Daikin Industries, Ltd.

Zeon Corporation

Sadashige Irie

Mitsuru Kishine

Tsuyoshi Noguchi

Hiroyuki Tanaka

Masaki Irie

Satoshi Tokuno

Manabu Fujisawa

Masanori Kitaichi

Hirofumi Nishibayashi

Yousuke Nishimura

Kazuyoshi Mimura

Takahiro Kitahara

Takayuki Araki

Yoshito Tanaka

Yutaka Ueta

Hideki Kono

Kouhei Takemura

Hideya Saito

Kenji Ishii

Yoshiyuki Takase

Yosuke Nishimura

Hiroshi Aihara

Nobuyoshi Emori

Mitsuo Tsukamoto

Katsuhide Otani

Yoshiki Maruya

Takanori Arakawa

Yoshinori Hori

The present invention provides a process for preparing a fluorine-containing elastomer in a high productivity comparable to that of non-iodine transfer polymerization process by carrying out an iodine transfer polymerization at high pressure. The present invention also provides a fluorine-containing elastomer prepared by this process, and fluorine-containing molded articles. The process is a batch copolymerization process conducted under conditions that the reduced temperature of the critical constant is at least 0.95 and the reduced pressure of the critical constant is at least 0.80 wherein the reduced temperature and the reduced pressure are calculated using the Peng-Robinson formula from the critical temperature, the critical pressure and the composition ratio of each of the monomers in the gaseous phase in a reaction vessel, in which ethylenically unsaturated compounds containing at least one fluoroolefine are copolymerized in the presence of a compound having the formula: R&#xb7;Iwherein Ris a saturated or unsaturated fluorohydrocarbon or chlorofluorohydrocarbon group having 1 to 16 carbon atoms, and x is the number of bonds of Rand an integer of 1 to 4.

Process for preparing vulcanizable fluorine-containing elastomer

A fluororesin composition including a tetrafluoroethylene/hexafluoropropylene-based copolymer and 0.01 to 3 parts by mass per 100 parts the copolymer of a polytetrafluoroethylene having a standard specific gravity of 2.15 to 2.30, and being obtained by mixing an aqueous dispersion of the tetrafluoroethylene/hexafluoropropylene-based copolymer with an aqueous dispersion of the polytetrafluoroethylene, causing coagulation, drying the polymer mixture and melt-extruding the same.

Fluororesin composition and electric wire

The present invention provides a process for preparing a fluorine-containing elastomer in a high productivity comparable to that of non-iodine transfer polymerization process by carrying out an iodine transfer polymerization at high pressure. The present invention also provides a fluorine-containing elastomer prepared by this process, and fluorine-containing molded articles. The process is a batch copolymerization process conducted under conditions that the reduced temperature of the critical constant is at least 0.95 and the reduced pressure of the critical constant is at least 0.80 wherein the reduced temperature and the reduced pressure are calculated using the Peng-Robinson formula from the critical temperature, the critical pressure and the composition ratio of each of the monomers in the gaseous phase in a reaction vessel,

The present invention provides a process for preparing a fluorine-containing polymer having few branched chains and little weight change in high temperatures, which is a new process wherein composition distribution substantially does not occur. The fluorine-containing polymer is prepared by a batch copolymerization process conducted under conditions of reduced temperature of at least 0.95 and reduced pressure of at least 0.80 of the critical constant calculated from critical temperature, critical pressure and composition ratio of each monomer in the gaseous phase of the reaction vessel using the Peng-Robinson formula.

Process for preparing fluorine-containing polymer

A transparent elastomer composition is obtained by co-coagulation of an emulsion of fluorine-containing resin fine particles having an average particle size of from 20 to 150 nm and an emulsion of elastomer particles, in which the fluorine-containing resin fine particles are finely dispersed uniformly in the elastomer. The transparent elastomer composition provides an elastomeric molded article having excellent mechanical strength, abrasion resistance and transparency.

Transparent elastomer composition

According to the present invention, it is possible to provide a molding material, for example, a sealing material for semiconductor-related production apparatuses which comprises a fluorine-containing multi-segment polymer being excellent in mechanical properties (particularly at high temperature), abrasion resistance and transparency and ensuring reduced contamination and reduced gas permeation while maintaining inherent characteristics of a fluorine-containing elastomer such as flexibility, elasticity, sealing property, chemical resistance and heat resistance. A molding material comprising a fluorine-containing multi-segment polymer having an elastomeric fluorine-containing polymer chain segment and a non-elastomeric fluorine-containing polymer chain segment, in which the elastomeric fluorine-containing polymer chain segment imparts flexibility to the whole polymer and has perhaloolefin units as a recurring unit in an amount of not less than 95% by mole.

Molding material

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.

To provide a fluorine-containing rubber composition comprising (a-1) a non-perfluoro fluorine-containing rubber and (b-1) a fluorine-containing multi-segment polymer comprising an elastomeric fluorine-containing polymer chain segment and non-elastomeric fluorine-containing polymer chain segment, in which structural units of each of the elastomeric fluorine-containing polymer chain segment and the non-elastomeric fluorine-containing polymer chain segment comprise not less than 90% by mole of a perhalo olefin unit. The fluorine-containing rubber composition is capable of providing a clean sealing material for semi-conductor production apparatuses without using a filler.

Fluorine-containing rubber composition

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Settsu, Japan

Sadashige Irie