Abstract: 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° 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.

Abstract: 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° 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.

Abstract: 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° 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.

Abstract: 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 ?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.

Abstract: 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 ?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.

Abstract: 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 ?m, 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 ?m 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/m2 when air including polyalphaolefin particles with a count median diameter of 0.25 ?m is continuously passed through the filter medium at a velocity of 5.3 cm/sec and pressure loss reaches 300 Pa.

Abstract: 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.

Abstract: 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): CH2?CH—Rf??(I) wherein Rf represents a C1 to C10 perfluoroalkyl group, the comonomer (b) being at least one monomer selected from the group consisting of 1,1,3,3,3-pentafluoro-1-propylene and 1,2,3,3,3-pentafluoro-1-propylene.

Abstract: 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.

Abstract: 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 ?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.

Abstract: 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 2.0×10?4 and (2) a cylinder extrusion pressure of not higher than 45 MPa at a reduction ratio of 1600.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 ?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.

Abstract: 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 ?m, 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 ?m 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/m2 when air including polyalphaolefin particles with a count median diameter of 0.25 ?m is continuously passed through the filter medium at a velocity of 5.3 cm/sec and pressure loss reaches 300 Pa.

Abstract: 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): CH2?CH—Rf??(I) wherein Rf represents a C1 to C10 perfluoroalkyl group, the comonomer (b) being at least one monomer selected from the group consisting of 1,1,3,3,3-pentafluoro-1-propylene and 1,2,3,3,3-pentafluoro-1-propylene.

Abstract: 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.

Abstract: 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 S2/S1 is not lower than 0.90.