Abstract: The air filter medium of the present invention is an air filter medium including a stack of a porous polytetrafluoroethylene (PTFE) membrane and an air-permeable support member, a repulsive force generated in the medium when the medium is compressed in a thickness direction thereof is equal to or greater than 30 kPa and equal to or less than 150 kPa at a compression ratio of 30%, and at least one main surface of the air filter medium is formed by the air-permeable support member and has a maximum coefficient of friction of 24 gf or less. The air filter medium of the present invention is an air filter medium that uses a porous PTFE membrane and in which a decrease in collection efficiency due to pleating is inhibited.

Abstract: An air conditioner of the present disclosure includes a fan filter unit whose power consumption efficiency determined by the following equation is 600 kWh/(m2·yr) or less when the fan filter unit is operated in such a manner that blowing efficiency ? of a fan is 0.75. In the following equation, Q represents a nominal flow rate (m3/sec) of an air filter unit, ?P represents a pressure loss (Pa) of the air filter unit measured when air passes through the air filter unit at the nominal flow rate of the unit, and S represents an opening area (m2) of the air filter unit. Equation: power consumption efficiency kWh/(m2·yr)={(Q×?P)/(?×1000)}×(24×365)/S. The air conditioner of the present disclosure is suitable for reducing power consumption even when including the air filter unit which is large in size and has high filtration performance. An air filter unit of the present disclosure is suitable for the air conditioner of the present disclosure.

Abstract: The air filter medium of the present invention is an air filter medium including a stack of a porous polytetrafluoroethylene (PTFE) membrane and an air-permeable support member, a repulsive force generated in the medium when the medium is compressed in a thickness direction thereof is equal to or greater than 30 kPa and equal to or less than 150 kPa at a compression ratio of 30%, and at least one main surface of the air filter medium is formed by the air-permeable support member and has a maximum coefficient of friction of 24 gf or less. The air filter medium of the present invention is an air filter medium that uses a porous PTFE membrane and in which a decrease in collection efficiency due to pleating is inhibited.

Abstract: A waterproof sound-transmitting member includes a waterproof sound-transmitting membrane and a support layer. The support layer includes a polyolefin-based resin foam. The support layer has a loss modulus of 1.0×107 Pa or less and a loss factor of 1.0×10?1 or more. The waterproof sound-transmitting membrane is, for example, a stretched porous polytetrafluoroethylene membrane. The waterproof sound-transmitting membrane may include an adhesive layer.

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: A waterproof sound-transmitting member includes a waterproof sound-transmitting membrane and a support layer. The support layer includes a polyolefin-based resin foam. The support layer has a loss modulus of 1.0×107 Pa or less and a loss factor of 1.0×10?1 or more. The waterproof sound-transmitting membrane is, for example, a stretched porous polytetrafluoroethylene membrane. The waterproof sound-transmitting membrane may include an adhesive layer.

Abstract: Provided is a water-proof sound transmitting member that is less likely to be bonded to a housing at a position other than a normal attachment position. The present invention provides a waterproof sound transmitting member (2) having a multilayer structure. This water-proof sound transmitting member (2) includes: a water-proof sound transmitting membrane (11) to be attached to a housing having a hole that allows sound to pass therethrough; a support layer (12) to be attached to the housing together with the waterproof sound transmitting membrane (11), the support layer (12) allowing sound to pass therethrough; and a housing-side adhesive layer (21) for bonding the waterproof sound transmitting membrane (11) to the housing. The entire peripheral portion of the support layer (12) extends outwardly beyond the housing-side adhesive layer (21).

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: 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: A water-proof sound-transmitting member that can be separated reliably from a releasing paper when an overhanging portion of a tab is pulled can be produced by producing a laminate by laminating a first layer, a preliminary membrane body, a second layer, and a preliminary tab body in this order; inserting a blade into the laminate from the first layer side to cut the first layer, the preliminary membrane body and the second layer so as to form the water-proof sound-transmitting membrane between adhesive layers, and providing, in a surface of the preliminary tab body on a side of the second layer, a notch, followed by cutting the preliminary tab body to form the tab.

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 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: A water-proof sound-transmitting membrane 10 includes a polytetrafluoroethylene porous membrane 1 and has a surface density of 1 to 20 g/m2. The polytetrafluoroethylene porous membrane 1 includes a first porous layer 1a, and a second porous layer 1b stacked on and integrated with the first porous layer 1a by a binding force acting between polytetrafluoroethylene matrices.

Abstract: Provided is a water-proof sound transmitting member that is less likely to be bonded to a housing at a position other than a normal attachment position. The present invention provides a waterproof sound transmitting member (2) having a multilayer structure. This water-proof sound transmitting member (2) includes: a water-proof sound transmitting membrane (11) to be attached to a housing having a hole that allows sound to pass therethrough; a support layer (12) to be attached to the housing together with the waterproof sound transmitting membrane (11), the support layer (12) allowing sound to pass therethrough; and a housing-side adhesive layer (21) for bonding the waterproof sound transmitting membrane (11) to the housing. The entire peripheral portion of the support layer (12) extends outwardly beyond the housing-side adhesive layer (21).

Abstract: A water-proof sound-transmitting membrane 10 includes a polytetrafluoroethylene porous membrane 1 and has a surface density of 1 to 20 g/m2. The polytetrafluoroethylene porous membrane 1 includes a first porous layer 1a, and a second porous layer 1b stacked on and integrated with the first porous layer 1a by a binding force acting between polytetrafluoroethylene matrices.

Abstract: Provided is a water-proof sound-transmitting member that can be separated reliably from a releasing paper when an overhanging portion of a tab is pulled.

Abstract: Disclosed is a process for production of a polytetrafluoroethylene (PTFE) sheet, which is superior in productivity compared to conventional processes and can reduce the cost of production. Also disclosed is a process for production of a PTFE seal tape. The processes comprise the following steps (i) to (iii): (i) applying a force to a PTFE particle suspension comprising PTFE particles, a surfactant and water (a dispersion medium) so that the particles can come close to each other or contact with each other, thereby forming a PTFE-containing solid material having the water and the surfactant included therein; (ii) shaping the solid material into a sheet-like form; and (iii) reducing the water content in the sheet-like solid material.

Abstract: Disclosed is a process for production of a polytetrafluoroethylene (PTFE) sheet, which is superior in productivity compared to conventional processes and can reduce the cost of production. Also disclosed is a process for production of a PTFE seal tape. The processes comprise the following steps (i) to (iii): (i) applying a force to a PTFE particle suspension comprising PTFE particles, a surfactant and water (a dispersion medium) so that the particles can come close to each other or contact with each other, thereby forming a PTFE-containing solid material having the water and the surfactant included therein; (ii) shaping the solid material into a sheet-like form; and (iii) reducing the water content in the sheet-like solid material.

Abstract: The present invention provides a water-proof sound-transmitting membrane including a polytetrafluoroethylene (PTFE) porous membrane, in which the waterproofness is enhanced further with little lowering of the sound transmittance. The water-proof sound-transmitting membrane includes the PTFE porous membrane. The PTFE porous membrane includes a first porous layer, and a second porous layer stacked on and integrated with the first porous layer by a binding force acting between PTFE matrices. The first porous layer and the second porous layer each are composed of PTFE with a number-average molecular weight of 5.0×107 or more determined by a standard specific gravity method. At least one layer selected from the first porous layer and the second porous layer has an average pore diameter of 1 ?m or less. The water-proof sound-transmitting membrane has a surface density of 1 g/m2 to 10 g/m2.