Daikin Industries, Ltd.

Raytech Corporation

Yasuhiko Sawada

Taku Yamanaka

Shunji Kasai

Nobuhiko Tsuda

Tetsuo Shimizu

Masayuki Tsuji

Hiroyuki Yoshimoto

Taketo Kato

Yoshinori Nanba

Makoto Ono

Takahiro Taira

Masayoshi Miyamoto

Shinichi Chaen

Yoshihiro Yamamoto

Shuji Tagashira

Yoshiyuki Shibuya

Kunihiko Inui

Kazuya Kawahara

Chie Sawauchi

Kazuhiko Shimada

Kazuhiro Mishima

Toshinari Tanaka

Mayumi Yamauchi

Hirotoshi Yoshida

Masahiko Yamada

Masamichi Sukegawa

Hiroyuki Sato

Yasukazu Nakatani

Gen Kojima

Hirokazu Yukawa

Minoru Iida

Hiroshi Torii

Hideto Suzuki

Yoneho Tabata

Toshirou Miura

Kohei Yasuda

Shigetoshi Ikeda

Minoru Kawai

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 an aqueous dispersion of a low-molecular-weight polytetrafluoroethylene (PTFE), which contains an easily removable surfactant, and has a good dispersion stability. Specifically, the present invention provides an aqueous dispersion of a low-molecular-weight PTFE comprising tetrafluoroethylene (TFE) units, or TFE units and modifying monomer units which are copolymerizable with the TFE units, wherein the aqueous dispersion contains from 70 to 9,000 ppm, based on the aqueous dispersion, of a fluorine-containing compound of the formula (1) below:X&#x2014;(CF)&#x2014;Y&#x2003;&#x2003;(1)where X is H or F; m is an integer from 3 to 5; and Y is &#x2014;SOM, &#x2014;SOM, &#x2014;SOR, &#x2014;SOR, &#x2014;COOM, &#x2014;POMor &#x2014;POM, M being H, NHor an alkali metal, and R being an alkyl group having 1 to 12 carbons, and the low-molecular-weight PTFE has an average primary particle size of from 100 to 350 nm.

Aqueous dispersion of low molecular weight polytetrafluoroethylene, low molecular weight polytetrafluoroethylene powder, and method for producing low molecular weight polytetrafluoroethylene

The present invention provides a modified polytetrafluoroethylene fine powder which can be processed into molded articles high in thermal stability, chemical resistance and transparency and for which the extrusion pressure can be lowered. The present invention is a modified polytetrafluoroethylene fine powder, wherein the cylinder extrusion pressure at a reduction ratio of 1600 is not higher than 50 MPa and the haze value of molded article a for measurement formed therefrom is not higher than 60.

Modified polytetrafluoroethylene fine powder and modified polytetrafluoroethylene molded product

Provided is a dripping inhibitor excellent in handling characteristics. The present invention provides a dripping inhibitor including a modified polytetrafluoroethylene, the inhibitor having an average particle size of 300 to 800 &#x3bc;m, an apparent density of 0.40 to 0.52 g/ml, a compression ratio of 1.20 or less, an aggregate disintegration degree with 50-sec vibration of 70% or more, a cylinder extrusion pressure at a reduction ratio 1500 of 80 MPa or less, and a standard specific gravity (SSG) of 2.140 to 2.230.

Dripping inhibitor and resin compound

A process for producing a polytetrafluoroethylene fine powder including: (1) a step of preparing an aqueous dispersion containing polytetrafluoroethylene, water and a surfactant (A); (2) a step of initiating coagulation of the polytetrafluoroethylene in said aqueous dispersion by agitating said aqueous dispersion; (3) a step of adding a surfactant (B) after the step (2); (4) a step of terminating coagulation after the step (3); (5) a step of collecting a wet powder of the polytetrafluoroethylene; and (6) a step of drying the wet powder of the polytetrafluoroethylene.

Process for producing polytetrafluoroethylene fine powder

A polytetrafluoroethylene resin comprising polytetrafluoroethylene having a two-dimensional branched structure in the molecule is produced by exposing polytetrafluoroethylene to an ionizing radiation at a dose of no more than 10 kGy.

Polytetrafluoroethylene resins that can be processed by shaping, shaped products thereof, and processes for producing the resins and shaped products

The present invention provides a tetrafluoroethylene polymer aqueous dispersion obtained by carrying out a TFE polymerization in an aqueous medium in the presence of a fluorovinyl group-containing emulsifier, wherein the TFE polymer aqueous dispersion contains a particle comprising a TFE polymer dispersed in the aqueous medium, the fluorovinyl group-containing emulsifier comprises a fluorovinyl group-containing compound, and the TFE polymer aqueous dispersion has a fluorine-containing surfactant content of not higher than 1000 ppm by mass.

Aqueous tetrafluoroethylene polymer dispersion, process for producing the same, tetrafluoroethylene polymer powder, and molded tetrafluoroethylene polymer

A method for manufacturing a polytetrafluoroethylene fine powder characterized by including the steps of (1) preparing an aqueous dispersion containing polytetrafluoroethylene, water, and a surfactant (A); (2) coagulating the polytetrafluoroethylene in the aqueous dispersion by agitating the aqueous dispersion with a discharge flow-type impeller; (3) collecting a wet powder of the polytetrafluoroethylene; and (4) drying the wet powder of the polytetrafluoroethylene.

Method for manufacturing fine polytetrafluoroethylene powder

Provided are modified polytetrafluoroethylene particles having excellent moldability and processability. The modified polytetrafluoroethylene particles each have a core-shell structure that includes a particle core and a particle shell, the particle core having repeating units of tetrafluoroethylene and a comonomer (a), the particle shell having repeating units of tetrafluoroethylene and a comonomer (b), the comonomer (a) being a (perfluoroalkyl)ethylene represented by the following formula (I):CH&#x2550;CH&#x2014;Rf&#x2003;&#x2003;(I)

Modified polytetrafluoroethylene particles, method for producing the same, and modified polytetrafluoroethylene molded product

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

The present invention provides a polytetrafluoroethylene powder having moldability/processability as well as electrical characteristics in microwave bands. The present invention is a modified polytetrafluoroethylene powder which has (1) a dielectric loss tangent at 12 GHz of not higher than 2.0&#xd7;10and (2) a cylinder extrusion pressure of not higher than 45 MPa at a reduction ratio of 1600.

Modified polytetrafluoroethylene powder and method for producing tetrafluoroethylene polymer

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.

The present invention provides a low-molecular weight polytetrafluoroethylene powder that, when used as an additive in a coating material, etc., can form a coating with excellent texture and gliding properties, while also improving dispersibility and viscosity; and a production process therefor. The present invention is a process for producing a low-molecular weight polytetrafluoroethylene powder, the process comprising: an emulsion polymerization step of polymerizing at least tetrafluoroethylene in the presence of a polymerization initiator and an aqueous medium to produce emulsified particles thereof; an agglomeration step of agglomerating the emulsified particles to form an agglomerated powder thereof; and a suspension polymerization step of polymerizing at least tetrafluoroethylene in the presence of the agglomerated powder, a polymerization initiator, and an aqueous medium.

Low molecular weight polytetrafluoroethylene powder and preparation method therefor

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Settsu, Japan

Yasuhiko Sawada