Abstract: The present invention provides a polymerization inhibitor preventing the self-polymerization of TFE and the generation of a modified polymer of a polymerization inhibitor in a distillation step, particularly in a rectification step, of TFE. The present invention provides a method of distilling tetrafluoroethylene in the presence of a polymerization inhibitor comprising a cyclohexadiene compound of the formula: R1-A-R2 wherein R1 is a hydrocarbon group having 1 to 5 carbon atoms, R2 is a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and A is a cyclohexadiene ring. The cyclohexadiene compound is preferably ?-terpinene or ?-terpinene.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance and particularly, does not cause cone break when coating an electric wire, a process for preparing the composition and a cable coated with the composition. Specifically, the present invention provides a fluororesin composition comprising a tetrafluoroethylene/hexafluoropropylene copolymer and polytetrafluoroethylene compounded thereto, which has a melt flow rate of at least 15 at 372° C. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

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 provides a polymerization inhibitor preventing the self-polymerization of TFE and the generation of a modified polymer of a polymerization inhibitor in a distillation step, particularly in a rectification step, of TFE. The present invention provides a method of distilling tetrafluoroethylene in the presence of a polymerization inhibitor comprising a cyclohexadiene compound of the formula: R1-A-R2 wherein R1 is a hydrocarbon group having 1 to 5 carbon atoms, R2 is a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and A is a cyclohexadiene ring. The cyclohexadiene compound is preferably ?-terpinene or ?-terpinene.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

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 fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: To a fluorine-containing polymer, 0.1 to 10% of a compound having an alkali metal or an alkaline earth metal in terms of the number of atoms of the alkali metal or the alkaline earth metal based on the total number of the above terminal groups, 0.1 to 10% of ammonia in terms of the number of ammonia molecules based on the total number of the above terminal groups, or 0.1 to 10% of a compound having an ammonium group in terms of the number of the ammonium groups based on the total number of the above terminal groups is added, and heated at a temperature of at least 200° C. in an atmosphere containing moisture. By this process, unstable terminal groups such as terminal carboxylic acid groups and coloration caused by such terminal groups are effectively removed from the fluorine-containing polymer, and furthermore unstable bonds in the backbones can be removed. The obtained fluorine-containing polymer contains 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.

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: After a melt-processable fluorine-containing copolymer is heated and molten, the copolymer is reheatd in a closed apparatus under a non-static condition at a temperature of, for example, 130° C. to the melting point of the fluorine-containing polymer, whereby a content of volatile materials in the copolymer is reduced to 30% or less of an initial content of volatile materials. Thereby, the content of volatile materials in the melt-processable fluorine-containing copolymer, which has been once molten, can be effectively decreased without using a large apparatus while avoiding the contamination of the copolymer with foreign particles.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance, a process for preparing the composition and a cable evenly coated with the composition. Specifically, the present invention provides a fluororesin composition wherein polytetrafluoroethylene is compounded to a terpolymer comprising tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinylether. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: To a fluorine-containing polymer, 0.1 to 10% of a compound having an alkali metal or an alkaline earth metal in terms of the number of atoms of the alkali metal or the alkaline earth metal based on the total number of the above terminal groups, 0.1 to 10% of ammonia in terms of the number of ammonia molecules based on the total number of the above terminal groups, or 0.1 to 10% of a compound having an ammonium group in terms of the number of the ammonium groups based on the total number of the above terminal groups is added, and heated at a temperature of at least 200° C. in an atmosphere containing moisture. By this process, unstable terminal groups such as terminal carboxylic acid groups and coloration caused by such terminal groups are effectively removed from the fluorine-containing polymer, and furthermore unstable bonds in the backbones can be removed. The obtained fluorine-containing polymer contains 1.

Abstract: The present invention provides a fluororesin composition, which is excellent in moldability and crack resistance and particularly, does not cause cone break when coating an electric wire, a process for preparing the composition and a cable coated with the composition. Specifically, the present invention provides a fluororesin composition comprising a tetrafluoroethylene/hexafluoropropylene copolymer and polytetrafluoroethylene compounded thereto, which has a melt flow rate of at least 15 at 372° C. Also, the present invention provides a process for preparing the composition which comprises kneading with a multi-screw kneader. Furthermore, the present invention provides a cable which is coated with the resin.

Abstract: A melt-processable fluorine-containing polymer is melt kneaded with a kneader which has a residence time of at least 10 minutes, a usable volume ratio (usable space in a container/space in a container) of larger than 0.3, and a power factor K of less than 8000, the power factor K being represented by the formula: K=Pv/&mgr;/n2 in which Pv is a power requirement per unit volume (W/m3), &mgr; is a melt viscosity (Pa.s), and n is a rotation speed (rps), to effectively remove terminal groups and bonds in the backbones, which are unstable during melt kneading, from the melt-processable fluorine-containing polymer, and obtain a colorless fluorine-containing polymer.

Abstract: To a fluorine-containing polymer, 0.1 to 10% of a compound comprising an alkali metal or an alkaline earth metal in terms of the number of atoms of the alkali metal or the alkaline earth metal based on the total number of the above terminal groups, 0.1 to 10% of ammonia in terms of the number of ammonia molecules based on the total number of the above terminal groups, or 0.1 to 10% of a compound having an ammonium group in terms of the number of the ammonium groups based on the total number of the above terminal groups is added, and heated at a temperature of at least 2000C in an atmosphere containing moisture. By this process, unstable terminal groups such as terminal carboxylic acid groups and coloration caused by such terminal groups are effectively removed from the fluorine-containing polymer, and furthermore unstable bonds in the backbones can be removed. The obtained fluorine-containing polymer contains 1.