Abstract: A waterproof member (20) includes a first adhesive layer (22), a second adhesive layer (24), and a porous layer (26). The porous layer (26) is disposed between the first adhesive layer (22) and the second adhesive layer (24). The first adhesive layer (22) and the second adhesive layer (24) each have a frame shape in plan view. When the first adhesive layer (22), the second adhesive layer (24), and the porous layer (26) are seen in plan view, the outer boundary of the porous layer (26) lies within the outer boundary of the first adhesive layer (22) and the outer boundary of the second adhesive layer (24). The first adhesive layer (22) is bonded directly to the second adhesive layer (24) in a region outside the outer boundary of the porous layer (26). The porous layer (26) has a peripheral surface that is shielded from outside by the first adhesive layer (22) and the second adhesive layer (24).

Abstract: The present invention provides a porous polytetrafluoroethylene membrane having a surface coated with a liquid-repellent agent. In this porous polytetrafluoroethylene membrane, the liquid-repellent agent is a polymer obtained by polymerization of monomers consisting essentially of CH2?CHCOOCH2CH2C6F13. This porous polytetrafluoroethylene membrane is suitable for use as a gas-permeable membrane that allows passage of gases but prevents entry of liquids and/or dust, specifically as a waterproof sound-transmitting membrane, a waterproof gas-permeable membrane, or a dustproof gas-permeable membrane.

Abstract: Provided is a black porous polytetrafluoroethylene membrane including a porous polytetrafluoroethylene membrane dyed black. A whiteness of a principal face of the black porous polytetrafluoroethylene membrane as measured according to JIS L 1015 (Hunter method) is 18.0 to 23.0%, and the whiteness of the principal face falls within a range of 18.0 and 25.0% after heating at 350° C. for 1 minute. This black porous PTFE membrane is suitable as a gas-permeable membrane that blocks entry of water and/or dust and that allows permeation of gases; specifically, the black porous PTFE membrane is suitable, for example, as a waterproof sound-transmitting membrane, a waterproof gas-permeable membrane, and a dustproof gas-permeable membrane.

Abstract: An exhalation collected in a breath bag capable of expanding and contracting is sucked into a gas inlet vessel 21 with a given volume (Va), and then the gas inlet vessel 21 is communicated by means of valve V2 with a cell 11 that is maintained at an atmospheric pressure by being pre-filled with a sample gas or reference gas. After the communication, the gas pressure is measured by a pressure sensor 16 attached to the cell 11. Whether the exhalation collected in the breath bag is below a given amount or not can be accurately judged.

Abstract: A waterproof sound-transmitting membrane (1) of the present invention includes a porous membrane (11) containing polytetrafluoroethylene as a main component and a supporting member (12) that supports the porous membrane (11). The supporting member (12) is joined to the porous membrane (11) placed thereon and is not subjected to stretching after the porous membrane (11) is placed thereon. The supporting member (12) is a mesh or a net having a fiber diameter of 45 to 60 ?m and an opening size of 700 to 1100 ?m across the supporting member (12). The waterproof sound-transmitting membrane (1) has a water entry pressure of 20 kPa or more as measured according to the method B (high hydraulic pressure method) of JIS L 1092.

Abstract: A waterproof sound-permeable membrane (10) includes a polytetrafluoroethylene (PTFE) membrane (20). The PTFE membrane (20) is obtained by stretching a PTFE sheet so as to obtain a porous PTFE membrane having a porous structure including a plurality of fibrils and pores between the plurality of fibrils and then applying a pressure to only a region of one principal surface of the porous PTFE membrane in a thickness direction of the porous PTFE membrane or by applying a greater pressure to a region of one principal surface of the porous PTFE membrane than to a remaining region of the one principal surface other than the region to which the greater pressure is applied, in the thickness direction of the porous PTFE membrane. The PTFE membrane (20) has a low-density portion (21) having the porous structure and a high-density portion (22) having a lower porosity than the low-density portion (21).

Abstract: Provides is a waterproof sound-permeable membrane (10) adapted to permit passage of sound and prevent entry of water. The waterproof sound-permeable membrane (10) includes a sound-permeation region (11) having a polytetrafluoroethylene (PTFE) membrane (20). The polytetrafluoroethylene membrane (20) has an average pore diameter of 0.02 ?m or more and 0.1 ?m or less as measured according to ASTM F316-86 and has a porosity of 5% or more and 25% or less. The waterproof sound-permeable membrane (10) is suitable for application to an electronic device containing an acoustic device.

Abstract: Provided is a waterproof gas-permeable membrane (1) having higher levels of both gas permeability and waterproofness than conventional ones. The waterproof gas-permeable membrane (1) includes: a non-porous resin film (2) having through holes (21a to 21g) formed to extend through the thickness of the resin film (2); and a liquid-repellent layer (3) formed on a principal surface of the resin film (2) and having openings (31) positioned in register with the through holes (21a to 21g). The through holes (21a to 21g) extend straight and have a diameter of 15 ?m or less. The through holes (21a to 21g) are distributed at a hole density of 1×103 holes/cm2 or more and 1×109 holes/cm2 or less in the resin film (2). The through holes (21a to 21g) extend in oblique directions with respect to a direction perpendicular to the principal surface of the resin film (2). The through holes (21a to 21g) that extend in different oblique directions are present together.

Abstract: Provided is a porous polytetrafluoroethylene (PTFE) membrane having a PF value of 36 or more and a mass per unit area of 0.90 g/m2 or less. The PF value is determined by the following equation: PF value={?log(PT (%)/100)/(PL(Pa)/9.8)}×100. PT (permeability) is determined by PT (%)=100?CE (%), CE (collection efficiency) is determined by a value measured using dioctyl phthalate particles with a particle diameter of 0.10 ?m to 0.20 ?m under a condition of a permeate flow rate of 5.3 cm/sec, and PL (pressure loss) is determined by a value measured under a condition of a permeate flow rate of 5.3 cm/sec. This porous PTFE membrane is suitable for air filter media.

Abstract: The present invention provides a filter medium causing a low pressure drop. The present invention is a filter medium including a porous fluororesin membrane and an air-permeable support member laminated on at least one surface of the porous fluororesin membrane. In this filter medium, the air-permeable support member is a blended nonwoven fabric containing: core-sheath fibers (A) having a polyester core and a polyolefin sheath; polyester fibers (B); and core-sheath fibers (C) having a polyester core and a copolymerized polyester sheath.

Abstract: A waterproof sound-transmitting membrane (1) of the present invention includes a porous membrane (11) containing polytetrafluoroethylene as a main component and a supporting member (12) that supports the porous membrane (11). The supporting member (12) is joined to the porous membrane (11) placed thereon and is not subjected to stretching after the porous membrane (11) is placed thereon. The supporting member (12) is a mesh or a net having a fiber diameter of 45 to 60 ?m and an opening size of 700 to 1100 ?m across the supporting member (12). The waterproof sound-transmitting membrane (1) has a water entry pressure of 20 kPa or more as measured according to the method B (high hydraulic pressure method) of JIS L 1092.

Abstract: A waterproof sound-transmitting membrane of the present disclosure includes: a non-porous resin film having formed therein a plurality of through holes extending through a thickness of the non-porous resin film; and a liquid-repellent layer formed on a principal surface of the resin film and having openings at positions corresponding to positions of the plurality of through holes. The through holes have a diameter of 4.0 ?m or more and 12.0 ?m or less, and the waterproof sound-transmitting membrane has a through-thickness air permeability of 2.0 cm3/(cm2·second) or more and 50 cm3/(cm2·second) or less in terms of Frazier number as measured according to JIS L 1096. With this waterproof sound-transmitting membrane placed over an opening of a housing of an electronic device or the like, entry of water into the housing from outside can be prevented, in addition to which the characteristics of sound transmitted through the membrane can be kept even when the membrane has a reduced effective area.

Abstract: The sound-transmitting structure (100) of the present invention includes a sound-transmitting membrane (1) that allows passage of sounds and prevents passage of foreign matters and a case (120) having a sound-transmitting opening (122). This sound-transmitting membrane (1) includes a supporting member (12) that is a nonwoven fabric containing an elastomer and a porous resin membrane (11) disposed on the supporting member (12) and containing polytetrafluoroethylene as a main component. The sound-transmitting membrane (1) covers the sound-transmitting opening (122) with the supporting member (12) welded to the case (120).

Abstract: The present invention provides a porous polytetrafluoroethylene membrane having a surface coated with a liquid-repellent agent. In this porous polytetrafluoroethylene membrane, the liquid-repellent agent is a polymer obtained by polymerization of monomers consisting essentially of CH2=CHCOOCH2CH2C6F13. This porous polytetrafluoroethylene membrane is suitable for use as a gas-permeable membrane that allows passage of gases but prevents entry of liquids and/or dust, specifically as a waterproof sound-transmitting membrane, a waterproof gas-permeable membrane, or a dustproof gas-permeable membrane.

Abstract: Provided is a black porous polytetrafluoroethylene membrane including a porous polytetrafluoroethylene membrane dyed black. A whiteness of a principal face of the black porous polytetrafluoroethylene membrane as measured according to JIS L 1015 (Hunter method) is 18.0 to 23.0%, and the whiteness of the principal face falls within a range of 18.0 and 25.0% after heating at 350° C. for 1 minute. This black porous PTFE membrane is suitable as a gas-permeable membrane that blocks entry of water and/or dust and that allows permeation of gases; specifically, the black porous PTFE membrane is suitable, for example, as a waterproof sound-transmitting membrane, a waterproof gas-permeable membrane, and a dustproof gas-permeable membrane.

Abstract: The present invention provides a covered electric wire including an insulating layer made of a porous polytetrafluoroethylene membrane and having both good electrical properties and good mechanical properties. The present invention is a covered electric wire including a conductor wire and an insulating layer covering the conductor wire. This insulating layer is made of a porous polytetrafluoroethylene membrane showing an endothermic peak in a temperature range of 327° C. or higher and 335° C. or lower but not showing an endothermic peak in a temperature range of higher than 335° C. and 380° C. or lower, as measured by differential scanning calorimetry at a heating rate of 10° C./min.

Abstract: The present invention is a method for producing a composite including a matrix and a dispersed material dispersed in the matrix. The method includes introducing a raw material for dispersed material which constitutes a dispersed material into a fluid including a melt of a raw material for matrix which constitutes a matrix or a solution containing a raw material for matrix by a vapor deposition method, to obtain a composite.

Abstract: The present invention provides a filter medium causing a low pressure drop. The present invention is a filter medium including a porous fluororesin membrane and an air-permeable support member laminated on at least one surface of the porous fluororesin membrane. In this filter medium, the air-permeable support member is a blended nonwoven fabric containing: core-sheath fibers (A) having a polyester core and a polyolefin sheath; polyester fibers (B); and core-sheath fibers (C) having a polyester core and a copolymerized polyester sheath.

Abstract: Provided is a filter medium including a porous polytetrafluoroethylene (PTFE) membrane and a gas-permeable supporting member that are integrated to ensure sufficient stiffness, having excellent gas permeability, and providing excellent bonding between respective layers included in the filter medium. The gas-permeable supporting member includes: a substrate having gas-permeability; and a fiber layer that is placed on the substrate so as to be in contact with the porous PTFE membrane. The gas-permeable supporting member has a structure in which fibers of the fiber layer enter into the substrate and are entangled with the substrate so that the fiber layer is bonded to the substrate. The fiber layer contains polyolefin-containing fibers that are bonded to the porous membrane.

Abstract: An exhalation collected in a breath bag capable of expanding and contracting is sucked into a gas inlet vessel 21 with a given volume (Va), and then the gas inlet vessel 21 is communicated by means of valve V2 with a cell 11 that is maintained at an atmospheric pressure by being pre-filled with a sample gas or reference gas. After the communication, the gas pressure is measured by a pressure sensor 16 attached to the cell 11. Whether the exhalation collected in the breath bag is below a given amount or not can be accurately judged.