Daikin Industries, Ltd.

Mitsuo Tsukamoto

Hideya Saito

Tatsuya Morikawa

Yoshiyuki Hiraga

Hideki Nakaya

Mitsuhiro Otani

Kenji Otoi

Masao Otsuka

Mitsuru Kishine

Yutaka Ueta

Masanori Kitaichi

Tadahiro Yabu

Sadashige Irie

Tomohisa Noda

Hiroshi Aihara

Yuji Imahori

Katsuhide Otani

Yoshiki Maruya

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.

Method for purifying material to be treated and method for producing coagulated material

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 [&#x3c1;]-monomer critical density [&#x3c1;] ratio of [&#x3c1;/&#x3c1;] not less than 1.1.

Process for producing fluoropolymer

The present invention provides an ethylene-hexafluoropropylene copolymer which is suitable as a hose or seal for engine oil of an automobile and has sufficient amine resistance, while maintaining heat resistance, oil resistance and chemical resistance close to that of conventional fluorine rubber. The ethylene-hexafluoropropylene copolymer comprises 35 to 60% by mole of ethylene structural unit, 25 to 50% by mole of hexafluoropropylene structural unit and 0 to 15% by mole of structural unit derived from a monomer copolymerizable therewith and has a fluorine content of at least 60% by weight and number average molecular weight of 3,000 to 500,000.

Ethylene-hexafluoropropylene copolymer elastomer

The present invention relates to a process for preparing an elastomeric ethylene-hexafluoropropylene copolymer with excellent vulcanization properties, which comprises emulsion polymerizing ethylene, hexafluoropropylene and when in demand, a monomer copolymerizable therewith in a aqueous medium at a low temperature of &#x2212;20&#xb0; C. to 40&#xb0; C. using a radical polymerization initiator.

Process for preparing elastomeric ethylene-hexafluoropropylene copolymer

A process for preparing a fluorine-containing polymer through emulsion polymerization method which enhances productivity while maintaining excellent physical properties of the fluorine-containing polymer and comprises (a) a first polymerization step for emulsion-polymerizing a fluorine-containing monomer or a mixture of a fluorine-containing monomer and a non-fluorine-containing monomer in an aqueous medium in the presence of a radical polymerization initiator and an emulsifying agent, (b) a dilution step for diluting the obtained aqueous emulsion of polymer particles with water to reduce the number of emulsified polymer particles per unit amount of aqueous medium in the emulsion and a concentration of emulsifying agent, and (c) a second polymerization step for emulsion-polymerizing a fluorine-containing monomer and/or a non-fluorine-containing monomer in the obtained diluted emulsified solution.

Process for preparing fluorine-containing polymer

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Settsu, Japan

Mitsuo Tsukamoto