Asahi Glass Company, Limited

Nobuyuki Kasahara

Tetsuji Shimohira

Ichiro Terada

Atsushi Watakabe

Hisao Kawazoe

Shin Tatematsu

Susumu Saito

Hiroshi Yamamoto

Toshiyuki Tanaka

Shigeki Kobayashi

Kazuya Oharu

Satoru Hommura

Kazuhiko Yamada

Yasuhiko Matsuoka

Yutaka Furukawa

Naoto Ota

Katsuya Ueno

Hiroki Nagai

Hiroshi Hatano

Chitoshi Suzuki

Yoshinori Toyota

Shigeru Ikai

Masakuni Sato

Yoshinobu Takano

Noriaki Miyake

Fusaaki Takeo

Satoshi Shiratori

Noriaki Miyaki

Terence Edwin Attwood

Steven McDonald

Philip David Mackrell

Shigeki Hiraoka

To provide a plastic optical fiber using amorphous fluorinated polymers whereby transmission loss and bending loss are low, no cracking takes place during stretching, and a wide range of molding conditions is acceptable. A plastic optical fiber comprising an inner layer, an outer layer having a refractive index lower than the refractive index of the inner layer, and a protective coating layer covering the outer periphery of the outer layer, wherein the inner layer contains an amorphous fluorinated polymer (a) having no C&#x2014;H bond, the outer layer contains an amorphous fluorinated polymer (c) which may have a C&#x2014;H bond only at a terminal of the main chain, the glass transition temperature (Tgc) of the fluorinated polymer (c) is at least the glass transition temperature (Tga) of the fluorinated polymer (a), the plastic optical fiber is a stretched one, the fracture elongation of the fluorinated polymer (a) and the fracture elongation of the fluorinated polymer (c) are at least 120% and larger than the stretching ratio.

Plastic optical fiber and method for its production

To provide an electrolyte polymer for polymer electrolyte fuel cells, made of a perfluorinated polymer having sulfonic groups, characterized in that in a test of immersing 0.1 g of the polymer in 50 g of a fenton reagent solution containing 3% of an aqueous hydrogen peroxide solution and 200 ppm of bivalent iron ions at 40&#xb0; C. for 16 hours, the amount of eluted fluorine ions detected in the solution is not more than 0.002% of the total amount of fluorine in the polymer immersed. The electrolyte polymer of the present invention has very few unstable terminal groups and has an excellent durability, and therefore, is suitable as a polymer constituting an electrolyte membrane for polymer electrolyte fuel cells and a polymer contained in a catalyst layer.

Electrolyte polymer for polymer electrolyte fuel cells, process for its production and membrane-electrode assembly

A process for producing a perfluoropolymer, the process including extruding a polymer obtained by polymerizing a perfluoromonomer to prepare strands, and bringing a gas comprising from 3 to 50 volume % of fluorine gas into contact with the strands; the process being conducted on an apparatus that includes an extruder for melting and extruding the polymer obtained by polymerizing a perfluoromonomer, a die having a plurality of pores for preparing the strands from the molten polymer extruded, and a fluorination tank for bringing the gas comprising from 3 to 50 volume % of fluorine gas into contact with the strands.

Process for producing perfluoropolymer, production apparatus and process for producing electrolyte membrane for polymer electrolyte fuel cells

A gas/liquid mixing equipment of the present invention comprises a stirring vessel, a stirring shaftinserted horizontally in the stirring vesseland a helical ribbon impellerattached to the stirring shaft, 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.

Gas/liquid mixing equipment, gas/liquid mixing method, polymer and method for its production

To provide a process for efficiently producing a perfluoropolymer having unstable terminal groups reduced. A process for producing a fluorination-treated perfluoropolymer, which comprises melting a thermoplastic perfluoropolymer to form strands and contacting the polymer strands with a fluorine gas. For fluorination-treatment of the perfluoropolymer, an apparatusis used, which comprises a melt extruderfor melting and extruding the perfluoropolymer, a diefor forming the melt extruded polymer into continuous strandsand a fluorination tankfor contacting the continuous strandswith a fluorine gas.

Process for producing fluorination-treated perfluoropolymer

A thickened ion exchange polymer dispersion is obtained by applying ultrasonic vibration or a shearing force to an ion exchange polymer dispersion having a fluorinated polymer having sulfonic acid groups as an ion exchange polymer uniformly dispersed in a dispersion medium so that the viscosity of the dispersion at 25&#xb0; C. at a shear rate of 10 (1/s) increases 2-2000 times in a thickening step. When formed into a membrane, the dispersion can forms an ion exchange membrane having a uniform and small thickness, high strength, which is free from cracking and shows constant swelling in water and steam. Further, a layer formed by applying a coating solution containing this dispersion and a catalyst powder comprising catalyst metal particles and a carbon support loaded with the catalyst metal particles to a substrate can be used to prepare a membrane-electrode assembly as a catalyst layer for at least one of the cathode and the anode by providing the catalyst layer adjacently to an ion exchange membrane. Because the catalyst layer is highly strong, has few defects and is excellently smooth, a high-performance membrane-electrode assembly for solid polymer electrolyte fuel cells can be obtained.

Ion exchange polymer dispersion, process for its production and its use

A method for precisely producing a polyether having a relatively high molecular weight by means of a double metal cyanide complex catalyst is provided. A method for continuously producing a polyether, which comprises ring opening addition polymerization of an alkylene oxide in the presence of a double metal cyanide complex catalyst, wherein substantially no vapor phase part is present in a reactor.

Method for continuously producing a polyether

Method for producing a fluoroalcohol

Growing community of inventors

Yokohama, Japan

Nobuyuki Kasahara