Patent application number | Description | Published |
20090281231 | TETRAFLUOROETHYLENE POLYMER AND AQUEOUS DISPERSION THEREOF - The invention provides a TFE polymer capable of providing stretched materials excellent in membrane homogeneity. The present invention is related to a tetrafluoroethylene polymer having stretchability and non-melt-processability and having a standard specific gravity of 2.140 to 2.165, wherein, with regard to the heat-of-fusion curve obtained by subjecting the tetrafluoroethylene polymer in the form of an unbaked polymer to be measured having no history of being heated to a temperature of 300° C. or higher to differential scanning calorimetry at a programming rate of 2° C./minute, the ratio between the amount of heat, S | 11-12-2009 |
20100087599 | FLUORORESIN COMPOSITION, FLUORORESIN MOLDED ARTICLE AND METHOD FOR PRODUCING THE SAME - The invention provides a fluororesin composition capable of providing a molded article having low relative dielectric constant, excellent in a temperature stability and causing only small transmission losses. The invention is a fluororesin composition wherein a rate of change in relative dielectric constant between 25° C. and 80° C. of a molded article produced therefrom under a standard condition is not greater than 0.2%. | 04-08-2010 |
20100204345 | AQUEOUS DISPERSION OF LOW MOLECULAR WEIGHT POLYTETRAFLUOROETHYLENE, LOW MOLECULAR WEIGHT POLYTETRAFLUOROETHYLENE POWDER, AND METHOD FOR PRODUCING LOW MOLECULAR WEIGHT POLYTETRAFLUOROETHYLENE - 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: | 08-12-2010 |
20120123031 | ORGANOSOL COMPOSITION OF FLUORINE-CONTAINING POLYMER - The present invention provides an organosol composition that is stable even in the case that the PTFE particle content is high. The present invention relates to an organosol composition of PTFE particles, comprising PTFE particles (A), a polymer (B), and an organic solvent (S), wherein (1) the polymer (B) is soluble in the organic solvent (S), (2) the amount of the PTFE particles (A) is not lower than 50% by mass of the total amount of the PTFE particles (A) and the polymer (B), and (3) the precipitation ratio of the PTFE particles after 48 hours is not higher than 60% when the total solids concentration of the PTFE particles (A) and the polymer (B) is 5% by mass. | 05-17-2012 |
20130097982 | FILTER MEDIUM EQUIPPED WITH POROUS FILM, METHOD OF MANUFACTURING SAME, FILTER PACK, AND FILTER UNIT - A filter medium includes a porous film and a support material supporting the porous film. The porous film includes polytetrafluoroethylene, has an average pore diameter of at least 2.5 μm, and has a porosity of at least 95%. A pressure loss is less than 100 Pa when air is passed through the filter medium at a velocity of 5.3 cm/sec. A collection efficiency of NaCl particles is at least 95% when air including NaCl particles with a particle diameter of 0.3 μm is passed through the filter medium at a velocity of 5.3 cm/sec. A PF value is at least 30, where PF={−log [(100−collection efficiency (%))/100]/pressure loss (Pa)}×1000. A dust holding capacity of polyalphaolefin particles held in the filter medium is at least 15 g/m | 04-25-2013 |
20130122302 | PROCESS FOR PRODUCING POLYTETRAFLUOROETHYLENE FINE POWDER - 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. | 05-16-2013 |
20130184395 | DRIPPING INHIBITOR AND RESIN COMPOUND - 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 μm, 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. | 07-18-2013 |
20130184401 | METHOD FOR MANUFACTURING FINE POLYTETRAFLUOROETHYLENE POWDER - 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. | 07-18-2013 |
20130267621 | POLYTETRAFLUOROETHYLENE MIXTURE - 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. | 10-10-2013 |
20130281558 | 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. | 10-24-2013 |
20140200310 | METHOD FOR PRODUCING AQUEOUS POLYTETRAFLUOROETHYLENE DISPERSION - The present invention aims to provide a novel method for producing an aqueous dispersion containing non-melt-processable polytetrafluoroethylene particles. The present invention relates to a method for producing an aqueous dispersion containing non-melt-processable polytetrafluoroethylene particles, the method including polymerizing tetrafluoroethylene in an aqueous medium in the presence of perfluoro hexanoic acid or its salt. | 07-17-2014 |
20150082757 | 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 - A composition, a mixed power 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° 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. | 03-26-2015 |