Abstract: This invention provide an aqueous PTFE dispersion and a process for efficiently producing the aqueous PTFE dispersion for coagulation processing having excellent coagulation properties of PTFE microparticles. The process involves adding a synthetic adsorbent, having a specific surface area of from 100 to 2,000 m2/g, to an aqueous PTFE dispersion containing both PTFE microparticles, having an average particle size of from 0.10 to 0.50 ?m, and a nonionic surfactant, followed by stirring or shaking and then separation into a liquid phase and a solid phase, and recovering an aqueous PTFE dispersion which contains from 45 to 70 mass % of PTFE microparticles having an average particle size of from 0.10 to 0.50 ?m and from 1.4 to 2.1 mass %, based on the mass of the PTFE microparticles, of a nonionic surfactant.

Abstract: A gas/liquid mixing equipment of the present invention comprises a stirring vessel 1, a stirring shaft 10 inserted horizontally in the stirring vessel 1 and a helical ribbon impeller 20 attached to the stirring shaft 10, whereby a high gas absorption performance can be secured even with low shearing. Further, a polymer can be produced with high productivity. A gas/liquid mixing method of the present invention is a method which comprises employing the above-mentioned gas/liquid mixing equipment, and a method for producing a polymer of the present invention is a method which comprises polymerizing feed monomers containing gaseous monomers in aqueous solvents, wherein the gaseous monomers and the aqueous solvents are mixed by such a gas/liquid mixing method. A polymer of the present invention is produced by the above-mentioned method for producing a polymer.

Abstract: To provide a good and simple method for decomposing and detoxifying a hardly decomposable fluorinated organic compound. Specifically, a fluorinated organic compound is decomposed by bringing an aqueous solution of the fluorinated organic compound into contact with a catalyst containing a metal oxide. The metal oxide may preferably be an oxide of at least one metal selected from the group consisting of Ni, Pd, Cu, Mn, Fe and Co, and more preferably be nickel oxide. The contact temperature is preferably within the range of from 0 to 100° C. Preferably, the fluorinated organic compound to be decomposed is an organic fluorocarboxylic acid, an organic fluorosulfonic acid or a salt thereof, which is used as a surfactant or an surface treatment agent.

Abstract: The present invention provides a method for producing a polytetrafluoroethylene fine powder, which comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator to produce an aqueous polytetrafluoroethylene emulsion, mixing and coagulating the aqueous emulsion to separate a polytetrafluoroethylene fine powder, and then drying the polytetrafluoroethylene fine powder in a wet state in an atmosphere containing ammonia.

Abstract: To provide a method for producing a PTFE fine powder having a low paste extrusion pressure property by a simple method. The method for producing a PTFE fine power comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator, to produce an aqueous PTFE emulsion, and coagulating it in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonia, an ammonium salt and urea in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of PTFE.

Abstract: To provide a method for producing a PTFE fine powder which can produce a PTFE fine powder having a low paste extrusion pressure property by a simple method. In the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator, tetrafluoroethylene is subjected to emulsion polymerization to produce an aqueous polytetrafluoroethylene and the aqueous medium is mixed and coagulated to separate a polytetrafluoroethylene fine powder, and then the polytetrafluoroethylene fine powder in a wet state is dried in an atmosphere containing ammonia to produce the polytetrafluoroethylene fine powder.

Abstract: To provide a fluorinated elastic copolymer having high crosslinkability, having high flowability and excellent in the compression set and the resistance to bases, and its production process. A process for producing a fluorinated elastic copolymer, which comprises copolymerizing (a) tetrafluoroethylene and (b) propylene and as the case requires, (c) a perfluoro(alkyl vinyl ether) in the presence of an iodine compound represented by the formula RI2 (wherein R is a hydrocarbon group or perfluoroalkyl group having at least 3 carbon atoms) at a temperature of from 0° C. to 50° C., and a fluorinated elastic copolymer obtained by the production process.

Abstract: A polymerization medium having small ozone depletion potential and small global warming potential and having a small chain transfer constant is used, to efficiently produce a fluoropolymer having a high molecular weight and having excellent heat resistance, solvent resistance, chemical resistance, etc. A process for producing a fluoropolymer, which comprises polymerizing a fluoromonomer having a carboxylic acid type functional group and a fluoroolefin using a hydrofluorocarbon as a medium, wherein the hydrofluorocarbon as the medium has 4 to 10 carbon atoms and has a ratio (molar basis) of the number of hydrogen atoms/the number of fluorine atoms (H/F ratio) of from 0.05 to 20.

Abstract: To provide a good and simple method for decomposing and detoxifying a hardly decomposable fluorinated organic compound. Specifically, a fluorinated organic compound is decomposed by bringing an aqueous solution of the fluorinated organic compound into contact with a catalyst containing a metal oxide. The metal oxide may preferably be an oxide of at least one metal selected from the group consisting of Ni, Pd, Cu, Mn, Fe and Co, and more preferably be nickel oxide. The contact temperature is preferably within the range of from 0 to 100° C. Preferably, the fluorinated organic compound to be decomposed is an organic fluorocarboxylic acid, an organic fluorosulfonic acid or a salt thereof, which is used as a surfactant or an surface treatment agent.

Abstract: To provide an aqueous polytetrafluoroethylene (PTFE) emulsion which does not substantially contain ammonium perfluorooctanoate, and which is obtained by emulsion polymerization. Further, to provide a PTFE fine powder which is obtained from the aqueous PTFE emulsion and is excellent in a paste extrusion processability, and a porous material. An aqueous polytetrafluoroethylene emulsion obtained by carrying out emulsion polymerization of tetrafluoroethylene alone or together with another copolymerizable monomer in an aqueous medium, wherein a fluorinated emulsifier of the formula (1): CF2CF2(O)mCF2CF2OCF2COOA wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4, and m is an integer of 0 or i, is used in an amount of from 1,500 to 20,000 ppm, based on the final yield of polytetrafluoroethylene.

Abstract: Provided is a process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier by using a weakly basic anion-exchange resin to adsorb and remove a fluorinated emulsifier with excellent efficiency from an aqueous fluorinated polymer dispersion. Also provided is a process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier, wherein the process includes: adding an organic carboxylic acid represented by the following formula (1): Q(CH2)m(CH(OH))nCOOH??(1) wherein Q is H, CH3 or COOH, m and n each independently represent 0 or an integer of from 1 to 4, and 4?n+m?1, to an aqueous fluorinated polymer dispersion containing a fluorinated emulsifier; and then contacting with a weakly basic anion-exchange resin to adsorb and remove the fluorinated emulsifier.

Abstract: To provide a polytetrafluoroethylene (PTFE) aqueous dispersion, which does not substantially contain ammonium perfluorooctanoate and is excellent in mechanical stability, wettability, permeability and coating property, and its product. A PTFE aqueous dispersion comprising from 15 to 70 mass % of PTFE fine particles having an average particle size of from 0.1 to 0.5 ?m, from 1×10?5 to 0.5 mass %, based on the mass of the PTFE, of a fluorinated emulsifier of the formula (1): XCF2CF2(O)mCF2CF2OCF2COOA, wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4 and m is an integer of 0 or 1, and from 1 to 20 mass %, based on the mass of the PTFE, of a nonionic surfactant.

Abstract: A fluororesin aqueous dispersion comprising from 20 to 70 mass % of microparticles of a fluororesin and from 1 to 12 mass %, based on the mass of the fluororesin, of a non-ionic surfactant represented by the formula (1): R1—O-A-X??(1) wherein R1 is a C6-18 alkyl group, O is an oxygen atom, A is a polyoxyalkylene group comprising from 1 to 3 oxybutylene groups and from 5 to 20 oxyethylene groups, and X is a hydrogen atom or a methyl group.

Abstract: To provide a method for efficiently producing a fluoropolymer by an aqueous emulsion polymerization in which a fluorocarboxylic acid compound is used. A method for producing a fluoropolymer, which comprises polymerizing a fluoromonomer by emulsion polymerization in the presence of a polymerization catalyst in an aqueous medium containing a fluorocarboxylic acid, wherein the aqueous medium in the polymerization has a pH of at most 4.

Abstract: A simple and efficient method for regenerating a basic anion-exchange resin, whereby at the time of removing a fluorinated emulsifier from a basic anion-exchange resin having the fluorinated emulsifier adsorbed thereon, it is unnecessary to provide a safety device/recovery technique necessary for handling an organic solvent by the use of a combustible organic solvent represented by an alcohol, and a burden imposed by e.g. treatment against COD load, is eliminated. A basic anion-exchange resin having a fluorinated emulsifier adsorbed thereon is contacted with an aqueous alkaline solution having a temperature of from 60 to 105° C. to elute the fluorinated emulsifier thereby to regenerate the basic anion-exchange resin.

Abstract: The present invention provides a process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier by using a weakly basic anion-exchange resin to let it adsorb and remove a fluorinated emulsifier with excellent efficiency from an aqueous fluorinated polymer dispersion. A process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier, which comprises adding an organic carboxylic acid represented by the following formula (1) Q(CH2)m(CH(OH))nCOOH??(1) (wherein Q is H, CH3 or COOH, each of m and n which are independent of each other, is 0 or an integer of from 1 to 4, and 4?n+m?1.) to an aqueous fluorinated polymer dispersion containing a fluorinated emulsifier, followed by contact with a weakly basic anion-exchange resin to adsorb and remove the fluorinated emulsifier.

Abstract: An aqueous dispersion of polytetrafluoroethylene (PTFE) comprising from 55 to 70 mass % of PTFE fine particles having an average particle diameter of from 0.1 to 0.5 ?m, from 0.0001 to 0.02 mass %, based on PTFE, of a specific C8 fluorine-containing carboxylic acid salt (APFO) such as ammonium perfluorooctanoate, from 1 to 20 mass %, based on PTFE, of a specific nonionic surfactant and from 0.01 to 0.3 mass %, based on PTFE, of a specific C5-7 fluorine-containing carboxylic acid salt such as ammonium perfluorohexanoate. The aqueous dispersion of PTFE has excellent properties which can form crack-resistant coatings which do not undergo coloration during baking or form problematic ionic impurities by improving the friction stability of aqueous PTFE dispersions even at APFO concentrations without viscosity increase.

Abstract: To obtain a high concentration aqueous PTFE dispersion containing PTFE at a concentration of from 60 to 75 mass % by dissolving from 0.001 to 0.1 mass %, based on the mass of PTFE, of a specific carboxylic acid salt such as ammonium laurate in a low concentration aqueous dispersion of polytetrafluoroethylene (PTFE) comprising from 1 to 40 mass % of PTFE fine particles, from 0.0001 to 0.02 mass %, based on the mass of PTFE, of a specific fluorine-containing carboxylic acid type emulsifier (for example, ammonium perfluorooctanoate), and from 1 to 20 mass %, based on the mass of PTFE, of a specific nonionic surfactant, and then concentrating the low concentration aqueous dispersion of PTFE.

Abstract: To provide a polytetrafluoroethylene (PTFE) aqueous dispersion, which does not substantially contain ammonium perfluorooctanoate and is excellent in mechanical stability, wettability, permeability and coating property, and its product. A PTFE aqueous dispersion comprising from 15 to 70 mass % of PTFE fine particles having an average particle size of from 0.1 to 0.5 ?m, from 1×10?5 to 0.5 mass %, based on the mass of the PTFE, of a fluorinated emulsifier of the formula (1): XCF2CF2(O)mCF2CF2OCF2COOA, wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4 and m is an integer of 0 or 1, and from 1 to 20 mass %, based on the mass of the PTFE, of a nonionic surfactant.

Abstract: To provide a fluororesin which does not substantially contain perfluorooctanoic acid or its salt, and which has a low residual amount of a fluorinated emulsifier. A fluororesin which is obtained by emulsion-polymerizing a fluorinated monomer in an aqueous medium containing a fluorinated emulsifier of the formula (1): XCF2CF2(O)mCF2CF2OCF2COOA wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4, and m is an integer of from 0 or 1, and coagulating the obtained aqueous emulsion, followed by drying, wherein the residual amount of the fluorinated emulsifier of the formula (1) is at most 10 ppm.