Daikin Industries, Ltd.

Asahi Kasei E-materials Corporation

Asahi Kasei Kabushiki Kaisha

Tadashi Ino

Masahiro Kondo

Takashi Yoshimura

Naoto Miyake

Noriyuki Shinoki

Masaharu Nakazawa

Tadaharu Isaka

Naoki Sakamoto

Takahiko Murai

Yuichi Inoue

Takuya Arase

Kuon Miyazaki

Takayuki Nakamura

Masayoshi Tatemoto

Kenji Ichikawa

Masanori Ikeda

Shinichi Chaen

Shigeo Daimon

Nobuki Uraoka

Takehiro Koga

Nobuyuki Uematsu

Kazuhiro Ohtsuka

Kentaro Kikuchi

Tomohisa Konishi

Tetsuo Shimizu

Masayuki Tsuji

Katsuhiko Imoto

Yoshiyuki Shibuya

Michio Asano

Tomohiro Isogai

Takuji Ishikawa

Fumihiro Kamiya

Kenji Ishii

Yoshihide Higashihata

Takahiro Tago

Ikuo Kitamura

Tatsuo Suzuki

Eiji Honda

Norihito Tanaka

Kohei Kita

Yuki Yotsumoto

Hideki Iijima

Yasuhiro Hashimoto

Takatomo Nishino

Nobuhiro Shinka

Yuko Iizuka

The invention provides a powder that is easily redispersible in a liquid medium such as water. The powder contains a fluoropolymer. The fluoropolymer contains at least one group A selected from the group consisting of &#x2014;SOY, &#x2014;COOR, &#x2014;SOX, &#x2014;SONR, and &#x2014;COOX, wherein Y is a halogen atom; R is a C1-C4 alkyl group; X is Mor NR, where M is a hydrogen atom or an L-valent metal, the L-valent metal being a metal in group 1, group 2, group 4, group 8, group 11, group 12, or group 13 of the periodic table; and Rs are each individually a hydrogen atom or a C1-C4 alkyl group. The powder exhibits a dispersion of 50% or higher. The dispersion is calculated by filtering a composition obtainable by mixing the powder with water through a mesh having an opening of 20 &#x3bc;m.

Fluoropolymer powder and method for producing same

The present invention provides a polymer electrolyte membrane having excellent strength, a small dimensional change, and a low membrane resistance. The polymer electrolyte membrane includes a porous film having pores and a polymer electrolyte contained in the pores. The porous film is obtained by copolymerizing tetrafluoroethylene and an ethylenic comonomer to provide polytetrafluoroethylene and then stretching the polytetrafluoroethylene. The porous film has an average pore size of greater than 0.20 &#x3bc;m.

Polymer electrolyte film

The present invention provides a polymer electrolyte membrane having excellent strength, a small dimensional change, and a low membrane resistance. The polymer electrolyte membrane includes a porous film and a polymer electrolyte. The porous film has a fibril/node area ratio of 90/10 to 75/25.

Polymer electrolyte membrane

The present invention aims to provide an ionomer that can exhibit high oxygen permeability, especially under both low- and high-humidified conditions, and high power generation durability. The high oxygen permeable ionomer includes a specific repeating unit A and repeating unit B and has an equivalent weight of 250 to 930 and a glass transition temperature of 100&#xb0; C. to 130&#xb0; C.

Ionomer having high oxygen permeability

A method for preparing a fluoropolymer aqueous dispersion, including: step (A) of preparing a fluoropolymer aqueous dispersion comprising a fluoropolymer having at least one selected from the group consisting of &#x2014;SOY and &#x2014;COOR (wherein Y is a halogen, and R is a C1 to C4 alkyl) by emulsion polymerization; step (B) of heating the fluoropolymer aqueous dispersion to 50&#xb0; C. or higher; and step (C) of contacting the fluoropolymer aqueous dispersion with an ion exchange resin for cation exchange after step (B), thereby providing a purified fluoropolymer aqueous dispersion, the fluoropolymer aqueous dispersion being adjusted to pH 7 or lower from the end of the polymerization in step (A) to the end of step (C).

Method for producing aqueous fluorine-containing polymer dispersing element, and purified aqueous fluorine-containing polymer dispersing element

A method for producing an electrolyte emulsion, the method including: Step (1) in which an ethylenic fluoromonomer and a fluorovinyl compound having an SOZgroup, wherein Zis a halogen element, are copolymerized at a polymerization temperature of 0&#xb0; C. or higher and 40&#xb0; C. or lower to provide a precursor emulsion containing a fluoropolymer electrolyte precursor; and Step (2) in which a basic reactive liquid is added to the precursor emulsion and the fluoropolymer electrolyte precursor is chemically treated, whereby an electrolyte emulsion with a fluoropolymer electrolyte dispersed therein is provided, wherein the electrolyte emulsion has an equivalent weight (EW) of 250 or more and 700 or less.

Electrolyte emulsion and process for producing same

The present invention is aimed to provide a highly-productive method for producing a stabilized fluoropolymer. The present invention relates to a method for producing a stabilized fluoropolymer, comprising the step of bringing a fluoropolymer to be treated into contact with a fluorinating agent to produce a stabilized fluoropolymer, while maintaining the concentration of hydrogen fluoride present in a reaction vessel at not higher than 1.0% by volume.

Method for producing stabilized fluoropolymer

The present invention provides a fluoropolymer electrolyte material which has improved processability and which is easily produced. The electrolyte emulsion of the present invention comprises an aqueous medium and a fluoropolymer electrolyte dispersed in the aqueous medium. The fluoropolymer electrolyte has a monomer unit having an SOZ group (Z is an alkali metal, an alkaline-earth metal, hydrogen, or NRRRR, and R, R, R, and Reach are individually a C1-C3 alkyl group or hydrogen). The fluoropolymer electrolyte has an equivalent weight (EW) of 250 or more and 700 or less and a proton conductivity at 110&#xb0; C. and relative humidity 50% RH of 0.10 S/cm or higher. The fluoropolymer electrolyte is a spherical particulate substance having an average particle size of 10 to 500 nm. The fluoropolymer electrolyte has a ratio (the number of SOF groups)/(the number of SOZ groups) of 0 to 0.01.

A coating material including a perfluorocarbon sulfonic acid resin which is a copolymer including a polymerization unit represented by &#x2014;(CF&#x2014;CFZ)&#x2014;, in the formula, Z being H, Cl, F, or a C1-C3 perfluoroalkyl group, and a polymerization unit represented by &#x2014;(CF&#x2014;CF(&#x2014;O&#x2014;(CF)&#x2014;SOH))&#x2014;, in the formula, m being an integer of 1 to 12, and the perfluorocarbon sulfonic acid resin has an equivalent weight EW of 200 to 1000. Also disclosed is a laminate including a base material and a hydrophilic layer formed from the coating material.

Coating material and layered body

A method for producing a fluoropolymer dispersion where a fine particle containing a fluoropolymer is dispersed in an aqueous dispersion medium, the fluoropolymer having a sulfonic acid group, and the method including a polymerization reaction step of emulsion polymerizing a fluorovinyl ether derivative and a fluorine-containing ethylenic monomer to give a fluoropolymer precursor, a hydrolysis step of hydrolyzing, in an aqueous medium, &#x2014;SOX, where Xrepresents a halogen atom, which the fluoropolymer precursor has thereby to give the fluoropolymer, the fluorovinyl ether derivative being represented by the following general formula (II):CF&#x2550;CF&#x2014;O&#x2014;(CFCFY&#x2014;O)&#x2014;(CFY)-A&#x2003;&#x2003;(II)wherein Y, n, Y, m and Aare as defined herein, the fluoropolymer precursor having a fluorovinyl ether derivative unit content of 5 to 40 mole percent, and the fluoropolymer dispersion being produced without drying the fluoropolymer precursor and the fluoropolymer.

Fluoropolymer dispersion and process for producing fluoropolymer dispersion

The present invention provides an electrolyte having high conductivity even under high-temperature low-humidification conditions (e.g. at a temperature of 100 to 120&#xb0; C. and a humidity of 20 to 50% RH) and thereby makes it possible to realize a higher performance fuel cell. The present invention is a fluoropolymer electrolyte having an equivalent weight (EW) of not less than 250 but not more than 700 and a proton conductivity of not lower than 0.10 S/cm as measured at a temperature of 110&#xb0; C. and a relative humidity of 50% RH and comprising a COOZ group- or SOZ group-containing monomer unit, wherein Z represents an alkali metal, an alkaline earth metal, hydrogen atom or NRRRRin which R, R, Rand Reach independently represents an alkyl group containing 1 to 3 carbon atoms or hydrogen atom.

Polyelectrolyte and process for producing the polyelectrolyte

The present invention provides a method for producing a stabilized fluoropolymer which comprises producing the stabilized fluoropolymer by subjecting a treatment target substance containing a sulfonic-acid-derived-group-containing fluoropolymer to a fluorination treatment, wherein the sulfonic-acid-derived-group-containing fluoropolymer is a fluoropolymer containing &#x2014;SOM (in which M represents H, NRRRRor M; R, R, Rand Rare the same or different and each represents H or an alkyl group containing 1 to 4 carbon atoms; and Mrepresents an L-valent metal), and the treatment target substance has a moisture content of not higher than 500 ppm by mass.

Stabilized fluoropolymer and method for producing same

The invention provides a technique enabling the separation and recovery of an unreacted fluoromonomer from an aqueous fluoropolymer dispersion obtained by emulsion polymerization, without using any extraction solvent, and enabling the prevention of a hydrolysis of &#x2014;SOF and a like sulfonic acid precursor functional group convertible to sulfonic acid group. Thus, the invention provides a recovering method fluoromonomer having a sulfonic acid precursor functional group convertible to a sulfonic acid group and remaining unreacted from an aqueous fluoropolymer dispersion obtained by emulsion polymerization of the fluoromonomer, wherein the unreacted fluoromonomer is recovered from the aqueous fluoropolymer dispersion by evaporation, wherein the aqueous fluoropolymer dispersion has an acidic pH.

Process for the recovery of fluoromonomers

The present invention provides a novel production process by which unstable terminal groups can be sufficiently stabilized under mild conditions. The present invention is related to a method for producing an &#x2014;SOH group-containing fluoropolymer wherein a fluoropolymer to be treated having a &#x2014;SOX group-containing monomer unit (X representing F or Cl) is subjected to a procedure comprising at least the steps A, B and C defined below in that order:

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Settsu, Japan

Tadashi Ino