Daikin Industries, Ltd.

Katsuhide Otani

Takahisa Aoyama

Tetsuo Shimizu

Takahiro Taira

Yoshiki Maruya

Mitsuru Kishine

Yutaka Ueta

Satoshi Komatsu

Masanori Kitaichi

Yoshiyuki Hiraga

Hideya Saito

Kiyohiko Ihara

Sadashige Irie

Hiroshi Aihara

Mitsuo Tsukamoto

To provide a suitable material having improved impermeability to liquid chemicals and cracking resistance while retaining excellent heat resistance and processability inherent in FEP-based fluororesins, a molded article of which is useful in the field of semiconductor production apparatus and the like. The present invention provides a fluorine-containing resin material comprising a fluorine-containing copolymer comprising 85 to 95.5% by mole of a repeating unit derived from tetrafluoroethylene, 5 to 10% by mole of a repeating unit derived from hexafluoropropylene and 0.1 to 5% by mole of a repeating unit derived from at least one higher perfluoro(vinyl ether) represented by the formula (1):CF&#x2550;CF&#x2014;O&#x2014;Rf&#x2003;&#x2003;(1)wherein Rfis a perfluoroalkyl group having 5 to 10 carbon atoms or a perfluoro(alkoxyalkyl) group having 4 to 17 carbon atoms, and molded article thereof.

Fluorine-containing resin material lowly permeable to liquid chemical

Fluorocopolymer and fluororesin composition lowly permeable to liquid chemical

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

The fine powder of high molecular weight fluorine containing resins having melt viscosities of 10 to 10 poise, apparent density of 0.4 to 1.5 g/cc, and specific surface area of 2 m /g or less, mold goods of the fine powder and these production methods. By utilizing the fine powder of high molecular weight flourine containing fused resins that have previously not been employed, the mold goods obtained from the fine powder have fewer liquated particles and have become the most suitable especially for manufacturing semiconductors. The powder's products have greater resistance to flex fatigue, abrasion, resistance, etc.

Fine powder of high molecular weight fluorine containing fused resins, its mold goods, and the dedicated production methods

A polymerization process, in which when at least one of fluorine-containing olefin monomers in gaseous phase or supercritical phase or a monomer mixture of the fluorine-containing olefin monomer and other monomer copolymerizable therewith is subjected to batch polymerization in an aqueous medium while being diffused to the aqueous medium, a diffusing amount of the monomer or monomer mixture to the aqueous medium is not less than 80% of the theoretical consumption of the monomer or monomer mixture when polymerized at the theoretical polymerization rate. According to the present invention, a polymerization rate is determined by the polymerization reaction but not by the diffusion of monomer gas, and thus higher polymerization rate can be achieved.

Process for the polymerizing of flourine-containing olefin monomer

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Settsu, Japan

Katsuhide Otani