an action of the phase transfer catalyst to give hexafluoropropylene oxide (HFPO). After the reaction, the organic phase and the aqueous phase are taken out from the small space to obtain an organic phase comprising the hexafluoropropylene oxide (HFPO).

Abstract: A method of purifying a treatment target substance containing a fluorine-containing surfactant which includes removing at least part of the fluorine-containing surfactant from the treatment target substance by contacting the treatment target substance with a gas containing carbon dioxide. The fluorine-containing surfactant is an ether oxygen-free anionic compound represented by one of general formulae (1) and (2) as defined herein.

Abstract: The present invention has for its object to provide a method of producing fluoropolymers with high productivity under comparatively low temperature and low pressure conditions which are conducive to reduced cost of commercial-scale production equipment. The present invention is directed to a method of producing a fluoropolymer which comprises polymerizing a radical polymerizable monomer in a defined reaction-field, said radical polymerizable monomer comprising a fluorine-containing ethylenic monomer and said defined reaction-field being in supercriticality-expression state with a monomer density [?m]-monomer critical density [?0] ratio of [?m/?0] not less than 1.1.

Abstract: The present invention provides a method of removing fluorine-containing surfactants from treatment target substances containing fluorine-containing surfactants and a method of producing aggregates comprising polymer from aqueous dispersions thereof. The present invention is a method of purifying a treatment target substance comprising carrying out a removing treatment of a fluorine-containing surfactant by bringing the treatment target substance containing the fluorine-containing surfactant into contact with a substance [A], wherein the substance [A] is a gas under standard conditions (105 Pa, 0° C.).

Abstract: A fluoropolymer producing method which comprises polymerizing a radical polymerizable monomer in a manner of continuous polymerization to give the fluoropolymer, wherein the defined reaction-field is in a supercriticality-expression state and under a pressure of not higher than 40 MPa and a temperature of not higher than that higher by 100° C. than the supercriticality-expression temperature of the defined reaction-field, said radical polymerizable monomer comprises a fluorine-containing ethylenic monomer, and said fluoropolymer has a weight average molecular weight [Mw] of not lower than 150, 000 as determined on the polystyrene equivalent basis and a ratio [Mw/Mn] of the weight average molecular weight [Mw] on the polystyrene equivalent basis to a number average molecular weight [Mn] of the fluoropolymer on the polystyrene equivalent basis is higher than 1 but not higher than 3.