Daikin Industries, Ltd.

Asahi Kasei Kabushiki Kaisha

Shinichi Chaen

Nobuki Uraoka

Jun Asano

Katsutoshi Yamamoto

Osamu Inoue

Toshio Kusumi

Osamu Tanaka

Taku Yamanaka

Yoshiyuki Shibuya

Kunihiko Inui

Shunji Kasai

Makoto Ono

Yasuhiko Sawada

Shinji Tamaru

Makoto Kobayashi

Hideyuki Kiyotani

Seigo Yamamoto

Hitoshi Niinuma

Li Bao

Tomohisa Konishi

Masahiko Yamada

Tadashi Ino

Yuichi Inoue

Kuon Miyazaki

Kentaro Kikuchi

Kohei Yasuda

Taketo Kato

Hirotoshi Yoshida

Seiichi Hirano

Takahiro Taira

Satoshi Hara

Norihito Tanaka

The present invention aims to provide a modified polytetrafluoroethylene fine powder capable of providing a stretched body having high strength, a small pore size, and excellent homogeneity. The modified polytetrafluoroethylene fine powder of the present invention has non-melt-processability, has a standard specific gravity of 2.155 or lower, includes 0.015 mol % or more of a polymer unit derived from perfluoro(methyl vinyl ether) in all the monomer units, is obtained by emulsion polymerizing tetrafluoroethylene and at least the perfluoro(methyl vinyl ether) in the presence of a fluorosurfactant having a LogPOW value of 3.4 or lower, and has an extrusion pressure of 20.0 MPa or lower.

Modified polytetrafluoroethylene fine powder and uniaxially stretched porous body

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 porous body having high strength, a small pore size, and excellent homogeneity. The porous body of the present invention includes polytetrafluoroethylene and has a microstructure that includes nodes and fibrils. The microstructure further includes, in addition to the nodes and the fibrils, fused points where a fibril that links two nodes and another fibril that links another two nodes are fused with each other.

Porous body, polymer electrolyte membrane, filter material for filter, and filter unit

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

A filtering medium includes first and second porous membranes mainly composed of fluororesin, and a plurality of air permeable supports to support the first and second membranes. The second membrane is disposed downstream of the first membrane. When air containing polyalphaolefin particles with a count median diameter of 0.25 &#x3bc;m is continuously passed through at a flow rate of 5.3 cm/sec and pressure loss is increased by 250 Pa, the first membrane has a dust retention amount larger than the second membrane. The filtering medium has a pressure loss of less than 200 Pa when air is passed through at a flow rate of 5.3 cm/sec. A collecting efficiency of NaCl particles with a particle diameter of 0.3 &#x3bc;m is 99.97% or more when air containing the NaCl particles is passed through at a flow rate of 5.3 cm/sec. The dust retention amount is 25 g/mor more.

Filtering medium for air filter, filter pack, air filter unit, and method for producing filtering medium for air filter

A mixed powder and a material for molding have polytetrafluoroethylene as a main component. Each includes polytetrafluoroethylene that can be fibrillated, a non-hot melt processable component that is not fibrillated, and a hot melt processable component with a melting point of lower than 320&#xb0; C. that is not fibrillated. The non-hot melt processable component that is not fibrillated is contained in a range of 20 to 40% by weight of the total weight. The hot melt processable component is contained at equal to or more than 0.1% by weight but less than 20% by weight of the total weight. A drawn porous body includes a plurality of fibrils, and a plurality of knotted portions that are connected to each other by the fibrils.

Mixed powder and material for molding having PTFE as main component, and drawn porous body

A composition, a mixed powder and a material for molding have polytetrafluoroethylene as a main component. Each includes polytetrafluoroethylene that can be fibrillated, a non-hot melt processable component that is not fibrillated, and a hot melt processable component with a melting point of lower than 320&#xb0; C. that is not fibrillated. The hot melt processable component is contained at equal to or more than 0.1% by weight but less than 20% by weight of a total weight. A filtering medium for an air filter includes a porous membrane made of these components, and an air permeable support. The porous membrane is manufactured, by mixing these components, extruding the mixture, rolling and drawing.

Composition having PTFE as main component, mixed powder, material for molding, filtering medium for filter, air filter unit, and a method for manufacturing a porous membrane

Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a PTFE porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a fibrillable modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.

Polytetrafluoroethylene mixture

Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a polytetrafluoroethylene porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the modified polytetrafluoroethylene having an extrusion pressure to a cylinder, at a reduction ratio of 1600, of 70 MPa or higher.

A method of laminating at least two gas permeable sheet materials includes: (1) providing at least a first gas permeable sheet material, wherein at least a portion of at least a surface region of the first sheet material is thermoplastic material; (2) providing at least a second gas permeable sheet material of polytetrafluoroethylene; (3) superposing the sheet materials; and (4) contacting the sheet materials with a heating means to heat the thermoplastic material to a temperature from 140&deg; to 230&deg; C., so as to melt the thermoplastic material and laminate the sheet materials to one another, without the application of direct pressure in the thickness direction of the sheet materials during the contacting step so as to form a gas permeable laminate.

Method of laminating gas permeable sheet material

A filter medium with excellent flame-resistant properties and an air filter unit using the same are provided which have a flame-resistant air permeable supporting material on at least one surface of a polytetrafluoroethylene (PTFE) porous film and which can be used as a ceiling device, etc.

Fire-retardant filter medium and air filter unit

To provide a PTFE composite fiber having remarkably improved thermal bonding property, PTFE cotton-like materials which can be used for producing a non-woven fabric by thermal bonding method, processes for production thereof, a process for producing a split yarn, a process for producing a monofilament and a process for producing a multifilament having loop and/or branched structure. A thermofusing resin layer is provided on the surface of the PTFE fiber. After lamination of the PTFE film and the thermofusing resin film, uniaxial stretching is carried out at a temperature between the melting points of the respective films.

Polytetrafluoroethylene cotton-like materials

Polytetrafluoroethylene porous composite film

Polytetrafluoroethylene composite fiber, cotton-like materials obtained

Porous polytetrafluoroethylene film and process for preparation thereof

Growing community of inventors

Settsu, Japan

Shinichi Chaen